The Cost of Seasonal Influenza: A Systematic Literature Review on the Humanistic and Economic Burden of Influenza in Older (≥ 65 Years Old) Adults

INTRODUCTION

Adults aged ≥ 65 years contribute a large proportion of influenza-related hospitalizations and deaths due to increased risk of complications, which result in high medical costs and reduced health-related quality of life (HRQoL). Although seasonal influenza vaccines are recommended for older adults, the effectiveness of current vaccines is dependent on several factors including strain matching and recipient demographic factors. This systemic literature review aimed to explore the economic and humanistic burden of influenza in adults aged ≥ 65 years.

METHODS

An electronic database search was conducted to identify studies assessing the economic and humanistic burden of influenza, including influenza symptoms that impact the HRQoL and patient-related outcomes in adults aged ≥ 65 years. Studies were to be published in English and conducted in Germany, France, Spain, and Italy, the UK, USA, Canada, China, Japan, Brazil, Saudi Arabia, and South Africa.

RESULTS

Thirty-eight studies reported on the economic and humanistic burden of influenza in adults aged ≥ 65 years. Higher direct costs were reported for people at increased risk of influenza-related complications compared to those at low risk. Lower influenza-related total costs were found in those vaccinated with adjuvanted inactivated trivalent influenza vaccine (aTIV) compared to high-dose trivalent influenza vaccine (TIV-HD). Older age was associated with an increased occurrence and longer duration of certain influenza symptoms.

CONCLUSION

Despite the limited data identified, results show that influenza exerts a high humanistic and economic burden in older adults. Further research is required to confirm findings and to identify the unmet needs of current vaccines.

Randomized phase-III study of low-dose cytarabine and etoposide + /- all-trans retinoic acid in older unfit patients with NPM1-mutated acute myeloid leukemia

The aim of this randomized clinical trial was to evaluate the impact of all-trans retinoic acid (ATRA) in combination with non-intensive chemotherapy in older unfit patients (> 60 years) with newly diagnosed NPM1-mutated acute myeloid leukemia. Patients were randomized (1:1) to low-dose chemotherapy with or without open-label ATRA 45 mg/m2, days 8-28; the dose of ATRA was reduced to 45 mg/m2, days 8-10 and 15 mg/m2, days 11-28 after 75 patients due to toxicity. Up to 6 cycles of cytarabine 20 mg/day s.c., bid, days 1-7 and etoposide 100 mg/day, p.o. or i.v., days 1-3 with (ATRA) or without ATRA (CONTROL) were intended. The primary endpoint was overall survival (OS). Between May 2011 and September 2016, 144 patients (median age, 77 years; range, 64-92 years) were randomized (72, CONTROL; 72, ATRA). Baseline characteristics were balanced between the two study arms. The median number of treatment cycles was 2 in ATRA and 2.5 in CONTROL. OS was significantly shorter in the ATRA compared to the CONTROL arm (p = 0.023; median OS: 5 months versus 9.2 months, 2-years OS rate: 7% versus 10%, respectively). Rates of CR/CRi were not different between treatment arms; infections were more common in ATRA beyond treatment cycle one. The addition of ATRA to low-dose cytarabine plus etoposide in an older, unfit patient population was not beneficial, but rather led to an inferior outcome.The clinical trial is registered at clinicaltrialsregister.eu (EudraCT Number: 2010-023409-37, first posted 14/12/2010).

High Clinical Burden of Influenza Disease in Adults Aged ≥ 65 Years: Can We Do Better? A Systematic Literature Review

INTRODUCTION

Influenza is a respiratory infection associated with a significant clinical burden globally. Adults aged ≥ 65 years are at increased risk of severe influenza-related symptoms and complications due to chronic comorbidity and immunosenescence. Annual influenza vaccination is recommended; however, current influenza vaccines confer suboptimal protection, in part due to antigen mismatch and poor durability. This systematic literature review characterizes the global clinical burden of seasonal influenza among adults aged ≥ 65 years.

