CD28-negative cytolytic effector T cells frequently express NK receptors and are present at variable proportions in circulating lymphocytes from healthy donors and melanoma patients.

In humans, NK receptors are expressed by natural killer cells and some T cells, the latter of which are preferentially alphabetaTCR+ CD8+ cytolytic T lymphocytes (CTL). In this study we analyzed the expression of nine NK receptors (p58.1, p58.2, p70, p140, ILT2, NKRP1A, ZIN176, CD94 and CD94/NKG2A) in PBL from both healthy donors and melanoma patients. The percentages of NK receptor-positive T cells (NKT cells) varied strongly, and this variation was more important between individual patients than between individual healthy donors. In all the individuals, the NKT cells were preferentially CD28-, and a significant correlation was found between the percentage of CD28- T cells and the percentage of NK receptor+ T cells. Based on these data and the known activated phenotype of CD28- T cells, we propose that the CD28- CD8+ T cell pool represents or contains the currently active CTL population, and that the frequent expression of NK receptors reflects regulatory mechanisms modulating the extent of CTL effector function. Preliminary results indicate that some tumor antigen-specific T cells may indeed be CD28- and express NK receptors in vivo.

Human CD8 T-cell responses to Epstein-Barr virus and Cytomegalovirus in healthy donors and melanoma patients

