Electrocardiographic and haemodynamic alterations caused by three different test solutions of local anaesthetics to detect accidental intravascular injection in children

Background The aim of this study was to investigate ECG and haemodynamic alterations provoked by a test dose of bupivacaine, epinephrine, and their combination. Methods Paediatric patients undergoing general anaesthesia were randomized into three groups. After anaesthesia induction and tracheal intubation, 0.2 ml kg−1 (max. 3 ml) of the corresponding test solution was i.v. injected: bupivacaine 0.125% (Group B), bupivacaine 0.125% plus epinephrine 1:200 000 (Group BE), or epinephrine 1:200 000 (Group E). ECG was printed and analysed post hoc. Non-invasive arterial pressure (AP) was measured at 1 and 2 min after test dose injection. Increases in T-wave of ≥25%, in heart rate (HR) of ≥10 beats min−1, and in systolic AP of ≥15 mm Hg above baseline value were considered a positive result. Results A total of 105 children aged 0.2-16 (median 6.8) yr were enrolled. Test dose injection provoked T-wave elevation in 0%, 85%, and 89% of patients in Groups B, BE, and E, respectively. A positive increase in HR was found in 0%, 68%, and 76%. A positive increase in AP at 1 min was found in 0%, 88%, and 94% and at 2 min in 0%, 42%, and 59%. A decrease in HR of ≥10 beats min−1 was observed in 6%, 76%, and 69%. Alterations in T-wave and HR were significantly influenced by age. Conclusions ECG and haemodynamic alterations after i.v. injection of a local anaesthetic test dose were significantly influenced by epinephrine. T-wave elevation, increase in AP, and changes in HR are highly reliable variables, particularly when age is taken into accoun

The Impact of Latent Herpesvirus Infections on the Mobilization of Recent Thymic Emigrants and Extrathymic T-cells in Response to Acute Aerobic Exercise in Man

T-cells typically mature in the thymus gland, which eventually succumbs to age-related atrophy, resulting in a decreased naïve T-cell repertoire in middle to later years. Aged individuals and those with persistently reactivating herpesvirus infections have an increased reliance on the extrathymic maturation of T-cells due to the shrinking effects that age and latent viral infection has on the naïve T-cell repertoire. Acute bouts of aerobic exercise are known to mobilize T-cells that exhibit both a naïve and late-stage differentiation phenotype into the blood compartment; however, it is not known if recent thymic emigrants (RTE) or extrathymic T-cells contribute to the lymphocytosis associated with exercise. PURPOSE: To examine the impact of latent cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infection on the mobilization of RTE and extrathymic T-cells in response to acute exercise. METHODS: Otherwise healthy CMV or EBV seropositive (CMV+ or EBV+) and CMV or EBV seronegative (CMV- or EBV-) males (age 23-35y) completed a 30-min cycling protocol at 85% of maximum power. Lymphocytes isolated from whole blood before, immediately after, and one hour after exercise were surface stained with monoclonal antibodies to identify phenotypes of RTE (CD103+/CD62L-) and extrathymic T-cells believed to mature in the liver (CD3+/CD25-/CD122+) and the epithelium of the small intestine (CD3+/CD4-/CD8-; TCRγδ+/ CD8αα+; CD3-/CD2+/CD7+). Cell populations were analyzed by flow cytometry and antibodies against CMV and EBV were determined in serum by ELISA. RESULTS: Preliminary analyses show that the proportion of RTE among the total CD3+/CD4+ or CD3+/CD8+ T-cell subsets did not change immediately after exercise, but was elevated above baseline 1h later due to the preferential egress of late stage differentiated T-cells. Neither CMV nor EBV status influenced the proportions of RTE in blood in response to exercise. T-cells mainly found in intestinal mucosa (i.e. CD3+/CD4-/CD8- and CD3-/CD2+/CD7+) were found to increase in blood immediately after exercise; an effect that appeared to be more pronounced in EBV but not CMV-infected subjects. CONCLUSION: An acute bout of aerobic exercise elicits the mobilization of T-cells exhibiting phenotype characteristics of extrathymically matured T-cells, suggesting that extrathymic T-cell mobilization contributes to the lymphocytosis associated with acute exercise. This effect appears to be amplified in subjects carrying a latent EBV but not CMV infection. Future research should attempt to establish the impact of long-term exercise and latent herpesvirus infections on the frequency of RTE and extrathymic T-cells in the aged, as this could have significant implications for age-associated immune dysfunction

Voluntary Counselling, HIV Testing and Adjunctive Cotrimoxazole Reduces Mortality in Tuberculosis Patients in Thyolo, Malawi.

