Spray-induced gene silencing to identify powdery mildew gene targets and processes for powdery mildew control

Spray-induced gene silencing (SIGS) is an emerging tool for crop pest protection. It utilizes exogenously applied double-stranded RNA to specifically reduce pest target gene expression using endogenous RNA interference machinery. In this study, SIGS methods were developed and optimized for powdery mildew fungi, which are widespread obligate biotrophic fungi that infect agricultural crops, using the known azole-fungicide target cytochrome P450 51 (CYP51) in the Golovinomyces orontii-Arabidopsis thaliana pathosystem. Additional screening resulted in the identification of conserved gene targets and processes important to powdery mildew proliferation: apoptosis-antagonizing transcription factor in essential cellular metabolism and stress response; lipid catabolism genes lipase a, lipase 1, and acetyl-CoA oxidase in energy production; and genes involved in manipulation of the plant host via abscisic acid metabolism (9-cis-epoxycarotenoid dioxygenase, xanthoxin dehydrogenase, and a putative abscisic acid G-protein coupled receptor) and secretion of the effector protein, effector candidate 2. Powdery mildew is the dominant disease impacting grapes and extensive powdery mildew resistance to applied fungicides has been reported. We therefore developed SIGS for the Erysiphe necator-Vitis vinifera system and tested six successful targets identified using the G. orontii-A. thaliana system. For all targets tested, a similar reduction in powdery mildew disease was observed between systems. This indicates screening of broadly conserved targets in the G. orontii-A. thaliana pathosystem identifies targets and processes for the successful control of other powdery mildew fungi. The efficacy of SIGS on powdery mildew fungi makes SIGS an exciting prospect for commercial powdery mildew control.

Volatile anaesthesia and peri-operative outcomes related to cancer: a feasibility and pilot study for a large randomised control trial

Published data suggest that the type of general anaesthesia used during surgical resection for cancer may impact on patient long-term outcome. However, robust prospective clinical evidence is essential to guide a change in clinical practice. We explored the feasibility of conducting a randomised controlled trial to investigate the impact of total intravenous anaesthesia with propofol vs. inhalational volatile anaesthesia on postoperative outcomes of patients undergoing major cancer surgery. We undertook a randomised, double-blind feasibility and pilot study of propofol total intravenous anaesthesia or volatile-based maintenance anaesthesia during cancer resection surgery at three tertiary hospitals in Australia and the USA. Patients were randomly allocated to receive propofol total intravenous anaesthesia or volatile-based maintenance anaesthesia. Primary outcomes for this study were successful recruitment to the study and successful delivery of the assigned anaesthetic treatment as per randomisation arm. Of the 217 eligible patients approached, 146 were recruited, a recruitment rate of 67.3% (95%CI 60.6-73.5%). One hundred and forty-five patients adhered to the randomised treatment arm, 99.3% (95%CI 96.2-100%). Intra-operative patient characteristics and postoperative complications were comparable between the two intervention groups. This feasibility and pilot study supports the viability of the protocol for a large, randomised controlled trial to investigate the effect of anaesthesia technique on postoperative cancer outcomes. The volatile anaesthesia and peri-operative outcomes related to cancer (VAPOR-C) study that is planned to follow this feasibility study is an international, multicentre trial with the aim of providing evidence-based guidelines for the anaesthetic management of patients undergoing major cancer surgery.

An MDS-specific frailty index based on cumulative deficits adds independent prognostic information to clinical prognostic scoring

The frailty index (FI) is based on the principle that the more deficits an individual has, the greater their risk of adverse outcomes. It is expressed as a ratio of the number of deficits present to the total number of deficits considered. We developed an MDS-specific FI using a prospective MDS registry and assessed its ability to add prognostic power to conventional prognostic scores in MDS. The 42 deficits included in this FI included measurements of physical performance, comorbidities, laboratory values, instrumental activities of daily living, quality of life and performance status. Of 644 patients, 440 were eligible for FI calculation. The median FI score was 0.25 (range 0.05-0.67), correlated with age and IPSS/IPSS-R risk scores and discriminated overall survival. With a follow-up of 20 months, survival was 27 months (95% CI 24-30.4). By multivariate analysis, age >70, FI, transfusion dependence, and IPSS were significant covariates associated with OS. The incremental discrimination improvement of the frailty index was 37%. We derived a prognostic score with five risk groups and distinct survivals ranging from 7.4 months to not yet reached. If externally validated, the MDS-FI could be used as a tool to refine the risk stratification of current clinical prognostication models.