METHODS

An electronic database search was conducted and supplemented with a conference abstract search. Included studies described clinical outcomes in the ≥ 65 years population across several global regions and were published in English between January 1, 2012 and February 9, 2022.

RESULTS

Ninety-nine publications were included (accounting for > 156,198,287 total participants globally). Clinical burden was evident across regions, with most studies conducted in the USA and Europe. Risk of influenza-associated hospitalization increased with age, particularly in those aged ≥ 65 years living in long-term care facilities, with underlying comorbidities, and infected with A(H3N2) strains. Seasons dominated by circulating A(H3N2) strains saw increased risk of influenza-associated hospitalization, intensive care unit admission, and mortality within the ≥ 65 years population. Seasonal differences in clinical burden were linked to differences in circulating strains.

CONCLUSIONS

Influenza exerts a considerable burden on adults aged ≥ 65 years and healthcare systems, with high incidence of hospitalization and mortality. Substantial influenza-associated clinical burden persists despite increasing vaccination coverage among adults aged ≥ 65 years across regions included in this review, which suggests limited effectiveness of currently available seasonal influenza vaccines. To reduce influenza-associated clinical burden, influenza vaccine effectiveness must be improved. Next generation vaccine production using mRNA technology has demonstrated high effectiveness against another respiratory virus-SARS-CoV-2-and may overcome the practical limitations associated with traditional influenza vaccine production.

Managing hematological cancer patients during the COVID-19 pandemic: an ESMO-EHA Interdisciplinary Expert Consensus

BACKGROUND

The COVID-19 pandemic has created enormous challenges for the clinical management of patients with hematological malignancies (HMs), raising questions about the optimal care of this patient group.

METHODS

This consensus manuscript aims at discussing clinical evidence and providing expert advice on statements related to the management of HMs in the COVID-19 pandemic. For this purpose, an international consortium was established including a steering committee, which prepared six working packages addressing significant clinical questions from the COVID-19 diagnosis, treatment, and mitigation strategies to specific HMs management in the pandemic. During a virtual consensus meeting, including global experts and lead by the European Society for Medical Oncology and the European Hematology Association, statements were discussed and voted upon. When a consensus could not be reached, the panel revised statements to develop consensual clinical guidance.

RESULTS AND CONCLUSION

The expert panel agreed on 33 statements, reflecting a consensus, which will guide clinical decision making for patients with hematological neoplasms during the COVID-19 pandemic.

Fermentative Production of N-Alkylated Glycine Derivatives by Recombinant Corynebacterium glutamicum Using a Mutant of Imine Reductase DpkA From Pseudomonas putida

Sarcosine, an N-methylated amino acid, shows potential as antipsychotic, and serves as building block for peptide-based drugs, and acts as detergent when acetylated. N-methylated amino acids are mainly produced chemically or by biocatalysis, with either low yields or high costs for co-factor regeneration. Corynebacterium glutamicum, which is used for the industrial production of amino acids for decades, has recently been engineered for production of N-methyl-L-alanine and sarcosine. Heterologous expression of dpkA in a C. glutamicum strain engineered for glyoxylate overproduction enabled fermentative production of sarcosine from sugars and monomethylamine. Here, mutation of an amino acyl residue in the substrate binding site of DpkA (DpkAF117L) led to an increased specific activity for reductive alkylamination of glyoxylate using monomethylamine and monoethylamine as substrates. Introduction of DpkAF117L into the production strain accelerated the production of sarcosine and a volumetric productivity of 0.16 g L-1 h-1 could be attained. Using monoethylamine as substrate, we demonstrated N-ethylglycine production with a volumetric productivity of 0.11 g L-1 h-1, which to the best of our knowledge is the first report of its fermentative production. Subsequently, the feasibility of using rice straw hydrolysate as alternative carbon source was tested and production of N-ethylglycine to a titer of 1.6 g L-1 after 60 h of fed-batch bioreactor cultivation could be attained.

