Current Mechanistic Understandings of Lymphedema and Lipedema: Tales of Fluid, Fat, and Fibrosis.

Lymphedema and lipedema are complex diseases. While the external presentation of swollen legs in lower-extremity lymphedema and lipedema appear similar, current mechanistic understandings of these diseases indicate unique aspects of their underlying pathophysiology. They share certain clinical features, such as fluid (edema), fat (adipose expansion), and fibrosis (extracellular matrix remodeling). Yet, these diverge on their time course and known molecular regulators of pathophysiology and genetics. This divergence likely indicates a unique route leading to interstitial fluid accumulation and subsequent inflammation in lymphedema versus lipedema. Identifying disease mechanisms that are causal and which are merely indicative of the condition is far more explored in lymphedema than in lipedema. In primary lymphedema, discoveries of genetic mutations link molecular markers to mechanisms of lymphatic disease. Much work remains in this area towards better risk assessment of secondary lymphedema and the hopeful discovery of validated genetic diagnostics for lipedema. The purpose of this review is to expose the distinct and shared (i) clinical criteria and symptomatology, (ii) molecular regulators and pathophysiology, and (iii) genetic markers of lymphedema and lipedema to help inform future research in this field.

Liver-Specific, but Not Retina-Specific, Hepcidin Knockout Causes Retinal Iron Accumulation and Degeneration.

The liver secretes hepcidin (Hepc) into the bloodstream to reduce blood iron levels. Hepc accomplishes this by triggering degradation of the only known cellular iron exporter ferroportin in the gut, macrophages, and liver. We previously demonstrated that systemic Hepc knockout (HepcKO) mice, which have high serum iron, develop retinal iron overload and degeneration. However, it was unclear whether this is caused by high blood iron levels or, alternatively, retinal iron influx that would normally be regulated by retina-produced Hepc. To address this question, retinas of liver-specific and retina-specific HepcKO mice were studied. Liver-specific HepcKO mice had elevated blood and retinal pigment epithelium (RPE) iron levels and increased free (labile) iron levels in the retina, despite an intact blood-retinal barrier. This led to RPE hypertrophy associated with lipofuscin-laden lysosome accumulation. Photoreceptors also degenerated focally. In contrast, there was no change in retinal or RPE iron levels or degeneration in the retina-specific HepcKO mice. These data indicate that high blood iron levels can lead to retinal iron accumulation and degeneration. High blood iron levels can occur in patients with hereditary hemochromatosis or result from use of iron supplements or multiple blood transfusions. Our results suggest that high blood iron levels may cause or exacerbate retinal disease.

Ferroportin-mediated iron export from vascular endothelial cells in retina and brain.

Retinal iron accumulation has been implicated in the pathogenesis of age-related macular degeneration (AMD) and other neurodegenerative diseases. The retina and the brain are protected from the systemic circulation by the blood retinal barrier (BRB) and blood brain barrier (BBB), respectively. Iron levels within the retina and brain need to be tightly regulated to prevent oxidative injury. The method of iron entry through the retina and brain vascular endothelial cells (r&bVECs), an essential component of the BRB and BBB, is not fully understood. However, localization of the cellular iron exporter, ferroportin (Fpn), to the abluminal membrane of these cells, leads to the hypothesis that Fpn may play an important role in the import of iron across the BRB and BBB. To test this hypothesis, a mouse model with deletion of Fpn within the VECs in both the retina and the brain was developed through tail vein injection of AAV9-Ple261(CLDN5)-icre to both experimental Fpnf/f, and control Fpn+/+ mice at P21. Mice were aged to 9 mo and changes in retinal and brain iron distribution were observed. In vivo fundus imaging and quantitative serum iron detection were used for model validation. Eyes and brains were collected for immunofluorescence. Deletion of Fpn from the retinal and brain VECs leads to ferritin-L accumulation, an indicator of elevated iron levels, in the retinal and brain VECs. This occurred despite lower serum iron levels in the experimental mice. This result suggests that Fpn normally transfers iron from retinal and brain VECs into the retina and brain. These results help to better define the method of retina and brain iron import and will increase understanding of neurodegenerative diseases involving iron accumulation.