4179Feasibility and validation of routine CMR-based phenotyping for the prediction of heart failure admission or death in patients with systolic dysfunction

Background

Standardized patient phenotyping using cardiovascular magnetic resonance (CMR) imaging has been shown to be of clinical value for prediction of adverse events in patients with heart failure and reduced ejection fraction (HFrEF). Studies have validated the prognostic capacity of function (LV, RV and LA) and replacement fibrosis burden in patients with ischemic and non-ischemic cardiomyopathy. The translation and validation of routine CMR-based phenotyping into clinical practice has yet to be demonstrated in prospective studies.

Purpose

This study was designed to explore feasibility and prognostic value of routine CMR-based patient phenotyping in a high-volume clinical referral center for patients with HFrEF.

Methods

One thousand three hundred and ninety-three consecutive patients with chronic HFrEF were prospectively recruited between January 2015 and June 2018. Chronic HFrEF was defined by LVEF≤50% by CMR, with no recent (within 90 days) acute myocardial infarction or myocarditis diagnosis. Patients with congenital heart disease and those without LGE CMR protocol were excluded. All patients underwent standardized CMR protocols with multi-chamber volumetric analysis and regional myocardial fibrosis coding. Pharmacy, ECG, laboratory and patient reported data was used for statistical modelling. A minimum three-month follow-up was mandated to identify the composite clinical outcome of heart failure hospitalization or death.

Results

The cohort had a median age of 61 years with 23% being female. The median follow-up was 737 days with 146 patients (10.5%) experiencing the composite outcome. Numerous imaging and non-imaging variables were significantly different between patients with and without the composite outcome, including: median LVEF (32% vs 39%, p<0.0001), RVEF (46% vs 51% p<0.0001), LV mass (77g/m2 vs. 65g/m2, p<0.0001), digoxin (19% vs. 9%, p<0.0001) and diuretic (63% vs 41%, p<0.0001) use. Presence of replacement fibrosis (HR=2.09, p=0.001), particularly midwall striae (HR=2.01, p<0.0001), diffuse (HR=3.88, p<0.0001) and RV insertion site fibrosis (HR=1.54, p=0.022) patterns, were significantly associated with the combined endpoint. A stepwise multivariable model was applied using all eligible variables and resulted in robust accuracy for prediction of the combined outcome with a concordance index of 0.751 (Figure 1).

Conclusions

This study demonstrates the feasibility and prognostic value of automated patient phenotyping that captures patient reported data, imaging, and administrative data for risk prediction modelling in HFrEF. The incremental application of machine learning is being explored.

Acknowledgement/Funding

J White: Early Investigator Award (Heart and Stroke Foundation of Alberta), Calgary Health Trust

Aspergillus galactomannan detection in exhaled breath condensate compared to bronchoalveolar lavage fluid for the diagnosis of invasive aspergillosis in immunocompromised patients

OBJECTIVES

Exhaled breath condensate (EBC) is a noninvasive means of sampling the airways that has shown significant promise in the diagnosis of many disorders. There have been no reports of its usefulness in the detection of galactomannan (GM), a component of the cell wall of Aspergillus. The suitability of EBC for the detection of GM for the diagnosis of invasive aspergillosis (IA) using the Platelia Aspergillus enzyme-linked immunosorbent assay was investigated.

METHODS

Prospective, cross-sectional study of lung transplant recipient and haemotologic malignancy patients at a university centre. EBC samples were compared to concomitant bronchoalveolar lavage (BAL) samples among lung transplant recipients and healthy controls. EBC was collected over 10 minutes using a refrigerated condenser according to the European Respiratory Society/American Thoracic Society recommendations, with the BAL performed immediately thereafter.

