Phase 1 trial of navitoclax and sorafenib in patients with relapsed or refractory solid tumors with hepatocellular carcinoma expansion cohort

Navitoclax (ABT-263) is an oral BCL2 homology-3 mimetic that binds with high affinity to pro-survival BCL2 proteins, resulting in apoptosis. Sorafenib, an oral multi kinase inhibitor also promotes apoptosis and inhibits tumor angiogenesis. The efficacy of either agent alone is limited; however, preclinical studies demonstrate synergy with the combination of navitoclax and sorafenib. In this phase 1 study, we evaluated the combination of navitoclax and sorafenib in a dose escalation cohort of patients with refractory solid tumors, with an expansion cohort in hepatocellular carcinoma (HCC). Maximum tolerated dose (MTD) was determined using the continual reassessment method. Navitoclax and sorafenib were administered continuously on days 1 through 21 of 21-day cycles. Ten patients were enrolled in the dose escalation cohort and 15 HCC patients were enrolled in the expansion cohort. Two dose levels were tested, and the MTD was navitoclax 150 mg daily plus sorafenib 400 mg twice daily. Among all patients, the most common grade 3 toxicity was thrombocytopenia (5 patients, 20%): there were no grade 4 or 5 toxicities. Patients received a median of 2 cycles (range 1-36 cycles) and all patients were off study treatment at data cut off. Six patients in the expansion cohort had stable disease, and there were no partial or complete responses. Drug-drug interaction between navitoclax and sorafenib was not observed. The combination of navitoclax and sorafenib did not increase induction of apoptosis compared with navitoclax alone. Navitoclax plus sorafenib is tolerable but showed limited efficacy in the HCC expansion cohort. These findings do not support further development of this combination for the treatment of advanced HCC. This phase I trial was conducted under ClinicalTrials.gov registry number NCT01364051.

Outcome of neoadjuvant treatment for pancreatic cancer in elderly patients: comparative, observational cohort study

BACKGROUND

Use of neoadjuvant therapy for elderly patients with pancreatic cancer has been debatable. With FOLFIRINOX (folinic acid, 5-fluorouracil, irinotecan, oxaliplatin) or gemcitabine plus nab-paclitaxel (GnP) showing tremendous effects in improving the overall survival of patients with borderline resectable and locally advanced pancreatic cancer, there is no definitive consensus regarding the use of this regimen in the elderly.

METHODS

This study evaluated the eligibility of elderly patients with borderline resectable or locally advanced pancreatic cancer for neoadjuvant therapy. Patients registered in the database of pancreatic cancer at the University of Colorado Cancer Center, who underwent neoadjuvant treatment between January 2011 and March 2019, were separated into three age groups (less than 70, 70-74, 75 or more years) and respective treatment outcomes were compared.

RESULTS

The study included 246 patients with pancreatic cancer who underwent neoadjuvant treatment, of whom 154 and 71 received chemotherapy with FOLFIRINOX and GnP respectively. Among these 225 patients, 155 were younger than 70 years, 36 were aged 70-74 years, and 34 were aged 75 years or older. Patients under 70 years old received FOLFIRINOX most frequently (124 of 155 versus 18 of 36 aged 70-74 years, and 12 of 34 aged 75 years or more; P < 0.001). Resectability was similar among the three groups (60.0, 58.3, and 55.9 per cent respectively; P = 0.919). Trends towards shorter survival were observed in the elderly (median overall survival time 23.6, 18.0, and 17.6 months for patients aged less than 70, 70-74, and 75 or more years respectively; P = 0.090). After adjusting for co-variables, age was not a significant predictive factor.

CONCLUSION

The safety and efficacy of multiagent chemotherapy in patients aged 75 years or over were similar to those in younger patients. Modern multiagent regimens could be a safe and viable treatment option for clinically fit patients aged at least 75 years.

Clinical outcomes of breast cancer patients treated in phase I clinical trials at University of Colorado Cancer Center

Patients with metastatic breast cancer (MBC) refractory to standard of care therapies have a poor prognosis. The purpose of this study was to assess patient characteristics and clinical outcomes for patients with MBC treated on phase I clinical trials. We performed a retrospective review of all patients with MBC who were enrolled in phase I clinical trials at the University of Colorado Cancer Center from January 2012 to June 2018. A total of 208 patients were identified. Patients had a mean age of 57 years and received on average 2.1 (range 0-10) prior lines of chemotherapy. The majority of patients had hormone receptor-positive/HER2-negative breast cancer (58.6%) and 30.3% had triple-negative breast cancer. The median progression free survival (PFS) was 2.8 months (95% CI, 2.3-3.9) and median overall survival (OS) was 11.5 months (95% CI, 9.6-13.2). Independent factors associated with longer PFS in multivariable analysis were treatment in a breast cancer-selective trial or cohort (p = 0.016), age >50 years (p = 0.002), and ≤2 prior lines of chemotherapy in the metastatic setting (p = 0.025). Phase I clinical trials remain a valuable option for select patients with MBC and enrollment should be encouraged when available.

Widespread Cortical Thickness Is Associated With Neuroactive Steroid Levels

Background

Neuroactive steroids are endogenous molecules with regenerative and neuroprotective actions. Both cortical thickness and many neuroactive steroid levels decline with age and are decreased in several neuropsychiatric disorders. However, a systematic examination of the relationship between serum neuroactive steroid levels and in vivo measures of cortical thickness in humans is lacking.

Methods

Peripheral serum levels of seven neuroactive steroids were assayed in United States military veterans. All (n = 143) subsequently underwent high-resolution structural MRI, followed by parcellelation of the cortical surface into 148 anatomically defined regions. Regression modeling was applied to test the association between neuroactive steroid levels and hemispheric total gray matter volume as well as region-specific cortical thickness. False discovery rate (FDR) correction was used to control for Type 1 error from multiple testing.

Results

Neuroactive steroid levels of allopregnanolone and pregnenolone were positively correlated with gray matter thickness in multiple regions of cingulate, parietal, and occipital association cortices (r = 0.20–0.47; p < 0.05; FDR-corrected).

Conclusion

Positive associations between serum neuroactive steroid levels and gray matter cortical thickness are found in multiple brain regions. If these results are confirmed, neuroactive steroid levels and cortical thickness may help in monitoring the clinical response in future intervention studies of neuroregenerative therapies.

Multicenter Study of the Real-World Use of Ceftaroline versus Vancomycin for Acute Bacterial Skin and Skin Structure Infections

The objective of this study was to determine if real-world ceftaroline treatment in adults hospitalized for acute bacterial skin and skin structure infections (ABSSSI) is associated with decreased infection-related length of stay (LOSinf) compared to that with vancomycin. This was a retrospective, multicenter, cohort study from 2012 to 2017. Cox proportional hazard regression, propensity score matching, and inverse probability of treatment weighting (IPTW) were used to determine the independent effect of treatment group on LOSinf The patients were adults hospitalized with ABSSSI and treated with ceftaroline or vancomycin for ≥72 h within 120 h of diagnosis at four academic medical centers and two community hospitals in Arizona, Florida, Michigan, and West Virginia. A total of 724 patients were included (325 ceftaroline treated and 399 vancomycin treated). In general, ceftaroline-treated patients had characteristics consistent with a higher risk of poor outcomes. The unadjusted median LOSinf values were 5 (interquartile range [IQR], 3 to 7) days and 6 (IQR, 4 to 8) days in the vancomycin and ceftaroline groups, respectively (hazard ratio [HR], 0.866; 95% confidence interval [CI], 0.747 to 1.002). The Cox proportional hazard model (adjusted HR [aHR], 0.891; 95% CI, 0.748 to 1.060), propensity score-matched (aHR, 0.955; 95% CI, 0.786 to 1.159), and IPTW (aHR, 0.918; 95% CI, 0.793 to 1.063) analyses demonstrated no significant difference in LOSinf between groups. Patients treated with ceftaroline were significantly more likely to meet criteria for discharge readiness at day 3 in unadjusted and adjusted analyses. Although discharge readiness at day 3 was higher in ceftaroline-treated patients, LOSinf values were similar between treatment groups. Clinical and nonclinical factors were associated with LOSinf.

Characterization of immune responses to anti-PD-1 mono and combination immunotherapy in hematopoietic humanized mice implanted with tumor xenografts

Background

The success of agents that reverse T-cell inhibitory signals, such as anti-PD-1/PD-L1 therapies, has reinvigorated cancer immunotherapy research. However, since only a minority of patients respond to single-agent therapies, methods to test the potential anti-tumor activity of rational combination therapies are still needed. Conventional murine xenograft models have been hampered by their immune-compromised status; thus, we developed a hematopoietic humanized mouse model, hu-CB-BRGS, and used it to study anti-tumor human immune responses to triple-negative breast cancer (TNBC) cell line and patient-derived colorectal cancer (CRC) xenografts (PDX).