Increased serum proteins in non-exudative AMD retinas.

The blood retinal barrier (BRB) closely regulates the retinal microenvironment. Its compromise leads to the accumulation of retinal fluid containing potentially harmful plasma components. While eyes with non-exudative age-related macular degeneration (AMD) were previously felt to have an intact BRB, we propose that the BRB in non-exudative AMD eyes may be subclinically compromised, allowing entry of retina-toxic plasma proteins. We test this hypothesis by measuring retinal levels of abundant plasma proteins that should not cross the intact BRB. Two cohorts of frozen, post mortem neurosensory retinas were studied by Western analysis. One cohort from Alabama had 4 normal controls and 4 eyes with various forms of AMD. Another cohort from Minnesota had 5 intermediate AMD eyes and 5 normals. Both cohorts were age/post mortem interval (PMI) matched. The non-exudative AMD retinas in the Alabama cohort had significantly higher levels of albumin and complement component 9 (C9) than normal controls. The positive control exudative AMD donor retina had higher levels of all but one serum protein. In both macular and peripheral neurosensory retina samples, intermediate AMD retinas in the Minnesota cohort had significantly higher levels of albumin, fibrinogen, IgG, and C9 than controls. Our results suggest that there may be moderate subclinical BRB leakage in non-exudative AMD. Potentially harmful plasma components including complement or iron could enter the neurosensory retina in AMD patients prior to advanced disease. Thus, therapies aiming to stabilize the BRB might have a role in the management of non-exudative AMD.

Methyl donor supplementation suppresses the progression of liver lipid accumulation while modifying the plasma triacylglycerol lipidome in periparturient Holstein dairy cows.

Co-supplementation of methyl donors may lower hepatic lipid content in transition cows. To define the ability of methyl donor supplementation (MDS) to reduce hepatic lipid content and modify the plasma lipidome, 30 multiparous Holstein cows (2.04 ± 0.69 lactations; 689 ± 58 kg of body weight; 3.48 ± 0.10 units of body condition score) were fed a ration with or without rumen-protected methyl donors (22 g/d of Met, 10 g/d of choline chloride, 3 g/d of betaine, 96 mg/d of riboflavin, and 1.4 mg/d of vitamin B12) from d -28 before expected calving through d 14 postpartum. Cows were randomly enrolled based on predefined selection criteria (body condition score and parity). Base diets without MDS were formulated for gestation (15.4% crude protein with a predicted Lys-to-Met ratio of 3.25; 1.44 Mcal of net energy for lactation/kg of dry matter) and lactation (16.6% crude protein with a predicted Lys-to-Met ratio of 3.36; 1.64 Mcal of net energy for lactation/kg of dry matter). Blood sampling occurred from d -28 relative to expected calving through d 14 postpartum. Liver tissue was biopsied at d -28 relative to expected calving and on d 5 and 14 postpartum. In addition to routine analyses, serum AA concentrations on d 10 and 12 were quantified using mass spectrometry. Plasma triacylglycerol (TAG) and cholesteryl esters (CE) were qualitatively measured using time-of-flight mass spectrometry. Data were analyzed using a mixed model with repeated measures. Dry matter intake and milk yield were not modified by MDS. The transition from d -28 relative to expected parturition to d 14 postpartum was characterized by increased plasma fatty acid (0.15 to 0.71 mmol/L) and ß-hydroxybutyrate (0.34 to 0.43 mmol/L) levels and liver lipid content (3.91 to 9.16%). Methyl donor supplementation increased the serum Met level by 26% and decreased the serum Lys-to-Met ratio by 21% on d 10 and 12, respectively. Moreover, the increase in hepatic lipid content from d 5 through 14 postpartum was suppressed with MDS relative to control (3.57 vs. -0.29%). Dietary MDS modified the TAG and CE lipidome. For example, MDS increased plasma TAG 46:3 (carbon number:double bond) by 116% relative to control cows on d 5 postpartum. Moreover, MDS tended to increase plasma CE 34:6. In contrast, MDS lowered plasma TAG 54:8 by 39% relative to control cows on d 5 postpartum. We concluded that in the absence of gains in dry matter intake and milk and milk protein yields, dietary MDS slows the progression of hepatic lipid accumulation and modifies the plasma TAG lipidome in transition cows.