RESULTS

A total of 476 EBC specimens with 444 matched BAL specimens collected from lung transplant recipients (n = 197) or haemotologic malignancy patients (n = 133) were examined. Both diluted and untreated EBC optical density (OD) values (0.0830, interquartile range (IQR) 0.0680-0.1040; and 0.1130, IQR 0.0940-0.1383), respectively, from all patients regardless of clinical syndrome were significantly higher than OD values in healthy control EBCs (0.0508, IQR 0.0597-0.0652; p < 0.0001). However, the OD index values did not correlate with the diagnosis of IA (44 samples were associated with IA). Furthermore, no significant correlation was found between EBC GM and the matched BAL specimen.

CONCLUSIONS

GM is detectable in EBC; however, no correlation between OD index values and IA was noted in lung transplant recipients.

A phase 1b/2b multicenter study of oral panobinostat plus azacitidine in adults with MDS, CMML or AML with ⩽30% blasts

Treatment with azacitidine (AZA), a demethylating agent, prolonged overall survival (OS) vs conventional care in patients with higher-risk myelodysplastic syndromes (MDS). As median survival with monotherapy is <2 years, novel agents are needed to improve outcomes. This phase 1b/2b trial (n=113) was designed to determine the maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) of panobinostat (PAN)+AZA (phase 1b) and evaluate the early efficacy and safety of PAN+AZA vs AZA monotherapy (phase 2b) in patients with higher-risk MDS, chronic myelomonocytic leukemia or oligoblastic acute myeloid leukemia with <30% blasts. The MTD was not reached; the RP2D was PAN 30 mg plus AZA 75 mg/m². More patients receiving PAN+AZA achieved a composite complete response ([CR)+morphologic CR with incomplete blood count+bone marrow CR (27.5% (95% CI, 14.6–43.9%)) vs AZA (14.3% (5.4–28.5%)). However, no significant difference was observed in the 1-year OS rate (PAN+AZA, 60% (50–80%); AZA, 70% (50–80%)) or time to progression (PAN+AZA, 70% (40–90%); AZA, 70% (40–80%)). More grade 3/4 adverse events (97.4 vs 81.0%) and on-treatment deaths (13.2 vs 4.8%) occurred with PAN+AZA. Further dose or schedule optimization may improve the risk/benefit profile of this regimen.

Acute Subdural Haematoma in the Presence of an Intrathecal Catheter Placed for the Prevention of Post-Dural Puncture Headache

A 31-year-old term primigravid woman had an intrathecal catheter placed following a dural puncture during attempted epidural analgesia during labour. After 23 hours she developed sudden loss of consciousness and an urgent brain computed tomography scan demonstrated a large left hyper-acute subdural haematoma. Craniotomy revealed active bleeding from a ruptured left temporal bridging vein. She was extubated 12 hours after surgery and was discharged home 11 days later without neurological deficit. Although subdural haematoma is a recognised complication of dural puncture, it has not been reported in the presence of an intrathecal catheter. An intrathecal catheter may not always prevent cerebrospinal fluid efflux, so subdural haematoma remains a potential complication of inadvertent dural puncture.

Subdural Hematomas during CML Therapy with Imatinib Mesylate

Seven of one hundred twenty-one patients with chronic myeloid leukemia (CML) treated with imatinib mesylate developed subdural hematomas. All had advanced disease and were treated initially at a dose of 600 mg per day. Three patients had thrombocytopenia (platelet < 10 x 10(9)/l), one had leukocytosis (white blood cell count > 150 x 10(9)/l) and three had neither around the time of diagnosis of the subdural hematomas. Four patients required surgical evacuation. One patient, in blast crisis, died as a consequence of the subdural hematoma. Three patients survived but died of progressive CML. The remaining three patients having recommenced imatinib, are alive and well, and one has achieved a major cytogenetic response. Subdural hematomas must be considered even in mildly symptomatic patients receiving imatinib regardless of their peripheral blood counts. Patients who survive can be cautiously restarted on imatinib. Further studies are required to study the potential relationship between imatinib mesylate and subdural hematomas.

