Metabolic and physiologic effects of an endotoxin challenge in healthy obese subjects

Rapport de synthèseEnjeux et contexteL'épidémie d'obésité est un enjeu majeur de santé publique, et l'augmentation parallèle du nombre de patients obèses admis aux soins intensifs appelle à une meilleure connaissance des spécificités de la physiopathologie de cette population. De nombreuses anomalies physiologiques associées à l'obésité sont connues, notamment une inflammation sub-clinique chronique. Cependant, les connaissances concernant la réponse inflammatoire lors d'une agression des sujets obèses sont pour l'heure assez limitées. Bien que les réponses inflammatoires in vitro du tissu adipeux soient augmentées, les données in vivo sont pour l'instant non-conclusives.L'injection intraveineuse d'endotoxine est un test hautement reproductible provoquant une inflammation de durée limitée. Il s'agit d'un test validé pour l'étude in vivo lors des réponses inflammatoires. L'endotoxine est un lipopolysaccharide contenu dans les membranes externes des bactéries gram- négatives, notamment de E.Coli. Notre équipe possède une expérience de ces tests avec endotoxine acquise lors d'une série de recherches sur les propriétés modulatrices de l'inflammation des acides gras polyinsaturés oméga-3.Lors de l'élaboration de ce projet, la réponse du sujet obèse à l'endotoxine restait méconnue. L'objectif de l'essai est d'étudier les spécificités des réponses à l'endotoxine, notre hypothèse étant que les réponses physiologiques, métaboliques et endocrines sont amplifiées chez cette catégorie de sujets.Présentation de l'étudeAfin de tester notre hypothèse, nous avons conçu une étude prospective randomisée, avec 2 procédures (injection d'endotoxine vs de placebo) en cross-over: le protocole d'investigation durait chaque fois 8h. Huit volontaires obèses grade I (BMI médian de 33.8 kg/m2) sans morbidité ont été enrôlés. Les variables étudiées étaient: les fréquences cardiaque et respiratoire, la température, la tension artérielle, le débit cardiaque et la saturation veineuse en oxygène, ainsi qu'une calorimétrie indirecte en continu. Les symptômes tels que myalgie, céphalée et nausée ont également été consignés. Des marqueurs hormonaux et inflammatoires (Cortisol, ACTH, catécholamines, insuline, glucose, glucagon, leptine, TNF-alpha, IL-6 et CRP) ont été dosés de manière répétée.Statistiques : Pour limiter les effets de la variabilité inter-individuelle et permettre une comparaison des réponses, le calcul des aires sous la courbe (AUC) selon la méthode trapézoïdale a été utilisé. Le groupe étudié étant de « petite taille », bien ceci soit habituel pour les études de physiologie, et les réponses n'étant pas normalement distribuées, des tests non-paramétriques ont été appliqués : nous savons que la puissance statistique de notre étude est limitée. Considérant les désagréments majeurs (bien que rapidement réversibles) vécus par les volontaires soumis à des infections d'endotoxine, leurs réponses ont été comparées de manières qualitative à celles des non-obèse mesurés lors de précédentes études pour éviter de répliquer ces expériences désagréables et parfaitement prévisibles.Les résultats de cette étude sont parfaitement superposables à celles trouvées chez les sujets de BMI normal, invalidant notre hypothèse de départ d'une éventuelle réponse exacerbée.Conclusions et perspectivesCette étude est la première publication concernant la réponse du patient obèse à un test d'endotoxine. La similitude des résultats chez les patients obèses et non-obèses montre que l'obésité n'est pas en soi un facteur augmentant les réponses inflammatoires.Ces résultats concernent des sujets obèses sains et ne peuvent pas être extrapolés aux sujets obèses avec comorbidités, appelant à de futures investigations chez cette catégorie de patients.

Prevalence of anaemia in inflammatory bowel disease in Switzerland: a cross-sectional study in patients from private practices and university hospitals.

