Vascular endothelial growth factor correlates with matrix metalloproteinase-9 in the pleural effusion

Immunological aspects of host-pathogen crosstalk in the co-pathogenesis of diabetes and latent tuberculosis

Introduction

Diabetes is a potent risk factor for the activation of latent tuberculosis and worsens the tuberculosis (TB) treatment outcome. The major reason for mortality and morbidity in diabetic patients is due to their increased susceptibility to TB. Thus, the study was conducted to understand the crosstalk between M. tuberculosis and its host upon latent tuberculosis infection and under hyperglycemic conditions or diabetes.

Methods

An animal model was employed to study the relationship between latent tuberculosis and diabetes. BCG immunization was done in mice before infection with M. tuberculosis, and latency was confirmed by bacillary load, histopathological changes in the lungs and gene expression of hspX, tgs1, tgs3 and tgs5. Diabetes was then induced by a single high dose of streptozotocin (150 mg/kg body weight). Host factors, like various cytokines and MMPs (Matrix metalloproteinases), which play an important role in the containment of mycobacterial infection were studied in vivo and in vitro.

Results

A murine model of latent TB was developed, which was confirmed by CFU counts (<10⁴ in the lungs and spleen) and granuloma formation in lungs in the latent TB group. Also, the gene expression of hspX, tgs1, and tgs5 was upregulated, and after diabetes induction, blood glucose levels were >200 mg/dl. An in vitro study employing a THP-1 macrophage model of latent and active tuberculosis under normal and high glucose conditions showed that dormant bacilli were better contained in the presence of 5.5 mM glucose concentration as compared with active bacilli. However, the killing and restriction efficiency of macrophages decreased, and CFU counts increased significantly with an increase in glucose concentration.

Discussion

The decreased levels of MCP-1, decreased expression of mmp-9, and increased expression of mmp-1 in the latent group at high glucose concentrations could explain the failure of granuloma formation at high glucose conditions.

Vascular endothelial growth factor levels in tuberculosis: A systematic review and meta-analysis

Background

Changes in endothelial function are implicated in the spread of tuberculosis (TB). Studies suggest a role for the vascular endothelial growth factor (VEGF) in TB-related endothelial function changes. However, the findings of studies investigating the VGEF profile in TB are not consistent, and no formal systematic review and meta-analysis exists summarizing these studies.

Methods

We did a meta-analysis of studies assessing VEGF levels in patients with TB. A systematic search on June 25, 2021, was conducted for eligible studies that made VEGF measurements in an unstimulated sample, e.g., a blood fraction (plasma or serum), cerebrospinal fluid (CSF), pleural effusion (PE), or bronchoalveolar lavage fluid, and ascites or pericardial fluid for patients with TB and controls without TB. Also, studies that made simultaneous measurements of VEGF in blood and PE or CSF in the same patients with TB were included. Longitudinal studies that provided these data at baseline or compared pre-post anti-tuberculosis treatment (ATT) levels of VEGF were included. The primary outcome was the standardized mean difference (SMD) of VEGF levels between the comparison groups.

Results

52 studies were included in the meta-analysis. There were 1787 patients with TB and 3352 control subjects of eight categories: 107 patients with transudative pleural effusion, 228 patients with congestive heart failure (CHF)/chronic renal failure (CRF), 261 patients with empyema and parapneumonic effusion (PPE), 241 patients with cirrhosis, 694 healthy controls (with latent TB infection or uninfected individuals), 20 patients with inactive tuberculous meningitis (TBM), 123 patients with non-TBM, and 1678 patients with malignancy. The main findings are as follows: (1) serum levels of VEGF are higher in patients with active TB compared with healthy controls without other respiratory diseases, including those with latent TB infection or uninfected individuals; (2) both serum and pleural levels of VEGF are increased in patients with TPE compared with patients with transudative, CHF/CRF, or cirrhotic pleural effusion; (3) ascitic/pericardial fluid, serum, and pleural levels of VEGF are decreased in patients with TB compared with patients with malignancy; (4) pleural levels of VEGF are lower in patients with TPE compared with those with empyema and PPE, whereas serum levels of VEGF are not different between these patients; (5) both CSF and serum levels of VEGF are increased in patients with active TBM compared with controls, including patients with inactive TBM or non-TBM subjects; (6) post-ATT levels of VEGF are increased compared with pre-ATT levels of VEGF; and (7) the mean age and male percentage of the TB group explained large and total amount of heterogeneity for the meta-analysis of blood and pleural VEGF levels compared with healthy controls and patients with PPE, respectively, whereas these moderators did not show any significant interaction with the effect size for other analyses.

