PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “ADE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources

Treatment of imported malaria in adults: a multicentre study in France.

BACKGROUND: Data about anti-malarial drugs prescription practices in Europe and the safety of imported malaria treatments are scanty. In 1999, a French consensus development conference published guidelines for the prevention and treatment of imported P. falciparum malaria. The impact of these guidelines has not been evaluated. AIM: To investigate the impact of these guidelines on the prescription of anti-malarials, and to evaluate the incidence of acute drug events (ADEs) leading to discontinuation of treatment. DESIGN: Cross-sectional survey. METHODS: Members of the medical staff in 14 French infectious and tropical disease wards completed a standardized form for each patient treated for imported malaria in 2001. A propensity score matching technique was used to estimate the risk of ADEs leading to discontinuation of the regimen. RESULTS: In the 474 patients studied, quinine was the first-line anti-malarial most often prescribed. Only 3% of patients received halofantrine. Mefloquine was associated with a RR of 4.9 (95%CI 3.2-7.4, p < 0.00001) risk of discontinuation of treatment due to ADEs. DISCUSSION: The very limited use of halofantrine indicates that the main practice recommendations of the guidelines have been taken into account. Mefloquine was associated with a substantial risk of discontinuing the treatment because of ADEs. This is a serious limitation for the use of mefloquine in the treatment of out-patients with imported malaria.

Adult↗

Primary fibroblasts of Cockayne syndrome patients are defective in cellular repair of 8-hydroxyguanine and 8-hydroxyadenine resulting from oxidative stress.

Cockayne syndrome (CS) is a genetic human disease with clinical symptoms that include neurodegeneration and premature aging. The disease is caused by the disruption of CSA, CSB, or some types of xeroderma pigmentosum genes. It is known that the CSB protein coded by the CS group B gene plays a role in the repair of 8-hydroxyguanine (8-OH-Gua) in transcription-coupled and non-strand discriminating modes. Recently we reported a defect of CSB mutant cells in the repair of another oxidatively modified lesion 8-hydroxyadenine (8-OH-Ade). We show here that primary fibroblasts from CS patients lack the ability to efficiently repair these particular types of oxidatively induced DNA damages. Primary fibroblasts of 11 CS patients and 6 control individuals were exposed to 2 Gy of ionizing radiation to induce oxidative DNA damage and allowed to repair the damage. DNA from cells was analyzed using liquid chromatography/isotope dilution mass spectrometry to measure the biologically important lesions 8-OH-Gua and 8-OH-Ade. After irradiation, no significant change in background levels of 8-OH-Gua and 8-OH-Ade was observed in control human cells, indicating their complete cellular repair. In contrast, cells from CS patients accumulated significant amounts of these lesions, providing evidence for a lack of DNA repair. This was supported by the observation that incision of 8-OH-Gua- or 8-OH-Ade-containing oligodeoxynucleotides by whole cell extracts of fibroblasts from CS patients was deficient compared to control individuals. This study suggests that the cells from CS patients accumulate oxidatively induced specific DNA base lesions, especially after oxidative stress. A deficiency in cellular repair of oxidative DNA damage might contribute to developmental defects in CS patients.

Adenine↗

Comparative effects of hypotension due to isoflurane, nitroglycerin, and adenosine on subendocardial microcirculation: observation of the in situ beating swine heart under critical stenosis.

