Desflurane Preconditioning Induces Time-dependent Activation of Protein Kinase C Epsilon and Extracellular Signal-regulated Kinase 1 and 2 in the Rat Heart In Vivo

Background: Activation of protein kinase C epsilon (PKC-[epsilon]) and extracellular signal-regulated kinase 1 and 2 (ERK1/2) are important for cardioprotection by preconditioning. The present study investigated the time dependency of PKC-[epsilon] and ERK1/2 activation during desflurane-induced preconditioning in the rat heart.

Methods: Anesthetized rats were subjected to regional myocardial ischemia and reperfusion, and infarct size was measured by triphenyltetrazoliumchloride staining (percentage of area at risk). In three groups, desflurane-induced preconditioning was induced by two 5-min periods of desflurane inhalation (1 minimal alveolar concentration), interspersed with two 10-min periods of washout. Three groups did not undergo desflurane-induced preconditioning. The rats received 0.9% saline, the PKC blocker calphostin C, or the ERK1/2 inhibitor PD98059 with or without desflurane preconditioning (each group, n = 7). Additional hearts were excised at four different time points with or without PKC or ERK1/2 blockade: without further treatment, after the first or the second period of desflurane-induced preconditioning, or at the end of the last washout phase (each time point, n = 4). Phosphorylated cytosolic PKC-[epsilon] and ERK1/2, and membrane translocation of PKC-[epsilon] were determined by Western blot analysis (average light intensity).

Results: Desflurane significantly reduced infarct size from 57.2 +/- 4.7% in controls to 35.2 +/- 16.7% (desflurane-induced preconditioning, mean +/- SD, P < 0.05). Both calphostin C and PD98059 abolished this effect (58.8 +/- 13.2% and 64.2 +/- 15.4% respectively, both P < 0.05 versus desflurane-induced preconditioning). Cytosolic phosphorylated PKC-[epsilon] reached its maximum after the second desflurane-induced preconditioning and returned to baseline after the last washout period. Both calphostin C and PD98059 inhibited PKC-[epsilon] activation. ERK1/2 phosphorylation reached its maximum after the first desflurane-induced preconditioning and returned to baseline after the last washout period. Calphostin C had no effect on ERK1/2 phosphorylation.     

Distinct molecular phenotype of malignant CD34(+) hematopoietic stem and progenitor cells in chronic myelogenous leukemia

Chronic myelogenous leukemia (CML) is a malignant disorder of the hematopoietic stem cell characterized by the BCR-ABL oncogene. We examined gene expression profiles of highly enriched CD34(+) hematopoietic stem and progenitor cells from patients with CML in chronic phase using cDNA arrays covering 1.185 genes. Comparing CML CD34(+) cells with normal CD34(+) cells, we found 158 genes which were significantly differentially expressed. Gene expression patterns reflected BCR-ABL-induced functional alterations such as increased cell-cycle and proteasome activity. Detoxification enzymes and DNA repair proteins were downregulated in CML CD34(+) cells, which might contribute to genetic instability. Decreased expression of junction plakoglobulin and CXC chemokine receptor 4 (CXCR-4) might facilitate the release of immature precursors from bone marrow in CML. GATA-2 was upregulated in CML CD34(+) cells, suggesting an increased self-renewal in comparison with normal CD34(+) cells. Moreover, we found upregulation of the proto-oncogene SKI and of receptors for neuromediators such as opioid mu1 receptor, GABA B receptor, adenosine A1 receptor, orexin 1 and 2 receptors and corticotropine-releasing hormone receptor. Treatment of CML progenitor cells with the selective adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) resulted in a dose-dependent significant inhibition of clonogenic growth by 40% at a concentration of 10(-5) M, which could be reversed by the equimolar addition of the receptor agonist 2-chloro-N6-cyclopentyladenosine (P<0.05). The incubation of normal progenitor cells with DPCPX resulted in an inhibition of clonogenic growth to a significantly lesser extent in comparison with CML cells (P<0.05), suggesting that the adenosine A1 receptor is of functional relevance in CML hematopoietic progenitor cells.     

The influence of mitochondrial KATP-channels in the cardioprotection of preconditioning and postconditioning by sevoflurane in the rat in vivo