Are live bird markets reservoirs of avian influenza?

Live bird markets (LBM) are essential for marketing poultry in many developing countries, and they are a preferred place for many people to purchase poultry for consumption throughout the world. Live bird markets are typically urban and have a permanent structure in which birds can be housed until they are sold. Live bird markets bring together a mixture of bird species that meet the preferences of their customers and that are commonly produced by multiple suppliers. The mixture of species, the lack of all-in-all-out management, and multiple suppliers are all features that make LBM potential sources of avian influenza viruses (AIV), especially for their supply flocks. Live bird markets have been linked to many outbreaks of avian influenza internationally and in the United States. Avian influenza virus is endemic in many, but not all, LBM systems. For instance, AIV has not been isolated from the Southern California LBM system since December 2005, although the risk of new introductions remains. The California LBM system is much smaller than the New York system, handles fewer birds, and has fewer bird suppliers, which, combined with recent avian influenza prevention and control plans, have enabled it to be AIV free for nearly 3 yr.

A functional link between Wnt signaling and SKP2-independent p27 turnover in mammary tumors

Loss of the CDK inhibitor p27(KIP1) is widely linked with poor prognosis in human cancer. In Wnt10b-expressing mammary tumors, levels of p27(KIP1) were extremely low; conversely, Wnt10b-null mammary cells expressed high levels of this protein, suggesting Wnt-dependent regulation of p27(KIP1). Interestingly we found that Wnt-induced turnover of p27(KIP1) was independent from classical SCF(SKP2)-mediated degradation in both mouse and human cells. Instead, turnover required Cullin 4A and Cullin 4B, components of an alternative E3 ubiquitin ligase induced in response to active Wnt signaling. We found that CUL4A was a novel Wnt target gene in both mouse and human cells and that CUL4A physically interacted with p27(KIP1) in Wnt-responding cells. We further demonstrated that both Cul4A and Cul4B were required for Wnt-induced p27(KIP1) degradation and S-phase progression. CUL4A and CUL4B are therefore components of a conserved Wnt-induced proteasome targeting (WIPT) complex that regulates p27(KIP1) levels and cell cycle progression in mammalian cells.

Lipopolysaccharide and TNF-α Activate the Nuclear Factor Kappa B Pathway in the Human Placental JEG-3 Cells

Up-regulation of pro-inflammatory cytokines, cyclooxygenase (COX-2) and prostaglandins is a critical factor driving human term labour and inflammation-associated preterm labour. Nuclear factor kappa B (NF-kappaB) is activated in response to a number of inflammatory mediators, including cytokines and lipopolysaccharide (LPS). The aim of this study was (i) to investigate if TNF-alpha and LPS activate the NF-kappaB pathway; and (ii) to use short interfering RNA (siRNA) against inhibitor kappaB kinase (IKK)-beta to confirm the role of the NF-kappaB pathway in the regulation of pro-inflammatory mediators in human placental JEG-3 cells. JEG-3 cells (3 independent experiments) were (i) incubated in the presence or absence of 10 microg/ml LPS or 20 ng/ml TNF-alpha, or (ii) transfected with 100 nM IKK-beta siRNA. Incubation of JEG-3 cells with LPS and TNF-alpha increased the expression of cytoplasmic IKK-beta and phosphorylated IkappaB-alpha, and nuclear NF-kappaB proteins p50 and p65. This was associated with a concurrent increase in COX-2 protein, and IL-6 and PGF2alpha release from JEG-3 cells. Treatment of cells with BAY 11-7082 at 50 microM significantly inhibited basal, LPS- and TNF-alpha-induced NF-kappaB and COX-2 expression, and IL-6 and PGF2alpha release. Transfection of JEG-3 cells with IKK-beta siRNA significantly decreased IL-6 and PGF2alpha release. The data presented in this study demonstrate that pro-inflammatory mediators regulate the NF-kappaB transcription pathway in human JEG-3 cells, and the IKK-beta/NF-kappaB pathway is a regulator of inflammatory mediators in placental JEG-3 cells.