BACKGROUND: Although isoflurane may cause subendocardial hypoperfusion in the presence of coronary stenosis because of its coronary arteriolar dilatory effects, it is not known how the subendocardial microcirculation is affected. The authors examined the effects of isoflurane on poststenotic subendocardial microvessels with coronary stenosis. METHODS: The authors observed subendocardial microvessels in in situ beating swine hearts with or without critical stenosis of the left anterior descending coronary artery (LAD) with a needle-type videomicroscope during isoflurane- (ISO-H), adenosine- (ADE-H), and nitroglycerin- (NTG-H) induced hypotension (mean arterial pressure, 55 mmHg). Regional myocardial function, oxygen balance, and lactate metabolism in the region perfused by the LAD also were determined. RESULTS: In swine with stenosis, there were no differences in heart rate, cardiac output, and LAD blood flow among the three types of hypotension. Regional lactate production and anterior interventricular venous pO2 were similar during ISO-H and NTG-H but higher during ADE-H. With videomicroscopy, about half as many subendocardial microvessels could be visualized during ADE-H as with ISO-H and NTG-H. The average decrease in the systolic diameter of subendocardial microvessels of greater than 100 microm was 9 +/- 6% during ISO-H and 12 +/- 5% during NTG-H, but no consistent phasic diameter changes were observed during ADE-H. In swine without stenosis, a systolic diameter decrease was observed during all three types of hypotension. CONCLUSIONS: These findings suggest that hypotension induced by isoflurane or nitroglycerin preserves phasic diameter changes in subendocardial microvessels in the presence of critical coronary stenosis, whereas that induced by adenosine does not.

Adenosine↗

17D yellow fever virus infection of P388D1 cells mediated by monoclonal antibodies: properties of the macrophage Fc receptor.

Thirteen IgG monoclonal antibodies to the envelope protein of 17D yellow fever virus (17D YF) were produced. All of the antibodies, whether type-specific to 17D YF or flavivirus cross-reactive, mediated antibody-dependent enhancement (ADE) of virus growth in P388D1 cells. There was no consistent relationship between ADE titres and the degree or pattern of neutralizing and/or haemagglutination inhibition activity. Monoclonal antibodies of different isotypes were used to investigate further the properties of P388D1 Fc receptors. The effects of trypsin treatment of P388D1 on ADE were similar to those previously described in experiments measuring direct binding of IgG proteins or rosetting of sheep red blood cells (SRBC) by macrophages, demonstrating sensitivity to digestion by trypsin of the Fc receptor for monomeric IgG2a but not for IgG2b. Aggregated myeloma proteins of IgG2a and IgG2b isotypes competed equally well with either IgG2a or IgG2b monoclonal antibodies to 17D YF in inhibition of ADE. However, selective inhibition by the homologous isotype was observed when rosetting by P388D1 of SRBC coated with IgG2a or IgG2b monoclonal antibodies was examined. These results may help to explain apparent discrepancies previously reported between experiments utilizing direct binding of IgG proteins and those using rosetting of antibody-coated SRBC to examine Fc receptor properties and indicate that immune complexes of virus and antibody resemble aggregated immunoglobulins with respect to macrophage Fc receptor function and differ from antibody-coated SRBCs.

Animals↗

Chaotic desynchronization of multistrain diseases.

Multistrain diseases are diseases that consist of several strains, or serotypes. The serotypes may interact by antibody-dependent enhancement (ADE), in which infection with a single serotype is asymptomatic, but infection with a second serotype leads to serious illness accompanied by greater infectivity. It has been observed from serotype data of dengue hemorrhagic fever that outbreaks of the four serotypes occur asynchronously. Both autonomous and seasonally driven outbreaks were studied in a model containing ADE. For sufficiently small ADE, the number of infectives of each serotype synchronizes, with outbreaks occurring in phase. When the ADE increases past a threshold, the system becomes chaotic, and infectives of each serotype desynchronize. However, certain groupings of the primary and secondary infectives remain synchronized even in the chaotic regime.

Animals↗

Hydroxylation of N-(Delta-Isopentenyl)adenine to Zeatin: Relative Activities of Organ Systems from Actinidia arguta.