Methods

BALB/c-Rag2^nullIl2rγ^nullSIRPα^NOD (BRGS) pups were humanized through transplantation of cord blood (CB)-derived CD34+ cells. Mice were evaluated for human chimerism in the blood and assigned into experimental untreated or nivolumab groups based on chimerism. TNBC cell lines or tumor tissue from established CRC PDX models were implanted into both flanks of humanized mice and treatments ensued once tumors reached a volume of ~150mm³. Tumors were measured twice weekly. At end of study, immune organs and tumors were collected for immunological assessment.

Results

Humanized PDX models were successfully established with a high frequency of tumor engraftment. Humanized mice treated with anti-PD-1 exhibited increased anti-tumor human T-cell responses coupled with decreased Treg and myeloid populations that correlated with tumor growth inhibition. Combination therapies with anti-PD-1 treatment in TNBC-bearing mice reduced tumor growth in multi-drug cohorts. Finally, as observed in human colorectal patients, anti-PD-1 therapy had a strong response to a microsatellite-high CRC PDX that correlated with a higher number of human CD8+ IFNγ+ T cells in the tumor.

Conclusion

Hu-CB-BRGS mice represent an in vivo model to study immune checkpoint blockade to human tumors. The human immune system in the mice is inherently suppressed, similar to a tumor microenvironment, and thus allows growth of human tumors. However, the suppression can be released by anti-PD-1 therapies and inhibit tumor growth of some tumors. The model offers ample access to lymph and tumor cells for in-depth immunological analysis. The tumor growth inhibition correlates with increased CD8 IFNγ+ tumor infiltrating T cells. These hu-CB-BRGS mice provide a relevant preclinical animal model to facilitate prioritization of hypothesis-driven combination immunotherapies.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0518-z) contains supplementary material, which is available to authorized users.

Smaller hippocampal CA1 subfield volume in posttraumatic stress disorder

BACKGROUND

Smaller hippocampal volume in patients with posttraumatic stress disorder (PTSD) represents the most consistently reported structural alteration in the brain. Subfields of the hippocampus play distinct roles in encoding and processing of memories, which are disrupted in PTSD. We examined PTSD-associated alterations in 12 hippocampal subfields in relation to global hippocampal shape, and clinical features.

METHODS

Case-control cross-sectional studies of U.S. military veterans (n = 282) from the Iraq and Afghanistan era were grouped into PTSD (n = 142) and trauma-exposed controls (n = 140). Participants underwent clinical evaluation for PTSD and associated clinical parameters followed by MRI at 3 T. Segmentation with FreeSurfer v6.0 produced hippocampal subfield volumes for the left and right CA1, CA3, CA4, DG, fimbria, fissure, hippocampus-amygdala transition area, molecular layer, parasubiculum, presubiculum, subiculum, and tail, as well as hippocampal meshes. Covariates included age, gender, trauma exposure, alcohol use, depressive symptoms, antidepressant medication use, total hippocampal volume, and MRI scanner model.

RESULTS

Significantly lower subfield volumes were associated with PTSD in left CA1 (P = 0.01; d = 0.21; uncorrected), CA3 (P = 0.04; d = 0.08; uncorrected), and right CA3 (P = 0.02; d = 0.07; uncorrected) only if ipsilateral whole hippocampal volume was included as a covariate. A trend level association of L-CA1 with PTSD (F_{4, 221}  = 3.32, P = 0.07) is present and the other subfield findings are nonsignificant if ipsilateral whole hippocampal volume is not included as a covariate. PTSD-associated differences in global hippocampal shape were nonsignificant.

CONCLUSIONS

The present finding of smaller hippocampal CA1 in PTSD is consistent with model systems in rodents that exhibit increased anxiety-like behavior from repeated exposure to acute stress. Behavioral correlations with hippocampal subfield volume differences in PTSD will elucidate their relevance to PTSD, particularly behaviors of associative fear learning, extinction training, and formation of false memories.

Immune and autoimmune-related adverse events associated with immune checkpoint inhibitors in cancer therapy

The recent development of monoclonal antibodies that disinhibit the immune system from recognizing and attacking tumor cells has revolutionized the treatment of cancer. Among these agents are drugs that specifically block cytotoxic T-lymphocyte protein 4 (CTLA-4), programmed cell death protein 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1) signaling, called immune checkpoint inhibitors (ICIs). While these agents are generally well tolerated, ICI therapy can lead to loss of self-tolerance and the development of autoimmunity, manifesting as immune-related adverse events (IRAEs). Although potentially linked to increased antitumor responses, the morbidity associated with IRAEs can be significant and in rare circumstances, fatal. Virtually any organ can be affected and the patients present with a broad range of signs and symptoms. Moreover, ICIs have varying IRAEs and have distinct toxicity profiles based on their mechanism of action. Fortunately, most of the IRAEs can be managed with immunosuppression and supportive care, but contingent on early recognition and prompt treatment. With increasing advances in drug development, including combination ICI therapy, these agents are becoming one of the most prescribed oncology drugs and clinicians should be knowledgeable about the recognition and management of IRAEs.

Smaller Hippocampal Volume in Posttraumatic Stress Disorder: A Multisite ENIGMA-PGC Study: Subcortical Volumetry Results From Posttraumatic Stress Disorder Consortia

BACKGROUND

Many studies report smaller hippocampal and amygdala volumes in posttraumatic stress disorder (PTSD), but findings have not always been consistent. Here, we present the results of a large-scale neuroimaging consortium study on PTSD conducted by the Psychiatric Genomics Consortium (PGC)-Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) PTSD Working Group.

METHODS

We analyzed neuroimaging and clinical data from 1868 subjects (794 PTSD patients) contributed by 16 cohorts, representing the largest neuroimaging study of PTSD to date. We assessed the volumes of eight subcortical structures (nucleus accumbens, amygdala, caudate, hippocampus, pallidum, putamen, thalamus, and lateral ventricle). We used a standardized image-analysis and quality-control pipeline established by the ENIGMA consortium.

RESULTS

In a meta-analysis of all samples, we found significantly smaller hippocampi in subjects with current PTSD compared with trauma-exposed control subjects (Cohen's d = -0.17, p = .00054), and smaller amygdalae (d = -0.11, p = .025), although the amygdala finding did not survive a significance level that was Bonferroni corrected for multiple subcortical region comparisons (p < .0063).

CONCLUSIONS

Our study is not subject to the biases of meta-analyses of published data, and it represents an important milestone in an ongoing collaborative effort to examine the neurobiological underpinnings of PTSD and the brain's response to trauma.

Abstract B175: Rational combination of mTOR and Aurora kinase A inhibition in preclinical models of triple-negative breast cancer

Background: Alisertib is a highly selective inhibitor of Aurora kinase A and has antiproliferative and proapoptotic activity in a subset of triple-negative breast cancer (TNBC) cell lines and patient-derived tumor xenograft (PDX) models. Cellular senescence and increased expression of genes in the PI3K/AKT/mTOR pathway has been observed in TNBC models following treatment with alisertib that demonstrate de novo or acquired resistance. The purpose of this study was to investigate the combination of alisertib and the TORC1/2 inhibitor TAK-228 in preclinical TNBC models. Methods: MDA-MB-468, HCC1187, HCC1937, CAL51, and BT20 cells were plated in 96 well plates and exposed to increasing concentrations of alisertib (25nM-125nM), TAK-228 (25nM-125nM), or the combination and proliferation was assessed using the Cell Titer-Glo (CTG) assay. Apoptosis was assessed using long-term live cell microscopy and caspase 3/7 staining. Western blotting was used to assess changes in pS6, p4EBP1, and survivin expression. TNBC p53 wildtype CAL51 cells were transfected with the fluorescent ubiquitin cell cycle indicator (FUCCI) reporters and exposed to increasing concentrations of alisertib, TAK-228, or the combination to evaluate the effect on cell cycle progression, growth, and apoptosis. TNBC PDX models CU_TNBC_004 and CU_TNBC_007 were treated with vehicle, alisertib (30mg/kg), TAK-228 (0.5mg/kg), or the combination and assessed for tumor growth inhibition and translational markers by immunofluorescence (IF) and senescence-associated- ß-galactosidase (SA-ß-gal) staining. Results: A combination effect was observed for alisertib and TAK-228 in vitro with a decrease in cellular proliferation with the combination as measured by CTG. We observed an increase in cell death with the combination, as opposed to cell cycle arrest with single-agent treatment. Alisertib treatment was associated with an increase in survivin not observed with combination treatment. TAK-228 treatment was associated with a decrease in pS6 and p4EBP1 as a single agent or in combination. The combination of TAK-228 and alisertib resulted in greater tumor growth inhibition in vivo as compared to either single agent alone, accompanied by an increase in apoptosis as measured by BAX and DR5 expression and a decrease in senescence as evaluated by SA-ß-gal and phenotypic changes. Single agents in the CAL51 FUCCI system resulted in a dose-dependent effect on cell cycle progression and apoptosis by live cell microscopy. The combination, however, led to a complete block of cell growth and simultaneous apoptosis, leading to no expansion of cells after treatment and a gradual loss of the cell population. Conclusions: The combination of alisertib and TAK-228 in vitro and in vivo in TNBC models resulted in greater antiproliferative and proapoptotic activity. This combination is currently being investigated in a phase I dose escalation trial in patients with advanced solid tumors with a planned expansion cohort in metastatic TNBC to further evaluate the mechanism of the combination (NCT02719691).