Trends in laparoscopic colorectal surgery over time from 2005-2014 using the NSQIP database.

BACKGROUND: Laparoscopy, originally pioneered by gynecologists, was first adopted by general surgeons in the late 1980s. Since then, laparoscopy has been adopted in the surgical specialties and colorectal surgery for treatment of benign and malignant disease. Formal laparoscopic training became a required component of surgery residency programs as validated by the Fundamentals of Laparoscopic Surgery curriculum; however, some surgeons may be more apprehensive of widespread adoption of minimally invasive techniques. Although an overall increase in the use of laparoscopy in colorectal surgery is anticipated over a 10-year period, it is unknown if a similar increase will be seen in higher risk or more acutely ill patients. METHODS: Using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database from 2005-2014, colorectal procedures were identified by Current Procedural Terminology codes and categorized to open or laparoscopic surgery. The proportion of colorectal surgeries performed laparoscopically was calculated for each year. Separate descriptive statistics was performed and categorized by age and body mass index (BMI). American Society of Anesthesiology (ASA) classification and emergency case status variables were added to the project to help assess complexity of cases. RESULTS: During the 10-year study period, the number of colorectal cases increased from 3114 in 2005 to 51,611 in 2014 as more hospitals joined NSQIP. A total of 277,376 colorectal cases were identified; of which, 114,359 (41.2%) were performed laparoscopically. The use of laparoscopy gradually increased each year, from 22.7% in 2005 to 49.8% in 2014. Laparoscopic procedures were most commonly performed in the youngest age group (18-49 years), overweight and obese patients (BMI 25-34.9), and in ASA class 1-2 patients. Over the 10-year period, there was a noted increase in the use of laparoscopy in every age, BMI, and ASA category, except ASA 5. The percent of emergency cases receiving laparoscopic surgery also doubled from 5.5% in 2005 to 11.5% in 2014. CONCLUSIONS: Over a 10-year period, there was a gradual increase in the use of laparoscopy in colorectal surgery. Further, there was a consistent increase of laparoscopic surgery in all age groups, including the elderly, in all BMI classes, including the obese and morbidly obese, and in most ASA classes, including ASA 3-4, as well as in emergency surgeries. These trends suggest that minimally invasive colorectal surgery appears to be widely adopted and performed on more complex or higher risk patients.

Migrant women living with HIV in Europe: are they facing inequalities in the prevention of mother-to-child-transmission of HIV?: The European Pregnancy and Paediatric HIV Cohort Collaboration (EPPICC) study group in EuroCoord.