By incubating explants from Actinidia arguta seedlings on a nutrient medium supplemented with 20 to 30 micromolar N(6)-(Delta(2)-isopentenyl)adenine (i(6)Ade) and then measuring zeatin (io(6)Ade) accumulation in tissues, the distribution of i(6)Ade hydroxylase activities in whole plants could be determined. Based on analyses with three entire plants, it is estimated that, as an organ system, roots contain approximately 68% of the plant's hydroxylase, while stems and leaves account for about 26% and 6%, respectively, of the total activity. Depending on the part of the root examined, hydroxylase activities ranged from 20 to 148 nanomoles io(6)Ade accumulated per gram fresh weight per 24 hours of incubation. Stem activities ranged from 17 to 165 nanomoles per gram fresh weight per 24 hours with the lowest activities being found at the tip. Leaf activities were substantially lower (1-10 nanomoles per leaf depending on position) than either root or stem.

Journal Article↗

2-Chloroadenosine induction of vagally-mediated and atropine-resistant bronchomotor responses in anaesthetized guinea-pigs.

1. The bronchoconstrictor effects of intravenous administration of adenosine derivatives in anaesthetized non-curarized guinea-pigs have been studied. 2. 2-Chloroadenosine (2-Cl-Ade), 5'-N-ethylcarboxamideadenosine (NECA) and L-N6-phenylisopropyl-adenosine (L-PIA) all produced dose-dependent, transient increases in tracheal insufflation pressure, with an order of potency (NECA greater than or equal to 2-Cl-Ade much greater than L-PIA) typical of A2-receptor mediated biological responses. 3. 2-Chloradenosine-induced bronchoconstrictor responses disappeared after vagotomy or topical application of tetrodotoxin (TTX) on cervical vagal trunks. 4. 2-Chloradenosine-induced bronchospasm was unaffected by atropine (1 mg kg-1 i.v.), physostigmine (50 micrograms kg-1 i.v.) and hexamethonium (30 mg kg-1 i.v.) but was significantly reduced by theophylline (25 mg kg-1 i.v.). 5. The magnitude of 2-Cl-Ade-induced bronchospasm was significantly reduced by acute (10 micrograms kg-1 i.v.) or chronic (55 mgkg-1 s.c. four days before the experiment) pretreatment with capsaicin. 6. Guanethidine (20 mg kg-1 s.c on two consecutive days), prazosin (10 micrograms kg-1 i.v.), diphenhydramine (1 mg kg-1 i.v.) and indomethacin (1 mg kg-1 i.v.) failed to block the bronchomotor response to 2-Cl-Ade. In contrast, cyproheptadine (1-5 mgkg-1 i.v.) markedly reduced, but did not abolish the bronchospasm elicited by the purine derivative. 7. We conclude that in anaesthetized non-curarized guinea-pigs, a transient vagally-mediated bronchospasm can be induced by stimulation of A2-purinoceptors. This effect is complex and involves, at least in part, stimulation of capsaicin-sensitive sensory nerves and 5-hydroxytryptamine release. This experimental model might be useful for the further study of the potential role of adenosine in asthma, and for the evaluation of new antiasthma drugs.

2-Chloroadenosine↗

Curriculum structure and the European Credit Transfer System for European dental schools: part I.

This paper presents a proposed curriculum structure and system of European Credit Transfer (ECTS) for undergraduate dental schools throughout Europe. It is the result of the work of a Taskforce ('Taskforce II'), appointed by DentEd, a thematic network of European dental schools and the Association for Dental Education in Europe (ADEE). There has been pan-European discussion of the document in draft stages (it was distributed to 200 dental schools) and following amendment, it was agreed formally at the National Assembly of ADEE in Athens, Greece, in September 2005. The main elements of the paper relate to: (i) a description of the framework proposed with relevance to the Bologna recommendations and common directive on recognition for professional qualifications as they apply to Dentistry; (ii) the structure of an undergraduate dental curriculum; (iii) student exchange and ECTS. In addition, the paper presents a series of requirements, guidelines and recommendations for action. ADEE expects that the 'requirements' proposed will be followed by dental schools in Europe, whilst the 'guidelines' and 'recommendations' also provided are open to local interpretation. The paper is also published on the ADEE website.

Advisory Committees↗

Applying the performance improvement team concept to the medication order process.