Summary The mechanisms regulating the protective immune T-cell responses generated against the persistent Epstein-Barr virus (EBV) and Cytomegaloviru_s (CNIV) remain poorly understood. We analyzed the dynamics of cellular differentiation and T-cell receptor (TCR) clonotype selection of EBV- and CMV-specific T-cells in healthy adults and melanoma patients. While these responses could be subdivided into four T lymphocyte populations, théir proportions varied between EBV and CMV specific responses. Phenotypic and TCR clonotypic analyses supported a linear model of differentiation from the early-differentiated (EM/CD28pos) subset to the late-differentiatdc (EMRA/CD28neg) subset. In-depth clonal composition analyses revealed TCR repertoires, which were highly restricted for CMV- and relatively diverse for EBV-specific cells. Virtually all virus-specific clonotypes identified in the EMRA/CD28neg subset were also found within the pool of less differentiated "memory" cells. However, striking differences in the patterns of dominance were observed among these subsets, as some clonotypes were selected with differentiation, while others were not. Latedifferentiated CMV-specific clonotypes were mostly characterized by TCRs with lower dependency on CD8 co-receptor interaction. Yet all clonotypes displayed similar functional avidities, suggesting a compensatory role of CD8 in the clonotypes of lower TCR avidity. Importantly, clonotype selection and composition of each virus-specific subset upon differentiation was highly preserved over time, with the presence of the same dominant clonotypes at specific differentiation stages within a period of four years. This work was extended to the study of EBV-specific CD8 T-cell responses in melanoma patients undergoing transient lymphodepletion, followed by adoptive cell transfer (ACT) and immune reconstitution for thè treatment of their tumors. Following treatment regimen, we first observed an increase in the proportion of virus-specific T-cells in 3 out of 5 patients, accompanied by a more differentiated phenotype (EMRA/CD28neg), compared to specific cells of healthy individuals. Yet, similarly to healthy donors, clonotype selection and composition of virus-specific T-cells varied along the pathway of cellular differentiation, with some clonotypes being selected with differentiation, while others were not. Intriguingly, no novel clonotypes emerged following transient immuno-suppression and homeostatic proliferation, finding which was subsequently explained by the absence of EBV reactivation. The distribution of each clonotype within early- and late-differentiated T-cell subsets in 4 out 5 patients was highly stable over time, with those clonotypes initially found before the start of treatment that were again present at specific differentiation stages after transient lymphodepletion and ACT. These findings uncover novel features of the highly sophisticated control of steady state protective T-cell immune responses against persistent herpesviruses in healthy adults. Furthermore they reveal the striking stability of these responses in terms of clonotype selection and composition with T-cell differentiation even in situations where the immune system has been. challenged. Résumé : Les mécanismes qui régulent les réponses immunitaires de type protectrices, générées contre les virus chroniquement persistants tels que l'Epstein-Barr (EBV) ou le Cytomegalo (CMV) restent largement inconnus. Nous avons analysé la différenciation des lymphocytes T spécifiques pour ces virus, ainsi que la composition des clonotypes T (par leur récepteur T) chez les donneurs sains. Les réponses immunes peuvent être classifiées en quatre souspopulations majeures de lymphocytes T, cependant, leur proportion varie entre les réponses spécifiques contre EBV ou CMV. Ces analyses soutiennent le modèle linéaire de différenciation, à partir de la population non différenciée (EM/CD28pos) vers la population plus différenciée (ENIIZA/CD28neg). De plus, nos données sur la composition clonale de ces cellules T spécifiques ont révélé des répertoires TCR restreints, pour la réponse anti-CMV, et relativement diversifiés contre EBV. Tous les clonotypes spécifiques de ces virus identifiés dans la sous-population différenciée EMRA/CD28neg, ont également été retrouvés dans la population de cellules "mémoires". Toutefois, de fortes différences ont été observées dans les schémas de domination de ces sous-populations, en effet, certains clonotypes étaient sélectionnés avec la différenciation, alors que d'autres ne l'étaient pas. Nous avons également démontré que ces clonotypes différenciés et spécifiques pour le CMV sont caractérisés par des TCRs à faible dépendance en regard de la coopération du corécepteur CD8. Néanmoins, tous les clonotypes affichent une avidité fonctionnelle similaire, suggérant un rôle compensatoire du CD8, dans le cas des clonotypes avec une faible avidité du TCR En définitive, la composition et la sélection des clonotypes spécifiques pour chaque virus et pour chaque sous-population suit un schéma de différenciation hautement conservé au cours du temps, avec la présence de ces mêmes clonotypes au même stade de différenciation sur une période de quatre ans. Ce travail a été étendu à l'étude des réponses T CD8+ spécifiques pour le virus EBV chez les patients atteints de mélanome et recevant dans le cadre du traitement de leurs tumeurs une lymphodéplétion transitoire, suivie d'un transfert adoptif de cellules et d'une reconstitution immunitaire. Au cours de cette thérapie, nous avons en premier lieu observé pour 3 des 5 patients une augmentation de la proportion de cellules T spécifiques pour le virus, accompagné d'un phénotype plus différencié (EMRA/CD28neg), et ceci comparativement à des cellules spécifiques d'individus sains. Pourtant, comme nous l'avons observé chez les donneurs sains, la sélection et la composition des clonotypes T spécifiques varient tout au long de la différenciation cellulaire, avec certains clonotypes sélectionnés et d'autres qui ne le sont pas. Étonnamment, aucun nouveau clonotype n'a émergé après l'immuno-suppression transitoire et la prolifération homéostatique. Cette observation trouve son explication par une absence de réactivation du virus EBV chez ces patients, et ce malgré leur traitement. De plus, la distribution de chaque clonotype parmi ces sous-populations non-différenciées et différenciées reste stable au cours du traitement. Ainsi, les mêmes clonotypes initialement identifiés avant le début du traitement sont présents aux mêmes stades de différenciation après la lymphodéplétion et la prolifération homéostatique. Ces résultats ont permis d'identifier de nouveaux mécanismes impliqués dans la régulation hautement «sophistiquée » des réponses immunitaires T contre les virus persistants EBV et CMV chez les donneurs sains. En particulier, ils révèlent la grande stabilité de ces réponses en termes de sélection et de composition des clonotypes avec la différenciation cellulaire, et ce dans les situations chroniques, ainsi que dans les situations dans lesquelles le système immunitaire a été profondément perturbé.

Gambling against neglect: unconscious spatial biases induced by reward reinforcement in healthy people and brain-damaged patients.

