Exercise rapidly increases eukaryotic elongation factor 2 phosphorylation in skeletal muscle of men

Protein synthesis in skeletal muscle is known to decrease during contractions but the underlying regulatory mechanisms are unknown. Here, the effect of exercise on skeletal muscle eukaryotic elongation factor 2 (eEF2) phosphorylation, a key component in protein translation machinery, was examined. Eight healthy men exercised on a cycle ergometer at a workload eliciting ∼67% peak pulmonary oxygen consumption     with skeletal muscle biopsies taken from the vastus lateralis muscle at rest as well as after 1, 10, 30, 60 and 90 min of exercise. In response to exercise, there was a rapid (i.e. < 1 min) 5- to 7-fold increase in eEF2 phosphorylation at Thr56 that was sustained for 90 min of continuous exercise. The in vitro activity of skeletal muscle eEF2 kinase was not altered by exercise indicating that the increased activity of eEF2 kinase to eEF2 is not mediated by covalent mechanisms. In support of this, the increase in AMPK activity was temporally unrelated to eEF2 phosphorylation. However, skeletal muscle eEF2 kinase was potently activated by Ca²⁺–calmodulin in vitro , suggesting that the higher eEF2 phosphorylation in working skeletal muscle is mediated by allosteric activation of eEF2 kinase by Ca²⁺ signalling via calmodulin. Given that eEF2 phosphorylation inhibits eEF2 activity and mRNA translation, these findings suggest that the inhibition of protein synthesis in contracting skeletal muscle is due to the Ca²⁺-induced stimulation of eEF2 kinase.     

Massive foreign body impalement of the shoulder and chest wall

Impalement injuries to the upper extremity are rare. A case is described of penetration of a 10 x 3.5-inch fence post into the left shoulder of a 16-year-old boy, pinning the shoulder to the chest wall. Sequelae of potential serious brachioplexus, vascular, and intrathoracic injuries are reviewed. The author presents a systematic treatment approach to the assessment, extrication, and microneurovascular repair of damaged structures, and to soft tissue reconstruction following massive foreign body injuries.     

Selection for donor-specific cytotoxic T lymphocytes within the allografted human heart.

Lymphocytes were cultured from cardiac biopsies following heart transplantation using interleukin-2-conditioned medium. Using the technique of limiting dilution analysis the frequency of donor specific cytotoxic T lymphocytes was measured in cells cultured from biopsies and compared with that in peripheral blood lymphocytes taken at the same time as the biopsy. The graft cell population showed a considerably higher frequency of donor-specific CTL when compared with the PBL. CTL frequencies in the graft cells were always higher against the donor than against third-party cells. These data demonstrate that there was either selective sequestration or selective expansion of donor-reactive T cells in the heart following cardiac transplantation. These results emphasize the need to investigate more closely the events occurring in the heart, and may explain the lack of specificity and sensitivity in immune monitoring (IM) or cytoimmune monitoring (CIM) seen in many centers.     

Production of epidermal growth factor and transforming growth factor-alpha by the androgen-responsive LNCaP human prostate cancer cell line

Epidermal growth factor (EGF)-related polypeptides may be involved in the growth of human prostate cancer cells, and in the androgen stimulation of hormone-responsive prostatic carcinomas. We have shown that androgen-responsive LNCaP cells, like the autonomous DU 145 human prostate cancer cell line, synthesize and secrete EGF and related polypeptides, including immunoreactive transforming growth factor-alpha (TGF-alpha). As determined by radioimmunoassay, intracellular EGF levels were approximately 100 times those of TGF-alpha, but together these accounted for less than half of the total EGF-like polypeptides detected in a radioreceptor assay. Although LNCaP cell growth was stimulated by dihydrotestosterone (DHT), there was no evident effect on immunoreactive EGF levels in the medium after correction for cell number. Moreover, metabolic labeling experiments showed no effect of the androgen on EGF synthesis by LNCaP cells. Gel filtration chromatography of conditioned medium showed both high molecular weight species and the mature 6,000 dalton form of immunoreactive EGF. We conclude that although LNCaP prostate cancer cell growth is stimulated by DHT, it is unlikely that it is mediated directly via increased EGF synthesis by the tumor cells.     

