Novel Image-Guided Flexible-Probe Transbronchial Microwave Ablation for Stage 1 Lung Cancer.

BACKGROUND: Image-guided percutaneous thermal ablation is an established treatment option for early-stage lung cancer in medically inoperable patients but carries a high risk of pleura-related complications, particularly pneumothorax. OBJECTIVE: This study aimed to determine if image-guided transbronchial microwave ablation (tMWA) is a feasible approach to treat peripheral stage 1 lung cancer. METHOD: A prospective, single-arm, multicenter study sought to enroll 40 adults who were medically inoperable or declined surgery for peripheral stage 1 lung tumors (≤20 mm). Ablation was performed using navigational bronchoscopy and a flexible MWA probe, guided by cone-beam CT with augmented fluoroscopy. Follow-up at 1, 6, and 12 months included CT imaging of the ablation zone and possible tumor recurrence, adverse events (AEs), pulmonary function, and quality of life. RESULTS: Across 2 sites, 11 tumors (10 NSCLC, 1 carcinoid) were treated in 10 enrolled patients. Median tumor diameter was 13 × 14 mm (7-19 mm) and median minimum ablative margin was 11 mm (5-19 mm). Technical success and technique efficacy were achieved in all patients. No tumor recurrence was seen during 12-month follow-up. No pneumothorax, pleural effusion, or bronchopleural fistula were noted. Minor AEs included scant hemoptysis, pain, cough, and dyspnea. Two serious AEs occurred ≤30 days of ablation and included a COPD exacerbation (day 9) and a death of unknown cause (day 15). The death led the sponsor to halt enrollment. Pulmonary function and quality-of-life indices remained stable. CONCLUSIONS: Image-guided tMWA is a technically feasible approach for peripheral early-stage lung cancer but warrants further evaluation of safety and efficacy in larger cohorts.

Association between renin-angiotensin antagonism and COVID-19-related mortality in patients with essential hypertension: A single center, retrospective cohort study.

There is conflicting evidence in select mouse models and humans that suggest angiotensin-converting enzyme 2 expression is increased due to treatment with angiotensin converting enzyme inhibitors and angiotensin receptor blockers (ACEI/ARBs). Given the wide range of conditions that these medications treat, further evaluation is necessary to determine safety in the context of COVID-19. We sought to determine the association between use of ACEI/ARBs and COVID-19 severity in patients with essential hypertension. We included 714 patients with essential hypertension diagnosed with COVID-19 and admitted to University of Iowa Healthcare from March 1, 2020 to June 29, 2021. Severity of COVID-19 infection was assessed based on mortality, length of stay in hospital, intensive care unit admission, and use of supplemental oxygen, invasive ventilation, and vasopressors. Multivariable logistic and linear regression analyses were used for binary and continuous outcomes, respectively. Prior exposure to ACEI/ARBs before admission was significantly associated with lower mortality (OR: 0.454, p = .015), shorter length of stay in hospital (p < .001), and decreased adjusted odds of intensive care admission (OR: 0.719; p < .042). The present results suggest that patients with essential hypertension hospitalized with COVID-19 who had a prescription for ACEI/ARBs prior to admission exhibited less severe COVID-19 and lower in-hospital mortality.

Concentration-dependent effects of transforming growth factor ß1 on corneal wound healing.

PURPOSE: There is an unmet challenge to promote wound healing in non-healing wounds such as in the post-LASIK (laser-assisted in situ keratomileusis) cornea. Using human corneal fibroblasts (HCFs) in cell culture, we investigated the concentration dependence of the growth factor transforming growth factor ß1 (TGFß1) on wound closure. Although high concentrations of TGFß1 leads to scarring, we asked whether low concentrations of TGFß1 could promote wound healing without generating a large fibrotic response. METHODS: HCFs were cultured in supplemented serum-free media (SSFM). Cell migration was assessed by scratch-wounding. SMAD 2/3 and p38 mitogen-activated protein kinase (p38MAPK) localization and α-smooth muscle actin (α-SMA) organization were evaluated by immunocytochemistry. Active TGFß was quantified using a luciferase bio-assay. RESULTS: We found that neutralizing antibody to TGFß1 reduced cell migration by 73%, compared to immunoglobulin G (IgG) control, establishing that endogenous TGFß1 (determined to be 0.01 ng/ml) is necessary to promote cell migration. To evaluate the concentration-dependent effects of TGFß1 on wound closure, HCF migration was quantified to determine the impact of increasing concentrations of TGFß1 (0.01-1.0 ng/ml). Compared to control (cells in SSFM), the higher concentrations (0.1 and 1.0 ng/ml TGFß1) significantly decreased cell migration (63%-86%), induced myofibroblast differentiation (83%-88%), increased SMAD 2/3 localization into the nucleus (72%-79%) and inhibited the activation of p38MAPK (51%-63%). In contrast, addition of the lower concentration of TGFß1 (0.01 ng/ml TGFß1) promoted a cell migration rate that was similar to endogenous TGFß, reduced SMAD 2/3 nuclear localization, and stimulated p38MAPK activation. A TGFß1 blocking antibody and the p38MAPK inhibitor, SB202192, was used to demonstrate that p38MAPK activation is necessary for TGFß1-induced cell migration. CONCLUSIONS: Together, our data demonstrate that low concentrations of TGFß1 promote p38MAPK activation that is a key to HCF migration, suggesting that a low concentration of TGFß may be useful in treating non-healing corneal wounds.