Randomized phase-II trial evaluating induction therapy with idarubicin and etoposide plus sequential or concurrent azacitidine and maintenance therapy with azacitidine

The aim of this randomized phase-II study was to evaluate the effect of substituting cytarabine by azacitidine in intensive induction therapy of patients with acute myeloid leukemia (AML). Patients were randomized to four induction schedules for two cycles: STANDARD (idarubicin, cytarabine, etoposide); and azacitidine given prior (PRIOR), concurrently (CONCURRENT), or after (AFTER) therapy with idarubicin and etoposide. Consolidation therapy consisted of allogeneic hematopoietic-cell transplantation or three courses of high-dose cytarabine followed by 2-year maintenance therapy with azacitidine in the azacitidine-arms. AML with CBFB-MYH11, RUNX1-RUNX1T1, mutated NPM1, and FLT3-ITD were excluded and accrued to genotype-specific trials. The primary end point was response to induction therapy. The statistical design was based on an optimal two-stage design applied for each arm separately. During the first stage, 104 patients (median age 62.6, range 18-82 years) were randomized; the study arms PRIOR and CONCURRENT were terminated early due to inefficacy. After randomization of 268 patients, all azacitidine-containing arms showed inferior response rates compared to STANDARD. Event-free and overall survival were significantly inferior in the azacitidine-containing arms compared to the standard arm (p < 0.001 and p = 0.03, respectively). The data from this trial do not support the substitution of cytarabine by azacitidine in intensive induction therapy.

Xylose as preferred substrate for sarcosine production by recombinant Corynebacterium glutamicum

The aim of this work was to study the fermentative production of the N-methylated amino acid sarcosine by C. glutamicum. Characterization of the imine reductase DpkA from Pseudomonas putida revealed that it catalyses N-methylamination of glyoxylate to sarcosine. Heterologous expression of dpkA in a C. glutamicum strain engineered for glyoxylate overproduction enabled fermentative production of sarcosine from sugars and monomethylamine. Glucose-based fermentation reached sarcosine production titers of 2.4 ± 0.1 g L^-1. Sarcosine production based on the second generation feedstocks xylose and arabinose led to higher product titers of 2.7 ± 0.1 g L^-1 and 3.4 ± 0.3 g L^-1, respectively, than glucose-based production. Optimization of production conditions with xylose and potassium acetate blends increased sarcosine titers to 8.7 ± 0.2 g L^-1 with a yield of 0.25 g g^-1. This is the first example in which a C. glutamicum process using lignocellulosic pentoses is superior to glucose-based production.

Epidemiological, genetic, and clinical characterization by age of newly diagnosed acute myeloid leukemia based on an academic population-based registry study (AMLSG BiO)

We describe genetic and clinical characteristics of acute myeloid leukemia (AML) patients according to age from an academic population-based registry. Adult patients with newly diagnosed AML at 63 centers in Germany and Austria were followed within the AMLSG BiO registry (NCT01252485). Between January 1, 2012, and December 31, 2014, data of 3525 patients with AML (45% women) were collected. The median age was 65 years (range 18-94). The comparison of age-specific AML incidence rates with epidemiological cancer registries revealed excellent coverage in patients < 70 years old and good coverage up to the age of 80. The distribution according to the European LeukemiaNet (ELN) risk categorization from 2010 was 20% favorable, 31% intermediate-1, 28% intermediate-2, and 21% adverse. With increasing age, the relative but not the absolute prevalence of patients with ELN favorable and intermediate-1 risk (p < 0.001), with activating FLT3 mutations (p < 0.001), with ECOG performance status < 2 (p < 0.001), and with HCT-CI comorbidity index < 3 (p < 0.001) decreased. Regarding treatment, obesity and favorable risk were associated with an intensive treatment, whereas adverse risk, higher age, and comorbidity index > 0 were associated with non-intensive treatment or best supportive care. The AMLSG BiO registry provides reliable population-based distributions of genetic, clinical, and treatment characteristics according to age.