Discussion

The important limitation of the study is that we could not address the high heterogeneity among studies. There might be unmeasured factors behind this heterogeneity that need to be explored in future research. Meta-analysis findings align with the hypothesis that TB may be associated with abnormal vascular function, and both local and systemic levels of VEGF can be used to trace this abnormality.

Pleural biomarkers in diagnostics of malignant pleural effusion: a narrative review

Although cytology and pleural biopsy of pleural effusion (PE) are the gold standards for diagnosing malignant pleural effusion (MPE), these tools’ diagnostic accuracy is plagued by some limitations such as low sensitivity, considerable inter-observer variation and invasiveness. The assessment of PE biomarkers may hence be seen as an objective and non-invasive diagnostic alternative in MPE diagnostics. In this review, we summarize the characteristics and diagnostic accuracy of available PE biomarkers, including carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), carbohydrate antigens 125 (CA125), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 15-3 (CA15-3), a fragment of cytokeratin 19 (CYFRA 21-1), chitinase-like proteins (CLPs), vascular endothelial growth factor (VEGF) and its soluble receptor, endostatin, calprotectin, cancer ratio, homocysteine, apolipoprotein E (Apo-E), B7 family members, matrix metalloproteinase (MMPs) and tissue-specific inhibitors of metalloproteinases (TIMPs), reactive oxygen species modulator 1 (Romo1), tumor-associated macrophages (TAMs) and monocytes, epigenetic markers (e.g., cell-free microRNA and mRNA). We summarized the evidence from systematic review and meta-analysis for traditional tumor markers’ diagnostic accuracy. According to the currently available evidence, we conclude that the traditional tumor markers have high specificity (around 0.90) but low sensitivity (around 0.50). The diagnostic accuracy of novel tumor markers needs to be validated by further studies. None of these tumor biomarkers would have sufficient diagnostic accuracy to confirm or exclude MPE when used alone. A multi-biomarker strategy, also encompassing the use of artificial intelligence algorithms, may be a valuable perspective for improving the diagnostic accuracy of MPE.

Pleural and serum markers for diagnosis of malignant pleural effusion

BACKGROUND

Differentiation between benign and malignant exudative pleural effusion remains a clinical challenge. Recently, several markers have been reported to increase the diagnostic accuracy of malignant pleural effusion, with controversial results.

METHODS

Patients with exudative pleural effusion were divided into 2 groups: a malignant pleural effusion group (39 patients) diagnosed by malignant cells in pleural fluid cytology or by malignant infiltration of the pleura on pleural biopsy, and a benign pleural effusion group (51 patients) with neither malignant cells in pleural fluid cytology nor malignant infiltration of the pleura on pleural biopsy. Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 were determined in both serum and pleural fluid samples, using commercially available enzyme-linked immunosorbent assay kits.

RESULTS

The etiology of malignant pleural effusion in the malignant group was breast cancer in 43.6% and bronchogenic carcinoma in 25.6%. There was a statistically significant difference between the 2 groups regarding sex, with more males in the benign group. There was no significant difference between groups regarding age. The median levels of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 were higher in the malignant group than in the benign group, and the differences were highly significant in both pleural fluid (p < 0.001) and serum (p < 0.001).

CONCLUSION

Matrix metaloproteinase-9 and tissue inhibitor of metalloproteinase-1 in serum and pleural fluid samples might be valuable markers for differentiating benign from malignant pleural effusions.

