Lassa virus in novel hosts: insights into the epidemiology of lassa virus infections in southern Nigeria.

Identification of the diverse animal hosts responsible for spill-over events from animals to humans is crucial for comprehending the transmission patterns of emerging infectious diseases, which pose significant public health risks. To better characterize potential animal hosts of Lassa virus (LASV), we assessed domestic and non-domestic animals from 2021-2022 in four locations in southern Nigeria with reported cases of Lassa fever (LF). Birds, lizards, and domestic mammals (dogs, pigs, cattle and goats) were screened using RT-qPCR, and whole genome sequencing was performed for lineage identification on selected LASV positive samples. Animals were also screened for exposure to LASV by enzyme-linked immunosorbent assay (ELISA). Among these animals, lizards had the highest positivity rate by PCR. Genomic sequencing of samples in most infected animals showed sub-lineage 2 g of LASV. Seropositivity was highest among cattle and lowest in pigs. Though the specific impact these additional hosts may have in the broader virus-host context are still unknown - specifically relating to pathogen diversity, evolution, and transmission - the detection of LASV in non-rodent hosts living in proximity to confirmed human LF cases suggests their involvement during transmission as potential reservoirs. Additional epidemiological data comparing viral genomes from humans and animals, as well as those circulating within the environment will be critical in understanding LASV transmission dynamics and will ultimately guide the development of countermeasures for this zoonotic health threat.

TKIs beyond immunotherapy predict improved survival in advanced HCC.

PURPOSE: For patients with advanced HCC, predictors of immunotherapy response are scarce, and the benefits of tyrosine kinase inhibitor (TKI) treatment after immunotherapy are unclear. We explored whether clinical features, such as target lesion response, immune-mediated toxicity, or subsequent TKI therapy predict immunotherapy response. METHODS: We retrospectively studied 77 patients with advanced HCC receiving immunotherapy. Patient characteristics and outcomes were assessed using various statistical methods, including the log-rank test and Kaplan-Meier methods. Cox proportional hazard modeling was used for multivariable survival analysis. RESULTS: For all patients, median overall survival (mOS) was 13 months (95% CI 8-19), and median progression-free survival (mPFS) was 6 months (95% CI 4-10). Patients with partial response (PR) and stable disease (SD) compared to progressive disease (PD) had prolonged mPFS (27 vs. 5 vs. 1 month(s), p < 0.0001) and mOS (not met vs. 11 vs. 3 months, p < 0.0001). Patients with vs. without immune-mediated toxicities trended towards longer mPFS (9 vs. 4 months p = 0.133) and mOS (17 vs. 9 months; p = 0.095). Patients who did vs. did not receive a tyrosine kinase inhibitor (TKI) after immunotherapy had a significantly improved mOS (19 vs. 5 months, p = 0.0024)). Based on multivariate modeling, the hazard ratio (HR) of overall survival (OS) of patients receiving TKI vs. no TKI was 0.412 (p = 0.0043). CONCLUSION: We show that disease control predicts prolonged mOS and mPFS. Furthermore, TKI therapy administered after immunotherapy predicts prolonged mOS in patients with advanced HCC.

Underuse of exon mutational analysis for gastrointestinal stromal tumors.

BACKGROUND: Tyrosine kinase inhibitors (TKI) have become the guideline-recommended therapy for high-risk resected and advanced gastrointestinal stromal tumors (GISTs). Exon mutational analysis (EMA) is used to inform pretherapy response to TKI and may predict overall prognosis. Despite these benefits, EMA remains underused, and its impact on TKI therapy decision-making remains unexplored. MATERIALS AND METHODS: A retrospective cohort was established from 104 patients receiving treatment for GISTs from 2006 to 2017. Current National Comprehensive Cancer Network guidelines indicate that EMA should be considered for all patients undergoing TKI therapy to identify genotypes that are likely, or unlikely, to respond to treatment. We first tracked guideline-considered EMA use and subsequent impact on treatment decision-making. A questionnaire was then administered to gastrointestinal medical oncologists to assess EMA perception. RESULTS: Among 104 GIST patients, 54 (52%) received TKI therapy. Of these, only 22 (41%) received EMA. Informed by EMA, treatment decisions included 59% who continued with original TKI therapy, 32% who switched to an alternative TKI, and 9% who discontinued or received no TKI. Although 92% of physicians indicated EMA was a valuable tool, only 62% indicated they used it "frequently" or "always" to inform treatment decisions. CONCLUSIONS: Less than half of patients receiving TKI therapy for GISTs received EMA at a comprehensive cancer center. Despite this low uptake, when it was performed, EMA guided alternative treatment decision in 41% of patients. Physician survey responses indicated that interventions targeting physician education and an electronic medical record reminder may improve EMA uptake.