Meis2 as a critical player in MN1-induced leukemia

Meningioma 1 (MN1) is an independent prognostic marker for normal karyotype acute myeloid leukemia (AML), with high expression linked to all-trans retinoic acid resistance and poor survival. MN1 is also a potent and sufficient oncogene in murine leukemia models, strongly dependent on the MEIS1/AbdB-like HOX protein complex to transform common myeloid progenitors, block myeloid differentiation, and promote leukemic stem cell self-renewal. To identify key genes and pathways underlying leukemic activity, we functionally assessed MN1 cell phenotypic heterogeneity, revealing leukemic and non-leukemic subsets. Using gene expression profiling of these subsets combined with previously published comparisons of full-length MN1 and mutants with varying leukemogenic activity, we identified candidate genes critical to leukemia. Functional analysis identified Hlf and Hoxa9 as critical to MN1 in vitro proliferation, self-renewal and impaired myeloid differentiation. Although critical to transformation, Meis1 knockdown had little impact on these properties in vitro. However, we identified Meis2 as critical to MN1-induced leukemia, with essential roles in proliferation, self-renewal, impairment of differentiation and disease progression in vitro and in vivo. Here, we provide evidence of phenotypic and functional hierarchy in MN1-induced leukemic cells, characterise contributions of Hlf, Hoxa9 and Meis1 to in vitro leukemic properties, and reveal Meis2 as a novel player in MN1-induced leukemogenesis.

DNMT3A mutant transcript levels persist in remission and do not predict outcome in patients with acute myeloid leukemia

We investigated the prognostic impact of minimal residual disease (MRD) monitoring in acute myeloid leukemia patients harboring DNA methyltransferase 3A-R882H/-R882C mutations (DNMT3A^mut). MRD was determined by real-time quantitative PCR (RQ-PCR) in 1494 samples of 181 DNMT3A^mut patients. At the time of diagnosis, DNMT3A^mut transcript levels did not correlate with presenting clinical characteristics and concurrent gene mutations as well as the survival end points. In Cox regression analyses, bone marrow (BM) DNMT3A^mut transcript levels (log10-transformed continuous variable) were not associated with the rate of relapse or death. DNMT3A^mut transcript levels were significantly higher in BM than in blood after induction I (P=0.01), induction II (P=0.05), consolidation I (P=0.004) and consolidation II (P=0.008). With regard to the clinically relevant MRD time points, after two cycles of induction and at the end of therapy, DNMT3A^mut transcript levels had no impact on the end point remission duration and overall survival. Of note, only a minority of the patients achieved RQ-PCR negativity, whereas most had constantly high DNMT3A^mut transcript levels, a finding which is consistent with the persistence of clonal hematopoiesis in hematological remission.

Acute myeloid leukemia derived from lympho-myeloid clonal hematopoiesis

We studied acute myeloid leukemia (AML) patients with lympho-myeloid clonal hematopoiesis (LM-CH), defined by the presence of DNA methyltransferase 3A (DNMT3A) mutations in both the myeloid and lymphoid T-cell compartment. Diagnostic, complete remission (CR) and relapse samples were sequenced for 34 leukemia-related genes in 171 DNMT3A mutated adult AML patients. AML with LM-CH was found in 40 patients (23%) and was associated with clonal hematopoiesis of indeterminate potential years before AML, older age, secondary AML and more frequent MDS-type co-mutations (TET2, RUNX1 and EZH2). In 82% of AML patients with LM-CH, the preleukemic clone was refractory to chemotherapy and was the founding clone for relapse. Both LM-CH and non-LM-CH MRD-positive AML patients who achieved CR had a high risk of relapse after 10 years (75% and 75%, respectively) compared with patients without clonal hematopoiesis in CR with negative MRD (27% relapse rate). Long-term survival of patients with LM-CH was only seen after allogeneic hematopoietic stem cell transplantation (HSCT). We define AML patients with LM-CH as a distinct high-risk group of AML patients that can be identified at diagnosis through mutation analysis in T cells and should be considered for HSCT.