Identification of candidate host serum and saliva biomarkers for a better diagnosis of active and latent tuberculosis infection

In our work, we aim to identify new candidate host biomarkers to discriminate between active TB patients (n = 28), latent infection (LTBI; n = 27) and uninfected (NoTBI; n = 42) individuals. For that, active TB patients and their contacts were recruited that donated serum and saliva samples. A multiplex assay was performed to study the concentration of different cytokines, chemokines and growth factors. Proteins with significant differences between groups were selected and logistic regression and the area under the ROC curve (AUC) was used to assess the diagnostic accuracy. The best marker combinations that discriminate active TB from NoTBI contacts were [IP-10 + IL-7] in serum and [Fractalkine + IP-10 + IL-1α + VEGF] in saliva. Best discrimination between active TB and LTBI was achieved using [IP-10 + BCA-1] in serum (AUC = 0.83) and IP-10 in saliva (p = 0.0007; AUC = 0.78). The levels of TNFα (p = 0.003; AUC = 0.73) in serum and the combination of [Fractalkine+IL-12p40] (AUC = 0.83) in saliva, were able to differentiate between NoTBI and LTBI contacts. In conclusion, different individual and combined protein markers could help to discriminate between active TB and both uninfected and latently-infected contacts. The most promising ones include [IP-10 + IL-7], [IP-10 + BCA-1] and TNFα in serum and [Fractalkine + IP-10 + IL-1α + VEGF], IP-10 and [Fractalkine+IL-12p40] in saliva.

Systematic review and meta-analysis of vascular endothelial growth factor as a biomarker for malignant pleural effusions

Conventional methods may fail to identify the cause of pleural effusion (PE), thus establishing reliable biomarkers is deemed necessary. This study aimed at examining the role of vascular endothelial growth factor (VEGF) as a biomarker in the differentiation between malignant and benign PEs in adults. A comprehensive literature search in PubMed (Medline), Scopus (ELSEVIER), and Cochrane Central Register of Controlled Trials (CENTRAL) databases was conducted using keywords. We included studies that evaluated pleural and/or serum levels of VEGF among patients presenting with undiagnosed PE and the association between these levels and the final diagnosis. We performed a meta‐analysis to calculate the summary effect using the random effects model. Statistical analysis was performed with the statistical package for meta‐analysis Comprehensive Meta‐Analysis. Twenty studies were included in the systematic review, while 11 of them in the meta‐analysis. Pleural fluid VEGF levels among patients with malignant PE were increased by 1.93 ng/mL as compared to patients with benign PE (95% CI: 1.32–2.54, Q = 173, df (Q): 10, I² = 94.2%, P < 0.05). Serum VEGF levels among patients with malignant PE were increased respectively by 1.90 ng/mL (95% CI: 0.93–2.88, Q = 182, df (Q): 6, I² = 96.7%, P < 0.05). This study showed that malignant PEs were associated with higher levels of both pleural fluid and serum VEGF. VEGF appears to represent a promising biomarker for the differential diagnosis between benign and malignant PEs.

Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in diagnosis of pleural effusion of malignant origin

OBJECTIVES

The aim of the present study was to evaluate the diagnostic accuracy of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in differentiating benign from malignant exudative pleural effusions.

METHODS

This is a unicentre observational study including 97 consecutive patients with exudative pleural effusions. Metalloproteinase-9, tissue inhibitor of metalloproteinase-1, lactate dehydrogenase, ferritin, carcinoembryonic antigen and carbohydrate antigen 15-3 were measured in pleural effusion and serum by enzyme-linked immunosorbent assay. The activity of metalloproteinase-9 was also evaluated by substrate zymography. The data were correlated with final diagnosis of pleural effusions to evaluate the diagnostic accuracy.

RESULTS

Of the 97 eligible patients, 6 were excluded. Of the 91 patients included in the study, 70 had malignant pleural effusions and 21 had benign pleural effusions. Both in sera and pleural effusions, matrix metalloproteinase-9 (P < 0.0001), tissue inhibitor of metalloproteinase-1 (P < 0.0001) and carcinoembryonic antigen (P < 0.0001) levels were higher in neoplastic patients than in benign group. Zymography analysis showed a most prominent band at a molecular weight of 92 kDa (metalloproteinase-9) whereas a less intense band was observed at 72 kDa (metalloproteinase-2). A significant correlation was found between metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 levels in pleural effusion (P < 0.0001; r = 0.8) and serum (P < 0.03; r = 0.2). Pleural effusion metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 levels showed higher value of sensitivity (97 and 91%, respectively) and specificity (90 and 95%, respectively) compared with other standard markers. Serum metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 levels showed similar results. Among 70 neoplastic patients, 29 had negative pleural cytology. Of these, 25 presented elevated levels of metalloproteinase-9 and tissue inhibitor of metalloproteinase-1, whereas 4 patients had elevated levels of one of the two markers.