OBJECTIVES: To assess the feasibility and effectiveness of voluntary counselling, HIV testing and adjunctive cotrimoxazole in reducing mortality in a cohort of tuberculosis (TB) patients registered under routine programme conditions in a rural district of Malawi. DESIGN: 'Before' and 'after' cohort study using historical controls. METHODS: Between 1 July 1999 and 30 June 2000 all TB patients were started on standardized anti-TB treatment, and offered voluntary counselling and HIV testing (VCT). Those found to be HIV-positive were offered cotrimoxazole at a dose of 480 mg twice daily, provided there were no contraindications. Side-effects were monitored clinically. End-of-treatment outcomes in this cohort (intervention group) were compared with a cohort registered between 1 July 1998 and 30 June 1999 in whom VCT and cotrimoxazole was not offered (control group). FINDINGS: A total of 1986 patients was registered in the study: 1061 in the intervention group and 925 in the control cohort. In the intervention group, 1019 (96%) patients were counselled pre-test, 964 (91%) underwent HIV testing and 938 (88%) were counselled post-test. The overall HIV-seroprevalence rate was 77%. A total of 693 patients were given cotrimoxazole of whom 14 (2%) manifested minor dermatological reactions. The adjusted relative risk of death in the intervention group compared with the control group was 0.81 (P < 0.001). The number needed to treat with VCT and adjunctive cotrimoxazole to prevent one death during anti-TB treatment was 12.5. INTERPRETATION: This study shows that VCT and adjunctive cotrimoxazole is feasible, safe and reduces mortality rates in TB patients under routine programme conditions

A single exercise bout enhances the manufacture of viral-specific T-cells from healthy donors: implications for allogeneic adoptive transfer immunotherapy

Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections remain a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). The adoptive transfer of donor-derived viral-specific cytotoxic T-cells (VSTs) is an effective treatment for controlling CMV and EBV infections after HSCT; however, new practical methods are required to augment the ex vivo manufacture of multi-VSTs from healthy donors. This study investigated the effects of a single exercise bout on the ex vivo manufacture of multi-VSTs. PBMCs isolated from healthy CMV/EBV seropositive participants before (PRE) and immediately after (POST) 30-minutes of cycling exercise were stimulated with CMV (pp65 and IE1) and EBV (LMP2A and BMLF1) peptides and expanded over 8 days. The number (fold difference from PRE) of T-cells specific for CMV pp65 (2.6), EBV LMP2A (2.5), and EBV BMLF1 (4.4) was greater among the VSTs expanded POST. VSTs expanded PRE and POST had similar phenotype characteristics and were equally capable of MHC-restricted killing of autologous target cells. We conclude that a single exercise bout enhances the manufacture of multi-VSTs from healthy donors without altering their phenotype or function and may serve as a simple and economical adjuvant to boost the production of multi-VSTs for allogeneic adoptive transfer immunotherapy

The impact of latent CMV infection on NK-cell mobilization and expression of KLRG1 and CD57 in response to acute exercise.

Natural killer (NK) cells are cytotoxic effectors of the innate immune system that are able to distinguish healthy autologous cells from tumors and virally infected cells. NK-cells kill the targeted cells by releasing cytotoxic proteins, a process that is governed by inhibitory surface receptors, such as KLRG1. Additionally, activated NK-cells are able to proliferate in response to immunological stimuli, a process that is inhibited in NK-cells expressing the senescence marker CD57. Acute bouts of exercise are known to mobilize NK cells into the blood compartment, which could alter immunity; however, whether or not exercise alters NK-cell KLRG1 and CD57 expression has not been fully elucidated. Furthermore, as latent CMV infection is associated with an increased frequency of inhibitory NK cells, it is not known if CMV status influences NK-cell mobilization in response to acute exercise. PURPOSE: To examine the impact of latent CMV infection on the mobilization of NK-cells and their expression of KLRG1 and CD57 in response to acute exercise. METHODS: Otherwise healthy CMV seropositive (CMV+) and CMV seronegative (CMV-) males (age 23-35 years) completed a 30-min cycling protocol at 85% of maximum power. Lymphocytes isolated from whole blood before, immediately after, and one hour after exercise were surface-stained with monoclonal antibodies against CD3, CD56, KLRG1 and CD57 and analyzed by 4-color flow cytometry. RESULTS: Preliminary analysis of the data show a prodigious increase in the number of CD56 dim (mature, highly cytotoxic subset) NK-cells immediately after exercise in all subjects, which subsequently fell below pre-exercise values 1 hour later. In CMV- subjects, the proportion of CD56 bright (immature, mildly cytotoxic) NK cells was considerably higher 1 hour post-exercise than before exercise, but the number of cells changed very little suggesting that the increased proportion was due merely to the egress of CD56 dim NK cells. Interestingly, CMV seropositivity was associated with a near complete absence of CD56 bright NK cells that was unaffected by exercise. Neither exercise nor CMV status influenced the proportion of NK-cells expressing KLRG1 or CD57. CONCLUSION: Preliminary analysis of this data indicates that acute exercise preferentially mobilizes CD56 dim NK cells without altering KLRG1 and CD57 expression. Latent CMV infection is associated with a lowered proportion of CD56 bright NK-cells; however, the NK-cell response to exercise was not influenced by CMV status. Future work will examine the role of aging on NK-cell response to exercise and CMV status