A pharmacokinetic comparison of cyclosporin oral solution and cyclosporin capsules in heart and lung transplant recipients

Pharmacokinetic profiles were obtained for 16 heart or lung recipients following the administration of identical doses of cyclosporin as oral solution and capsules on consecutive days. A comparison of pharmacokinetic parameters (AUC, C_max, C_min and t_max) showed that there were no significant differences between the two formulations except for the t_max, which was significantly longer for the capsules. The mean variation in day-to-day trough levels produced by the two different forms was 25.6%. A retrospective study was carried out of consecutive cyclosporin levels in patients at steady state on oral solution. The mean variation in day-to-day trough levels was 32.3%. This was not significantly different from the variation in consecutive trough levels seen in the oral solution/capsule comparison. This study shows that cyclosporin capsules can be substituted for oral solution without causing acute changes in cyclosporin blood levels, and that the pharmacokinetics of the two formulations are similar.This work was carried out in partial fulfillment of the requirements for the Master of Science Degree in Clinical Pharmacy, University of London     

Transient depletion of nucleus accumbens dopamine content may contribute to initial akinesia induced by MPTP in common marmosets

Acute treatment of common marmosets with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) caused an initial profound akinesia and other motor deficits. However, over the following months akinesia gradually disappeared although the animals remained clumsy and poorly coordinated. At 10 days following MPTP treatment there was a profound decrease in the dopamine, HVA and DOPAC content of the caudate nucleus, putamen and nucleus accumbens. By 3-4 months following MPTP treatment the animals had largely recovered from their akinesia, but the caudate nucleus and putamen dopamine, HVA and DOPAC content remained low. In contrast, the dopamine content of the nucleus accumbens had returned towards normal and the metabolite levels were higher than at 10 days. No overall alterations in 5HT or 5HIAA levels were observed at either time point. The transient and reversible nature of dopamine loss in the nucleus accumbens may contribute to the initial profound akinesia exhibited by common marmosets treated with MPTP. The restoration of dopamine levels in the nucleus accumbens may be partially responsible for the subsequent recovery of motor function that occurs in MPTP-treated marmosets.     

IFN-alpha-induced murine B16 melanoma cancer vaccine cells: induction and accumulation of cell-associated IL-15.

Long-term treatment of mouse cancer cells with interferon-alpha (IFN-alpha) converts parental B16 melanoma cells to B16alpha vaccine cells. Inoculation of syngeneic mice with B16alpha vaccine cells triggers immunity to the parental B16 tumor that is mediated by host macrophages, T cells, and natural killer (NK) cells. Lymph node cells from mice inoculated with irradiated B16alpha vaccine cells, but not with irradiated parental cells, proliferate when cultured in vitro, suggesting long-term in vivo activation of lymphoid cells. Long-term IFN-alpha treatment of B16alpha vaccine cells induced both interleukin-15 (IL-15) mRNA and IL-15 protein. The bulk of the induced IL-15 remained cell associated, either cytoplasmic or associated with the cell membrane. Immunofluorescence microscopy studies showed that the cell-associated IL-15 was broadly distributed throughout the cytoplasm. These observations suggest that long-term IFN-alpha treatment may induce primarily the truncated isoform of IL-15. Vaccination with irradiated B16alpha vaccine cells may promote tumor immunity by releasing high levels of cell-associated IL-15 when spontaneously lysed or directly killed by innate immune cells. The release of accumulated cell-associated IL-15 may then trigger a host T cell response to tumor antigens and cause host development of immunity to the B16 tumor cells.     