CONCLUSIONS

Our results showed that metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 might be valuable markers in differentiating benign from malignant pleural effusions. Their levels are neither influenced by the histology and tumour origin nor by the presence of tumour cells in pleural effusions. Thus, their use in clinical practice could help in the selection of patients needing more invasive procedures, such as thoracoscopic biopsy.

Effect of tumor microenvironment on tumor VEGF during anti-VEGF treatment: systems biology predictions

BACKGROUND

Vascular endothelial growth factor (VEGF) is known to be a potent promoter of angiogenesis under both physiological and pathological conditions. Given its role in regulating tumor vascularization, VEGF has been targeted in various cancer treatments, and anti-VEGF therapy has been used clinically for treatment of several types of cancer. Systems biology approaches, particularly computational models, provide insight into the complexity of tumor angiogenesis. These models complement experimental studies and aid in the development of effective therapies targeting angiogenesis.

METHODS

We developed an experiment-based, molecular-detailed compartment model of VEGF kinetics and transport to investigate the distribution of two major VEGF isoforms (VEGF121 and VEGF165) in the body. The model is applied to predict the dynamics of tumor VEGF and, importantly, to gain insight into how tumor VEGF responds to an intravenous injection of an anti-VEGF agent.

RESULTS

The model predicts that free VEGF in the tumor interstitium is seven to 13 times higher than plasma VEGF and is predominantly in the form of VEGF121 (>70%), predictions that are validated by experimental data. The model also predicts that tumor VEGF can increase or decrease with anti-VEGF treatment depending on tumor microenvironment, pointing to the importance of personalized medicine.

CONCLUSIONS

This computational study suggests that the rate of VEGF secretion by tumor cells may serve as a biomarker to predict the patient population that is likely to respond to anti-VEGF treatment. Thus, the model predictions have important clinical relevance and may aid clinicians and clinical researchers seeking interpretation of pharmacokinetic and pharmacodynamic observations and optimization of anti-VEGF therapies.

The value of matrix metalloproteinase-9 and vascular endothelial growth factor receptor 1 pathway in diagnosing indeterminate pleural effusion

OBJECTIVES

Our aim was to determine the diagnostic value of the matrix metalloproteinase-9/vascular endothelial grow factor receptor-1 pathway in differentiating pleural effusions (PE) of varying origin.

METHODS

In the last two years, 55 consecutive patients with exudative PE have been enrolled. In all patients, we measured PE levels of vascular endothelial grow factor receptor-1 (VEGFR-1) in soluble form, through enzyme-linked immunosorbent assay (ELISA) (results expressed in pg/ml) and western blot, and of matrix metalloproteinase-9 (MMP-9), through ELISA (results expressed in ng/ml). The values recorded were then statistically compared with the etiologic diagnosis of the PEs.

RESULTS

Between the PEs analysed, 40 were found to be malignant and 15 to be benign. VEGFR-1 in soluble form (sVEGFR-1) was significantly higher in malignant than in benign effusions (P < 0.0001), using ELISA; the same was shown by the western blot analysis method. MMP-9 levels results also indicated significantly more malignant than benign effusions (P < 0.0001). VEGFR-1 in soluble form showed a sensitivity and specificity of 92% and 93%, respectively, (cut-off value >852; AUC: 0.9) in predicting the malignant nature of a PE. Sensitivity and specificity of MMP-9 in predicting the malignant nature of a PE were, respectively, 95% and 73% (cut-off value >639; AUC: 0.8). In the pleural fluids, the values of the two markers were significantly related to each other (r = 0.5; P < 0.0001). Eighteen patients with malignancies, diagnosed by pleural biopsy, had negative cytological findings. Of these patients, sixteen (89%) presented elevated levels of both markers.