Comprehensive mutational analysis of primary and relapse acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by differentiation block at the promyelocyte stage. Besides the presence of chromosomal rearrangement t(15;17), leading to the formation of PML-RARA (promyelocytic leukemia-retinoic acid receptor alpha) fusion, other genetic alterations have also been implicated in APL. Here, we performed comprehensive mutational analysis of primary and relapse APL to identify somatic alterations, which cooperate with PML-RARA in the pathogenesis of APL. We explored the mutational landscape using whole-exome (n=12) and subsequent targeted sequencing of 398 genes in 153 primary and 69 relapse APL. Both primary and relapse APL harbored an average of eight non-silent somatic mutations per exome. We observed recurrent alterations of FLT3, WT1, NRAS and KRAS in the newly diagnosed APL, whereas mutations in other genes commonly mutated in myeloid leukemia were rarely detected. The molecular signature of APL relapse was characterized by emergence of frequent mutations in PML and RARA genes. Our sequencing data also demonstrates incidence of loss-of-function mutations in previously unidentified genes, ARID1B and ARID1A, both of which encode for key components of the SWI/SNF complex. We show that knockdown of ARID1B in APL cell line, NB4, results in large-scale activation of gene expression and reduced in vitro differentiation potential.

[Myelodysplastic syndromes]

Myelodysplastic syndrome (MDS) encompasses a heterogeneous group of diseases originating in hematopoietic stem cells and is characterized by inefficient hematopoiesis and dysplastic changes in the bone marrow. In peripheral blood patients show anemia (mostly macrocytic), frequently accompanied by neutropenia and thrombocytopenia. Thus, clinically the patients suffer from fatigue (anemia), increased bleeding (thrombocytopenia) and infectious complications (neutropenia). Approximately one quarter of MDS patients develop acute myeloid leukemia (AML) in the course of the disease, which is characterized by a 20 % or more increase of blasts in the bone marrow. The estimated overall survival as well as the risk for AML transformation can be calculated with the international prognostic scoring system (IPSS) as well as the revised IPSS score (IPSS-R). Novel sequencing methods (e.g. next generation sequencing) allow the detection of recurrent gene mutations in MDS patients. Genes of the splicing machinery as well as genes involved in epigenetic regulation (e.g. ASXL1 and TET2) are most frequently mutated in MDS. Therapy is selected based on the patient risk profile (IPSS). Allogeneic stem cell transplantation is a curative approach for high risk patients (i.e. IPSS int-2 and higher) with a good performance status and a biological age below 70 years. Otherwise, high risk patients are treated with demethylating agents (e.g. decitabine and azacitidine). Low risk patients (IPSS low and int-1) mainly receive supportive therapy including iron chelation. An exceptional position is presented by MDS with an isolated 5q deletion as it can be treated with lenalidomide with good success. Enrolling patients in clinical trials is strongly recommended to improve the prospects of this disease.

Constitutive IRF8 expression inhibits AML by activation of repressed immune response signaling

Myeloid differentiation is blocked in acute myeloid leukemia (AML), but the molecular mechanisms are not well characterized. Meningioma 1 (MN1) is overexpressed in AML patients and confers resistance to all-trans retinoic acid-induced differentiation. To understand the role of MN1 as a transcriptional regulator in myeloid differentiation, we fused transcriptional activation (VP16) or repression (M33) domains with MN1 and characterized these cells in vivo. Transcriptional activation of MN1 target genes induced myeloproliferative disease with long latency and differentiation potential to mature neutrophils. A large proportion of differentially expressed genes between leukemic MN1 and differentiation-permissive MN1VP16 cells belonged to the immune response pathway like interferon-response factor (Irf) 8 and Ccl9. As MN1 is a cofactor of MEIS1 and retinoic acid receptor alpha (RARA), we compared chromatin occupancy between these genes. Immune response genes that were upregulated in MN1VP16 cells were co-targeted by MN1 and MEIS1, but not RARA, suggesting that myeloid differentiation is blocked through transcriptional repression of shared target genes of MN1 and MEIS1. Constitutive expression of Irf8 or its target gene Ccl9 identified these genes as potent inhibitors of murine and human leukemias in vivo. Our data show that MN1 prevents activation of the immune response pathway, and suggest restoration of IRF8 signaling as therapeutic target in AML.