BACKGROUND: Anaemia represents a common complication of inflammatory bowel disease (IBD). Most studies on anaemia in IBD patients have been performed in tertiary referral centres (RC) and data from gastroenterologic practices (GP) are lacking. We investigated the frequency and severity of anaemia in IBD patients from tertiary referral centres and gastroenterologic practices compared to the general population. METHODS: Data were acquired from patients included in the Swiss IBD Cohort Study. IBD activity was evaluated by CDAI and modified Truelove and Witts severity index (MTWSI). Anaemia was defined as haemoglobin ≤120g/L in women and ≤130g/L in men. RESULTS: 125 patients from RC (66 with Crohn's disease (CD) and 59 with ulcerative colitis (UC)) and 116 patients from GP (71 CD and 45 UC) were included and compared to 6074 blood donors. Anaemia was found in 21.2% (51/241) of the IBD patients and more frequently in patients from RC as compared to GP and healthy controls (28.8% vs. 12.9% vs. 3.4%; P<0.01). IBD patients from RC suffered more frequently from active disease compared to IBD patients in GP (36% vs. 23%, P=0.032). Supplementation therapy (iron, vitamin B12, folic acid) was performed in 40% of anaemic IBD patients in GP as compared to 43% in RC. CONCLUSIONS: Anaemia is a common complication in patients with IBD and significantly more prevalent in patients from referral centres as compared to patients from gastroenterologic practices. Physicians treating IBD patients should pay attention to the presence of anaemia and ensure sufficient supplementation therapy.

Assessment of adipose tissue metabolism by means of subcutaneous mircrodialysis in patients with sepsis of circulatory failure

Summary: To evaluate the role of adipose tissue in the metabolic stress response of critically ill patients, the release of glycerol and lactate by subcutaneous adipose tissue was assessed by means of microdialysis in patients with sepsis or circulatory failure and in healthy subjects. Patients with sepsis had lower plasma free fatty acid concentrations and non-significant elevations of plasma glycerol concentrations, but higher adipose-systemic glycerol concentrations gradients than healthy subjects or patients with circulatory failure, indicating a stimulation of subcutaneous adipose lipolysis. They also had a higher lipid oxidation. Lipid metabolism (adipose-systemic glycerol gradients, lipid oxidation) was not altered in patients with circulatory failure. These observations highlight major differences in lipolysis and lipid utilization between patients with sepsis and circulatory failure. Hyperlactataemia was present in both groups of patients, but the adipose-systemic lactate concentration gradient was not increased, indicating that lactate production by adipose tissue was not involved. This speaks against a role of adipose tissue in the development of hyperlactataemia in critically ill patients.

Cerebrospinal fluid biomarkers of central nervous system dysfunction in HIV-infected patients