Calcium modulators of the anellated dihydropyridine type. Synthesis and pharmacologic action

The anellated dihydropyridines 4a-l can be gained by Hantzsch-like synthesis from 5,5-dimethylcyclohexanedione (1), the aromatic aldehydes 2a-l and methyl-beta-aminocrotonate (3). Cyclisation of the side chains with bromosuccinimide or pyridiniumbromideperbromide leads to the octahydrofuro[3,4-b]chinoline-diones 4m-p. Structures of type 4 are characterized by the spectroscopic data. Positive inotropic effects, caused by calcium agonism, are exerted by the tested substances at the isolated, electrically stimulated left guinea pig atrium, 4j being the most potent with an intrinsic activity of 0.79, compared with ethyl 4-[2-(difluoromethoxy)phenyl]-1, 4,5,7-tetrahydro-2-methyl-5-oxo-furo[3,4-b]pyridine-3-carboxylate. BaCl2-induced contractions at the guinea pig ileum are suppressed dose-dependently.     

Case series: Combined spinal epidural anesthesia for Cesarean delivery andex utero intrapartum treatment procedure

PURPOSE: To report the use of regional anesthesia and iv nitroglycerin to provide anesthesia and uterine relaxation for three Cesarean deliveries (CD) involving ex utero intrapartum treatment (EXIT) of potentially life-threatening airway obstruction in the newborn. CLINICAL FEATURES: Case 1--a 36-yr-old woman at 38 weeks' gestation was scheduled for an elective CD for fetal skeletal dysplasia and micrognathia. Case 2--a 34-yr-old woman at 35 weeks gestation had a fetal ultrasound revealing fixed neck flexion and micrognathia consistent with fetal arthrogryposis. Case 3--a 27-yr-old woman presented at 38 weeks gestation for CD for severe fetal micrognathia, with mandibular growth below the fifth percentile. For each case, a combined spinal epidural anesthetic was performed with 0.75% bupivacaine, fentanyl and morphine intrathecally followed by placement of a multiorifice epidural catheter. Prior to uterine incision patients received a loading dose followed by an iv infusion of nitroglycerin. Uterine relaxation was sufficient in all cases for delivery of the fetus, and allowed for evaluation by direct laryngoscopy and intubation while maintaining fetal-placental circulation. The surgical procedures were completed without incident. CONCLUSIONS: Anesthesia and uterine relaxation for CD and EXIT procedures can be safely provided with regional anesthesia and iv nitroglycerin.     

Development of a new Adolescent Patient-Provider Interaction Scale (APPIS) for youth at risk for STDs/HIV

PurposeAlthough an adult model of patient-provider mutual exchange of information has been proposed, there is no guiding model for adolescents or measurement methodology. Our purpose was to develop a new scale of patient-provider interaction for adolescents accessing reproductive health care and at risk for sexually transmitted diseases (STDs) and human immunodeficiency virus (HIV), and assess the reliability and validity of the scale.MethodsThe Adolescent Patient-Provider Interaction Scale (APPIS) was developed from the Roter and Hall theory of doctor-patient relationships, previously validated adolescent satisfaction and communication scales, and focus group and individual elicitation interviews. To assess construct validity, the new nine-item APPIS was compared with the satisfaction scale used by the Young Adult Health Care Survey (YAHCS), and Kahn’s Provider Communication Scale. Pearson correlation coefficients were used to examine convergence across scales, and factor analysis of the APPIS was performed.ResultsThe study recruited 192 African American girls aged 17.9 ± 1.7 years (range 15–21 years) from three sites: a county STD clinic (n = 51), urban adolescent clinic (n = 99), and a family planning clinic (n = 42). Most participants (85%) rated their overall health care highly (≥ 7 on a 10-point scale); 49% felt that both the provider and patient were “in charge” of the visit, and 88% “strongly agreed” or “agreed” that there was an equal “exchange of information” during the visit. The APPIS showed good internal consistency (Cronbach alpha = .75), and moderate convergence with the six-item YAHCS scale (r = .57, p < .001) and seven-item Kahn scale (r = .48, p < .001). Three factors emerged from exploratory factor analyses, supporting our conceptualization of patient-provider interaction as being multi-dimensional.ConclusionsA new theory-based scale of adolescent patient-provider interaction compares favorably with previous scales of health care satisfaction and communication. The new APPIS may be useful for evaluating approaches to improve health care outcomes for adolescents at-risk for STDs and HIV.