Orienting attention in space recruits fronto-parietal networks whose damage results in unilateral spatial neglect. However, attention orienting may also be governed by emotional and motivational factors; but it remains unknown whether these factors act through a modulation of the fronto-parietal attentional systems or distinct neural pathways. Here we asked whether attentional orienting is affected by learning about the reward value of targets in a visual search task, in a spatially specific manner, and whether these effects are preserved in right-brain damaged patients with left spatial neglect. We found that associating rewards with left-sided (but not right-sided) targets during search led to progressive exploration biases towards left space, in both healthy people and neglect patients. Such spatially specific biases occurred even without any conscious awareness of the asymmetric reward contingencies. These results show that reward-induced modulations of space representation are preserved despite a dysfunction of fronto-parietal networks associated with neglect, and therefore suggest that they may arise through spared subcortical networks directly acting on sensory processing and/or oculomotor circuits. These effects could be usefully exploited for potentiating rehabilitation strategies in neglect patients.

9C.09: TREATMENT WITH CANDESARTAN UNMASKS HIGHER URINARY NOREPINEPHRINE EXCRETION IN WHITE COAT HYPERTENSIVE PATIENTS COMPARED TO HEALTHY NORMOTENSIVE PARTICIPANTS.

OBJECTIVE: White coat hypertensive is a pre-hypertensive state that has been associated with increased sympathetic drive. The objective of the study was to compare the exposure of the kidney to sympathetic nerve activity using urinary normetanephrine (UNMN) as a marker of renal sympathetic exposure in white coat hypertensive (WCH) and healthy normotensive (HN) participants. DESIGN AND METHOD: This was a double-blind randomized placebo-controlled crossover study. WCH were included if office blood pressure was >140/80 mmHg and ambulatory blood pressure <135/85 mmHg and HN if OBP was <140/90 mmHg and ABP <135/85 mmHg Participants were randomized to receive either 16 mg of candesartan or a matched placebo for one week before study day. On the study day systemic and renal hemodynamics as well as plasma norepinephrine and urinary excretion of normetanephrine (measured by LC/MS-MS were measured after one hour of baseline, one hour of lower body negative pressure and one hour of recovery period. Excretion of UNMN was expressed as the total of UNMN excreted during these three hours (cumUNMN). Paired or unpaired t-test were used for comparison. RESULTS: 25 HN and 12 WCH participants were included in the study. Mean age (±standard deviation), BMI were respectively 31.0±10.5 years and 22.0 ± 2.2 Kg/m2 in HN and 40.7±17.8 years and 26.7 ± 6.3 Kg/m2 in WCH.Table 1 Baseline mean blood pressure, plasma noradrenaline and cumulated UNMN during placebo and candesartan(Figure is included in full-text article.)Mean blood pressure was higher during placebo and candesartan in WCH compared to HN. Cumulated UNMN was higher in both groups after candesartan treatment. Cumulated UNMN was higher in WCH than in HN only after candesartan treatment. CONCLUSIONS: Urinary excretion of normetanephrine is increased in WCH compared to HN when treated with candesartan. The increased excretion of uNMN when the renin angiotensin system is blocked might reflect an increased sensitivity of WCH to stress conditions such as orthostatic stress.

Energetics and mechanics of walking in patients with chronic low back pain and healthy matched controls.