Quantitative PCR identifies a minimal deleted region of 120 kb extending from the Philadelphia chromosome ABL translocation breakpoint in chronic myeloid leukemia with poor outcome

Fluorescence in situ hybridization (FISH) analysis has shown previously that 10-15% of chronic myeloid leukemias (CML) have hemizygous deletions of variable sizes affecting regions that flank the ABL and BCR translocation breakpoints on the derivative chromosome 9, and these patients have a poor outcome. FISH studies using large commercial genomic probes have previously suggested that haploinsufficiency of sequences flanking either ABL or BCR modify the disease process of CML and lead to an unfavorable prognosis. In this present study, real-time quantitative PCR (Q-PCR) analysis was used to identify and map much smaller hemizygous microdeletions in a subset of CML patients that were not deleted using large genomic FISH probes. Microdeletions were identified by Q-PCR in 25 of 71 patients selected based on less favorable outcome (chronic phase duration of less than 96 months and a survival time of less than 84 months). In contrast, no microdeletion was detected in any of 18 CML samples selected from a group with a more favorable outcome. Detailed mapping of the 25 Q-PCR microdeletions showed that the minimal deleted region extended approximately 120 kb from the 5' end of the ABL gene in the centromeric direction on the derivative chromosome 9, and the region 3' to BCR on chromosome 22 was excluded. Of the four ESTs and/or genes that map to the 120 kb region, the putative tumor suppressor PRDM12 is the strongest candidate gene. The potential role for each sequence in modifying the clinical behavior of CML is presented.

Toll-like receptor 3 mediates a more potent antiviral response than Toll-like receptor 4

We have recently described an IFN regulatory factor 3-mediated antiviral gene program that is induced by both Toll-like receptor (TLR)3 and TLR4 ligands. In our current study, we show that activation of IFN/viral response gene expression in primary macrophage cells is stronger and prolonged with TLR3 stimulation compared with that of TLR4. Our data also reveal that the cytoplasmic tails of both TLR3 and TLR4 can directly interact with myeloid differentiation factor 88 (MyD88). However, although Toll/IL-1 receptor homology domain-containing adaptor protein/MyD88 adaptor-like is able to associate with TLR4, we were unable to detect any interaction between Toll/IL-1 receptor homology domain-containing adaptor protein/MyD88 adaptor-like and TLR3. By using quantitative real-time PCR assays, we found that TLR3 expression is inducible by both TLR3 and TLR4 ligands, while TLR4 expression is not inducible by these same stimuli. Furthermore, using cells derived from mice deficient in the IFN-alphabetaR, we show that both TLR3 and TLR4 require IFN-beta autocrine/paracrine feedback to induce TLR3 expression and activate/enhance genes required for antiviral activity. More specifically, a subset of antiviral genes is initially induced independent of IFN-beta, yet the cytokine further enhances expression at later time points. This was in contrast to a second set of genes (including TLR3) that is induced only after IFN-beta production. Taken together, our data argue that, despite both TLR3 and TLR4 being able to use IFN-beta to activate/enhance antiviral gene expression, TLR3 uses multiple mechanisms to enhance and sustain the antiviral response more strongly than TLR4.

NKIATRE is a novel conserved cdc2-related kinase

The mitogen-activated protein kinases (MAPKs) and the cyclin-dependent kinases (CDKs) are key mediators of cell proliferation in response to extracellular signals. Recent additions to each of these families and the identification of kinases with structural features of both have provided insights into fundamental processes, such as cell division and differentiation. To identify novel serine kinases with features of MAPKs or CDKs, a degenerate PCR-based amplification approach was undertaken. The 57- and 52-kDa isoforms of a novel protein kinase, termed NKIATRE, were molecularly cloned from rat brain and jejunum cDNA libraries. Like the MAPKs, NKIATRE has a Thr-Xaa-Tyr motif in kinase subdomain VIII. NKIATRE also shows close homology to the cyclin-dependent kinase class of protein kinases and the cdc2-related kinases NKIAMRE, KKIALRE, and KKIAMRE, containing both conserved inhibitory phosphorylation sites and a putative cyclin-binding domain. Two isoforms of NKIATRE that differ in their carboxy-terminal ends have been identified. A functional nuclear localization signal is specific to the longer 57-kDa alpha isoform. Sequence similarity to the putative human tumor suppressor gene NKIAMRE, which is lost in leukemic patients with chromosome 5q deletions, suggests that NKIATRE may have a role in restricting cell growth or maintaining differentiation.