Citation Format: Jennifer R. Diamond, James D. Orth, Anastasia Ionkina, Kyrie Dailey, Todd M. Pitts, Anna Capasso, Joshua M. Marcus, Russell T. Burke, Sarah L. Davis, Jiyhe Kim, Aik-Choon Tan, Sue G. Eckhardt, John J. Tentler. Rational combination of mTOR and Aurora kinase A inhibition in preclinical models of triple-negative breast cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B175.

Abstract A012: Humanized patient-derived xenografts (PDXs) recapitulate clinical responses in microsatellite stable (MSS) and unstable (MSI-H) colorectal cancer (CRC)

Introduction: Recent data have demonstrated that patients with MSI-H metastatic CRC are more likely to respond to a PD-1 inhibitor as a single agent compared to patients with MSS CRC. Effective immunotherapy approaches for MSS CRC remain a critical unmet need. There is great interest in investigating immune checkpoint inhibition in combination with novel agents, but preclinical studies have been hampered by current models. To gain a better understanding of immune responses and facilitate preclinical evaluation of combination strategies with immunotherapy, we developed a “hematopoietic” humanized mouse model with the intent of leveraging this model for the development of rational combinations in MSS CRC patients. Methods: BRGS (in house breeding) newborn pups were transplanted with CD34+ cells purified from (HLA unmatched) umbilical cord blood at 48 hours. In order to better understand the immune context of these novel animal models, we selected an MSI-high CRC (MDA-C0999-203) and a MSS (CRC172) humanized PDX model. At 16 weeks, MDA-C0999-203 (MSI-H) and CRC172 (MSS) were implanted on both flanks of humanized mice and nonhumanized controls. When the average tumor size reached ~150-300 mm3, both groups of mice were randomized into vehicle and nivolumab (30mg/kg IP twice weekly) stratified by % chimerism (human CD45+ &gt;45%). At the end of the treatment, a portion of the tumor was immediately fixed in formalin for immunohistochemistry and pharmacodynamic analyses with seven-color multispectral imaging using the Perkin Elmer Vectra- 3 instrument, and compared to a surgical specimen from an untreated patient with an MSI-H tumor. Results: In the MSI-H model we observed tumor growth inhibition in the nivolumab-treated, humanized mice with respect to the humanized vehicle-treated control and the nonhumanized nivolumab-treated group (TGII 3.5% vs 76%). In a separate experiment, an MSS CRC humanized PDX model (CRC172) was treated with nivolumab as described above. Although initial control of tumor growth was observed, this was followed by rapid tumor progression (TGII 138.4%). In addition to flow cytometry, an MSI-H CRC tumor directly from a patient was stained for a variety of immunologic markers and analyzed by Vectra. The tumors contained both CD4- and CD8-positive cells, indicating T-cell infiltration. These data are consistent with what was observed by flow cytometry. Similar results were observed in an MSI-H CRC tumor grown as a xenograft in humanized mice both with and without nivolumab. However, in the MSS CRC PDX model, very few CD4 and CD8 cells were observed in the tumor or in the surrounding stroma. Conclusions: We have successfully established in vivo MSI-H and MSS humanized CRC PDXs. All mice were highly chimeric and the MSI-H model demonstrated high TILs, and responding tumors exhibited IFNγ production, high CD8%, higher effector memory % (HLADR+, CD45RO+), and decreased PD-L1 expression by flow cytometry. Interestingly, we also observed greater numbers of T cells in the lymph nodes of the MSI-H PDX. Moreover, immune infiltrates were observed in the MSI-H PDX compared to the MSS by immunohistochemistry. These data suggest that humanized PDX models may be useful in the development of rational combinations of immunotherapy.

Citation Format: Anna Capasso, Julie Lang, Todd M. Pitts, Christopher H. Lieu, Scott Kopetz, Sarah L. Davis, Kimberly Jordan, Stacey M. Bagby, Wells A. Messersmith, Roberta Pelanda, S. Gail Eckhardt. Humanized patient-derived xenografts (PDXs) recapitulate clinical responses in microsatellite stable (MSS) and unstable (MSI-H) colorectal cancer (CRC) [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A012.

Brain Structural Covariance Network Topology in Remitted Posttraumatic Stress Disorder

Posttraumatic stress disorder (PTSD) is a prevalent, chronic disorder with high psychiatric morbidity; however, a substantial portion of affected individuals experience remission after onset. Alterations in brain network topology derived from cortical thickness correlations are associated with PTSD, but the effects of remitted symptoms on network topology remain essentially unexplored. In this cross-sectional study, US military veterans (N = 317) were partitioned into three diagnostic groups, current PTSD (CURR-PTSD, N = 101), remitted PTSD with lifetime but no current PTSD (REMIT-PTSD, N = 35), and trauma-exposed controls (CONTROL, n = 181). Cortical thickness was assessed for 148 cortical regions (nodes) and suprathreshold interregional partial correlations across subjects constituted connections (edges) in each group. Four centrality measures were compared with characterize between-group differences. The REMIT-PTSD and CONTROL groups showed greater centrality in left frontal pole than the CURR-PTSD group. The REMIT-PTSD group showed greater centrality in right subcallosal gyrus than the other two groups. Both REMIT-PTSD and CURR-PTSD groups showed greater centrality in right superior frontal sulcus than CONTROL group. The centrality in right subcallosal gyrus, left frontal pole, and right superior frontal sulcus may play a role in remission, current symptoms, and PTSD history, respectively. The network centrality changes in critical brain regions and structural networks are associated with remitted PTSD, which typically coincides with enhanced functional behaviors, better emotion regulation, and improved cognitive processing. These brain regions and associated networks may be candidates for developing novel therapies for PTSD. Longitudinal work is needed to characterize vulnerability to chronic PTSD, and resilience to unremitting PTSD.

The development of regorafenib and its current and potential future role in cancer therapy

Regorafenib is a novel multikinase inhibitor that has demonstrated broad antitumor activity across various solid tumor types, in preclinical and clinical studies. Preclinical data show inhibitory activity of angiogenic, stromal and oncogenic tyrosine kinases through the targeting of vascular endothelial growth factor receptors 1, 2 and 3, tyrosine-protein kinase receptor TIE-2, platelet-derived growth factor receptor β, fibroblast growth factor receptor 1, proto-oncogene tyrosine-protein kinase receptor Ret, mast/stem cell growth factor receptor Kit, RAF proto-oncogene serine/threonine-protein kinase and wild-type and V600E mutant serine/threonine-protein kinase B-raf. Phase I trials have shown that the drug is relatively well tolerated at doses of 160 mg daily on a 3-weeks-on/1-week-off schedule, or 100 mg daily on a continuous schedule, with adverse effects typical of other multikinase inhibitors. Phase II studies demonstrated clinical benefit in a variety of tumor types, mostly associated with prolonged stable disease. Phase III studies include the CORRECT trial, which ultimately led to FDA approval of the drug in the setting of metastatic colorectal cancer previously treated with standard therapies. There is still much work to be done to determine the role of regorafenib in the future of cancer therapy. This review will focus on the development of regorafenib, from early preclinical work through phase I, II and III trials, as well as highlighting the current role and potential future directions of this novel agent.

Understanding soaring bird migration through interactions and decisions at the individual level

Many soaring bird species migrate southwards in autumn from their breeding grounds in Europe and Central Asia towards their wintering grounds. Our knowledge about interactions between migrating birds, thermal selection during migration and mechanisms that lead to flocking or convergent travel networks is still very limited. To start investigating these aspects we developed an individual-based simulation model that describes the local interactions between birds and their environment during their migratory flight, leading to emergent patterns at larger scales. The aim of our model is to identify likely decision rules with respect to thermal selection and navigation. After explaining the model, it is applied to analyse the migration of white storks (Ciconia ciconia) over part of its migration domain. A model base-run is accompanied by a sensitivity analysis. It appears that social interactions lead to the use of fewer thermals and slight increases in distance travelled. Possibilities for different model extensions and further model application are discussed.

Dystroglycan matrix receptor function in cardiac myocytes is important for limiting activity-induced myocardial damage

RATIONALE

Genetic mutations in a number of putative glycosyltransferases lead to the loss of glycosylation of dystroglycan and loss of its laminin-binding activity in genetic forms of human muscular dystrophy. Human patients and glycosylation defective myd mice develop cardiomyopathy with loss of dystroglycan matrix receptor function in both striated and smooth muscle.

OBJECTIVE

To determine the functional role of dystroglycan in cardiac muscle and smooth muscle in the development of cardiomyopathy in muscular dystrophies.