Healthcare literature suggests that most adverse drug events (ADEs) are the results of errors at the prescribing stage. These ADEs affect patients, physicians, pharmacists, nurses, and hospital administrators. Improving systems and providing education, rather than tracking the performance of individual prescribers, seem to be more effective in preventing and reducing ADEs. Pharmacists' participation on patient medical rounds and their presence in a satellite pharmacy increased their accessibility and their ability to share pertinent clinical information and thereby improved the medication order process and, ultimately, patient care. The pharmacy and medicine departments at one hospital took a proactive multidisciplinary approach that resulted in streamlining the medication order process, decreasing delays in initiating drug therapy, preventing ADEs, enhancing the knowledge of healthcare professionals, meeting the needs and expectations of patients and providers, and employing cost-effective drug therapy.

Adverse Drug Reaction Reporting Systems↗

Donor strains of the soft-rot bacterium Erwinia chrysanthemi and conjugational transfer of the pectolytic capacity.

Donor strains of Erwinia chrysanthemi ICPB EC16, a member of the soft-rot (pectolytic) section of the enterobacterial genus Erwinia, were obtained by chromosomal integration of an F'lac(+) plasmid originating from Escherichia coli. These stable donor strains, selected from an unstable F'lac(+) heterogenote by repeated platings of single Lac(+) colonies on lactose minimal agar, do not segregate (as does the parent F'lac(+) heterogenote) into Lac(-) or F(-) clones, in either the presence or absence of acridine orange. One representative donor strain (from the 12 that have been selected) has been examined in more detail; it can transfer ade(+), gal(+), gtu(+) (utilization of galacturonate), his(+), lac(+), leu(+), lys(+), mcu(+) (multiple carbohydrate utilization), pat(+) (production of polygalacturonic acid trans-eliminase), thr(+), and trp(+) in a polarized manner to appropriate recipient strains of E. chrysanthemi; the frequencies of ade(+), leu(+), and thr(+) transfer were higher than those of the other markers tested to date. This donor strain transfers lac(+) genes during a 6-h mating on membranes; most of the Lac(+) recombinants are donors of chromosomal markers. The kinetics of entry as well as the frequencies of transfer of chromosomal markers indicate that thr(+) and leu(+) enter the recipient as proximal markers and that lac(+) enters as a distal marker. Analysis of the recombinants demonstrates close linkage between thr and leu, ade and thr, his and pat, and his and trp loci. The results suggest that the integration of F'lac(+) into the chromosome of E. chrysanthemi has occurred at a region adjacent to the leu-thr loci, and that the chromosome is transferred in the following sequence: origin----leu--thr--ade--lys--mcu--pat--his--trp--gal--gtu--lac--F. Plant-tissue maceration occurs in Pat(+) recombinants and not in Pat(-) recombinants, even though both form another pectolytic enzyme, hydrolytic polygalacturonase. This genetic evidence supports the idea that the E. chrysanthemi polygalacturonic acid trans-eliminase plays an essential role in bringing about plant-tissue maceration.

Chromosomes, Bacterial↗

Two immunodominant domains of gp41 bind antibodies which enhance human immunodeficiency virus type 1 infection in vitro.

Four of eight human monoclonal antibodies (huMAbs) to gp41 were identified which could enhance human immunodeficiency virus type 1 (HIV-1) infection in vitro by complement-mediated antibody-dependent enhancement (C'-ADE). These enhancing huMAbs were mapped to two distinct domains on the HIV-1 gp41 transmembrane glycoprotein by using synthetic peptides. The first domain, amino acids 579 to 613 (peptide AA579-613), was recognized by three of the four enhancing huMAbs. The AA579-613 peptide blocked C'-ADE of HIV-1 infection in vitro whether it was mediated by these three huMAbs or by human polyclonal anti-HIV serum. The second domain, amino acids 644 to 663, bound the remaining enhancing huMAb. This peptide weakly blocked C'-ADE mediated by the huMAb and by an HIV immune globulin fraction but did not block C'-ADE mediated by a patient's serum. The patient's serum did react with the peptide in an enzyme immunoassay. The huMAbs to the two domains could interact in vitro to enhance HIV-1 infection in a synergistic manner. These two domains, which bind enhancing antibodies, are conserved between HIV-1 isolates as well as between HIV-2 and simian immunodeficiency virus isolates. These data demonstrate the existence of two conserved regions within the HIV-1 gp41 which bind enhancing antibodies; these two domains, amino acids 579 to 613 and 644 to 663, may prove important in HIV-1 vaccine development and in immunopathogenesis of HIV-1 infection.