Background :¦In addition to opportunistic infections of the central nervous system (CNS), which are due to immunosuppression related to HIV, the latter virus, itself, can cause neuropathological abnormalities which are located mainly in the basal ganglia and are characterized by microglial giant cells, reactive astrocytosis and perivascular monocytes. This HIV encephalopathy is characterized, clinically, by psycho-motor slowing, memory loss, difficulties in complex tasks requiring executive functions, as well as motor disorders .These cognitive deficits are grouped under the acronym of HIV-associated neurocognitive disorders (HAND). In fact, HANDs are subdivided in three groups in accordance with the severity of the cognitive impairment: Asymptomatic Neurocognitive Impairment (ANI), Mild/moderate Neurocognitive Disorders (MND) and HIV Associated Dementia (HAD).¦While the incidence of HAD has significantly decreased in the era of combined antiretrobiral therapy (cART), the prevalence of milder forms of HIV-associated neurocognitive disorders HAND seem to have increased. There are many potential reasons to explain this state of facts.¦An important question is to understand how soon the brain may be affected by HIV. Since performing a biopsy in these patients is not an issue, the study of the CSF represents the best available way to look at putative biomarkers of inflammation/neurodegeneration in the CNS. Here, we wanted to examined the putative usefulness of different biomarkers as early indicators of anti-retroviral failure at the level of the CNS. We chose to study the CSF levels of:¦Amyloid-β 1-42 (Aβ42), Tau total (tTau), phosphorylated Tau (pTau), Neopterin and S100-β.¦Indeed, these molecules are representative biomarkers of the major cells of the CNS, i.e. neurons,¦macrophages/microglia and astrocytes.¦To examine how sensitive were these CSF biomarkers to indicate CNS insults caused by HIV, we proposed to take advantage of the MOST (Monotherapy Switzerland/Thailand study) study, recently published in AIDS. Thus, we collaborated with Prof. Pietro Vernazza in St-Gall. In MOST study, monotherapy (MT) consisting in ritonavir-boosted lopinavir (LPV/r) was compared to continuous conventional antiretroviral therapy including several molecules, hereafter referred as CT¦Methods :We tested 61 cerebrospinal fluid (CSF) samples from 52 patients enrolled in MOST, including 34 CSF samples of CT and 27 of MT (mean duration on MT: 47+20 weeks) in patients who maintained full VL suppression in blood (<50cps/ml). Using enzyme-linked immunosorbent assay (ELISA), we determined the CSF concentration of S100-beta (astrocytosis), neopterin (microglia, inflammation), total Tau (tTau), phosphorylated Tau (pTau), and amyloid-beta 1-42 (Abeta), the latter three markers indicating neuronal damages. The CSF samples of 37 HIV-negative patients with Alzheimer dementia (AD) served as controls. Results are expressed in pg/ml and reported as median ± interquartile range. Mann Whitney-U test was used to compare the results of a given biomarker between two groups and the Fisher test to compare frequencies.¦Results: We found a higher concentration of S100-beta (570±1132) and neopterin (2.5±2.9) in the CSF of MT versus CT (0±532, p=0.002 and 1.2±2.5, p=0.058, respectively). A cutoff of 940 pg/ml for S100-beta allowed to discriminate MT (11 above versus 16 below) from CT (1 vs 33, p=0.0003). At a lesser extent, a cutoff of 11 pg/ml for neopterin separated MT (4 above versus 23) from CT (0 vs 34, p=0.034) (Figure).¦In AD, tTau was higher (270±414) and Abeta lower (234±328) than in CT (150±153, p=0.0078, and 466±489, p=0.007, respectively). Such as for CT, Abeta was lower in AD than in MT (390±412, p=0.01). However, contrasting with CT, the levels of tTau were not different between AD and MT (199±177, p=0.11). S100b (173±214; p=0.0006) and neopterin (1.1±0.9; p=0.0014) were lower in AD than MT.¦Conclusions: Despite full VL-suppression in blood, HIV monotherapy is sufficient to trigger inflammation and, especially, astrocytosis. CSF markers of patients on CT have the same profile as reported for healthy subjects, suggesting that CT permits a good control of HIV in the brain. Finally, the levels of tTau, which are relatively similar between AD and MT patients, suggest that neurons are damaged during monotherapy.

Osteoprotegerin and bone mineral density in hemodiafiltration patients.