PURPOSE: Walking in patients with chronic low back pain (cLBP) is characterized by motor control adaptations as a protective strategy against further injury or pain. The purpose of this study was to compare the preferred walking speed, the biomechanical and the energetic parameters of walking at different speeds between patients with cLBP and healthy men individually matched for age, body mass and height. METHODS: Energy cost of walking was assessed with a breath-by-breath gas analyser; mechanical and spatiotemporal parameters of walking were computed using two inertial sensors equipped with a triaxial accelerometer and gyroscope and compared in 13 men with cLBP and 13 control men (CTR) during treadmill walking at standard (0.83, 1.11, 1.38, 1.67 m s(-1)) and preferred (PWS) speeds. Low back pain intensity (visual analogue scale, cLBP only) and perceived exertion (Borg scale) were assessed at each walking speed. RESULTS: PWS was slower in cLBP [1.17 (SD = 0.13) m s(-1)] than in CTR group [1.33 (SD = 0.11) m s(-1); P = 0.002]. No significant difference was observed between groups in mechanical work (P ≥ 0.44), spatiotemporal parameters (P ≥ 0.16) and energy cost of walking (P ≥ 0.36). At the end of the treadmill protocol, perceived exertion was significantly higher in cLBP [11.7 (SD = 2.4)] than in CTR group [9.9 (SD = 1.1); P = 0.01]. Pain intensity did not significantly increase over time (P = 0.21). CONCLUSIONS: These results do not support the hypothesis of a less efficient walking pattern in patients with cLBP and imply that high walking speeds are well tolerated by patients with moderately disabling cLBP.

Brief cognitive assessment instruments in schizophrenia and bipolar patients, and healthy control subjects: A comparison study between the Brief Cognitive Assessment Tool for Schizophrenia (B-CATS) and the Screen for Cognitive Impairment in Psychiatry (SCIP)

Cognitive impairment in schizophrenia and psychosis is ubiquitous and acknowledged as a core feature of clinical expression, pathophysiology, and prediction of functioning. However, assessment of cognitive functioning is excessively time-consuming in routine practice, and brief cognitive instruments specific to psychosis would be of value. Two screening tools have recently been created to address this issue, i.e., the Brief Cognitive Assessment Tool for Schizophrenia (B-CATS) and the Screen for Cognitive Impairment in Psychiatry (SCIP). The aim of this research was to examine the comparative validity of these two brief instruments in relation to a global cognitive score. 161 patients with psychosis (96 patients diagnosed with schizophrenia and 65 patients diagnosed with bipolar disorder) and 76 healthy control subjects were tested with both instruments to examine their concurrent validity relative to a more comprehensive neuropsychological assessment battery. Scores from the B-CATS and the SCIP were highly correlated in the three diagnostic groups, and both scales showed good to excellent concurrent validity relative to a Global Cognitive Composite Score (GCCS) derived from the more comprehensive examination. The SCIP-S showed better predictive value of global cognitive impairment than the B-CATS. Partial and semi-partial correlations showed slightly higher percentages of both shared and unique variance between the SCIP-S and the GCCS than between the B-CATS and the GCCS. Brief instruments for assessing cognition in schizophrenia and bipolar disorders, such as the SCIP-S and B-CATS, seem to be reliable and promising tools for use in routine clinical practice.

Comparison of acute non-visual bright light responses in patients with optic nerve disease, glaucoma and healthy controls.

This study examined the effect of optic nerve disease, hence retinal ganglion cell loss, on non-visual functions related to melanopsin signalling. Test subjects were patients with bilateral visual loss and optic atrophy from either hereditary optic neuropathy (n = 11) or glaucoma (n = 11). We measured melatonin suppression, subjective sleepiness and cognitive functions in response to bright light exposure in the evening. We also quantified the post-illumination pupil response to a blue light stimulus. All results were compared to age-matched controls (n = 22). Both groups of patients showed similar melatonin suppression when compared to their controls. Greater melatonin suppression was intra-individually correlated to larger post-illumination pupil response in patients and controls. Only the glaucoma patients demonstrated a relative attenuation of their pupil response. In addition, they were sleepier with slower reaction times during nocturnal light exposure. In conclusion, glaucomatous, but not hereditary, optic neuropathy is associated with reduced acute light effects. At mild to moderate stages of disease, this is detected only in the pupil function and not in responses conveyed via the retinohypothalamic tract such as melatonin suppression.