CONCLUSIONS

Our data suggest that the VEGFR-1/MMP-9 pathway is significantly increased in malignant-rather than in benign-pleural effusions; thus, the measurement of their levels in the pleural effusion could be useful, throughout the diagnostic work-up, to select which cases would warrant a pleural biopsy.

Increased fibrosis and interstitial fluid pressure in two different types of syngeneic murine carcinoma grown in integrin β3-subunit deficient mice

Stroma properties affect carcinoma physiology and direct malignant cell development. Here we present data showing that α_Vβ₃ expressed by stromal cells is involved in the control of interstitial fluid pressure (IFP), extracellular volume (ECV) and collagen scaffold architecture in experimental murine carcinoma. IFP was elevated and ECV lowered in syngeneic CT26 colon and LM3 mammary carcinomas grown in integrin β₃-deficient compared to wild-type BALB/c mice. Integrin β₃-deficiency had no effect on carcinoma growth rate or on vascular morphology and function. Analyses by electron microscopy of carcinomas from integrin β₃-deficient mice revealed a coarser and denser collagen network compared to carcinomas in wild-type littermates. Collagen fibers were built from heterogeneous and thicker collagen fibrils in carcinomas from integrin β₃-deficient mice. The fibrotic extracellular matrix (ECM) did not correlate with increased macrophage infiltration in integrin β₃-deficient mice bearing CT26 tumors, indicating that the fibrotic phenotype was not mediated by increased inflammation. In conclusion, we report that integrin β₃-deficiency in tumor stroma led to an elevated IFP and lowered ECV that correlated with a more fibrotic ECM, underlining the role of the collagen network for carcinoma physiology.

Diagnostic accuracy of vascular endothelial growth factor for malignant pleural effusion: A meta-analysis

Since the diagnostic accuracy of conventional examinations for malignant pleural effusion (MPE) is limited, a number of studies have investigated the utility of pleural vascular endothelial growth factor (VEGF) in the diagnosis of MPE. The present meta-analysis aimed to determine the overall accuracy of a VEGF test in the diagnosis of MPE. A systematic review of studies published in English was conducted and the data concerning the accuracy of pleural VEGF assays in the diagnosis of MPE were pooled with random effects models. The overall test performance was summarized using receiver operating characteristic curves. Ten studies, based on 1,025 patients, met the inclusion criteria for the meta-analysis and the summary estimates for VEGF in the diagnosis of MPE were: sensitivity 0.75 [95% confidence interval (CI), 0.72-0.79], specificity 0.72 (95% CI, 0.68-0.76), positive likelihood ratio 2.94 (95% CI, 1.97-4.41), negative likelihood ratio 0.38 (95% CI, 0.27-0.51) and diagnostic odds ratio 9.05 (95% CI, 4.60-17.80). The summary receiver operating characteristic curve indicated that the maximum joint sensitivity and specificity was 0.75; the area under the curve was 0.82. Our findings suggest that the determination of pleural VEGF may improve the accuracy of MPE diagnosis, while the results of VEGF assays should be interpreted in parallel with conventional test results and other clinical findings.

An alternative therapy for idiopathic pulmonary fibrosis by doxycycline through matrix metalloproteinase inhibition

BACKGROUND

Idiopatiic pulmonary fibrosis (IPF) is a disease of dysregulated fibrogenesis with abnormal matrix metalloproteinase (MMPs) activity, angiogenesis, and profibrotic milieu wherein MMPs inhibition appears to be target-based therapy. We evaluated the role of doxycycline as a nonspecific inhibitor of MMPs in IPF patients.

MATERIALS AND METHODS

Patients of IPF diagnosed on the basis of ATS-ERS consensus criteria were put on oral doxycycline in an open prospective trial. They were followed up for long term with spirometry, 6 min walk test (6MWT), St. Georges respiratory questionnaire (SGRQ), forced vital capacity (FVC), and repeat bronchoscopy while on doxycycline monotherapy for over 24 weeks. Both the initial and follow-up broncho alveolar lavage fluids (BALF) from IPF patients (n = 6) and control subjects (n = 6) were looked for MMP-9, -3, tissue inhibitor of metalloproteinase (TIMP)-1 and vascular endothelial growth factor (VEGF) expression. Additionally, doxycycline's action on MMP activities in vitro was tested in BALF of IPF patients.