METHODS AND RESULTS

Using cre/lox-mediated gene targeting, we show here that loss of dystroglycan function in ventricular cardiac myocytes is sufficient to induce a progressive cardiomyopathy in mice characterized by focal cardiac fibrosis, increase in cardiac mass, and dilatation ultimately leading to heart failure. In contrast, disruption of dystroglycan in smooth muscle is not sufficient to induce cardiomyopathy. The specific loss of dystroglycan function in cardiac myocytes causes the accumulation of large, clustered patches of myocytes with membrane damage, which increase in number in response to exercise-induced cardiac stress, whereas exercised mice with normal dystroglycan expression accumulate membrane damage limited to individual myocytes.

CONCLUSIONS

Our findings suggest dystroglycan function as an extracellular matrix receptor in cardiac myocytes plays a primary role in limiting myocardial damage from spreading to neighboring cardiac myocytes, and loss of dystroglycan matrix receptor function in cardiac muscle cells is likely important in the development of cardiomyopathy in glycosylation-deficient muscular dystrophies.

Botulinum toxin abolishes sweating via impaired sweat gland responsiveness to exogenous acetylcholine

BACKGROUND

Botulinum toxin A (BTX) disrupts neurotransmitter release from cholinergic nerves. The effective duration of impaired sweat secretion with BTX is longer relative to that of impaired muscle contraction, suggesting different mechanisms in these tissues.

OBJECTIVES

The aim of this study was to test the hypothesis that BTX is capable of altering sweating by reducing the responsiveness of the sweat gland to acetylcholine.

METHODS

BTX was injected into the dorsal forearm skin of healthy subjects at least 3 days before subsequent assessment. On the day of the experiment, intradermal microdialysis probes were placed within the BTX-treated area and in an adjacent untreated area. Incremental doses of acetylcholine were administered through the microdialysis membranes while the sweat rate (protocol 1; n = 8) or a combination of sweat rate and skin blood flow (protocol 2; n = 8) were assessed.

RESULTS

A relative absence of sweating was observed at the BTX site for both protocols (protocol 1: 0.05 +/- 0.09 mg cm(-2) min(-1); protocol 2: 0.03 +/- 0.04 mg cm(-2) min(-1), both at the highest dose of acetylcholine), while the sweat rate increased appropriately at the control sites (protocol 1: 0.90 +/- 0.46 mg cm(-2) min(-1); protocol 2: 1.07 +/- 0.67 mg cm(-2) min(-1)). Cutaneous vascular conductance increased to a similar level at both the BTX and control sites.

CONCLUSIONS

These results demonstrate that BTX is capable of inhibiting sweat secretion by reducing the responsiveness of the sweat gland to acetylcholine, while not altering acetylcholine-mediated cutaneous vasodilatation.

Modeling Uhthoff's phenomenon in MS patients with internuclear ophthalmoparesis

OBJECTIVE

The goal of this investigation was to demonstrate that internuclear ophthalmoparesis (INO) can be utilized to model the effects of body temperature-induced changes on the fidelity of axonal conduction in multiple sclerosis (Uhthoff's phenomenon).

METHODS

Ocular motor function was measured using infrared oculography at 10-minute intervals in patients with multiple sclerosis (MS) with INO (MS-INO; n = 8), patients with MS without INO (MS-CON; n = 8), and matched healthy controls (CON; n = 8) at normothermic baseline, during whole-body heating (increase in core temperature 0.8 degrees C as measured by an ingestible temperature probe and transabdominal telemetry), and after whole-body cooling. The versional disconjugacy index (velocity-VDI), the ratio of abducting/adducting eye movements for velocity, was calculated to assess changes in interocular disconjugacy. The first pass amplitude (FPA), the position of the adducting eye when the abducting eye achieves a centrifugal fixation target, was also computed.

RESULTS

Velocity-VDI and FPA in MS-INO patients was elevated (p < 0.001) following whole body heating with respect to baseline measures, confirming a compromise in axonal electrical impulse transmission properties. Velocity-VDI and FPA in MS-INO patients was then restored to baseline values following whole-body cooling, confirming the reversible and stereotyped nature of this characteristic feature of demyelination.

CONCLUSIONS

We have developed a neurophysiologic model for objectively understanding temperature-related reversible changes in axonal conduction in multiple sclerosis. Our observations corroborate the hypothesis that changes in core body temperature (heating and cooling) are associated with stereotypic decay and restoration in axonal conduction mechanisms.

What would the world be like without animals for food, fiber, and labor? Are we morally obligated to do without them?

Numerous animal rights and animal liberation theorists have concluded that nonhuman animals have moral standing and noninterference rights. Therefore, they say that humans are morally obligated to stop using animals for food, fiber, labor, and research. I disagree with that conclusion for at least 2 reasons. First, it has been suggested that food production models are possible using large herbivores that might actually cause less harm (kill) to animals than a vegan food production model. This is because intensive crop production used to produce food for a vegan diet kills (harms) far more animals of the field than extensive agriculture (pasture production). So, a combined food production system that includes crops and pasture harvested by large herbivores to be used for human food may kill fewer animals than would a vegan-crop model. Second, pragmatically, it is improbable that all peoples of the world could ever be convinced that they must give up animals. In fact, it may be unethical to try to do that, because in poor countries, these animals are essential to the survival of the human populations. But what about the richer nations? Maybe they will or should be convinced to do without animals because of the moral strength of the animal rights and animal liberation theories. However, I believe that there are far too many obstacles for that to happen. What then are we morally obligated to do about animals? I suggest that animals do have moral standing, and that we are morally obligated to recognize their unique species-specific natures and treat them accordingly. That would mean treating animals according to their physical and behavioral needs or telos. That, I believe, is the most likely outcome of the conversation about animal rights.

Infective endocarditis caused by USA300 methicillin-resistant Staphylococcus aureus (MRSA)

We report seven cases of infective endocarditis caused by USA300 methicillin-resistant Staphylococcus aureus (MRSA) at an urban, tertiary care, academic institution. Five strains were community associated and two were healthcare associated. All patients were injection drug users. Staphylococcus aureus isolates were characterised as USA300-type MRSA using pulsed-field gel electrophoresis. Five cases were right-sided endocarditis and two cases were left-sided. The mean length of in-hospital antimicrobial therapy was 23 days and the mean length of total antibiotic therapy was 55 days. Complications included heart failure resulting in valve replacement in one patient as well as death in that patient. As USA300 strains of MRSA continue to increase in prevalence, clinicians must be aware of the increasing spectrum of illness in considering management and prevention strategies.

Epidemiology and outcomes of community-associated methicillin-resistant Staphylococcus aureus infection

Over a 2-year period (2003 to 2005) patients with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and community-acquired methicillin-susceptible Staphylococcus aureus (CA-MSSA) infections were prospectively identified. Patients infected with CA-MRSA (n = 102 patients) and CA-MSSA (n = 102 patients) had median ages of 46 and 53 years, respectively; the most common sites of infection in the two groups were skin/soft tissue (80 and 93%, respectively), respiratory tract (13 and 6%, respectively), and blood (4 and 1%, respectively). Fourteen percent of patients with CA-MRSA infections and 3% of patients with CA-MSSA infections had household contacts with similar infections (P < 0.01). Among the CA-MRSA isolates, the pulsed-field gel electrophoresis (PFGE) groups detected were USA300 (49%) and USA100 (13%), with 27 PFGE groups overall; 71% of the isolates were staphylococcal chromosome cassette mec (SCCmec) type IV, 29% were SCCmec type II, and 54% had the Panton-Valentine leucocidin (PVL) gene. Among the CA-MSSA isolates there were 33 PFGE groups, with isolates of the USA200 group comprising 11%, isolates of the USA600 group comprising 11%, isolates of the USA100 group comprising 10%, and isolates of the PVL type comprising 10%. Forty-six and 18% of the patients infected with CA-MRSA and CA-MSSA, respectively, were hospitalized (P < 0.001). Fifty percent of the patients received antibiotic therapy alone, 5% received surgery alone, 30% received antibiotics and surgery, 3% received other therapy, and 12% received no treatment. The median durations of antibiotic therapy were 12 and 10 days in the CA-MRSA- and CA-MSSA-infected patients, respectively; 48 and 56% of the patients in the two groups received adequate antimicrobial therapy, respectively (P < 0.001). The clinical success rates of the initial therapy in the two groups were 61 and 84%, respectively (P < 0.001); recurrences were more common in the CA-MRSA group (recurrences were detected in 18 and 6% of the patients in the two groups, respectively [P < 0.001]). CA-MRSA was an independent predictor of clinical failure in multivariate analysis (odds ratio, 3.4; 95% confidence interval, 1.7 to 6.9). In the community setting, the molecular characteristics of the S. aureus strains were heterogeneous. CA-MRSA infections were associated with a more adverse impact on outcome than CA-MSSA infections.

A 2.5-Mb contig constructed from Angus, Longhorn and horned Hereford DNA spanning the polled interval on bovine chromosome 1

The polled locus has been mapped by genetic linkage analysis to the proximal region of bovine chromosome 1. As an intermediate step in our efforts to identify the polled locus and the underlying causative mutation for the polled phenotype, we have constructed a BAC-based physical map of the interval containing the polled locus. Clones containing genes and markers in the critical interval were isolated from the TAMBT (constructed from Angus and Longhorn genomic DNA) and CHORI-240 (constructed from horned Hereford genomic DNA) BAC libraries and ordered based on fingerprinting and the presence or absence of 80 STS markers. A single contig spanning 2.5 Mb was assembled. Comparison of the physical order of STSs to the corresponding region of human chromosome 21 revealed the same order of genes within the polled critical interval. This contig of overlapping BAC clones from horned and polled breeds is a useful resource for SNP discovery and characterization of positional candidate genes.