Background: In pregnancy early interventions are recommended for prevention of mother-to-child-transmission (PMTCT) of HIV. We examined whether pregnant women who live with HIV in Europe and are migrants encounter barriers in accessing HIV testing and care. Methods: Four cohorts within the European Pregnancy and Paediatric HIV Cohort Collaboration provided data for pooled analysis of 11 795 pregnant women who delivered in 2002-12 across ten European countries. We defined a migrant as a woman delivering in a country different from her country of birth and grouped the countries into seven world regions. We compared three suboptimal PMTCT interventions (HIV diagnosis in late pregnancy in women undiagnosed at conception, late anti-retroviral therapy (ART) start in women diagnosed but untreated at conception and detectable viral load (VL) at delivery in women on antenatal ART) in native and migrant women using multivariable logistic regression models. Results: Data included 9421 (79.9%) migrant women, mainly from sub-Saharan Africa (SSA); 4134 migrant women were diagnosed in the current pregnancy, often (48.6%) presenting with CD4 count <350 cells/µl. Being a migrant was associated with HIV diagnosis in late pregnancy [OR for SSA vs. native women, 2.12 (95% CI 1.67, 2.69)] but not with late ART start if diagnosed but not on ART at conception, or with detectable VL at delivery once on ART. Conclusions: Migrant women were more likely to be diagnosed in late pregnancy but once on ART virological response was good. Good access to antenatal care enables the implementation of PMTCT protocols and optimises both maternal and children health outcomes generally.

Hepatitis C virus seroprevalence in pregnant women delivering live-born infants in North Thames, England in 2012.

To estimate HCV seroprevalence in subpopulations of women delivering live-born infants in the North Thames region in England in 2012, an unlinked anonymous (UA) cross-sectional survey of neonatal dried blood spot samples was conducted. Data were available from 31467 samples from live-born infants received by the North Thames screening laboratory. Thirty neonatal samples had HCV antibodies, corresponding to a maternal seroprevalence of 0·095% (95% confidence interval 0·067-0·136). Estimated HCV seroprevalences in women born in Eastern Europe, Southern Asia and the UK were 0·366%, 0·162% and 0·019%, respectively. For women born in Eastern Europe seroprevalence was highest in those aged around 27 years, while in women born in the UK and Asia-Pacific region, seroprevalence increased significantly with age. HCV seroprevalence in UK-born women whose infant's father was also UK-born was 0·016%. One of the 30 HCV-seropositive women was HIV-1 seropositive. Estimated HCV seroprevalence for women delivering live-born infants in North Thames in 2012 (0·095%) was significantly lower than that reported in an earlier UA survey in 1997-1998 (0·191%). Data indicate that the cohort of UK-born HCV-seropositive women is ageing and that, in this area of England, most perinatally HCV-exposed infants were born to women themselves born in Southern Asia or Eastern Europe.

The evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer: recommendations by an International TILs Working Group 2014.

BACKGROUND: The morphological evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer (BC) is gaining momentum as evidence strengthens for the clinical relevance of this immunological biomarker. Accumulating evidence suggests that the extent of lymphocytic infiltration in tumor tissue can be assessed as a major parameter by evaluation of hematoxylin and eosin (H&E)-stained tumor sections. TILs have been shown to provide prognostic and potentially predictive value, particularly in triple-negative and human epidermal growth factor receptor 2-overexpressing BC. DESIGN: A standardized methodology for evaluating TILs is now needed as a prerequisite for integrating this parameter in standard histopathological practice, in a research setting as well as in clinical trials. This article reviews current data on the clinical validity and utility of TILs in BC in an effort to foster better knowledge and insight in this rapidly evolving field, and to develop a standardized methodology for visual assessment on H&E sections, acknowledging the future potential of molecular/multiplexed approaches. CONCLUSIONS: The methodology provided is sufficiently detailed to offer a uniformly applied, pragmatic starting point and improve consistency and reproducibility in the measurement of TILs for future studies.

Towards more drug-like proteomimetics: two-faced, synthetic α-helix mimetics based on a purine scaffold.

Mimicry of two faces of an α-helix might yield more potent and more selective inhibitors of aberrant, helix-mediated protein-protein interactions (PPI). Herein, we demonstrate that a 2,6,9-tri-substituted purine is capable of disrupting the Mcl-1-Bak-BH3 PPI through effective mimicry of key residues on opposing faces of the Bak-BH3 α-helix.

Cortical parvalbumin GABAergic deficits with α7 nicotinic acetylcholine receptor deletion: implications for schizophrenia.