Contrasting effects of afferent and efferent vagal nerve stimulation on insulin secretion and blood glucose regulation.

Parasympathetic activation reduces hepatic glucose release and increases pancreatic insulin secretion in hyperglycemic conditions. Thus, vagal nerve stimulation (VNS) may potentially be effective in treating type II diabetes. To investigate this possibility, we hypothesized that VNS reduces blood glucose concentration [Glu] via insulin secretion. [Glu] together with insulin and glucagon serum concentrations were determined in anesthetized rats during baseline conditions and 120 min of cervical VNS with the nerve left intact for combined afferent and efferent VNS (n = 9) or the nerve sectioned proximal or distal from the stimulation electrode for selective efferent (n = 8) or afferent (n = 7) VNS, respectively. Afferent VNS caused a strong and sustained increase in [Glu] (+108.9 ± 20.9% or +77.6 ± 15.4%, after 120 min of combined afferent and efferent VNS or selective afferent VNS) that was not accompanied by an increase in serum insulin concentration. However, serum insulin levels increased significantly with selective efferent VNS (+71.2 ± 27.0% after 120 min of VNS) that increased [Glu] only temporarily (+28.8 ± 11.7% at 30 min of VNS). Efferent VNS initially increased serum glucagon concentration which remained elevated for 120 min when efferent VNS was combined with afferent VNS, but returned to baseline with selective efferent VNS. These findings demonstrate that afferent VNS causes a marked and sustained increase in [Glu] that is partly mediated by suppression of pancreatic insulin secretion. In contrast, efferent VNS stimulates pancreatic glucagon secretion that appears to be antagonized by insulin secretion in the case of selective efferent VNS. Selective efferent VNS may potentially be effective in treating type II diabetes.

Differential expression of the beta4 neuronal nicotinic receptor subunit affects tolerance development and nicotinic binding sites following chronic nicotine treatment.

The role of neuronal nicotinic acetylcholine receptors (nAChR) containing the ß4 subunit in tolerance development and nicotinic binding site levels following chronic nicotine treatment was investigated. Mice differing in expression of the ß4-nAChR subunit [wild-type (ß4(++)), heterozygote (ß4(+-)) and null mutant (ß4(--))] were chronically treated for 10 days with nicotine (0, 0.5, 1.0, 2.0 or 4.0mg/kg/h) by constant intravenous infusion. Chronic nicotine treatment elicited dose-dependent tolerance development. ß4(--) mice developed significantly more tolerance than either ß4(++) or ß4(+-) mice which was most evident following treatment with 4.0mg/kg/h nicotine. Subsets of [(125)I]-epibatidine binding were measured in several brain regions. Deletion of the ß4 subunit had little effect on initial levels of cytisine-sensitive [(125)I]-epibatidine binding (primarily α4ß2-nAChR sites) or their response (generally increased binding) to chronic nicotine treatment. In contrast, ß4 gene-dose-dependent decreases in expression 5IA-85380 resistant [(125)I]-epibatidine binding sites (primarily ß4*-nAChR) were observed. While these ß4*-nAChR sites were generally resistant to regulation by chronic nicotine treatment, significant increases in binding were noted for habenula and hindbrain. Comparison of previously published tolerance development in ß2(--) mice (less tolerance) to that of ß4(--) mice (more tolerance) supports a differential role for these receptor subtypes in regulating tolerance following chronic nicotine treatment.

uPA binding to PAI-1 induces corneal myofibroblast differentiation on vitronectin.