Heat stress enhances arterial baroreflex control of muscle sympathetic nerve activity via increased sensitivity of burst gating, not burst area, in humans

The relationship between muscle sympathetic nerve activity (MSNA) and diastolic blood pressure has been used to describe two sites for arterial baroreflex control of MSNA. By determining both the likelihood of occurrence for sympathetic bursts and the area of each burst for a given diastolic blood pressure, both a 'gating' and an 'area' control site has been described in normothermic humans. Assessing the effect of heat stress on these mechanisms will improve the understanding of baroreflex control of arterial blood pressure under this thermal condition. Therefore, the purpose of this study was to test the hypothesis that heat stress enhances arterial baroreflex control of burst gating and area. In 10 normotensive subjects (age, 32+/-2 years; mean+/-s.e.m.), MSNA (peroneal) was assessed using standard microneurographic techniques. Five minute periods of data were examined during normothermic and whole-body heating conditions. The burst incidence (i.e. number of sympathetic bursts per 100 cardiac cycles) and the area of each burst were determined for each cardiac cycle and were placed into 3 mmHg intervals of diastolic blood pressure. During normotheric conditions, there was a moderate, negative relationship between burst incidence and diastolic blood pressure (slope=-2.49+/-0.38; r(2)=0.73+/-0.06; mean+/-s.e.m.), while area per burst relative to diastolic blood pressure exhibited a less strong relationship (slope=-1.13+/-0.46; r(2)=0.45+/-0.09). During whole-body heating there was an increase in the slope of the relationship between burst incidence and diastolic blood pressure (slope=-4.69+/-0.44; r(2)=0.84+/-0.03) compared to normothermia (P<0.05), while the relationship between area per burst and diastolic blood pressure was unchanged (slope=-0.92+/-0.29; r(2)=0.41+/-0.08) (P=0.50). The primary finding of this investigation is that, at rest, whole-body heating enhanced arterial baroreflex control of MSNA through increased sensitivity of a 'gating' mechanism, as indicated by an increase in the slope of the relationship between burst incidence and diastolic blood pressure. This occurrence is likely to afford protection against potential decreases in arterial blood pressure in an effort to preserve orthostatic tolerance during heat stress.

Team approach to teaching participatory group process involving natural resources and agriculture

Contemporary issues are defined by people who share diverse and often strongly defended views about the topic. In Oregon, citizens are increasingly being asked or expected to participate in complex decisions that require a consensus. Rather than teach one professor's synthesis of a contemporary natural resource issue, faculty from six disciplines coach group process, interactive learning skills, and systems thinking as a way to address complex issues from multiple perspectives. Students learn by grappling with a natural resource issue of their choice within groups based on a diversity among majors, degree status, and gender. Students define situation (S), brainstorm new or different targets (T), and analyze two or more pathways (P), using an STP learning and action process. Exploring potential pathways involves defining possible consequences, stakeholder views, feasibility (ecological, social, economic, and political), and planning that includes expected behavior of the improved system over time. Students present their topics and improvements showing systemic relationships, systematic analysis, and integration of scientific facts and secondary data at midterm and during finals. Reflective learning is fostered throughout the course with prompted questions in a journal notebook. Grading criteria promote meaningful inquiry and participation in group process combined with integration of scientific facts and reflective learning.

Exogenous nitric oxide inhibits sympathetically mediated vasoconstriction in human skin

Two experiments were performed to identify whether nitric oxide (NO) inhibits sympathetically mediated vasoconstriction in human skin. In eight subjects increasing doses of sodium nitroprusside (SNP; 8.4 x 10(-6)-8.4 x 10(-3)m) were administered via intradermal microdialysis. At each dose of SNP, cutaneous vasoconstrictor responsiveness was assessed during a 3 min whole-body cold stress. The relative reduction in forearm cutaneous vascular conductance (CVC) during the cold stress was significantly attenuated for SNP doses greater than 8.4 x 10(-4)m (control: 63.0 +/- 4.1%, SNP 8.4 x 10(-6)m: 57.1 +/- 4.7%, SNP 8.4 x 10(-5)m: 57.0 +/- 3.6%, SNP 8.4 x 10(-4)m: 44.5 +/- 5.4% and SNP 8.4 x 10(-3)m: 28.8 +/- 7.9%). The second experiment was performed to identify whether this response was due to NO attenuating sympathetically mediated vasoconstriction or due to a non-specific effect of an elevated CVC secondary to SNP administration. In seven subjects forearm CVC during a whole-body cold stress was assessed at two sites: at a site dilated via microdialysis administration of SNP and at a site dilated with isoproterenol (ISO). CVC was not different between sites prior to (SNP: 0.42 +/- 0.11; ISO: 0.46 +/- 0.11 AU mmHg(-1) (AU, arbitrary units), P > 0.05) or following drug infusion (SNP: 1.36 +/- 0.21; ISO: 1.27 +/- 0.23 AU mmHg(-1), P > 0.05). The reduction in CVC during the subsequent cold stress was significantly less at the SNP site (38.1 +/- 6.2%) relative to the ISO site (65.0 +/- 5.5%; P= 0.007). These data suggest NO is capable of inhibiting sympathetically mediated vasoconstriction in the cutaneous vasculature.

Defining a middle ground for philosophers and production: bioethics

From the perspective of most animal scientists and producers, animal agriculture has become increasingly contentious over the last 10 to 20 years. Furthermore, our critics seem to be extremists whose views are biased and unreasonable. But guess what? The critics say the same thing about animal producers and scientists (us). So where is the middle ground and how do we get there? Should we even worry about trying to define the middle ground? Are these contentious issues a fad that will go away? Are these "extremist" critics so far outside reason that they will be ignored by society? Ignoring "them" is not likely to work because we have seen society changing its mind (developing a new social ethic) with regard to farm animals, in part because of what these critics are saying. As a result, it is vitally important for us to know and understand what is happening and why. For example, there isn't just one voice among the critics. There is actually a spectrum of opinion among the group which conventional agriculturalists usually call their critics. The WCC-204 committee generally agrees that the key to finding the middle ground between what is perceived as a polarized set of issues between "us" (animal scientists and producers) and "them" (philosopher critics) is for both sides to learn about the reasons why each side says what they do. Only then can all parties rationally begin to identify where the middle ground lies.

Pharmacokinetic and pharmacodynamic issues in the treatment of bacterial infectious diseases

This review outlines some of the many factors a clinician must consider when selecting an antimicrobial dosing regimen for the treatment of infection. Integration of the principles of antimicrobial pharmacology and the pharmacokinetic parameters of an individual patient provides the most comprehensive assessment of the interactions between pathogen, host, and antibiotic. For each class of agent, appreciation of the different approaches to maximize microbial killing will allow for optimal clinical efficacy and reduction in risk of development of resistance while avoiding excessive exposure and minimizing risk of toxicity. Disease states with special considerations for antimicrobial use are reviewed, as are situations in which pathophysiologic changes may alter the pharmacokinetic handling of antimicrobial agents.

Total mercury concentrations in lakes and fish of western Maryland, USA

The purpose of this study was to quantify total mercury concentrations in three species of fish in three lakes of western Maryland: Piney Creek reservoir, Deep Creek Lake, and Lake Habeeb. We measured total mercury concentrations in water from each lake and muscle tissue from 119 fish collected in fall 2000: 15 largemouth bass (Micropterus salmoides), 15 yellow perch (Perca flavescens), and 15 bluegill (Lepomis macrochirus) from the Piney Creek reservoir; 15 largemouth bass, 15 yellow perch, and 14 bluegill from Deep Creek Lake; and 15 largemouth bass and 15 bluegill from Lake Habeeb. Average total mercury concentrations (+/- SD) in surface waters were 0.96 +/- 0.03 ng L(-1) for the Piney Creek reservoir, 0.56 +/- 0.07 ng L(-1) for Deep Creek Lake, and 0.40 +/- 0.05 ng L(-1) for Lake Habeeb. These water quality differences were sometimes reflected in the total mercury concentration in fish muscle tissue. Total mercury concentrations in bluegill (0.05 +/- 0.02 microg g(-1)) and largemouth bass (0.10 +/- 0.03 microg g(-1)) from Lake Habeeb were significantly (p < 0.001) lower than the total mercury concentrations in bluegill and largemouth bass from the Piney Creek reservoir (bluegill: 0.13 +/- 0.04 microg g(-1) and largemouth bass: 0.37 +/- 0.18 microg g(-1)) and Deep Creek Lake (bluegill: 0.11 +/- 0.04 microg g(-1) and largemouth bass: 0.30 +/- 0.09 microg g(-1)). Yellow perch from the Piney Creek reservoir had significantly higher total mercury concentrations than yellow perch from Deep Creek Lake (0.20 +/- 0.08 microg g(-1) versus 0.13 +/- 0.04 microg g(-1)). In contrast, total mercury concentrations in largemouth bass from the Piney Creek reservoir and Deep Creek Lake were not significantly different. With the exception of largemouth bass from Lake Habeeb and yellow perch from Deep Creek Lake, there were relatively strong (r(2) > 0.39-0.79) log-log relationships between the size (weight and length) of the fish and total mercury concentrations in muscle tissue. The largest largemouth bass (> 800 g and > 38 cm) from both Deep Creek Lake and the Piney Creek reservoir had total mercury concentrations that exceeded the consumption advisory of 0.5 microg g(-1) that is used by many states and Canada. In contrast, total mercury concentrations in largemouth bass from Lake Habeeb did not exceed this consumption advisory. Our results suggest that fish consumption advisories are needed for largemouth bass in the Piney Creek reservoir and Deep Creek Lake.