P-glycoprotein-associated resistance to taxol and taxotere and its reversal by dexniguldipine-HCl, dexverapamil-HCl, or cyclosporin A

A series of different human MDR (multidrug-resistant) cell lines including a HeLa-MDR1 transfectant which exhibit high overexpression of the MDR1/P-glycoprotein gene, but no enhanced expression of the MRP (multidrug resistance associated protein) gene, showed different ratios of relative resistances to the taxanes taxol and taxotere. Using these cell lines the chemosensitizing efficacies of several structurally different chemosensitizers, i.e. the dihydropyridine dexniguldipine-HC1 (B8509-035), its main pyridine metabolite M1 (B8909-008), the cyclic peptide cyclosporin A, or the phenylalkylamine dexverapamil-HCl, were examined applying a 72 h tetrazolium based colorimetric MTT-assay, or a 96 h sulforhodamine B assay. Remarkably, we observed in some instances that the modulating efficacy of a particular chemosensitizer was strongly dependent on the cell line used for experimentation. Thus, dexniguldipine-HCl efficiently modulated taxane resistances of the ovarian carcinoma MDR cell line 2780AD in the submicromolar concentration range, whereas cyclosporin A and the other chemosensitizers were rather ineffective. Dexniguldipine-HCl or cyclosporin A, however, both showed a similarly strong modulating activity on the HeLa-MDR1 transfectant in clear contrast to the effects observed using the pyridine B8909-008, or dexverapamil-HCl, respectively, at the same final concentrations. Our results point to additional, as yet unidentified factors beyond the expression levels of P-glycoprotein which could contribute to the susceptibility of MDR cells to a combined treatment using taxanes and different chemosensitizing compounds. This result appears to be important considering the clinical application of chemosensitizers for combination therapy of tumors of different origin.

[Current treatment options in acute myeloid leukemia]

Genetic aberrations form the basis for diagnostic classification of patients with acute myeloid leukemia (AML) according to the World Health Organization (WHO) classification. Moreover, these aberrations predict response to induction chemotherapy, relapse-free survival, and overall survival of patients with AML. Understanding the pathogenetic role of cytogenetic and molecular changes has led to the development of targeted treatment strategies that require rapid diagnostic assessment of the genetic profile of each patient to select the best treatment available.

[Determination of renal carcinoma progression in small animals by means of flat-panel volumetric computer tomography]

PURPOSE

We investigated the feasibility of using flat panel volumetric computer tomography (fpVCT) for the detection of orthotopically implanted renal carcinomas in nude mice.

MATERIALS AND METHODS

One million renal cell carcinoma cells [A-498 line (Braunschweig, Germany), in 0.2 ml phosphate-buffered solution (PBS), pH 7.4] were injected into the left kidney of each of the eight nude mice. Each mouse was imaged twice (12 and 16 weeks after implantation) with fpVCT (GE prototype with circular gantry with two 1024 x 1024, 200 microm pixel size, aSi/CsI flat panel detector) after injection of 200 microl contrast medium to check for tumour spread. After 16 weeks the mice were killed and dissected, and the imaging findings in liver, kidneys and lung were compared with the macroscopic findings.

RESULTS

No local evidence of tumour or of metastatic spread was seen on fpVCT after 12 weeks in any of the mice. After 16 weeks fpVCT revealed tumour growth in 6 of the 16 kidneys. Two mice had each developed a multifocal renal cell carcinoma and one mouse, a bilateral renal tumour manifestation. In one mouse liver metastases were seen. The fpVCT findings correlated well with the observations recorded in the pathological examination.