A newly identified cytokine, osteoprotegerin (OPG) appears to be involved in the regulation of bone remodeling. In vitro studies suggest that OPG, a soluble member of the TNF receptor family of proteins, inhibits osteoclastogenesis by interrupting the intercellular signaling between osteoblastic stromal cells and osteoclast progenitors. As patients with chronic renal failure (CRF) often have renal osteodystrophy (ROD), we investigated the role of osteoprotegerin (OPG) in ROD, and investigated whether there was any relationship between serum OPG, intact parathyroid (PTH) (iPTH), vitamin D, and trabecular bone. Serum OPG combined with iPTH might be a useful tool in the noninvasive diagnosis of ROD, at least in cases in which the range of PTH values compromises reliable diagnosis. Thirty-six patients on maintenance hemodiafiltration (HDF) and a control group of 36 age and sex matched healthy subjects with no known metabolic bone disease were studied. The following assays were made on serum: iPTH, osteocalcin (BGP), bone alkaline phosphatase, 25(OH)-cholecalciferol, calcium, phosphate, OPG, IGF-1, estradiol, and free testosterone. Serum Ca++, P, B-ALP, BGP, IGF-1, iPTH, and OPG levels were significantly higher in HDF patients than in controls, while DXA measurements and quantitative ultrasound (QUS) parameters were significantly lower. On grouping patients according to their mean OPG levels, we observed significantly lower serum IGF-1, vitamin D3 concentrations, and lumbar spine and hip bone mineral density in the high OPG groups. No correlation was found between OPG and bone turnover markers, whereas a negative correlation was found between serum OPG and IGF-1 levels (r=-0.64, p=0.032). Serum iPTH concentrations were positively correlated with bone alkaline phosphatase (B-ALP) (r=0.69, p=0.038) and BGP (r=0.92, p<0.001). The findings made suggest that an increase in OPG levels may be a compensatory response to elevated bone loss. The low bone mineral density (BMD) levels found in the high OPG group might have been due to the significant decrease in serum IGF-1 and vitamin D3 observed. In conclusion, the findings made in the present study demonstrate that increased OPG in hemodiafiltration patients is only partly due to decreased renal clearance. As it may partly reflect a compensatory response to increased bone loss, this parameter might be helpful in the identification of patients with a marked reduction in trabecular BMD.

Endothelial dependant coronary vasoreactivity measured by 82Rb cardiac PET in obstructive sleep apnea patients before and after CPAP treatment

Introduction: Obstructive sleep apnea (OSA) is associated with an increased risk of cardiovascular diseases. Endothelial dysfunction is believed to be one of the pathophysiological mechanism underlying this association. Our aim was to compare endothelial dependent coronary vasoreactivity in obstructive sleep apnea (OSA) patients and controls by quantifying myocardial blood flow (MBF) response to cold pressure testing (CPT) with 82Rb cardiac PET/CT. Methods: Twenty-four OSA patients (2W/22M, mean age 58 yo, mean BMI 28.6 kg/m2) with an apnea-hypopnea index (AHI) >30/h and 9 healthy volunteers (AHI <10/h) underwent a full night sleep recording (PSG) and a dynamic 82 Rb cardiac PET/CT scan at rest, during CPT and adenosine stress. In OSA patients the same measurements (PSG and PET/CT) were respeated 6 weeks after initiating continuous positive airway pressure (autoCPAP) treatment. To reflect differences in baseline cardiac work, values were normalized according to ratepressure product (RPP). Results: At baseline, untreated OSA patients had a mean AHI of 48.8/h and showed a lower MBF response to CPT than controls (1.1 ± 0.2 mL/min/g vs. 1.3 ± 0.4 mL/min/g, P = 0.048). When treated with CPAP, CPT-MBF was not different between controls and well-treated OSA patients (1.2 ± 0.3 mL/min/g vs 1.3 ± 0.4 mL/min/g, P = 0.68), but it was significantly lower for insufficiently treated patients (n = 10) with a residual AHI >10/h (0.9 ± 0.2 mL/min/g vs 1.3 ± 0.4 mL/min/g, P = 0.03). There was also a trend toward a difference in CPT-MBF between insufficiently and well-treated OSA patients (1.2 ± 0.3 mL/min/g vs 0.9 ± 0.2 mL/min/g, P = 0.15). Conclusion: Untreated OSA patients have an impaired coronary endothelial function as measured by MBF response to CPT compared to control subjects. This difference disappears after 6 weeks of autoCPAP therapy but only in OSA patients showing a good response to CPAP (AHI <10/h). Further studies are needed to determine by which mechanism OSA and CPAP treatment influence coronary vasoreactivity.