Phenotypic and genetic correlations among floral traits in two species of Thalictrum

The evolution of dioecy in plants is expected to be followed by sex-specific selection, leading to sexual dimorphism. The extent of the response to selection depends on the genetic covariance structure between traits both within and between the sexes. Here I describe an investigation to determine phenotypic and genetic correlations between reproductive traits within cryptically dioecious Thalictrum pubescens and within morphologically dioecious T. dioicum. Females of T. pubescens produce flowers having stamens and pistils, appearing hermaphroditic. Genetic correlations were estimated as family-mean correlations among paternal half-sib families. Positive phenotypic and genetic correlations between parts of the same reproductive organs, as the anther and filament of the stamen, indicate developmental associations between these traits in both species. Negative genetic correlations were detected between pistil number and size of reproductive organs in T. dioicum and showed the same direction, but not significance, in T. pubescens. There was a negative phenotypic correlation between the number of stamens and the number of pistils within female flowers of T. pubescens. Within T. pubescens, there was a positive genetic correlation between the number of stamens in males and the number of pistils in females, indicating that floral evolution in males and females may not be independent in this species.

Effects of past abuse experiences on children's eyewitness memory

Relations between child maltreatment and children's eyewitness memory were examined. A matched sample of abused and nonabused 3- to 10-year-old children (n = 70) participated in a play session with an unfamiliar adult and were interviewed about the interaction 2 weeks later. Consistent with results from previous research, older compared to younger children's reports were more complete and accurate. Abused and nonabused children performed similarly with several exceptions: Nonabused children were more accurate in answering specific questions, made fewer errors in identifying the unfamiliar adult in a photo identification task, and (at least for younger boys) freely recalled more information. Most effects remained when group differences in IQ and behavioral symptomology were statistically controlled. Importantly, abused and nonabused children did not differ in their accuracy or suggestibility in response to questions that were relevant to abusive actions. Among abused children, however, those who suffered more severe sexual abuse made more omission errors to specific abuse-relevant questions. Contributions to psychological theory and legal implications for understanding children's eyewitness memory and testimony are discussed.

SdrG, a fibrinogen-binding bacterial adhesin of the microbial surface components recognizing adhesive matrix molecules subfamily from Staphylococcus epidermidis, targets the thrombin cleavage site in the Bbeta chain

Staphylococcus epidermidis is an important opportunistic pathogen and is a major cause of foreign body infections. We have characterized the ligand binding activity of SdrG, a fibrinogen-binding microbial surface component recognizing adhesive matrix molecules from S. epidermidis. Western ligand blot analysis showed that a recombinant form of the N-terminal A region of SdrG bound to the native Bbeta chain of fibrinogen (Fg) and to a recombinant form of the Bbeta chain expressed in Escherichia coli. By analyzing recombinant truncates and synthetic peptide mimetics of the Fg Bbeta chain, the binding site for SdrG was localized to residues 6-20 of this polypeptide. Recombinant SdrG bound to a synthetic 25-amino acid peptide (beta1-25) representing the N terminus of the Fg Bbeta chain with a KD of 1.4 x 10(-7) m as determined by fluorescence polarization experiments. This was similar to the apparent K(D) (0.9 x 10(-7) m) calculated from an enzyme-linked immunosorbent assay where SdrG bound immobilized Fg in a concentration-dependent manner. SdrG could recognize fibrinopeptide B (residues 1-14), but with a substantially lower affinity than that observed for SdrG binding to synthetic peptides beta1-25 and beta6-20. However, SdrG does not bind to thrombin-digested Fg. Thus, SdrG appears to target the thrombin cleavage site in the Fg Bbeta chain. In fact, SdrG was found to inhibit thrombin-induced fibrinogen clotting by interfering with fibrinopeptide B release.

Antioxidant status and oxidative stress in elite alpine ski racers

The goal of this study was to access antioxidant status and markers of oxidative damage in elite alpine ski racers during routine training. Subjects included 12 members of the U.S. Men's Alpine Ski Team attending a 10-day summer training camp. Blood draws were collected at rest and after exercise: (a) prior to training, (b) following 2 days of dry land training, and (c) after 4 days of on-snow skiing. Seven measures of antioxidant status were determined using colorimetric and HPLC methods (Trolox equivalent antioxidant capacity, uric oxidase, alpha-tocopherol, total glutathione, cytosolic glutathione peroxidase, and superoxide dismutase). Oxidative stress was assessed using 2 markers of lipid oxidation (malondialdehyde and lipid hydroperoxides) and 2 markers of protein oxidation (carbonylated total proteins and carbonylated hemoglobin). The results of this study suggest that antioxidant status of elite alpine skiers may decline over a period of intense training. However, elevations in markers of oxidative stress were not evident.

Effect of precooling on physical performance in multiple sclerosis

Many individuals with MS experience heat sensitivity that may be associated with transient increases in the frequency of clinical signs and symptoms. Although physical activity may be beneficial for those with MS, induced thermal loads may preclude participation in exercise and other daily activities. This project was designed to evaluate the effects of precooling on physical function. Six thermosensitive MS patients were studied. Participants performed a graded exercise test to determine maximal oxygen uptake (VO2max) on a combined arm-leg ergometer. Thermal load was induced by 30 min of exercise under noncooled and precooled conditions at a workrate corresponding to 60% VO2max. Precooling consisted of 30 min lower body immersion in 16 - 17 degrees C water. Fatigue and 25-ft walk performance were assessed before, immediately after, and 30 min following exercise. No treatment differences in VO2 were observed. Rectal temperature, heart rate, and rating of perceived exertion (RPE) were significantly lower during the precooled exercise trial compared to the noncooled trial. Immediately following exercise, 25-ft walk performance and fatigue scores showed significantly greater deterioration in the noncooled condition. Precooling was effective in preventing gains in core temperature with physical work and may allow heat-sensitive individuals with MS to exercise with greater physical comfort.

Formulation of poly(D,L-lactic-co-glycolic acid) microparticles for rapid plasmid DNA delivery

An optimised water-in-oil-in-water double emulsion process for the microencapsulation of plasmid DNA in poly(D,L-lactic-co-glycolic acid) (PLGA) was used to prepare microparticles from a range of different PLGA formulations. This process has been developed using pharmaceutically accepted solvents and is potentially scaleable. Incorporation of plasmid DNA in the microparticles of up to 11 microg/mg was obtained and the retention of plasmid DNA integrity was considerably greater than previously reported. Microparticle structure was determined, by scanning electron microscopy, to be hollow and size distribution characteristics were found to be independent of polymer formulation. The ability to vary the plasmid DNA release profile by changing the PLGA formulation and polymer concentration used in the encapsulation process was also demonstrated. This ability to control the release profile of the microparticles was shown to be especially important as the physical integrity of the encapsulated plasmid DNA was found to deteriorate with extended release times in vitro.

Multiple isoforms of porcine aromatase are encoded by three distinct genes

Cytochrome P450 aromatase, a product of the CYP 19 gene and the terminal enzyme in the estrogen biosynthetic pathway, is synthesized by the ovary, endometrium, placenta, and peri-implantation embryos in the pig and other mammals, albeit to varying levels, implying its functional role(s) in pregnancy events. The aromatase produced by the pig tissues exists as three distinct isoforms (type I - ovary, type II - placenta, and type III - embryo), with presumed differences in substrate specificities, expression levels, activity, and mode of regulation. In order to delineate the molecular mechanisms whereby estrogen synthesis is regulated in these diverse tissues, the present study examined if these aromatase isoforms represent products of multiple genes or of a single gene via complex splicing mechanisms. Porcine genomic DNA from a single animal was used as a template in the polymerase chain reaction (PCR) to amplify isoform-specific sequences corresponding to exons 4 and 7, respectively. Nucleotide sequence analysis of the generated fragments revealed the presence of only clones corresponding to the three known aromatase types. Screening a porcine Bacterial Artificial Chromosome (BAC) library for aromatase gene by PCR yielded a single clone approximately 80 kb in length. Southern blot analysis, using probes specific for exons 1A-1B, 2-3, 4-9, and 10 sequences indicated that the BAC genomic clone contains the entirety of the coding exons as well as the proximal promoter region. Sequence analysis of the fragment generated with exon 4 primers determined that this BAC clone contains only the type II gene. The presence and relative orientation of the untranslated 5'- exons 1A and 1B, previously demonstrated for the type III isoform were evaluated in the BAC clone and genomic DNA by PCR. The 265 bp fragment generated from both PCR reactions was confirmed by sequence analysis to contain exons 1A and 1B that are located contiguous to each other and separated by only three bp. A diagnostic procedure for typing aromatase isoforms was developed, based on the presence of specific restriction sites within isoform-specific exons. The use of this protocol confirmed the existence of only three aromatase isoforms in the porcine genome and indicated changes in aromatase types expressed by the uterine endometrium as a function of pregnancy stage. The presence of distinct genes encoding each of the aromatase isoform predicts important differences in the mechanisms underlying the molecular evolution and regulation of porcine aromatase, unique from those of other mammals, and suggests a critical role for P450 aromatase steroidal products in uterine functions related to pregnancy events.