RESULTS

Doxycycline intervention showed significant improvement in IPF patients in terms of change in 6MWT, SGRQ, FVC, and quality of life. The level of MMP-9, -3, TIMP-1 and VEGF in the BALF were found significantly higher in the IPF patients compared to the controls while doxycycline therapy reduced those parameters nearer to control value. Doxycycline also showed a significant dose-dependent reduction in the in vitro MMPs activities in BALF.

CONCLUSION

Doxycycline shows significant prospect in the treatment of IPF through its anti MMPs activities. This is the first report on a case series of long-term doxycycline monotherapy in IPF patients.

Zoledronic acid is effective against experimental malignant pleural effusion

RATIONALE

Aminobiphosphonates, such as zoledronic acid (ZA), exert potent indirect antitumor effects and are currently being tested against human solid tumors. The antitumor actions of aminobiphosphonates, including angiostasis, are relevant to the pathogenesis of malignant pleural effusion (MPE), but no study has addressed the efficacy of these compounds against malignant pleural disease.

OBJECTIVES

Here we hypothesized that treatment of immunocompetent mice with ZA would halt tumor progression in a mouse model of adenocarcinoma-induced MPE.

METHODS

To induce MPE in mice, Lewis lung carcinoma cells were delivered directly into the pleural space. Subsequently, animals were treated with ZA in both a prevention and a regression protocol.

MEASUREMENTS AND MAIN RESULTS

ZA treatment resulted in significant reductions in pleural fluid accumulation and tumor dissemination, while it significantly prolonged survival. These effects of ZA were linked to enhanced apoptosis of pleural tumor cells, decreased formation of new vessels in pleural tumors, and reduced pleural vascular permeability. In addition, ZA was able to inhibit the recruitment of mononuclear cells to pleural tumors, with concomitant reductions in matrix metalloproteinase-9 release into the pleural space. Finally, ZA limited the expression of proinflammatory and angiogenic mediators, as well as the activity of small GTP proteins Ras and RhoA, in tumor cells in vivo and in vitro.

CONCLUSIONS

ZA is effective against experimental MPE, suggesting that this intervention should be considered for testing in clinical trials.

Role for matrix metalloproteinase 9 in granuloma formation during pulmonary Mycobacterium tuberculosis infection

Recent studies have shown that matrix metalloproteinases (MMPs) are induced by Mycobacterium tuberculosis during pulmonary infection. Here, expression of MMP-9 during pulmonary M. tuberculosis infection was characterized to determine whether its production correlated with disease resistance in vivo and to determine what role, if any, MMP-9 might have in granuloma formation. Following aerosol infection with M. tuberculosis, dissemination of bacilli occurred earlier in the C57BL/6 resistant mouse strain than in the susceptible CBA/J strain, as was evident from an increased number of bacteria in the blood, spleen, and liver at day 14 after infection. In addition, early dissemination of the bacilli was associated with early induction of protective immunity as assessed from gamma interferon levels. Nonspecific blocking of MMPs in C57BL/6 mice early during infection reduced hematogenous spread of the bacilli, suggesting that MMPs indeed play a role in facilitating dissemination, likely via extracellular matrix degradation. The concentration of active MMP-9, specifically, was greater in the lungs of C57BL/6 mice than in those of the CBA/J mice at day 28, thereby suggesting that MMP-9 is not one of the MMPs directly involved in promoting early dissemination of M. tuberculosis. Instead, however, histological lung sections and flow cytometric analysis of lung cells from MMP-9-knockout mice showed that MMP-9 is involved in macrophage recruitment and granuloma development. These combined data support the idea that early MMP activity is an essential component of resistance to pulmonary mycobacterial infection and that MMP-9, specifically, is required for recruitment of macrophages and tissue remodeling to allow for the formation of tight, well-organized granulomas.