Volatile anesthetics induce myocardial preconditioning and can also protect the heart when given at the onset of reperfusion-a practice recently termed "postconditioning." We investigated the role of mitochondrial KATP (mKATP)-channels in sevoflurane-induced cardioprotection for both preconditioning and postconditioning alone and whether there is a synergistic effect of both. Rats were subjected to 25 min of coronary artery occlusion followed by 120 min of reperfusion. Infarct size was determined by triphenyltetrazolium staining. The following protocols were used: 1) preconditioning (S-Pre, n = 10, achieved by 2 periods of 5 min sevoflurane administration (1 MAC) followed by 10 min of washout); 2) sevoflurane postconditioning (1 MAC of sevoflurane given for 2 min at the beginning of reperfusion; S-Post, n = 10); 3) administration before and after ischemia (S-Pre + S-Post, n = 10). Protocols 1-3 were repeated in the presence of 5-hydroxydecanoate (5HD), a specific mKATP-channel-blocker (S-Pre + S-Post + 5HD, S-Pre + 5HD: n = 10; S-Post + 5HD: n = 9). Nine rats served as untreated controls (CON) or received 5HD alone (5HD, n = 10). Both S-Pre (23% +/- 13% of the area at risk, mean +/- sd) and S-Post (18% +/- 5%) reduced infarct size compared with CON (49% +/- 11%, both P < 0.05). S-Pre + S-Post resulted in a larger reduction of infarct size (12% +/- 5%, P = 0.054 versus S-Pre) compared with administration before or after ischemia alone. 5HD diminished the protection in all three sevoflurane treated groups (S-Pre + 5HD, 35% +/- 12%; S-Post + 5HD, 44% +/- 12%; S-Pre + S-Post + 5HD, 46% +/- 14%;) but given alone had no effect on infarct size (41% +/- 13%). Sevoflurane preconditioning and postconditioning protects against myocardial ischemia-reperfusion injury. The combination of preconditioning and postconditioning provides additive cardioprotection and is mediated, at least in part, by mKATP-channels.     

Crack use as a public health problem in Canada: call for an evaluation of 'safer crack use kits'

Oral crack use (smoking) is a relatively neglected public health problem in Canada, in comparison to injection drug use (IDU). There are indications that crack use in Canada may be increasing. Crack smoking involves particular risks and harms, including possible infectious disease transmission, which underline the need for targeted interventions. One pragmatic grassroots intervention that has only recently begun or been discussed in several Canadian cities is the distribution of 'safer crack use kits', which provide hardware for crack smoking devices along with harm reduction information. In addition to the direct benefits of using them, the kits may also bring previously 'hidden' marginalized crack smokers in contact with health and social services. There has been considerable controversy with regards to the distribution of the crack kits, within criminal justice, public health, and the general public; this resistance appears quite similar to that experienced when needle exchange programs (NEPs) were first being established. Systematic evaluation of the crack kits is urgently needed in order to produce definitive evidence of their health and other benefits, and to allow for evidence-based program and policy decisions in the interest of public health.     

Effects of nitrous oxide on the rat heart in vivo: another inhalational anesthetic that preconditions the heart?

BACKGROUND: For nitrous oxide, a preconditioning effect on the heart has yet not been investigated. This is important because nitrous oxide is commonly used in combination with volatile anesthetics, which are known to precondition the heart. The authors aimed to clarify (1) whether nitrous oxide preconditions the heart, (2) how it affects protein kinase C (PKC) and tyrosine kinases (such as Src) as central mediators of preconditioning, and (3) whether isoflurane-induced preconditioning is influenced by nitrous oxide. METHODS: For infarct size measurements, anesthetized rats were subjected to 25 min of coronary artery occlusion followed by 120 min of reperfusion. Rats received nitrous oxide (60%), isoflurane (1.4%) or isoflurane-nitrous oxide (1.4%/60%) during three 5-min periods before index ischemia (each group, n = 7). Control animals remained untreated for 45 min. Additional hearts (control, 60% nitrous oxide alone%, and isoflurane-nitrous oxide [0.6%/60%, in equianesthetic doses]) were excised for Western blot of PKC-epsilon and Src kinase (each group, n = 4). RESULTS: Nitrous oxide had no effect on infarct size (59.1 +/- 15.2% of the area at risk vs. 51.1 +/- 10.9% in controls). Isoflurane (1.4%) and isoflurane-nitrous oxide (1.4%/60%) reduced infarct size to 30.9 +/- 10.6 and 28.7 +/- 11.8% (both P < 0.01). Nitrous oxide (60%) had no effect on phosphorylation (2.3 +/- 1.8 vs. 2.5 +/- 1.7 in controls, average light intensity, arbitrary units) and translocation (7.0 +/- 4.3 vs. 7.4 +/- 5.2 in controls) of PKC-epsilon. Src kinase phosphorylation was not influenced by nitrous oxide (4.6 +/- 3.9 vs. 5.0 +/- 3.8; 3.2 +/- 2.2 vs. 3.5 +/- 3.0). Isoflurane-nitrous oxide (0.6%/60%, in equianesthetic doses) induced PKC-epsilon phosphorylation (5.4 +/- 1.9 vs. 2.8 +/- 1.5; P < 0.001) and translocation to membrane regions (13.8 +/- 13.0 vs. 6.7 +/- 2.0 in controls; P < 0.05). CONCLUSIONS: Nitrous oxide is the first inhalational anesthetic without preconditioning effect on the heart. However, isoflurane-induced preconditioning and PKC-epsilon activation are not influenced by nitrous oxide.     