Novel Cystic Fibrosis mutation L1093P: functional analysis and possible Native American origin

A novel mutation was detected using single-strand conformation polymorphism and heteroduplex analysis in a cystic fibrosis subject of mixed ancestry. Mutation 3410T-->C in exon 17b caused the novel missense mutation L1093P; the other chromosome has mutation N1303K. The 31-year-old subject is pancreatic insufficient, had an FEV(1) score that was 33% of normal prior to a heart/lung transplant, and sweat chloride values of 116 and 95 mM when tested at ages 1 and 11. Functional analysis using forskolin-stimulated efflux of (125)I in HEK cells transfected with an ABCC7 construct harboring the L1093P mutation confirmed that cAMP-mediated anion efflux was abnormal, but some function was preserved. Analysis of parental DNA established that N1303K was of English origin, while L1093P was of Greek, Irish or Native American (Cherokee) origin. Given the intensive screening for CF mutations in European populations, we hypothesize that L1093P is of Native American origin. Hum Mutat 15:208, 2000.

Is outpatient laparoscopic cholecystectomy safe and cost-effective? A model to study transition of care

BACKGROUND

There is increasing pressure to perform traditional inpatient surgical procedures in an outpatient setting. The aim of the current trial was to determine the safety and cost savings of performing laparoscopic cholecystectomy in an outpatient setting using a "mock" outpatient setting.

METHODS

Patients who were scheduled for laparoscopic cholecystectomy by four attending surgeons and for whom operating time was available in the outpatient center were studied. All patients received a standardized anesthetic, including ondansetron, and were discharged from the outpatient postanesthesia care unit if appropriate. At discharge, all patients were admitted to a clinical research center where they were observed in a "mock home" setting and monitored for complications that would have necessitated readmission. A decision analysis was created assuming all patients underwent outpatient surgery with either direct admission or discharge to home and readmission if complications developed.

RESULTS

Of 99 patients who were enrolled in this study, 96 patients would have met the discharge criteria for home. No major complications were observed in these 96 patients. Eleven patients experienced postoperative nausea and vomiting, 3 of whom required an additional 24 h of hospital observation. In the decision model, the optimal strategy would be to perform the procedure on an outpatient basis and readmit patients only for complications, with an average baseline cost savings of $742/patient.

CONCLUSIONS

The results show that outpatient laparoscopic cholecystectomy is safe and cost-effective in selected patients, and that the mock home setting provides a means of studying the safety of transition of care.

Two novel mutations in a cystic fibrosis patient of Chinese origin

Cystic fibrosis is rare in non-Caucasian populations, and in such populations little is known about the spectrum of mutations and polymorphisms in the CFTR gene. We studied a 23-year-old patient of Chinese ethnicity with sweat chloride values of 104 mM/l, pancreatic sufficiency, an FEV1 60% of normal, sputum cultures positive for Staphylococcus aureus and Burkholderia cepacia, and a history of allergic bronchopulmonary aspergillosis. Genetic screening for 31 common CFTR mutations was negative, leading us to search for unknown mutations using single-strand conformation polymorphism and heteroduplex analysis (SSCP/HA). Two novel mutations were detected. In exon 4, a deletion of 8 bp (451458, deltaGCTTCCTA) causes a frameshift and immediately creates a stop codon. In exon 16, mutation 3041G-->A causes the missense change G970D. Functional analysis using an isotopic flux assay indicated that the G970D mutation retains partial function; western blotting indicated that the protein is glycosylated. The patient is heterozygous for the common polymorphisms (2694T/G) in exon 14a and (GATT)6/7 in intron 6a, indicating that these variants arose in ancestors common to Caucasians and Chinese.