CONCLUSION

fpVCT is an innovative and noninvasive imaging procedure that can be used for longitudinal investigation of tumour progression following orthotopic implantation of renal cell carcinoma to small animals. The use of a system of this kind will make a decisive contribution to reducing the number of animals used in experimental test projects.

[Forms of urinary diversion--methods and imaging findings]

After cystectomy two principal types of urinary diversion are used for the surgical reconstruction of the urinary tract: incontinent and continent. In the continent type of urinary diversion, a differentiation must be made between those with and without catheterization for voiding. Besides urothelial cancer other reasons for urinary diversion include neurogenic bladder palsy (connatal or acquired) due to meningomyelocele or connatal diseases like bladder exstrophy. The main objective of the clinical urologist when selecting urinary diversion are to achieve continence and to preserve upper urinary tract function. Knowledge of the different forms of urinary diversion is critical for the exact interpretation of the images. This review presents the typical imaging techniques after a description of the basic surgical features of urinary diversion. CT urography and MR urography are becoming increasingly important as further imaging tools for controlling urinary diversions.

Consensus guidelines for microarray gene expression analyses in leukemia from three European leukemia networks

A plethora of studies have documented that gene expression profiling using DNA microarrays for various types of hematological malignancies provides novel information, which may have diagnostic and prognostic implications. However, to successfully use microarrays for this purpose, the quality and reproducibility of the whole procedure need to be guaranteed. Critical steps of the method are handling, processing and storage of the leukemic sample, purification of tumor cells (or lack thereof), RNA extraction methods, quality control of RNA, labeling techniques, hybridization, washing, scanning, spot filtering, normalization and initial interpretation, and finally the biostatistical analysis. These items have been extensively discussed and evaluated in different multi-center quality rounds within the three networks, that is, I-BFM-SG, the German Competence Network 'Acute and Chronic Leukemias' and the European LeukemiaNet. Based on the exchange of knowledge and experience between the three networks over the last few years, we have formulated guidelines for performing microarray experiments in leukemia. We confine ourselves to leukemias, but many of these requirements also apply to lymphomas or other clinical samples, including solid tumors.

Extraperitoneal bladder leakage after provision of topical negative therapy: a case report

Following surgical excision of a prevesical haematoma, topical negative pressure was used to promote wound closure. The development of a vesicocutaneous fistula at the incision site may have been an indirect complication of the therapy.

Expression of gastrin releasing Peptide receptor in renal cell carcinomas: a potential function for the regulation of neoangiogenesis and microvascular perfusion

PURPOSE

Gastrin releasing peptide (GRP) is a growth factor for renal cell carcinoma (RCC) and it has vasoactive properties. Blockade of GRP receptor inhibits the growth of GRP receptor positive and negative tumors in nude mice, suggesting GRP effects other than those related to tumor epithelium. Therefore, in this study we analyzed the effects of GRP receptor blockade on neoangiogenesis in RCC.

MATERIALS AND METHODS

GRP receptor expression was determined in human RCC and corresponding normal tissue by real-time reverse transcriptase-polymerase chain reaction, immunohistochemistry and confocal laser scanning microscopy. Multicellular spheroids of the A498 RCC line were implanted into dorsal skin fold chambers of athymic nude mice. Neoangiogenesis was measured by intravital microscopy after blockade of GRP receptors by the GRP antagonist RC-3095. The influence of GRP on vascular endothelial growth factor secretion in A498 cells was studied in vitro.

RESULTS

GRP receptor expression was immunolocalized in tumor cells and microvessels. Implanted tumor cell spheroids and spheroid microvessels of the chamber also expressed GRP receptors. Spheroid neoangiogenesis was significantly inhibited by RC-3095 when given immediately after spheroid implantation. Vascular endothelial growth factor secretion of A498 cells was not affected by GRP.