Neonatal micrognathia is associated with small upper airways on radiographic measurement

In order to determine if infants with clinical micrognathia identified in the newborn period have smaller upper airways than do normal infants, and if their airway size is related to risk of later apnoea, respiration-timed upper airway radiographic measurements were performed in 21 asymptomatic neonates with clinical micrognathia. Their radiographic measurements were compared with those of a previously reported cohort of 35 normal infants. The micrognathic infants and a control group of 27 infants referred for parental anxiety were followed for 6 mo on home apnoea monitors. Sleep apnoea at home requiring stimulation by the parents occurred in 6 of 7 infants with micrognathia associated with craniofacial anomalies, 9 of 14 (64%) infants with isolated micrognathia, but only 1 of the 27 control infants (p < 0.001). Upper airway measurements at term of the infants with isolated micrognathia who later experienced apnoea were significantly smaller than either those of normal infants (p < 0.01) or of micrognathic infants who did not have apnoea requiring stimulation (p < 0.05). In conclusion, upper airway measurements on timed lateral radiographs in asymptomatic micrognathic infants at term (corrected age) revealed them to be smaller than those of normal infants. Narrower upper airways were associated with increased risk of subsequent apnoea requiring stimulation.

Role of the cerebrovascular and metabolic responses in the delayed phases of injury after transient cerebral ischemia in fetal sheep

BACKGROUND AND PURPOSE

Perinatal hypoxic-ischemic injuries can trigger a cascade of events leading to delayed deterioration and cell death several hours later. The objective of this study was to characterize the cerebral blood flow responses and the changes in extracellular glucose and lactate during the delayed phases of injury and to determine their relationships with the pathophysiological events after hypoxic-ischemic injury.

METHODS

Two groups of near-term chronically instrumented fetal sheep were subjected to 30 minutes of cerebral hypoperfusion. In the first group, regional cerebral blood flow was measured over the next 24 hours with radiolabeled microspheres. In the second, cortical extracellular glucose and lactate were measured by microdialysis. Parietal electrocorticographic activity and cortical impedance were recorded continuously in both groups, and the extent of neuronal loss was determined histologically at 72 hours after injury.

RESULTS

Cerebral blood flow was transiently impaired in the cortex during reperfusion, whereas during the delayed phase, there was a marked increase in cerebral blood flow. The severity of cortical neuronal loss was related to the degree of hypoperfusion in the immediate reperfusion period and inversely related to the magnitude of the delayed hyperperfusion. Cortical extracellular lactate was elevated after injury, and both glucose and lactate secondarily increased during the delayed phase of injury.

CONCLUSIONS

The delayed phase is accompanied by a period of hyperperfusion that may protect marginally viable tissue.

Effects of sex and gonadectomy on cocaine metabolism in the rat

The purpose of the current study is to determine whether sex differences in metabolism of cocaine (COC) exist that could contribute to the greater behavioral sensitivity of females to COC administration. To investigate this question, concentrations of COC and its two principle metabolites benzoylecgonine (BE) and ecgonine methyl ester (EME) were measured by gas chromatography/mass spectroscopy in brain and plasma collected from male and female rats that were sacrificed between 5 and 90 min after injection COC (15 mg/kg i.p.). COC concentrations did not differ in plasma or brain tissue of males and females, but sex-specific patterns of metabolite distribution were detected. BE was 2-fold higher in plasma and brain of males than females, whereas EME was much higher in brain and plasma of females. The influence of gonadal hormones on COC metabolite patterns were determined using gonadectomized and prepubertal rats. Castration of male or female rats did not alter brain or plasma COC, but did decrease BE concentrations. Seven-day-old pups injected with 15 mg/kg of COC had higher blood and brain COC than adults and relatively low levels of metabolites. No sex differences were found for COC, BE, or EME in brain or plasma of pups. These findings indicate that although gonadal steroids influence COC metabolism, these effects do not explain sex differences in COC-induced behaviors.

Organophosphorus-induced neurotoxicity in the absence of neuropathy target esterase inhibition: the effects of triphenyl phosphine in the European ferret

Abou-Donia et al. (in Toxicologist, Vol. 30, 1996) have reported that repeated oral administration of the organo-phosphorus compound triphenyl phosphine (TPPn) to the domestic chicken results in neuropathological changes in the spinal cord and peripheral nerves, accompanied by ataxia and paralysis. This study also noted that single doses of TPPn resulted in no inhibition of the enzymes neuropathy target esterase (NTE) and acetylcholinesterase (AChE). We undertook the present study to determine the biochemical, neuropathological, and clinical effects of single doses of TPPn in the European ferret, a mammalian species shown to be susceptible to organophosphorus-induced neurotoxicity. Eight 12-week-old ferrets were each injected subcutaneously with either 250 mg TPPn/kg bw or 500 mg TPPn/kg bw, or with the peanut oil/ethyl ether vehicle. Twenty-four h after dosing, the brains of 5 animals from each dose group were examined for NTE and AChE activities. The remaining 3 animals in each group were observed for 6 days for the development of clinical signs, after which their brains were processed for the presence of axonal degeneration using the Fink-Heimer silver impregnation method. Single injections of TPPn had no effect on the activities of whole-brain NTE or AChE 24 h after injection. The animals observed for clinical signs showed increasing trunk and hindlimb ataxia beginning 4 days after injection, culminating in fore-and hindlimb paralysis 6 days after injection. All brains exposed to either dose of TPPn showed widespread axonal degeneration extending from the brainstem and cerebellum into midbrain and forebrain areas. The results of this study support the hypothesis that TPPn-induced neurotoxicity is a separate and distinct form of organophosphorus-induced neurotoxicity not dependent on NTE inhibition, and therefore not a variant of organophosphorus-induced delayed neurotoxicity (OPIDN).

Environmental modulation of the immune system via the endocrine system

Numerous studies have demonstrated that a variety of hormones have receptors and exert biologic actions on tissues of the immune system. Conversely, cytokines exert biologic actions on the endocrine system. This bidirectional interaction is likely involved in maintenance of physiological and immunologic homeostasis. This paper summarizes a variety of actions of growth hormone (GH), prolactin (PRL), insulin-like growth factor-I (IGF-I), glucocorticoids and thyroid hormones (TH) on the immune system. It then proceeds to put these actions into a hypothetical context whereby these hormones may mediate some changes in immune system function in response to environmental stimuli such as physical and emotional stress, nutritional deprivation and environmental temperature. In the first example, it is proposed that PRL secretion in response to stress may serve an immunomodulatory role in two ways. The first is by stimulating the immune system directly and the second is by dampening or reducing the degree to which glucocorticoids are secreted in response to stress. The second example suggests that the increase in GH secretion and reduced IGF-I secretion in response to protein/energy restriction may have two potential immunomodulatory actions. One action is a direct effect of GH on several components of the immune system. The other is the partitioning of nutrient use away from skeletal muscle growth and toward tissues of higher priority such as the immune system. The third example proposes that the increased secretion of TH during cold environmental temperatures not only increases basic metabolic rate, but also directly stimulates both primary and secondary lymphoid tissues. It is suggested, therefore, that these three hormones are involved in maintaining immune system homeostasis in response to environmental change.

Do domestic animals have minds and the ability to think? A provisional sample of opinions on the question

Faculty, staff, and graduate students in a number of departments, students in an undergraduate course, and some groups outside the university were polled to obtain their perceptions about whether domestic animals have minds, the ability to think, and differing degrees of intelligence (the surveys focused only on horses, cows, sheep, dogs, chickens, pigs, cats, and turkeys). A clear majority of all groups surveyed (except the Department of Zoology) said yes, they believe animals have minds, but a substantial number of those in animal sciences and zoology (17 to 25%) said no. A number of others in animal sciences, zoology, and philosophy (11 to 37%) refused to answer the question because the concept of mind was not defined. From 80 to 100% of respondents in other groups said yes to the question of minds. From 67 to 100% of all participants said yes, they perceive that animals have the ability to think, but a substantial number of animal scientists, zoologists, veterinarians, and English faculty said no, animals don't think (6 to 33%). On the question Do domestic animals differ in relative intelligence?, the responses varied from 88% in animal sciences to 100%. Surprisingly, when asked to rank different animal species by intelligence, there was a remarkable degree of similarity across all groups regardless of background; the overall ranking from highest intelligence to lowest was dog, cat, pig, horse, cow, sheep, chicken, and turkey. Most of the respondents believed that the possession of minds, thought, and intelligence were relevant factors in how animals should be treated and the prevalent concept was that we should not be cruel to animals, but should treat them humanely.