Expression of p210 and p190 BCR-ABL due to alternative splicing in chronic myelogenous leukaemia

The hallmark of chronic myelogenous leukaemia (CML) is the presence of the Philadelphia chromosome and its resultant fusion message, BCR-ABL, and fusion protein, p210. Patients with CML in blast crisis, or with Philadelphia positive acute lymphoblastic leukaemia (ALL), can have a smaller BCR-ABL fusion transcript possessing only the first exon of BCR fused to ABL. This smaller transcript encodes a 190 kD protein which is more strongly transforming than the p210 protein derived from the larger CML-associated transcript. We performed RT-PCR on samples from CML patients in chronic phase to determine the frequency and mechanism of p190 and p210 co-expression and to see if this correlated with clinical indices. We examined the peripheral blood or marrow of 67 patients with CML and found that 35 of them expressed both transcripts whereas the remainder expressed the p210-encoding transcript exclusively. Additional PCR products of an intermediate size were also frequently detected and have been isolated and sequenced. Data from two of these products indicate that they are the result of alternative splicing and include variable combinations of BCR exons. We believe that the expression of the p190-encoding transcript in the chronic phase of CML is also due to alternative splicing. A comparison of patients co-expressing the p190- and p210-encoding transcripts with those patients who expressed only the p210-encoding transcript detected significantly higher white blood cell (WBC) counts and blast cell counts at time of testing as well as significantly higher white blood cell counts at diagnosis.

Effects of Nd: and Ho:yttrium-aluminium-garnet lasers on human dentine fluid flow and dental pulp-chamber temperature in vitro

Dentine specimens were prepared from freshly extracted third molars and initial permeability measured. Each specimen was subjected to Nd:yttrium-aluminium-garnet (YAG) (1.06 or 1.32 microns wavelength) or Ho:YAG (2.10 microns wavelength) laser energy while temperatures in the pulp chambers were recorded. Permeability was again measured and the surfaces examined by scanning electron microscopy. Six crown segments were used for each laser variable and eight permeability measurements were taken before and eight after laser exposure, while temperature was recorded during treatment. All wavelengths reduced permeability but temperature rises were high enough to have caused pulpal damage, indicating that shorter treatment times and lower power settings may be necessary if used in vivo.

Intraembryonic hematopoietic cell migration during vertebrate development

Vertebrate hematopoietic stem cells are derived from vental mesoderm, which is postulated to migrate to both extra- and intraembryonic positions during gastrula and neurula stages. Extraembryonic migration has previously been documented, but the origin and migration of intraembryonic hematopoietic cells have not been visualized. The zebrafish and most other teleosts do not form yolk sac blood islands during early embryogenesis, but instead hematopoiesis occurs solely in a dorsal location known as the intermediate cell mass (IM) or Oellacher. In this report, we have isolated cDNAs encoding zebrafish homologs of the hematopoietic transcription factors GATA-1 and GATA-2 and have used these markers to determine that the IM is formed from mesodermal cells in a posterior-lateral position on the yolk syncytial layer of the gastrula yolk sac. Surprisingly, cells of the IM then migrate anteriorly through most of the body length prior to the onset of active circulation and exit onto the yolk sac. These findings support a hypothesis in which the hematopoietic program of vertebrates is established by variations in homologous migration pathways of extra- and intraembryonic progenitors.

Role of SAPK/ERK kinase-1 in the stress-activated pathway regulating transcription factor c-Jun

The stress-activated protein kinases (SAPKs), which are distantly related to the MAP kinases, are the dominant c-Jun amino-terminal protein kinases activated in response to a variety of cellular stresses, including treatment with tumour-necrosis factor-alpha and interleukin-beta (refs 1, 2). SAPK phosphorylation of c-Jun probably activates the c-Jun transactivation function. SAPKs are part of a signal transduction cascade related to, but distinct from, the MAPK pathway. We have now identified a novel protein kinase, called SAPK/ERK kinase-1 (SEK1), which is structurally related to the MAP kinase kinases (MEKs). SEK1 is a potent activator of the SAPKs in vitro and in vivo. An inactive SEK1 mutant blocks SAPK activation by extracellular stimuli without interfering with the MAPK pathway. Although alternative mechanisms of SAPK activation may exist, as an immediate upstream activator of the SAPKs, SEK1 further defines a signalling cascade that couples cellular stress agonists to the c-Jun transcription factor.