CONCLUSIONS

RCC angiogenesis is sensitive to GRP receptor blockade. Therefore, GRP receptors may not only stimulate tumor cell proliferation, but also affect tumor microcirculation.

Comparative analysis of COX-2, vascular endothelial growth factor and microvessel density in human renal cell carcinomas

AIMS

Cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) are frequently up-regulated in malignant tumours and play a role in proliferation, apoptosis, angiogenesis and tumour invasion. In the present study, the expression of COX-2 and VEGF in renal cell carcinoma (RCC) was analysed and correlated with the microvessel density (MVD).

METHODS AND RESULTS

COX-2 and VEGF were analysed by realtime reverse transcriptase-polymerase chain reaction and immunohistochemistry. The MVD was assessed by CD31 immunohistochemistry. The expression of COX-2 and VEGF was determined in the RCC cell lines A498 and Caki-1 under short-term hypoxia and in multicellular tumour cell aggregates. COX-2 was expressed in RCC by tumour epithelia, endothelia and macrophages in areas of cystic tumour regression and tumour necrosis. COX-2 protein in RCC was not altered in comparison with normal renal tissue. VEGF mRNA was up-regulated in RCC and positively correlated with MVD. RCC with high up-regulation of VEGF mRNA showed weak intracytoplasmic expression of VEGF in tumour cells. Intracytoplasmic VEGF protein expression was negatively correlated with MVD. In RCC with necrosis the MVD was reduced in comparison with RCC without necrosis. A498 RCC cells down-regulated COX-2 and up-regulated VEGF under conditions of hypoxia. In Caki-1 cells COX-2 expression remained stable, whereas VEGF was significantly up-regulated. In multicellular A498 cell aggregates COX-2 and VEGF were up-regulated centrally, whereas no gradient was found in Caki-1 cells.

CONCLUSIONS

COX-2 and VEGF are potential therapeutic targets because COX-2 and VEGF are expressed in RCC and associated cell populations such as endothelia and monocytes/macrophages.

Impact of vasoactive intestinal polypeptide and gastrin-releasing peptide on small bowel microcirculation and mucosal injury after hepatic ischemia/reperfusion in rats

BACKGROUND AND AIMS

Alterations in microvascular perfusion of the intestine after hepatic ischemia/reperfusion have been suggested as an important cause of postoperative septic complications. We therefore investigated small bowel microcirculation and mucosal injury after liver ischemia/reperfusion in a rat model. Furthermore, we analyzed the effects of the regulatory peptides vasoactive intestinal polypeptide and gastrin-releasing peptide for their splanchnic vasoactivity.

METHODS

Hepatic ischemia was induced by clamping of the left hepatic artery and vein for 40 min, followed by 60 min of reperfusion. The control group was treated similarly, but without clamping of the liver vessels. Ten minutes after clamping of the hepatic vessels, vasoactive intestinal polypeptide or gastrin-releasing peptide, respectively, were continuously infused intravenously in the experimental groups. Small bowel microcirculation and mucosal injury were assessed using intravital microscopy and the Chiu-score, respectively.

RESULTS

The functional capillary density of the small intestine following ischemia and reperfusion of the left hepatic lobe significantly decreased compared to normal controls in both the mucosa and the smooth intestinal muscle. Red blood cell velocity decreased, whereas leukocyte-endothelium adherence, stasis index and the mucosal injury score increased. Administration of vasoactive intestinal polypeptide resulted in an increase of functional capillary density in the mucosa and of the red blood cell velocity and a decrease in the stasis index. The mucosal injury score was significantly higher in reperfused animals without treatment. The application of gastrin-releasing peptide resulted in an isolated increase of the red blood cell velocity. Leukocyte adherences could not be altered by the regulatory peptides.

CONCLUSION

We conclude that hepatic ischemia/reperfusion injury leads to significant alterations of small bowel microcirculation and mucosal injury. Vasoactive intestinal polypeptide and gastrin-releasing peptide attenuate the damage in a different manner.