Negative phase time for Scattering at Quantum Wells: A Microwave Analogy Experiment

If a quantum mechanical particle is scattered by a potential well, the wave function of the particle can propagate with negative phase time. Due to the analogy of the Schr\"odinger and the Helmholtz equation this phenomenon is expected to be observable for electromagnetic wave propagation. Experimental data of electromagnetic wells realized by wave guides filled with different dielectrics confirm this conjecture now.Comment: 10 pages, 6 figure

Comparison of thromboelastometry (ROTEM®) with standard plasmatic coagulation testing in paediatric surgery

Background Thromboelastometry (ROTEM®) might be useful to detect intraoperative coagulation disorders early in major paediatric surgery. This observational trial compares this technique to standard coagulation tests. Methods Intraoperative blood sampling was obtained in children undergoing elective major surgery. At each time point, standard coagulation tests [activated partial thromboplastin time (aPTT), prothrombin time (PT), and fibrinogen level] and ROTEM® analyses (InTEM, ExTEM, and FibTEM) were performed simultaneously by trained hospital laboratory staff. Results A total of 288 blood samples from 50 subjects were analysed. While there was a poor correlation between PT and aPTT to ExTEM clotting time (CT) and InTEM CT, respectively, a good correlation was detected between PT and aPTT to clot formation time, and a very good correlation between fibrinogen level and FibTEM assay (r=0.882, P<0.001). Notably, 64% of PT and 94% of aPTT measurements were outside the reference range, while impaired CT was observed in 13% and 6.3%, respectively. Standard coagulation test results were available after a median of 53 min [inter-quartile range (IQR): 45-63 min], whereas 10 min values of ROTEM® results were available online after 23 min (IQR: 21-24 min). Conclusions PT and aPTT cannot be interchangeably used with ROTEM® CT. Based on the results of ROTEM®, recommended thresholds for PT and aPTT might overestimate the need for coagulation therapy. A good correlation was found between the fibrinogen level and the FibTEM assay. In addition, ROTEM® offered faster turnaround time

No impact of CMV or EBV seropositivity on the frequency of highly differentiated T-cells in Mexican-American adolescents

Recurring activations of the prevalent latent herpes viruses Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) induces immune cell division leading to the premature terminal differentiation of T-cells. Terminally differentiated T-cells are known to accumulate with age causing a reduction in the naïve T-cell repertoire, which compromises the ability of the adaptive immune system to respond to novel pathogens. Although CMV and EBV seropositivity are hallmarks of the “immune risk profile” and are known to influence the frequency of terminally differentiated T-cells and increase infection risk in adults, it is not known if CMV or EBV impacts on the frequency of these cells in a young subject cohort. PURPOSE: To examine the impact of CMV and EBV seropositivity on the frequency of highly differentiated blood T-cells in Mexican-American adolescents. METHODS: Fasted resting blood samples were obtained from 77 adolescents consisting of both males and females. The presence of antibodies against CMV and EBV was determined in serum by ELISA. Lymphocytes isolated from peripheral blood were assessed for a combination of cell surface markers to determine their stage of differentiation. Monoclonal antibodies and four-color flow cytometry were used to identify senescent (CD27-, CD28-, CD57+), naïve (CCR7+, CD45RA+), memory (CCR7-, CD45RA-) and effector memory (CCD7-, CD45RA+) T-cell markers on pan CD3+ T-cells, CD4+ T-cells and CD8+ T-cells. Differences in T-cell phenotype between the CMV/EBV seropositive and seronegative participants were compared using independent Student t-tests. RESULTS: The prevalence of latent CMV and EBV infection among the subject cohort was 16% and 44% respectively, while 7% of all participants were carrying a latent infection for both. No differences in senescent and memory phenotypes were found between the CMV or EBV seropositive and seronegative groups. CONCLUSION: Despite the known influence of latent CMV and EBV infection on the frequency of senescent T-cells in adults, these preliminary data indicate that CMV and EBV seropositivity has no impact on the frequency of senescent T-cells in adolescents. These data suggest that the increased frequency of terminally differentiated T-cells that are associated with CMV and EBV seropositivity in adults is probably due to long-term infections. Future studies will assess the impact of CMV and EBV seropositivity on immunosenescence in association with other factors known to have an effect on T-cells differentiation, such as BMI and physical activity status