Evaluation of vascular endothelial growth factor addition in vitro on mouse inner ear progenitor cell cultures

We analyzed progenitor cell cultures of inner ear tissue from newborn mice, and found proliferating cells, morphologically differentiating cells and subpopulations of cells expressing either neuronal or glial markers. In addition, we observed the expression of fetal liver kinase-1, a receptor for the vascular endothelial growth factor in a subpopulation of the cultured cells. Consistent with the expression of fetal liver kinase-1, addition of vascular endothelial growth factor at a dose of 10 ng/ml increased the expansion rate of inner ear-derived progenitor cells. Together with other published data, these results suggest that the vascular endothelial growth factor might be involved in inducing or supporting cochlear repair processes.

A simple laboratory measurement for discrimination of transudative and exudative pleural effusion: Pleural viscosity

BACKGROUND

The initial step in establishing the cause of an effusion is to determine whether the fluid is a transudate or exudate. Plasma viscosity is influenced by the concentration of plasma proteins and lipoproteins with the major contribution resulting from fibrinogen. In this study we aimed to evaluate the role of pleural fluid viscosity in discrimination of transudate and exudates.

MATERIALS AND METHODS

We studied prospectively 63 consecutive patients with pleural effusion in whom diagnostic or therapeutic thoracentesis had been performed. The criteria of Light were applied to differentiate transudates from exudates: 33 patients (23 male, 13 female, mean age=68+/-4 years) had exudates and 30 patients (17 male, 13 female, mean age=68+/-5) had transudates (due to congestive heart failure). Measurements of pleural fluid and plasma viscosity were performed using a viscometer.

RESULTS

There was no statistically significant difference between patients with transudate and exudates in respect to plasma viscosity. However, pleural viscosities of the patients with exudates were significantly higher than those of patients with transudate (1.37+/-0.16 mPa vs 0.93+/-0.03 mPa s p<0.001, respectively). Pleural viscosity has a high sensitivity, specificity (94%, 93%, respectively), positive and negative predictive value (97%, 97%, respectively) for the discrimination of transudative or exudatetive pleural fluid.

CONCLUSION

We have demonstrated for the first time that pleural viscosity of the exudative effusion is higher than that of transudative effusion with high sensitivity, specificity, positive and negative predictive value. Regarding the simplicity of this measurement, it may play a valuable role in the accurate and fast discrimination of pleural fluid.

Monitoring multiple angiogenesis-related molecules in the blood of cancer patients shows a correlation between VEGF-A and MMP-9 levels before treatment and divergent changes after surgical vs. conservative therapy

Anti-angiogenic therapies are currently in cancer clinical trials, but to date there are no established tests for evaluating the angiogenic status of a patient. We measured 11 circulating angiogenesis-associated molecules in cancer patients before and after local treatment. The purpose of our study was to screen for possible relationships among the different molecules and between individual molecules and tumor burden. We measured VEGF-A, PlGF, SCF, MMP-9, EDB+ -fibronectin, sVEGFR-2, sVEGFR-1, salphaVbeta3, sTie-2, IL-8 and CRP in the blood of 22 healthy volunteers, 17 early breast, 17 early colorectal, and 8 advanced sarcoma/melanoma cancer patients. Breast cancer patients had elevated levels of VEGF-A and sTie-2, colorectal cancer patients of VEGF-A, MMP-9, sTie-2, IL-8 and CRP, and melanoma/sarcoma patients of sVEGFR-1. salphaVbeta3 was decreased in colorectal cancer patients. A correlation between VEGF-A and MMP-9 was found. After tumor removal, MMP-9 and salphaVbeta3 significantly decreased in breast and CRP in colorectal cancer, whereas sVEGFR-1 increased in colorectal cancer patients. In sarcoma/melanoma patients treated regionally with TNF and chemotherapy we observed a rise in VEGF-A, SCF, VEGFR-2, MMP-9, Tie-2 and CRP, a correlation between CRP and IL-8, and a decreased in sVEGFR-1 levels. In conclusion, among all factors measured, only VEGF-A and MMP-9 consistently correlated to each other, elevated CRP levels were associated with tumor burden, whereas sVEGF-R1 increased after tumor removal in colorectal cancer. Treatment with chemotherapy and TNF induced changes consistent with an angiogenic switch. These results warrant a prospective study to compare the effect of surgical tumor removal vs. chemotherapy on some of these markers and to evaluate their prognostic/predictive value.