Jurors' reactions to satanic ritual abuse allegations

OBJECTIVE

Some of the most highly publicized child sexual abuse trials of this century have involved bizarre allegations of satanic ritual abuse, yet little is known about jurors' reactions to ritual abuse claims. We investigated how jurors' judgements of defendant guilt and witness credibility are affected by the presence or absence of satanic ritual abuse allegations.

METHOD

Two hundred forty-three mock jurors rendered judgments about a case involving childhood sexual abuse allegations made by either a 5-year-old child or a 30-year-old adult survivor. The presence or absence of satanic ritual abuse allegations was varied between subjects. Jurors' religiosity was measured.

RESULTS

Although jurors were significantly less likely to believe the satanic ritual allegations than other case details, they were as likely to vote guilty and to believe the victim in satanic as in nonsatanic cases. Victim age had no significant effect on mock jurors' judgments, but there were marked individual differences in decisions: When the allegations involved satanic ritual abuse, religious jurors were more likely than less religious jurors to believe the victim. Further, across all conditions, women made more pro-victim judgements than did men.

CONCLUSIONS

Our findings suggest that highly bizarre details may be discounted by jurors (particularly less religious jurors), but that jurors may set aside their skepticism of satanic ritual details and make judgments about child sexual abuse cases based on their perceptions of the credibility of nonsatanic allegations of harm. Whether or not this is an accurate approach to decision-making in these cases remains an empirical question.

Host defenses against disseminated candidiasis are impaired in intercellular adhesion molecule 1-deficient mice

Genetically engineered mice, which lack normal expression of intercellular adhesion molecule 1 (ICAM-1), were used to study the role of ICAM-1 in the host defense against disseminated candidiasis. The responses of ICAM-1-deficient mice and normal wild type mice were compared following an intravenous challenge with Candida albicans. ICAM-1-deficient mice lost more weight (P < .001) and had a significantly higher mortality (P < .001). Quantitative cultures revealed a greater tissue fungal burden in ICAM-1-deficient mice compared with normal mice, in both the kidney (P < .001) and the brain (P = .007). Extensive inflammation, composed primarily of histiocytes admixed with lymphocytes and occasional neutrophils, was present in the renal tissue of ICAM-1-deficient mice; this contrasted with a more localized and predominantly neutrophilic infiltrate in normal mice. This work suggests that the loss of ICAM-1 significantly impairs host defense against C. albicans, by impairing either neutrophil migration or phagocyte activation or both.

Survival after aberrant right subclavian artery-esophageal fistula: case report and literature review

Development of a fistula between an aberrant right subclavian artery and the esophagus is a rare cause of heretofore fatal hematemesis. We report the first known survivor of this devastating complication of the most common aortic arch anomaly. Intraoperative esophagogastroduodenoscopy, intraesophageal balloon tamponade, and arteriography were the keys to successful management. This lesion should be suspected in the setting of bright red, "arterial" hematemesis. Prolonged nasogastric and/or endotracheal intubation should be avoided in patients with a known aberrant right subclavian artery or other aortic arch anomaly.

Effects of the callipyge phenotype on serum creatinine, total cholesterol, low-density lipoproteins, very-low-density lipoproteins, high-density lipoproteins, and triacylglycerol in growing lambs

The goals of this study were to investigate the effects of the callipyge (CLPG) phenotype on serum creatinine and lipid profiles of growing lambs. Preliminary studies in our laboratories indicated that creatinine may have utility in distinguishing the CLPG phenotype and that expression of the CLPG gene altered concentrations of serum total cholesterol (TC). As a result, in this study, we examined the influence of the CLPG gene on concentrations of creatinine, TC, very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL), high-density lipoproteins (HDL), and triacylglycerol (TG) at varying stages of maturity in lambs. Ten homozygous (c/c) Polypay ewes were crossed with Dorset rams heterozygous for the CLPG gene (C/c). From this cross, 20 lambs (13 females and 7 males) were born, of which 11 were homozygotic (c/c) and 9 were heterozygotic (C/c; CLPG) based on muscle weights and longissimus dorsi (LD) area at slaughter. Blood samples were taken at monthly intervals and serum lipid constituents were assayed. At 1 mo of age, no differences (P > .05) in plasma lipids were detectable between phenotypes. However, at 2 mo age, CLPG lambs had higher (P < .01) concentration of TG, TC, HDL, and VLDL compared to homozygotic (c/c) lambs. Triglycerides and VLDL were elevated (P < .05) in CLPG lambs at 3 mo of age. By slaughter, no differences (P > .05) in serum lipid constituents were detectable between genotypes. Hence, the increase in serum TC is due to elevated levels of HDL and VLDL. These observations indicate that creatinine may be used to distinguish CLPG lambs and that the CLPG gene alters serum lipid profiles during the postnatal period.

Hormonal regulation of peripheral blood mononuclear cells in sheep

The presence of growth hormone receptors (GHR) on sheep peripheral blood mononuclear (PBMN) cells was studied in two ways. The first was to directly measure specific GH-binding sites on PBMN cells drawn from lambs from birth to 5 months of age. The second was to measure the effect of GH on resting and interleukin-2 (IL-2)-activated PBMN cells in vitro and also the effect of other hormones such as prolactin (PRL), insulin-like growth factor-1 (IGF-1), and glucocorticoid. The specific binding of [125I]human GH (hGH) was low on PBMN cells but increased (P < 0.05) with age up to 5 months. Interestingly, serum concentrations of GH-binding protein also increased (P < 0.01) with age and were highly correlated (r = 0.89; P < 0.05) with the specific binding of GH to PBMN cells. The addition of ovine GH (oGH) to PBMN cells in vitro resulted in increased (P < 0.01) proliferation (at a dose of 100 ng/ml). Higher doses of oGH (2 micrograms/ml) also increased PBMN cell proliferation. When PBMN cells were previously stimulated with IL-2, the dose of 100 ng/ml) oGH was no longer able to stimulate proliferation. IGF-1 inhibited (P < 0.04) resting PBMN cell proliferation at 100 ng/ml but had no effect on IL-2-activated PBMN cells. Other hormones such as PRL caused a stimulation of PBMN cell proliferation (P < 0.01) at 100 ng/ml, whereas dexamethasone (dex) inhibited PBMN cell proliferation at doses as low as 63 ng/ml. These studies show that GH, PRL, IGF-1, and glucocorticoids are effective in modulating the proliferation of PBMN cells from sheep and therefore suggest that a modulation of immune system function in vitro by these hormones is consistent with a purpose in vivo.

Liquid ventilation in premature lambs: uptake, biodistribution and elimination of perfluorodecalin liquid

Perfluorochemical (PFC) liquids are biologically inert and nonbiotransformable substances that, when used as breathing medium, may be transported across the lung epithelium in small quantities, distributed throughout the body, and ultimately vapourized through the lungs and transpired through the skin. To further evaluate the uptake, biodistribution and elimination of a PFC liquid (perfluorodecalin) in the neonatal population, arterial blood, tissue and expired gas samples were obtained from preterm lambs (105-114 days gestation). Two groups of premature lambs were studied: Group I (n = 4) lambs were liquid ventilated from birth for 1 h and killed without exposure to gas ventilation (GV) and Group II (n = 5) lambs were liquid ventilated for 1 h followed by up to 2 h of GV. Samples were analysed by electron-capture gas chromatography and data were expressed in nl of PFC/ml of blood or gas and nl of PFC/gm tissue. During liquid ventilation and subsequent GV, PFC blood levels significantly increased (P < 0.001) from baseline control levels (0.007 +/- 0.001 SE nl PFC/ml blood) to a high of 2.95 +/- 1.03 SE nl PFC/ml blood. Perfluorochemical levels measured in expired gas (Group II) demonstrated a rapid decrease as a function of time of GV. Tissue levels of PFC indicated that uptake of PFC in Group I was significantly different (P < 0.001) than baseline levels and organ dependent; the highest levels were in the lungs (221 +/- 26.2 SE nl PFC/g tissue) and the lowest in the liver (2.24 +/- 1.6 SE nl PFC/g tissue). Comparison of tissue levels of PFC between groups indicated a 34.8% mean decrease across organs in Group II compared with Group I. These data indicate that PFC uptake and elimination is organ dependent and that PFC liquids can be eliminated through the lungs upon return to GV. Sustained PFC blood levels may be related to residual PFC in the organs and lung as well as regional variation in ventilation-perfusion matching upon return to GV.