Dietary intake of children with inflammatory bowel disease and of healthy controls

Introduction: The assessment of dietary intake by examination is a tool that allows knowing the habits and detecting certain nutritional deficiencies. Thus, it is essential in chronic disease and especially in children, where deficiencies can have a negative impact on growth and pubertal development. Objectives: Compare the dietary intake between children with inflammatory bowel disease (IBD) and healthy controls. Methods: Twenty-nine healthy controls (12 girls; mean age: 12.7 ± 1.9 years) and 21 IBD patients (11 girls; 14.3 ± 1.3 years) recruited from August 2011 to October 2012. Dietary intake was assessed by 24h recall. Results: No differences were found between IBD patients and healthy controls regarding dietary intake (table). Both IBD patients and healthy controls had excessive protein consumption. Furthermore, there are deficiencies for some nutriments (fibers, calcium and magnesium). Qualitative analysis revealed that both, IBD patients and healthy controls showed increased snacking and bad lipids distribution, especially for saturated lipids. Conclusion: Both children with IBD and health controls have a food imbalance and a low intake of minerals and vitamins. No differences between children with IBD and healthy controls were found.

Personality changes in patients with beginning Alzheimer disease

Objective: To investigate personality traits in patients with Alzheimer disease, compared with mentally healthy control subjects. We compared both current personality characteristics using structured interviews as well as current and previous personality traits as assessed by proxies.Method: Fifty-four patients with mild Alzheimer disease and 64 control subjects described their personality traits using the Structured Interview for the Five-Factor Model. Family members filled in the Revised NEO Personality Inventory, Form R, to evaluate their proxies' current personality traits, compared with 5 years before the estimated beginning of Alzheimer disease or 5 years before the control subjects.Results: After controlling for age, the Alzheimer disease group presented significantly higher scores than normal control subjects on current neuroticism, and significantly lower scores on current extraversion, openness, and conscientiousness, while no significant difference was observed on agreeableness. A similar profile, though less accentuated, was observed when considering personality traits as the patients' proxies remembered them. Diachronic personality assessment showed again significant differences between the 2 groups for the same 4 domains, with important personality changes only for the Alzheimer disease group.Conclusions: Group comparison and retrospective personality evaluation are convergent. Significant personality changes follow a specific trend in patients with Alzheimer disease and contrast with the stability generally observed in mentally healthy people in their personality profile throughout their lives. Whether or not the personality assessment 5 years before the current status corresponds to an early sign of Alzheimer disease or real premorbid personality differences in people who later develop Alzheimer disease requires longitudinal studies.

Ambulatory monitoring of physical activities in patients with Parkinson's disease.

A new ambulatory method of monitoring physical activities in Parkinson's disease (PD) patients is proposed based on a portable data-logger with three body-fixed inertial sensors. A group of ten PD patients treated with subthalamic nucleus deep brain stimulation (STN-DBS) and ten normal control subjects followed a protocol of typical daily activities and the whole period of the measurement was recorded by video. Walking periods were recognized using two sensors on shanks and lying periods were detected using a sensor on trunk. By calculating kinematics features of the trunk movements during the transitions between sitting and standing postures and using a statistical classifier, sit-to-stand (SiSt) and stand-to-sit (StSi) transitions were detected and separated from other body movements. Finally, a fuzzy classifier used this information to detect periods of sitting and standing. The proposed method showed a high sensitivity and specificity for the detection of basic body postures allocations: sitting, standing, lying, and walking periods, both in PD patients and healthy subjects. We found significant differences in parameters related to SiSt and StSi transitions between PD patients and controls and also between PD patients with and without STN-DBS turned on. We concluded that our method provides a simple, accurate, and effective means to objectively quantify physical activities in both normal and PD patients and may prove useful to assess the level of motor functions in the latter.