Regorafenib in advanced hepatocellular carcinoma (HCC): considerations for treatment.

PURPOSE: We report our institutional observations of ten patients with advanced hepatocellular carcinoma (HCC) (seven and three were Child-Pugh class A and B, respectively) who received compassionate regorafenib therapy between June 2016 and January 2017. These patients did not fit the rigid criteria of a clinical trial and represented the use of regorafenib in an everyday clinic situation. METHODS: Regorafenib (160 mg P.O. daily) was administered to patients on a 4-week cycle (3 weeks on, 1 week off) until disease progression (assessed using mRECIST criteria) or discontinuation secondary to toxicity (assessed using CTCAE criteria). Relevant clinical data were abstracted from patient medical records and reviewed retrospectively. RESULTS: The median duration of patient treatment was 6.6 weeks, and the median time to disease progression was 12.5 weeks. Most common treatment emergent adverse events were fatigue, diarrhea, and hand-foot skin reaction. Elevated AST and ALT were the most commonly observed laboratory-assessed adverse events, which reached grade 3 status in the Child-Pugh class B patients only. We observed intolerance to regorafenib treatment in one patient who had previously received a liver transplant. We also saw lithium toxicity in one patient receiving long-term lithium treatment, suggesting a potential and unexpected drug-drug interaction with regorafenib. CONCLUSIONS: Taken together, our observations indicate that regorafenib is beneficial in the treatment of patients with advanced HCC who progressed on or demonstrated intolerance to sorafenib therapy; however, careful selection and close monitoring of patients is necessary to maximize the benefit while minimizing the toxicities of regorafenib treatment.

Systemic therapy for advanced hepatocellular carcinoma: an update.

Advanced hepatocellular carcinoma (HCC) is a deadly disease with few systemic therapeutic options. Sorafenib is the only agent to be FDA approved for the first-line treatment of patients with HCC. This drug increases overall survival (OS) by 3 months compared with placebo (10.7 months with sorafenib vs. 7.7 months with placebo). More recently, the RESORCE trial demonstrated efficacy of regorafenib in the second-line treatment of HCC: OS was increased from 7.8 months with placebo to 10.6 months with regorafenib after patients experienced disease progression on sorafenib. However, there is still an unmet need for effective systemic therapy of patients with advanced HCC. Numerous genetic pathways have been studied along with drugs to target these pathways but, thus far, drugs targeting cell proliferation, metastasis, angiogenesis, and metabolite use have been studied with minimal success. HCC can be divided into two subclasses: proliferative and non-proliferative, each dependent on separate pathways. HCC can be caused by alcoholic cirrhosis, hepatitis C virus (HCV), and hepatitis B virus (HBV); however no etiology-specific therapies have been demonstrated. Immunotherapy is currently being assessed in clinical trials and is demonstrating some efficacy. More research is needed to determine the most essential pathways to target in the war against this deadly cancer.

Intratumoral CD3 and CD8 T-cell Densities Associated with Relapse-Free Survival in HCC.

Immune cells that infiltrate a tumor may be a prognostic factor for patients who have had surgically resected hepatocellular carcinoma (HCC). The density of intratumoral total (CD3(+)) and cytotoxic (CD8(+)) T lymphocytes was measured in the tumor interior and in the invasive margin of 65 stage I to IV HCC tissue specimens from a single cohort. Immune cell density in the interior and margin was converted to a binary score (0, low; 1, high), which was correlated with tumor recurrence and relapse-free survival (RFS). In addition, the expression of programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) was correlated with the density of CD3(+) and CD8(+) cells and clinical outcome. High densities of both CD3(+) and CD8(+) T cells in both the interior and margin, along with corresponding Immunoscores, were significantly associated with a low rate of recurrence (P = 0.007) and a prolonged RFS (P = 0.002). In multivariate logistic regression models adjusted for vascular invasion and cellular differentiation, both CD3(+) and CD8(+) cell densities predicted recurrence, with odds ratios of 5.8 [95% confidence interval (CI), 1.6-21.8] for CD3(+) and 3.9 (95% CI, 1.1-14.1) for CD8(+) Positive PD-L1 staining was correlated with high CD3 and CD8 density (P = 0.024 and 0.005, respectively) and predicted a lower rate of recurrence (P = 0.034), as well as prolonged RFS (P = 0.029). Immunoscore and PD-L1 expression, therefore, are useful prognostic markers in patients with HCC who have undergone primary tumor resection. Cancer Immunol Res; 4(5); 419-30. ©2016 AACR.

Pancreatic cancer, treatment options, and GI-4000.