Morphology and distribution of nasal telangiectasia in HHT-patients with epistaxis

BACKGROUND: Epistaxis in hereditary hemorrhagic telangiectasia (HHT; Rendu-Osler-Weber syndrome) is a frequent symptom that may be caused by a multitude of different genetic and epigenetic phenomena. This investigation analyzes the distribution of nasal telangiectasia in 21 patients with HHT. METHODS: The patients were examined for endonasal telangiectasia by videoendoscopy with rigid endoscopes; in addition, the anterior portion of the nose was examined under the operating microscope. The endonasal findings were recorded on videotape and then evaluated in the media laboratory. RESULTS: Morphology of the nasal telangiectasia showed wide variations: the vessels were shaped like spots, loops, or spiders or they clustered and resembled raspberries. Gender did not have an influence on the phenotype of telangiectasia, whereas advancing age correlated with a higher density of telangiectasia. Patients with an intact nasal septum exhibited the bulk of telangiectasia in the anterior nasal cavity but also on the middle turbinates, the floor of the nose, and within the valve area. Patients with septal perforations displayed the majority of telangiectasia around the edge of the perforations, on the floor of the nose, and on the turbinates. Scattered telangiectasia also could be found in the profound parts of the nasal cavity and in the nasopharynx, especially in patients with septal perforations. CONCLUSION: The shapes of endonasal telangiectasia in HHT patients are very heterogeneous; predilection sites could first of all be found within the anterior portion of the nose. Morphology and distribution of endonasal telangiectasia change as a result of therapeutic interventions, development of septal perforations, and with advancing age. Therefore, repeat endoscopies are recommended to assess the actual stage of the disease before epistaxis therapy.     

Value of gradient-echo magnetic resonance imaging in the diagnosis of familial cerebral cavernous malformation

BACKGROUND: Cerebral cavernous malformations (CCMs) are congenital vascular anomalies that can cause seizures, intracranial hemorrhages, focal neurological deficits, and migrainelike headaches. Magnetic resonance (MR) imaging has substantially facilitated diagnosis of CCM. It is now widely accepted that familial clustering with an autosomal dominant inheritance pattern should be suspected in cases of multiple lesions. OBJECTIVE: To determine by MR imaging the penetrance of cavernous malformations in a 3-generation family that included 5 members with typical clinical signs and diagnostic findings. METHODS: All family members underwent routine MR T1-weighted and T2-weighted spin-echo sequences in addition to MR T2-weighted gradient-echo sequences. RESULTS: Four family members had been symptomatic with either brainstem bleeding, headaches, or focal neurological signs. The gradient-echo sequences yielded a dramatically higher sensitivity with regard to lesion number and distribution.As in previous reports of familial CCM, an increase in lesion number with increasing age, changes in lesion characteristics, de novo occurrence in serial MR imaging over time, and the phenomenon of anticipation could be confirmed in this family. CONCLUSION: Magnetic resonance gradient-echo sequences should be considered the method of choice for diagnosis of familial CCM.     

Cytotoxic T lymphocyte therapy for Epstein-Barr virus+ Hodgkin's disease

Epstein Barr virus (EBV)+ Hodgkin's disease (HD) expresses clearly identified tumor antigens derived from the virus and could, in principle, be a target for adoptive immunotherapy with viral antigen-specific T cells. However, like most tumor-associated antigens in immunocompetent hosts, these potential targets are only weakly immunogenic, consisting primarily of the latent membrane protein (LMP)1 and LMP2 antigens. Moreover, Hodgkin tumors possess a range of tumor evasion strategies. Therefore, the likely value of immunotherapy with EBV-specific cytotoxic effector cells has been questioned. We have now used a combination of gene marking, tetramer, and functional analyses to track the fate and assess the activity of EBV cytotoxic T lymphocyte (CTL) lines administered to 14 patients treated for relapsed EBV+ HD. Gene marking studies showed that infused effector cells could further expand by several logs in vivo, contribute to the memory pool (persisting up to 12 mo), and traffic to tumor sites. Tetramer and functional analyses showed that T cells reactive with the tumor-associated antigen LMP2 were present in the infused lines, expanded in peripheral blood after infusion, and also entered tumor. Viral load decreased, demonstrating the biologic activity of the infused CTLs. Clinically, EBV CTLs were well tolerated, could control type B symptoms (fever, night sweats, and weight loss), and had antitumor activity. After CTL infusion, five patients were in complete remission at up to 40 mo, two of whom had clearly measurable tumor at the time of treatment. One additional patient had a partial response, and five had stable disease. The performance and fate of these human tumor antigen-specific T cells in vivo suggests that they might be of value for the treatment of EBV+ Hodgkin lymphoma.