Low prevalence of behavioural and emotional problems among Swiss paediatric patients with inflammatory bowel disease.

OBJECTIVES: Whether behavioural and emotional maladjustment is more prevalent in children with inflammatory bowel disease (IBD) than in healthy controls remains controversial. The aim of this study was to assess paediatric IBD patients for problems with emotional and behavioural adjustment and to examine associations with clinical and demographic variables. METHODS: Data from paediatric patients with IBD enrolled in the Swiss IBD Cohort Study and the results of both the parent-rated Strengths and Difficulties Questionnaire (SDQ) and the self-reported Child Depression Inventory (CDI) were analysed. Of the 148 registered patients, 126 had at least one questionnaire completed and were included. RESULTS: The mean age of 71 patients with Crohn's disease (44 males, 27 females) was 13.4 years, and 12.8 years for the 55 patients with ulcerative or indeterminate colitis. The mean duration of disease was 1.2 and 2.7 years, respectively. The total score of the SDQ was abnormal in 11.4% of cases compared to 10% in the normal population. Abnormal sub-scores were found in 20.2% of subjects for the domain of emotional problems and in 17.1% for problems with peers. The total CDI T score indicated a significantly lower prevalence of clinical depression in IBD patients than in normal youth. No correlation between the total SDQ scores or the CDI T scores and gender, type or duration of IBD, inflammatory markers or disease scores was found. CONCLUSIONS: The prevalence of problems with behavioural and emotional adjustment among Swiss paediatric IBD patients is low and comparable to that of the normal population.

Glutathione precursor, N-acetyl-cysteine, improves mismatch negativity in schizophrenia patients.

In schizophrenia patients, glutathione dysregulation at the gene, protein and functional levels, leads to N-methyl-D-aspartate (NMDA) receptor hypofunction. These patients also exhibit deficits in auditory sensory processing that manifests as impaired mismatch negativity (MMN), which is an auditory evoked potential (AEP) component related to NMDA receptor function. N-acetyl-cysteine (NAC), a glutathione precursor, was administered to patients to determine whether increased levels of brain glutathione would improve MMN and by extension NMDA function. A randomized, double-blind, cross-over protocol was conducted, entailing the administration of NAC (2 g/day) for 60 days and then placebo for another 60 days (or vice versa). 128-channel AEPs were recorded during a frequency oddball discrimination task at protocol onset, at the point of cross-over, and at the end of the study. At the onset of the protocol, the MMN of patients was significantly impaired compared to sex- and age- matched healthy controls (p=0.003), without any evidence of concomitant P300 component deficits. Treatment with NAC significantly improved MMN generation compared with placebo (p=0.025) without any measurable effects on the P300 component. MMN improvement was observed in the absence of robust changes in assessments of clinical severity, though the latter was observed in a larger and more prolonged clinical study. This pattern suggests that MMN enhancement may precede changes to indices of clinical severity, highlighting the possible utility AEPs as a biomarker of treatment efficacy. The improvement of this functional marker may indicate an important pathway towards new therapeutic strategies that target glutathione dysregulation in schizophrenia.

Lack of tumor recognition by hTERT peptide 540-548-specific CD8(+) T cells from melanoma patients reveals inefficient antigen processing.