Although pancreatic cancer is but the eleventh most prevalent cancer in the US, it is predicted that of all the patients newly diagnosed with this disease in 2014, only 27% will still be alive at the end of the first year, which is reduced to 6% after 5 years. The choice of chemotherapy in the treatment of pancreatic cancer is dependent on disease stage and patient performance status but, in general, the most widely used approved regimens include 5-fluorouracil (5-FU) combinations and gemcitabine combinations. Recent therapeutic strategies have resulted in an improvement in survival of patients with pancreatic cancer but the magnitude of change is disappointing and vast improvements are still needed. The goal of immunotherapy is to enhance and guide the body's immune system to recognize tumor-specific antigens and mount an attack against the disease. Among newer immune therapies, GI-4000 consists of 4 different targeted molecular immunogens, each containing a different Ras protein (antigen) encoded by the most commonly found mutant RAS genes in solid tumors-RAS mutations exist in over 90% of pancreatic ductal adenocarcinomas. We will review pancreatic cancer epidemiology and its current treatment options, and consider the prospects of immunotherapy, focusing on GI-4000. We discuss the potential mechanism of action of GI-4000, and the performance of this vaccination series thus far in early phase clinical trials.

Angiotensin-induced abdominal aortic aneurysms in hypercholesterolemic mice: role of serum cholesterol and temporal effects of exposure.

OBJECTIVE: Understanding variations in size and pattern of development of angiotensin II (Ang II)-induced abdominal aortic aneurysms (AAA) may inform translational research strategies. Thus, we sought insight into the temporal evolution of AAA in apolipoprotein (apo)E(-/-) mice. APPROACH: A cohort of mice underwent a 4-week pump-mediated infusion of saline (n = 23) or 1500 ng/kg/min of Ang II (n = 85) and AAA development was tracked via in vivo ultrasound imaging. We adjusted for hemodynamic covariates in the regression models for AAA occurrence in relation to time. RESULTS: The overall effect of time was statistically significant (p<0.001). Compared to day 7 of AngII infusion, there was no decrease in the log odds of AAA occurrence by day 14 (-0.234, p = 0.65), but compared to day 21 and 28, the log odds decreased by 9.07 (p<0.001) and 2.35 (p = 0.04), respectively. Hemodynamic parameters were not predictive of change in aortic diameter (Δ) (SBP, p = 0.66; DBP, p = 0.66). Mean total cholesterol (TC) was higher among mice with large versus small AAA (601 vs. 422 mg/ml, p<0.0001), and the difference was due to LDL. AngII exposure was associated with 0.43 mm (95% CI, 0.27 to 0.61, p<0.0001) increase in aortic diameter; and a 100 mg/dl increase in mean final cholesterol level was associated with a 12% (95% CI, 5.68 to 18.23, p<0.0001) increase in aortic diameter. Baseline cholesterol was not associated with change in aortic diameter (p = 0.86). CONCLUSIONS: These are the first formal estimates of a consistent pattern of Ang II-induced AAA development. The odds of AAA occurrence diminish after the second week of Ang II infusion, and TC is independently associated with AAA size.

Pancreatic cancer, treatment options, and GI-4000.

Although pancreatic cancer is but the eleventh most prevalent cancer in the US, it is predicted that of all the patients newly diagnosed with this disease in 2014, only 27% will still be alive at the end of the first year and only 6% will make it past 5 years. The choice of chemotherapy in the treatment of pancreatic cancer is dependent on disease stage and patient performance status but, in general, the most widely used approved regimens include 5-fluorouracil (5-FU) combinations and gemcitabine combinations. Recent therapeutic strategies have resulted in an improvement in survival of patients with pancreatic cancer but the magnitude of change is disappointing and vast improvements are still needed. The goal of immunotherapy is to enhance and guide the body's immune system to recognize tumor-specific antigens and mount an attack against the disease. Among newer immune therapies, GI-4000 consists of 4 different targeted molecular immunogens, each containing a different Ras protein (antigen) encoded by the most commonly found mutant RAS genes in solid tumors--RAS mutations exist in over 90% of pancreatic ductal adenocarcinomas. We will review pancreatic cancer epidemiology and its current treatment options, and consider the prospects of immunotherapy, focusing on GI-4000. We discuss the potential mechanism of action of GI-4000, and the performance of this vaccination series thus far in early phase clinical trials.

Chronic methamphetamine exposure produces a delayed, long-lasting memory deficit.