Pharmacokinetics of Oxycodone and Paracetamol in the Elderly. Clinical Pharmacokinetic Study on Orthopaedic Surgical Patients and Healthy Volunteers

The proportion of elderly people over 65 years of age in Finland is expected to grow to over 25% by the 2025. It has been estimated that elderly people today consume nearly 40% of all drugs. Age brings about number of physiological changes that may affect the disposition, metabolism and excretion of drugs. The function of heart, lungs, liver and kidneys decreases even in healthy people, as they get older. The proportion of total body water decreases and the relative fat percentage increases. Also several other factors such as concurrent diseases, concomitant medication and nutritional factors have an effect on drug therapy in elderly. Age increases the risk of adverse drug reactions, which most often are dose-dependent. Despite all this there are not enough studies involving the elderly people and the elderly are most often excluded from clinical trials. Oxycodone is a strong opioid analgesic, which is used to treat moderate or severe pain. Paracetamol is a widely used nonopioid analgesic, which has become popular in the treatment of pain in many patient groups. In this series of studies the pharmacokinetics of oral and intravenous oxicodone as well as intravenous paracetamol in the elderly and young adult patients were investigated. Also a study investigating the interaction of oral antibiotic clarityhromycin, a known cytochrome P450 (CYP) 3A4 inhibitor, with oxycodone pharmacokinetics and pharmacodynamics in elderly and young healthy volunteers was carried out. The pharmacokinetics of oxycodone showed a clear age depency. Patients over 70 years had 50-80% higher mean exposure to oral oxycodone and a twofold greater plasma concentration than young adults 12 h after ingestion of the drug. Elderly patients had 40-80% greater exposure to intravenous oxycodone and patients over 80 years had over twofold greater plasma concentrations 8 h post dose than the young adults. The elderly patients had also greater exposure to intra venous paracetamol compared to young adults. Clarithromycin increased the exposure to oral oxycodone in both young and elderly volunteers. The elderly had marked interindividual variation in the pharmacokinetics and pharmacodynamics when clarithromycin was given concomitantly with oxycodone. Because the pharmacokinetics of oxycodone and intravenous paracetamol depend on the age of the subject, it is important to titrate the analgesic dose individually in the elderly.

Observations on the Pharmacokinetics and Pharmacodynamics of Dexmedetomidine. Clinical Studies on Healthy Volunteers and Intensive Care Patients

Patients treated in intensive care units require sedation and analgesia. However, sedative drugs also have potential adverse effects, and there is no single ideal sedativeanalgesic drug for these patients. Dexmedetomidine is an apha2-adrenoceptor agonist licenced for sedation of intensive care patients and patients undergoing surgery and other invasive procedures. Several routes of parenteral administration (intravenous, intramuscular, subcutaneous and intranasal) have been utilized. In the present series of studies, the pharmacokinetics and pharmacodynamics of intranasally administered dexmedetomidine as well as the gastrointestinal effects of intravenous dexmedetomidine were determined in healthy volunteers. Pharmacokinetics of dexmedetomidine during long lasting, high-dose infusions were characterized in intensive care patients. The bioavailability of intranasal dexmedetomidine was relatively good (65%), but interindividual variation was large. Dexmedetomidine significantly inhibited gastric emptying and gastrointestinal transit. In intensive care patients, the elimination half-life of dexmedetomidine was somewhat longer than reported for infusions of shorter duration and in less ill patients or healthy volunteers. Dexmedetomidine appeared to have linear pharmacokinetics up to the studied dose rate of 2.5 μg/kg/h. Dexmedetomidine clearance was decreasing with age and its volume of distribution was increased in hypoalbuminaemic patients, resulting in a longer elimination half-life and context-sensitive half-time. Intranasally administered dexmedetomidine was efficacious and well tolerated, making it appropriate for clinical situations requiring light sedation. The clinical significance of the gastrointestinal inhibitory effects of dexmedetomidine should be further evaluated in intensive care patients. The possibility of potentially altered potency and effect duration should be taken into account when administering dexmedetomidine to elderly or hypoalbuminaemic patients.