Telomerase is a ribonucleoprotein complex responsible for the maintenance of the length of the telomeres during cell division, which is active in germ-line cells as well as in the vast majority of tumors but not in most normal tissues. The wide expression of the human telomerase catalytic subunit (hTERT) in tumors makes it an interesting candidate vaccine for cancer. hTERT-derived peptide 540-548 (hTERT(540)) has been recently shown to be recognized in an HLA-A*0201-restricted fashion by T cell lines derived from peptide-stimulated peripheral blood mononuclear cells (PBMC) from healthy donors. As a first step to the inclusion of this peptide in immunotherapy clinical trials, it is crucial to assess hTERT(540)-specific T cell reactivity in cancer patients as well as the ability of hTERT-specific CD8(+) T lymphocytes to recognize and lyse hTERT-expressing target cells. Here, we have analyzed the CD8(+) T cell response to peptide hTERT(540) in HLA-A*0201 melanoma patients by using fluorescent HLA-A*0201/hTERT(540) peptide tetramers. HLA-A*0201/hTERT(540) tetramer(+) CD8(+) T cells were readily detected in peptide-stimulated PBMC from a significant proportion of patients and could be isolated by tetramer-guided cell sorting. hTERT(540)-specific CD8(+) T cells were able to specifically recognize HLA-A*0201 cells either pulsed with peptide or transiently transfected with a minigene encoding the minimal epitope. In contrast, they failed to recognize hTERT-expressing HLA-A*0201(+) target cells. Furthermore, in vitro proteasome digestion studies revealed inadequate hTERT processing. Altogether, these results raise questions on the use of hTERT(540) peptide for cancer immunotherapy.

Selective accumulation of differentiated FOXP3(+) CD4 (+) T cells in metastatic tumor lesions from melanoma patients compared to peripheral blood

Precise identification of regulatory T cells is crucial in the understanding of their role in human cancers. Here, we analyzed the frequency and phenotype of regulatory T cells (Tregs), in both healthy donors and melanoma patients, based on the expression of the transcription factor FOXP3, which, to date, is the most reliable marker for Tregs, at least in mice. We observed that FOXP3 expression is not confined to human CD25(+/high) CD4(+) T cells, and that these cells are not homogenously FOXP3(+). The circulating relative levels of FOXP3(+) CD4(+) T cells may fluctuate close to 2-fold over a short period of observation and are significantly higher in women than in men. Further, we showed that FOXP3(+) CD4(+) T cells are over-represented in peripheral blood of melanoma patients, as compared to healthy donors, and that they are even more enriched in tumor-infiltrated lymph nodes and at tumor sites, but not in normal lymph nodes. Interestingly, in melanoma patients, a significantly higher proportion of functional, antigen-experienced FOXP3(+) CD4(+) T was observed at tumor sites, compared to peripheral blood. Together, our data suggest that local accumulation and differentiation of Tregs is, at least in part, tumor-driven, and illustrate a reliable combination of markers for their monitoring in various clinical settings.

Improvement of saliva production in ENT cancer patients treated by IMRT

Intensity modulated radiotherapy (IMRT) is a conformal radiotherapy that produces concave and irregular target volume dose distributions. IMRT has a potential to reduce the volume of healthy tissue irradiated to a high dose, but this often at the price of an increased volume of normal tissue irradiated to a low dose. Clinical benefits of IMRT are expected to be most pronounced at the body sites where sensitive normal tissues surround or are located next to a target with a complex 3D shape. The irradiation doses needed for tumor control are often markedly higher than the tolerance of the radiation sensitive structures such as the spinal cord, the optic nerves, the eyes, or the salivary glands in the treatment of head and neck cancer. Parotid gland salivary flow is markedly reduced following a cumulative dose of 30 50 Gy given with conventional fractionation and xerostomia may be prevented in most patients using a conformal parotid-sparing radiotherapy technique. However, in cohort studies where IMRT was compared with conventional and conformal radiotherapy techniques in the treatment of laryngeal or oropharyngeal carcinoma, the dosimetric advantage of IMRT translated into a reduction of late salivary toxicity with no apparent adverse impact on the tumor control. IMRT might reduce the radiation dose to the major salivary glands and the risk of permanent xerostomia without compromizing the likelihood for cure. Alternatively, IMRT might allow the target dose escalation at a given level of normal tissue damage. We describe here the clinical results on postirradiation salivary gland function in head and neck cancer patients treated with IMRT, and the technical aspects of IMRT applied. The results suggest that the major salivary gland function can be maintained with IMRT without a need to compromise the clinical target volume dose, or the locoregional control.

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.