Dysfunction of cortical parvalbumin (PV)-containing GABAergic interneurons has been implicated in cognitive deficits of schizophrenia. In humans microdeletion of the CHRNA7 (α7 nicotinic acetylcholine receptor, nAChR) gene is associated with cortical dysfunction in a broad spectrum of neurodevelopmental and neuropsychiatric disorders including schizophrenia while in mice similar deletion causes analogous abnormalities including impaired attention, working-memory and learning. However, the pathophysiological roles of α7 nAChRs in cortical PV GABAergic development remain largely uncharacterized. In both in vivo and in vitro models, we identify here that deletion of the α7 nAChR gene in mice impairs cortical PV GABAergic development and recapitulates many of the characteristic neurochemical deficits in PV-positive GABAergic interneurons found in schizophrenia. α7 nAChR null mice had decreased cortical levels of GABAergic markers including PV, glutamic acid decarboxylase 65/67 (GAD65/67) and the α1 subunit of GABAA receptors, particularly reductions of PV and GAD67 levels in cortical PV-positive interneurons during late postnatal life and adulthood. Cortical GABAergic synaptic deficits were identified in the prefrontal cortex of α7 nAChR null mice and α7 nAChR null cortical cultures. Similar disruptions in development of PV-positive GABAergic interneurons and perisomatic synapses were found in cortical cultures lacking α7 nAChRs. Moreover, NMDA receptor expression was reduced in GABAergic interneurons, implicating NMDA receptor hypofunction in GABAergic deficits in α7 nAChR null mice. Our findings thus demonstrate impaired cortical PV GABAergic development and multiple characteristic neurochemical deficits reminiscent of schizophrenia in cortical PV-positive interneurons in α7 nAChR gene deletion models. This implicates crucial roles of α7 nAChRs in cortical PV GABAergic development and dysfunction in schizophrenia and other neuropsychiatric disorders.

Cortical synaptic NMDA receptor deficits in α7 nicotinic acetylcholine receptor gene deletion models: implications for neuropsychiatric diseases.

Microdeletion of the human CHRNA7 gene (α7 nicotinic acetylcholine receptor, nAChR) as well as dysfunction in N-methyl-d-aspartate receptors (NMDARs) have been associated with cortical dysfunction in a broad spectrum of neurodevelopmental and neuropsychiatric disorders including schizophrenia. However, the pathophysiological roles of synaptic vs. extrasynaptic NMDARs and their interactions with α7 nAChRs in cortical dysfunction remain largely uncharacterized. Using a combination of in vivo and in vitro models, we demonstrate that α7 nAChR gene deletion leads to specific loss of synaptic NMDARs and their coagonist, d-serine, as well as glutamatergic synaptic deficits in mouse cortex. α7 nAChR null mice had decreased cortical NMDAR expression and glutamatergic synapse formation during postnatal development. Similar reductions in NMDAR expression and glutamatergic synapse formation were revealed in cortical cultures lacking α7 nAChRs. Interestingly, synaptic, but not extrasynaptic, NMDAR currents were specifically diminished in cultured cortical pyramidal neurons as well as in acute prefrontal cortical slices of α7 nAChR null mice. Moreover, d-serine responsive synaptic NMDAR-mediated currents and levels of the d-serine synthetic enzyme serine racemase were both reduced in α7 nAChR null cortical pyramidal neurons. Our findings thus identify specific loss of synaptic NMDARs and their coagonist, d-serine, as well as glutamatergic synaptic deficits in α7 nAChR gene deletion models of cortical dysfunction, thereby implicating α7 nAChR-mediated control of synaptic NMDARs and serine racemase/d-serine pathways in cortical dysfunction underlying many neuropsychiatric and neurodevelopmental disorders, particularly those associated with deletion of human CHRNA7.

Topography-driven microclimate gradients shape forest structure, diversity, and composition in a temperate refugial forest.