Amino Acid Sequence↗

Yeast AMP pathway genes respond to adenine through regulated synthesis of a metabolic intermediate.

In Saccharomyces cerevisiae, AMP biosynthesis genes (ADE genes) are transcriptionally activated in the absence of extracellular purines by the Bas1p and Bas2p (Pho2p) transcription factors. We now show that expression of the ADE genes is low in mutant strains affected in the first seven steps of the pathway, while it is constitutively derepressed in mutant strains affected in later steps. Combined with epistasy studies, these results show that 5'-phosphoribosyl-4-succinocarboxamide-5-aminoimidazole (SAICAR), an intermediate metabolite of the pathway, is needed for optimal activation of the ADE genes. Two-hybrid studies establish that SAICAR is required to promote interaction between Bas1p and Bas2p in vivo, while in vitro experiments suggest that the effect of SAICAR on Bas1p-Bas2p interaction could be indirect. Importantly, feedback inhibition by ATP of Ade4p, catalyzing the first step of the pathway, appears to regulate SAICAR synthesis in response to adenine availability. Consistently, both ADE4 dominant mutations and overexpression of wild-type ADE4 lead to deregulation of ADE gene expression. We conclude that efficient transcription of yeast AMP biosynthesis genes requires interaction between Bas1p and Bas2p which is promoted in the presence of a metabolic intermediate whose synthesis is controlled by feedback inhibition of Ade4p acting as the purine nucleotide sensor within the cell.

Adenine↗

The identification, characterization, and mapping of a gene for flocculation in Saccharomyces sp.

Genetic studies of a flocculent haploid strain of Saccharomyces have revealed the flocculation to be dominant and controlled at a single gene locus. The flocculation character of both hybrids and haploids derived from such hybrids appears to be influenced by the repression or derepression status of the culture. Mapping studies of this flocculation gene have revealed that it is linked to ade 1 and therefore located on Chromosome I. Consequently, this is a different gene to the three flocculation genes studied by other laboratories because they have found such genes to be unlinked to ade 1. The flocculation gene being discussed in this paper has been designated FLO4. FLO4 has been located 32-33 cM from the Chromosome I centromere and 37 cM from ade 1 (i.e., FLO4 is on the opposite side of the centromere to ade 1).

Chromosome Mapping↗

Adenylyl cyclase P-site ligands accelerate differentiation in Ob1771 preadipocytes.

Differentiation of Ob1771 preadipocytes to adipocytes was characterized by morphological changes and elevated expression of the specific marker enzyme, glycerol-3-phosphate dehydrogenase. A differentiation response substantially more complete and rapid than that obtained with insulin and 3,5,3'-triiodothyronine was observed with established inhibitors of adenylyl cyclases: 2', 5'-dideoxyadenosine (2',5'-dd-Ado), 9-(cyclopentyl)adenine (9-CP-Ade), and 9-(arabinofuranosyl)adenine (9-Ara-Ade), coincident with decreased cellular cAMP levels. These ligands inhibit adenylyl cyclases noncompetitively, via a domain referred to as the P-site because of its requirement for an intact purine moiety. Differentiation was not induced by inosine, a nucleoside known not to act at the P-site, or by N6-(2-phenylisopropyl)adenosine or 1, 3-diethyl-8-phenylxanthine, agonist and antagonist, respectively, for adenosine A1 receptors. Also ineffective were IBMX or forskolin, agents that can raise intracellular cAMP levels. Potency of the differentiation response followed the order 2',5'-dd-Ado (1-20 microM) > 9-CP-Ade (10-100 microM) = 9-Ara-Ade (10-100 microM) >> inosine, consistent with their potencies to inhibit adenylyl cyclases. The data suggest that inhibition of adenylyl cyclase via the P-site and the consequent reduction in cell cAMP levels facilitate the induction of differentiation in Ob1771 cells. The findings raise the question whether the known endogenous P-site ligands participate in the differentiation response induced by hormones.