PURPOSE: Vitronectin (VN) in provisional extracellular matrix (ECM) promotes cell migration. Fibrotic ECM also includes VN and, paradoxically, strongly adherent myofibroblasts (Mfs). Because fibrotic Mfs secrete elevated amounts of urokinase plasminogen activator (uPA), we tested whether increased extracellular uPA promotes the persistence of Mfs on VN. METHODS: Primary human corneal fibroblasts (HCFs) were cultured in supplemented serum-free medium on VN or collagen (CL) with 1 ng/mL transforming growth factor ß1 (TGFß1). Adherent cells were quantified using crystal violet. Protein expression was measured by Western blotting and flow cytometry. Transfection of short interfering RNAs was performed by nucleofection. Mfs were identified by α-smooth muscle actin (α-SMA) stress fibers. Plasminogen activator inhibitor (PAI-1) levels were quantified by ELISA. RESULTS: TGFß1-treated HCFs secreted PAI-1 (0.5 uM) that bound to VN, competing with αvß3/αvß5 integrin/VN binding, thus promoting cell detachment from VN. However, addition of uPA to cells on VN increased Mf differentiation (9.7-fold), cell-adhesion (2.2-fold), and binding by the VN integrins αvß3 and -ß5 (2.2-fold). Plasmin activity was not involved in promoting these changes, as treatment with the plasmin inhibitor aprotinin had no effect. A dominant negative PAI-1 mutant (PAI-1R) that binds to VN but does not inhibit uPA prevented the increase in uPA-stimulated cell adhesion and reduced uPA-stimulated integrin αvß3/αvß5 binding to VN by 73%. CONCLUSIONS: uPA induction of TGFß1-dependent Mf differentiation on VN supports the hypothesis that elevated secretion of uPA in fibrotic tissue may promote cell adhesion and the persistence of Mfs. By blocking uPA-stimulated cell adhesion, PAI-1R may be a useful agent in combating corneal scarring.

Degradation of internalized αvß5 integrin is controlled by uPAR bound uPA: effect on ß1 integrin activity and α-SMA stress fiber assembly.

Myofibroblasts (Mfs) that persist in a healing wound promote extracellular matrix (ECM) accumulation and excessive tissue contraction. Increased levels of integrin αvß5 promote the Mf phenotype and other fibrotic markers. Previously we reported that maintaining uPA (urokinase plasminogen activator) bound to its cell-surface receptor, uPAR prevented TGFß-induced Mf differentiation. We now demonstrate that uPA/uPAR controls integrin ß5 protein levels and in turn, the Mf phenotype. When cell-surface uPA was increased, integrin ß5 levels were reduced (61%). In contrast, when uPA/uPAR was silenced, integrin ß5 total and cell-surface levels were increased (2-4 fold). Integrin ß5 accumulation resulted from a significant decrease in ß5 ubiquitination leading to a decrease in the degradation rate of internalized ß5. uPA-silencing also induced α-SMA stress fiber organization in cells that were seeded on collagen, increased cell area (1.7 fold), and increased integrin ß1 binding to the collagen matrix, with reduced activation of ß1. Elevated cell-surface integrin ß5 was necessary for these changes after uPA-silencing since blocking αvß5 function reversed these effects. Our data support a novel mechanism by which downregulation of uPA/uPAR results in increased integrin αvß5 cell-surface protein levels that regulate the activity of ß1 integrins, promoting characteristics of the persistent Mf.

Nicotine-mediated activation of dopaminergic neurons in distinct regions of the ventral tegmental area.

Nicotine activation of nicotinic acetylcholine receptors (nAChRs) within the dopaminergic (DAergic) neuron-rich ventral tegmental area (VTA) is necessary and sufficient for nicotine reinforcement. In this study, we show that rewarding doses of nicotine activated VTA DAergic neurons in a region-selective manner, preferentially activating neurons in the posterior VTA (pVTA) but not in the anterior VTA (aVTA) or in the tail VTA (tVTA). Nicotine (1 µM) directly activated pVTA DAergic neurons in adult mouse midbrain slices, but had little effect on DAergic neurons within the aVTA. Quantification of nAChR subunit gene expression revealed that pVTA DAergic neurons expressed higher levels of α4, α6, and ß3 transcripts than did aVTA DAergic neurons. Activation of nAChRs containing the α4 subunit (α4(*) nAChRs) was necessary and sufficient for activation of pVTA DAergic neurons: nicotine failed to activate pVTA DAergic neurons in α4 knockout animals; in contrast, pVTA α4(*) nAChRs were selectively activated by nicotine in mutant mice expressing agonist-hypersensitive α4(*) nAChRs (Leu9'Ala mice). In addition, whole-cell currents induced by nicotine in DAergic neurons were mediated by α4(*) nAChRs and were significantly larger in pVTA neurons than in aVTA neurons. Infusion of an α6(*) nAChR antagonist into the VTA blocked activation of pVTA DAergic neurons in WT mice and in Leu9'Ala mice at nicotine doses, which only activate the mutant receptor indicating that α4 and α6 subunits coassemble to form functional receptors in these neurons. Thus, nicotine selectively activates DAergic neurons within the pVTA through α4α6(*) nAChRs. These receptors represent novel targets for smoking-cessation therapies.