Macroclimate drives vegetation distributions, but fine-scale topographic variation can generate microclimate refugia for plant persistence in unsuitable areas. However, we lack quantitative descriptions of topography-driven microclimatic variation and how it shapes forest structure, diversity, and composition. We hypothesized that topographic variation and the presence of the forest overstory cause spatiotemporal microclimate variation affecting tree performance, causing forest structure, diversity, and composition to vary with topography and microclimate, and topography and the overstory to buffer microclimate. In a 20.2-ha inventory plot in the North American Great Plains, we censused woody stems ≥1 cm in diameter and collected detailed topographic and microclimatic data. Across 59-m of elevation, microclimate covaried with topography to create a sharp desiccation gradient, and topography and the overstory buffered understory microclimate. The magnitude of microclimatic variation mirrored that of regional-scale variation: with increasing elevation, there was a decrease in soil moisture corresponding to the difference across ~2.1° of longitude along the east-to-west aridity gradient and an increase in air temperature corresponding to the difference across ~2.7° of latitude along the north-to-south gradient. More complex forest structure and higher diversity occurred in moister, less-exposed habitats, and species occupied distinct topographic niches. Our study demonstrates how topographic and microclimatic gradients structure forests in putative climate-change refugia, by revealing ecological processes enabling populations to be maintained during periods of unfavorable macroclimate.

Postoperative Care and Outcomes in Solid-Organ Transplant Patients Undergoing Lower Extremity Fracture Treatment.

OBJECTIVES: To determine the postoperative outcomes in solid-organ transplant (SOT) patients undergoing operative treatment of lower extremity fractures. DESIGN: Retrospective comparative study. SETTING: Academic Level 1 trauma center. PATIENT SELECTION CRITERIA: Patients who underwent SOT and operative treatment of lower extremity fracture from 2013 to 2021 were identified, excluding pathologic fractures. OUTCOME MEASURES AND COMPARISONS: Postoperative complications, length of stay, time to death, 90-day and 1-year readmission rates, readmission causes, discharge location, and immunosuppressive regiments. RESULTS: Sixty-one patients with an average age of 67 years (range 29-88) were included. The mortality rate was 37.7%. The average follow-up was 15.2 months (range of 2 weeks-10 years). The majority of patients (32.8%) had received a liver transplant, and femoral neck fractures constituted the largest fracture group. The average length of stay was 10 days, with the shortest being 1 day and the longest being 126 days (SD 18). The majority of patients (57.3%) were not discharged home. Only 2 suffered from a postoperative complication requiring another procedure: hardware removal and liner exchange for periprosthetic joint infection, respectively. There was a 27.9% 90-day readmission rate with 2 deaths within that period with the most common being altered mental status (29.4%), genitourinary infections (17.6%), repeat falls (11.8%), and low hemoglobin requiring transfusion (11.8%). The longest average time to death analyzed by transplant type was found among lung transplant patients (1076 days, 62.5% mortality), followed by liver transplant patients (949 days, 35.0% mortality), and then kidney transplant patients (834 days, 38.9% mortality). The shortest time to death was 71 days from index procedure. CONCLUSIONS: Family members of SOT patients undergoing operative treatment of lower extremity fractures should be made aware of the high risk for 90-day readmission postoperatively (27.9%) and overall mortality (12.5%). Providers should be aware of the need for multidisciplinary involvement for inpatient care, monitoring postoperative complications, and facilitating discharge planning. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Identifying Tumor Microenvironment Biomarkers in Adherent and Cystic Vestibular Schwannomas.