Adenylyl Cyclases↗

Effects of L-arginine and N omega-nitro-L-arginine methyl ester on cardiac perfusion and function after 1-day cold preservation of isolated hearts.

BACKGROUND: Coronary flow responses to endothelium-dependent (acetylcholine [ACh] or 5-hydroxytryptamine [5-HT]) and endothelium-independent (adenosine [ADE] or nitroprusside [NP]) vasodilators may be altered before and after 1-day hypothermia during the perfusion of arginine vasopressin (AVP), D-arginine (D-ARG), L-arginine (L-ARG), or nitro-L-arginine methyl ester (L-NAME). METHODS AND RESULTS: Four groups of guinea pig hearts (37.5 degrees C [warm]) were perfused for 6 hours with AVP, L-ARG, L-NAME, or nothing (control). Five heart groups (cold) were perfused with AVP, D-ARG, L-ARG, L-NAME, or nothing (control), but after 2 hours they were perfused at low flow for 22 hours at 3.7 degrees C and again for 3 hours at 37.5 degrees C. ADE, butanedione monoxime, and NP were given for cardioprotection before, during, and after hypothermia. In warm groups, L-ARG did not alter basal flow or ADE, ACh, 5-HT, or NP responses, whereas L-NAME and AVP reduced basal flow and the ADE response, abolished ACh and 5-HT responses, and increased the NP response. In cold groups after hypothermia. L-ARG did not alter basal flow, but L-NAME, AVP, D-ARG, and control reduced flow. In the postcold L-ARG group, ACh increased peak flow, but NP did not increase flow in other cold groups. Effluent L-ARG and L-CIT in the cold control group fell from 64 +/- 9 and 9 +/- 1 micrograms/L at 1 hour to 36 +/- 5 and 5 +/- 1 micrograms/L at 25 hours, respectively. Left ventricular pressure and cardiac efficiency improved more in the postcold L-ARG group than in the postcold D-ARG, AVP, and L-NAME groups. CONCLUSIONS: Endogenous effluent levels of L-ARG and L-CIT decrease after 24 hours in isolated hearts, whereas perfusion of L-ARG improves cardiac performance, basal coronary flow, and vasodilator responses. In contrast, L-NAME, L-ARG, and AVP limit flow and performance but maintain a partial vasodilatory response to NP. Sustained release of NO may account for improved performance after L-ARG after hypothermia.

Animals↗

Impact of computerized physician order entry on medication prescription errors in the intensive care unit: a controlled cross-sectional trial.