Methamphetamine (METH) is a highly addictive and neurotoxic psychostimulant. Its use in humans is often associated with neurocognitive impairment. Whether this is due to long-term deficits in short-term memory and/or hippocampal plasticity remains unclear. Recently, we reported that METH increases baseline synaptic transmission and reduces LTP in an ex vivo preparation of the hippocampal CA1 region from young mice. In the current study, we tested the hypothesis that a repeated neurotoxic regimen of METH exposure in adolescent mice decreases hippocampal synaptic plasticity and produces a deficit in short-term memory. Contrary to our prediction, there was no change in the hippocampal plasticity or short-term memory when measured after 14 days of METH exposure. However, we found that at 7, 14, and 21 days of drug abstinence, METH-exposed mice exhibited a deficit in spatial memory, which was accompanied by a decrease in hippocampal plasticity. Our results support the interpretation that the deleterious cognitive consequences of neurotoxic levels of METH exposure may manifest and persist after drug abstinence. Therefore, therapeutic strategies should consider short-term as well as long-term consequences of methamphetamine exposure.

Benzo[a]pyrene potentiates the pathogenesis of abdominal aortic aneurysms in apolipoprotein E knockout mice.

The objective of this study was to determine the effect of benzo[a]pyrene (BaP), an abundant environmental polycyclic aromatic hydrocarbon compound, on the pathogenesis of abdominal aortic aneurysms (AAA). Earlier studies have shown that BaP promotes vasculopathy, including atherosclerosis, a predisposing factor for AAA development. In two experimental arms, 203 apolipoprotein E knockout (ApoE-/-) mice were evaluated in 4 groups: BaP, angiotensin II (AngII), BaP+AngII and control. Mice in the first arm were exposed to 5mg/kg/week of BaP for 42 days, and in the second arm to 0.71mg/kg daily for 60 days. In arm one, AAA incidence was higher in the BaP+AngII (14/28) versus AngII (8/27) group (p < 0.05), rupture (n=3) was observed only in BaP+AngII treated mice (p < 0.05). In the second arm, AAA incidence did not differ between AngII (17/30) and BaP+AngII (16/29) groups. However, intact AAA diameter was larger in the BaP+AngII (2.3 ± 0.1mm) versus AngII (1.9 ± 0.1mm) group (p < 0.05), but AAA rupture did not differ (p=NS). In both experimental arms, BaP+AngII mice showed increased expression of tumor necrosis factor alpha (TNF-α), cyclophilin A (Cyp A), and matrix metalloproteinase-9 (MMP9) (p < 0.05). No AAA occurred in control or BaP groups. These findings suggest the role of BaP exposure in potentiating AAA pathogenesis, which may have potential public health significance.

Quantitative estimates of the variability of in vivo sonographic measurements of the mouse aorta for studies of abdominal aortic aneurysms and related arterial diseases.

OBJECTIVES: Burgeoning interest in reducing the morbidity and mortality associated with abdominal aortic aneurysms (AAAs) has led to experimental strategies to elucidate the disease process and attain pharmacologic regression using the apolipoprotein E(-/-) (ApoE(-/-)) mouse model of angiotensin-induced AAAs and in vivo sonography. However, the variability of in vivo sonographic measurements of the mouse aorta has not been established. Thus, our purpose was to determine quantitative estimates of the variability of in vivo sonographic measurements of the mouse aorta as a guide for the design and assessment of studies focused on regression of AAAs and related arterial diseases. METHODS: We used Bland-Altman, locally weighted scatterplot-smoothing regression, and resampling (bootstrapping) methods for variability analyses of multiple in vivo short- and long-axis sonographic measurements of ApoE(-/-) mouse aortas. We measured distinct aortic sites in vivo at the baseline and after angiotensin-induced AAAs and ex vivo using digital calipers. RESULTS: We analyzed 236 data points from 10 male mice (14 weeks old; mean weight ± SD, 29.7 ± 1.6 g). Overall intramouse differences between short- and long-axis and in vivo and ex vivo measurements were 0.038 (95% confidence interval [CI], 0.031-0.046) and 0.085 (95% CI, 0.062-0.109) mm, respectively. Intermouse differences in short-axis measurements were 0.047 (95% CI, 0.042-0.053), 0.049 (95% CI, 0.044-0.055), and 0.039 (95% CI, 0.036-0.042) mm for infrarenal, suprarenal, and thoracic measurements, respectively; differences in long-axis measurements were 0.054 (95% CI, 0.044-0.064), 0.029 (95% CI, 0.024-0.034), and 0.046 (95% CI, 0.037-0.054) mm. Bland-Altman and locally weighted scatterplot-smoothing analyses showed excellent agreement between measures with no variation in discrepancies vis-à-vis the target measurement. CONCLUSIONS: These data establish previously undefined estimates of measurement variability relevant for in vivo sonographic studies of AAA regression in a commonly studied mouse model.