Standardization of a computerized method for calculating autonomic function test responses in healthy subjects and patients with diabetes mellitus

The objectives of the present study were 1) to compare results obtained by the traditional manual method of measuring heart rate (HR) and heart rate response (HRR) to the Valsalva maneuver, standing and deep breathing, with those obtained using a computerized data analysis system attached to a standard electrocardiograph machine; 2) to standardize the responses of healthy subjects to cardiovascular tests, and 3) to evaluate the response to these tests in a group of patients with diabetes mellitus (DM). In all subjects (97 healthy and 143 with DM) we evaluated HRR to deep breathing, HRR to standing, HRR to the Valsalva maneuver, and blood pressure response (BPR) to standing up and to a sustained handgrip. Since there was a strong positive correlation between the results obtained with the computerized method and the traditional method, we conclude that the new method can replace the traditional manual method for evaluating cardiovascular responses with the advantages of speed and objectivity. HRR and BPR of men and women did not differ. A correlation between age and HRR was observed for standing (r = -0.48, P<0.001) and deep breathing (r = -0.41, P<0.002). Abnormal BPR to standing was usually observed only in diabetic patients with definite and severe degrees of autonomic neuropathy.

Hyperventilation in panic disorder patients and healthy first-degree relatives

Our aim was to observe the induction of panic attacks by a hyperventilation challenge test in panic disorder patients (DSM-IV) and their healthy first-degree relatives. We randomly selected 25 panic disorder patients, 31 healthy first-degree relatives of probands with panic disorder and 26 normal volunteers with no family history of panic disorder. All patients had no psychotropic drugs for at least one week. They were induced to hyperventilate (30 breaths/min) for 4 min and anxiety scales were applied before and after the test. A total of 44.0% (N = 11) panic disorder patients, 16.1% (N = 5) of first-degree relatives and 11.5% (N = 3) of control subjects had a panic attack after hyperventilating (chi² = 8.93, d.f. = 2, P = 0.011). In this challenge test the panic disorder patients were more sensitive to hyperventilation than first-degree relatives and normal volunteers. Although the hyperventilation test has a low sensitivity, our data suggest that there is no association between a family history of panic disorder and hyperreactivity to an acute hyperventilation challenge test. Perhaps cognitive variables should be considered to play a specific role in this association since symptoms of a panic attack and acute hyperventilation overlap.

Gut permeability to lactulose and mannitol differs in treated Crohn's disease and celiac disease patients and healthy subjects

The gut barrier monitors and protects the gastrointestinal tract from challenges such as microorganisms, toxins and proteins that could act as antigens. There is evidence that gut barrier dysfunction may act as a primary disease mechanism in intestinal disorders. The aim of the present study was to evaluate the barrier function towards sugars after the appropriate treatment of celiac disease and Crohn's disease patients and compare the results with those obtained with healthy subjects. Fifteen healthy volunteers, 22 celiac disease patients after 1 year of a gluten-free diet, and 31 Crohn's disease patients in remission were submitted to an intestinal permeability test with 6.0 g lactulose and 3.0 g mannitol. Six-hour urinary lactulose excretion in Crohn's disease patients was significantly higher than in both celiac disease patients (0.42 vs 0.15%) and healthy controls (0.42 vs 0.07%). Urinary lactulose excretion was significantly higher in celiac disease patients than in healthy controls (0.15 vs 0.07%). Urinary mannitol excretion in Crohn's disease patients was the same as healthy controls (21 vs 21%) and these values were significantly higher than in celiac disease patients (10.9%). The lactulose/mannitol ratio was significantly higher in Crohn's disease patients in comparison to celiac disease patients (0.021 vs 0.013) and healthy controls (0.021 vs 0.003) and this ratio was also significantly higher in celiac disease patients compared to healthy controls (0.013 vs 0.003). In spite of treatment, differences in sugar permeability were observed in both disease groups. These differences in the behavior of the sugar probes probably reflect different mechanisms for the alterations of intestinal permeability.