OBJECTIVE: A subset of vestibular schwannomas (VSs), including cystic tumors, have higher postoperative morbidity because of the presence of adhesions between the tumor, facial nerve (FN), and brainstem. We identify tumor microenvironment (TME) biomarkers to better classify these tumors and predict the degree of tumor adherence. STUDY DESIGN: Retrospective case series. SETTING: Tertiary skull base referral center. METHODS: Adult patients with cystic and solid VS matched in tumor size who underwent surgical resection were included. Expressions of seven biomarkers of extracellular matrix remodeling and tumor immune response were quantified via immunohistochemistry. The distribution of CD45+ immune cells was evaluated in intratumoral and perivascular compartments. The degree of tumor adherence was categorized as none, adherent to FN, or adherent to both FN and brainstem. RESULTS: Twenty-eight patients were included. Cystic VSs were significantly more adherent than solid VSs ( p = 0.02). Patients with adherent VS had shorter duration of symptoms and were more likely to undergo subtotal resection. In solid tumors, matrix metalloproteinase (MMP)-2 expression ( p = 0.02) and CD163+ macrophage infiltration ( p = 0.007) were correlated with tumor size. Linear discriminant analyses (LDAs) demonstrated MMP-2, MMP-14, CD80, CD163, and perivascular CD45 to be individually predictive of the degree of tumor adherence (all p < 0.05), with perivascular CD45 being the best independent predictor ( p = 0.005). An LDA model including these biomarkers demonstrated 100% accurate discrimination of all three levels of tumor adherence ( p = 0.04). CONCLUSIONS: Adherent VS have a distinct proinflammatory TME characterized by elevated MMP expression, enrichment of tumor-associated macrophages, and perivascular immune cell infiltration.

Potential for a minor pine bark beetle pest, Dendroctonus terebrans (Coleoptera: Curculionidae: Scolytinae), to mediate host location by a major pine killer, Dendroctonus frontalis.

The southern pine beetle, Dendroctonus frontalis Zimmermann is an important mortality agent of Pinus in the eastern United States of America where it commonly shares hosts with the black turpentine beetle, Dendroctonus terebrans (Olivier), which infrequently kills trees. Unlike D. frontalis, which must kill its hosts to become established in the bark and reproduce, D. terebrans can occupy living hosts as a parasite. Olfactory mechanisms whereby D. frontalis initially locates hosts have not been demonstrated, whereas D. terebrans responds strongly to host odors. Because D. terebrans produces frontalin, the primary aggregation pheromone component for D. frontalis, and commonly arrives on hosts prior to D. frontalis, it has been hypothesized that D. terebrans pheromone components can mediate D. frontalis location of suitable, living trees. We assessed this possibility with studies of the semiochemical interactions between D. frontalis and D. terebrans. Coupled gas chromatography-electroantennographic detection analyses indicated that D. terebrans produces nine different olfactory stimulants for D. frontalis, nearly all of them known semiochemicals for D. frontalis. A trapping experiment designed to address the potentially confounding influence of lure contamination confirmed that the D. terebrans pheromone component exo-brevicomin enhances attraction of D. frontalis and thus could be an attractive kairomone. In ambulatory bioassays, male D. frontalis were strongly attracted to odors of frass of solitary female and paired D. terebrans, indicating their attraction to the naturally occurring semiochemicals of D. terebrans. Cues from D. terebrans may influence host and mate-finding success of D. frontalis and, thereby, the latter's virulence.

Matrix metalloproteinase 9: An emerging biomarker for classification of adherent vestibular schwannoma.

Background: The progression of vestibular schwannoma (VS) is intricately linked with interactions between schwannoma cells and the extracellular matrix. Surgical resection of VS is associated with substantial risks as tumors are adherent to the brainstem and cranial nerves. We evaluate the role of matrix metalloproteinase 9 (MMP9) in VS and explore its potential as a biomarker to classify adherent VS. Methods: Transcriptomic analysis of a murine schwannoma allograft model and immunohistochemical analysis of 17 human VS were performed. MMP9 abundance was assessed in mouse and human schwannoma cell lines. Transwell studies were performed to evaluate the effect of MMP9 on schwannoma invasion in vitro. Plasma biomarkers were identified from a multiplexed proteomic analysis in 45 prospective VS patients and validated in primary culture. The therapeutic efficacy of MMP9 inhibition was evaluated in a mouse schwannoma model. Results: MMP9 was the most highly upregulated protease in mouse schwannomas and was significantly enriched in adherent VS, particularly around tumor vasculature. High levels of MMP9 were found in plasma of patients with adherent VS. MMP9 outperformed clinical and radiographic variables to classify adherent VS with outstanding discriminatory ability. Human schwannoma cells secreted MMP9 in response to TNF-α which promoted cellular invasion and adhesion protein expression in vitro. Lastly, MMP9 inhibition decreased mouse schwannoma growth in vivo. Conclusions: We identify MMP9 as a preoperative biomarker to classify adherent VS. MMP9 may represent a new therapeutic target in adherent VS associated with poor surgical outcomes that lack other viable treatment options.