INTRODUCTION: Medication errors in the intensive care unit (ICU) are frequent and lead to attributable patient morbidity and mortality, increased length of ICU stay and substantial extra costs. We investigated if the introduction of a computerized ICU system (Centricity Critical Care Clinisoft, GE Healthcare) reduced the incidence and severity of medication prescription errors (MPEs). METHODS: A prospective trial was conducted in a paper-based unit (PB-U) versus a computerized unit (C-U) in a 22-bed ICU of a tertiary university hospital. Every medication order and medication prescription error was validated by a clinical pharmacist. The registration of different classes of MPE was done according to the National Coordinating Council for Medication Error Reporting and Prevention guidelines. An independent panel evaluated the severity of MPEs. We identified three groups: minor MPEs (no potential to cause harm); intercepted MPEs (potential to cause harm but intercepted on time); and serious MPEs (non-intercepted potential adverse drug events (ADE) or ADEs, being MPEs with potential to cause, or actually causing, patient harm). RESULTS: The C-U and the PB-U each contained 80 patient-days, and a total of 2,510 medication prescriptions were evaluated. The clinical pharmacist identified 375 MPEs. The incidence of MPEs was significantly lower in the C-U compared with the PB-U (44/1286 (3.4%) versus 331/1224 (27.0%); P < 0.001). There were significantly less minor MPEs in the C-U than in the PB-U (9 versus 225; P < 0.001). Intercepted MPEs were also lower in the C-U (12 versus 46; P < 0.001), as well as the non-intercepted potential ADEs (21 versus 48; P < 0.001). There was also a reduction of ADEs (2 in the C-U versus 12 in the PB-U; P < 0.01). No fatal errors occurred. The most frequent drug classes involved were cardiovascular medication and antibiotics in both groups. Patients with renal failure experienced less dosing errors in the C-U versus the PB-U (12 versus 35 serious MPEs; P < 0.001). CONCLUSION: The ICU computerization, including the medication order entry, resulted in a significant decrease in the occurrence and severity of medication errors in the ICU.

Adult↗

Halothane reduces release of adenosine, inosine, and lactate with ischemia and reperfusion in isolated hearts.

We investigated the protective effects of halothane on cardiac function of isolated hearts during global hypoperfusion and reperfusion by examining halothane's effects on altering coronary flow, myocardial oxygen utilization (MVO2), and release of adenosine (ADE), inosine (INO), and lactate (LAC). Isolated perfused guinea pig hearts were divided into three groups of perfusion at 25% (14 mm Hg), 10% (5.5 mm Hg), and 0% (no perfusion) from control perfusion pressure (PP, 55 mm Hg). Each of these PP groups was subdivided into three subgroups and perfused without halothane (control), with 0.23 +/- 0.01 mM (0.74%) halothane, or with 0.51 +/- 0.01 mM (1.65%) halothane. Halothane was present 10 min before reducing PP, during reduced PP (30 min), and for 10 min after reducing PP. Hypoperfusion was followed by 40 min of reperfusion at the control (100%, 55 mm Hg) PP. An additional group of control hearts was followed for the same period without reducing PP or perfusing with halothane. Exposure to 0.74% and 1.65% halothane, before reducing PP, decreased MVO2 and percent oxygen extraction (% O2E), but produced no significant change in coronary flow or release of ADE, ISO, or LAC. During early hypoperfusion (10 min) at 25% PP, 1.65% halothane significantly reduced release of ADE, INO, and LAC. During late hypoperfusion (40 min) the differences in LAC release diminished, but release of ADE and INO remained lower in the 1.65% halothane group. With early reperfusion there was a large increase in release of these metabolites, that was dependent on the decrease in perfusion pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

Endogenous Cerberus activity is required for anterior head specification in Xenopus.

We analyzed the endogenous requirement for Cerberus in Xenopus head development. 'Knockdown' of Cerberus function by antisense morpholino oligonucleotides did not impair head formation in the embryo. In contrast, targeted increase of BMP, Nodal and Wnt signaling in the anterior dorsal-endoderm (ADE) resulted in synergistic loss of anterior head structures, without affecting more posterior axial ones. Remarkably, those head phenotypes were aggravated by simultaneous depletion of Cerberus. These experiments demonstrated for the first time that endogenous Cerberus protein can inhibit BMP, Nodal and Wnt factors in vivo. Conjugates of dorsal ectoderm (DE) and ADE explants in which Cerberus function was 'knocked down' revealed the requirement of Cerberus in the ADE for the proper induction of anterior neural markers and repression of more posterior ones. This data supports the view that Cerberus function is required in the leading edge of the ADE for correct induction and patterning of the neuroectoderm.

Animals↗