Tumor biomechanical stiffness by magnetic resonance elastography predicts surgical outcomes and identifies biomarkers in vestibular schwannoma and meningioma.

Variations in the biomechanical stiffness of brain tumors can not only influence the difficulty of surgical resection but also impact postoperative outcomes. In a prospective, single-blinded study, we utilize pre-operative magnetic resonance elastography (MRE) to predict the stiffness of intracranial tumors intraoperatively and assess the impact of increased tumor stiffness on clinical outcomes following microsurgical resection of vestibular schwannomas (VS) and meningiomas. MRE measurements significantly correlated with intraoperative tumor stiffness and baseline hearing status of VS patients. Additionally, MRE stiffness was elevated in patients that underwent sub-total tumor resection compared to gross total resection and those with worse postoperative facial nerve function. Furthermore, we identify tumor microenvironment biomarkers of increased stiffness, including αSMA + myogenic fibroblasts, CD163 + macrophages, and HABP (hyaluronic acid binding protein). In a human VS cell line, a dose-dependent upregulation of HAS1-3, enzymes responsible for hyaluronan synthesis, was observed following stimulation with TNFα, a proinflammatory cytokine present in VS. Taken together, MRE is an accurate, non-invasive predictor of tumor stiffness in VS and meningiomas. VS with increased stiffness portends worse preoperative hearing and poorer postoperative outcomes. Moreover, inflammation-mediated hyaluronan deposition may lead to increased stiffness.

Local excision of rectal cancer followed by radical surgery because of poor prognostic features does not compromise the long term oncologic outcome.

AIM: The outcome of patients undergoing full-thickness local excision (LE) of rectal cancers may be compromised if poor prognostic features are found in the LE specimen. Our aim was to evaluate the long-term results of radical surgery performed after LE because poor prognostic factors are identified. METHOD: Patients with biopsy-proven rectal cancer who had undergone full-thickness LE followed by radical surgery because of a positive margin, T stage ≥3, lymphovascular invasion, poor differentiation or mucinous histology were identified from a prospective database. Their records were retrospectively reviewed and follow up was updated. RESULTS: Between 1995 and 2003, 17 patients underwent LE followed by radical surgery because of poor prognostic features. Combined chemotherapy and radiotherapy was given to 11 (65%) patients before radical surgery. Patients underwent radical surgery after a median of 14 (range: 0-40) weeks from LE. Nine underwent a low anterior resection and eight an abdominoperineal resection. At the time of radical surgery, residual disease was found in six (35%) patients (in lymph nodes in three; intramural in two; and both lymph nodes and intramural in one). Four of the patients with residual disease had undergone neoadjuvant therapy before radical surgery. The mean follow up was 110 (95% CI: 92-129) months. Recurrence-free survival at 10 years was 88%. There was no case of local recurrence, and two patients died of metastatic disease. CONCLUSION: In this series patients who underwent early radical surgery because of poor prognostic features found at LE had good overall and cancer-specific long-term survival. Even after neoadjuvant therapy, more than a third of patients had residual disease at the time of radical surgery. We therefore recommend radical surgery with neoadjuvant therapy when poor prognostic features are found at LE.