Ventral expression of GATA-1 and GATA-2 in the Xenopus embryo defines induction of hematopoietic mesoderm

The early embryonic events involved in the commitment of mesoderm to form blood have not been studied in detail for lack of molecular markers. We have studied the expression of the hematopoietic transcription factors GATA-1 and GATA-2 during Xenopus embryogenesis. During development GATA-1 expression is localized to the ventral region of the embryo and precedes the expression of embryonic globins. GATA-2 is highly expressed in the ventral region of the embryo by the end of gastrulation and later is expressed in the blood island region and the central nervous system. Lithium-induced dorsalization of embryos abrogates GATA-2 expression, and uv-induced ventralization of embryos leads to a radially symmetrical expression of GATA-2. Therefore, GATA-2 expression reflects the ventral character of the embryo. The expression of the GATA-binding proteins and globin in ventral marginal zone explants demonstrates that hematopoiesis is programmed as early as the blastula stage. GATA-1 and GATA-2 are also expressed in cultured animal cap explants, suggesting that these cells have hematopoietic potential. The developmental expression of GATA-1 and GATA-2 is consistent with their role in hematopoiesis in higher organisms and defines the ventral regions of the early embryo that give rise to hematopoietic progenitors. Our studies indicate that these genes will be useful in defining the inductive events that lead to the formation of hematopoietic mesoderm.

Novel members of the mitogen-activated protein kinase activator family in Xenopus laevis

Mitogen-activated protein (MAP) kinases comprise an evolutionarily conserved family of proteins that includes at least three vertebrate protein kinases (p42, p44, and p55 MAPK) and five yeast protein kinases (SPK1, MPK1, HOG1, FUS3, and KSS1). Members of this family are activated by a variety of extracellular agents that influence cellular proliferation and differentiation. In Saccharomyces cerevisiae, there are multiple physiologically distinct MAP kinase activation pathways composed of structurally related kinases. The recently cloned vertebrate MAP kinase activators are structurally related to MAP kinase activators in these yeast pathways. These similarities suggest that homologous kinase cascades are utilized for signal transduction in many, if not all, eukaryotes. We have identified additional members of the MAP kinase activator family in Xenopus laevis by a polymerase chain reaction-based analysis of embryonic cDNAs. One of the clones identified (XMEK2) encodes a unique predicted protein kinase that is similar to the previously reported activator (MAPKK) in X. laevis. XMEK2, a highly expressed maternal mRNA, is developmentally regulated during embryogenesis and expressed in brain and muscle. Expression of XMEK2 in yeast cells suppressed the growth defect associated with loss of the yeast MAP kinase activator homologs, MKK1 and MKK2. Partial sequence of a second cDNA clone (XMEK3) identified yet another potential MAP kinase activator. The pattern of expression of XMEK3 is distinct from that of p42 MAPK and XMEK2. The high degree of amino acid sequence similarity of XMEK2, XMEK3, and MAPKK suggests that these three are related members of an amphibian family of protein kinases involved in the activation of MAP kinase. Discovery of this family suggests that multiple MAP kinase activation pathways similar to those in yeast cells exist in vertebrates.

Isolation of a novel receptor tyrosine kinase cDNA expressed by developing erythroid progenitors

Activation of distinct receptor tyrosine kinases (RTK), such as the products of the c-fms and c-kit proto-oncogenes, profoundly affects hematopoietic development. We have isolated a novel RTK cDNA, called met-related kinase (MRK), which is expressed on early erythroid progenitors. MRK is also expressed in many hematopoietic cell lines, and is not lineage restricted. Several regions within the catalytic domain of MRK have amino acid similarity to the c-met proto-oncogene and v-sea oncogene. Specific polyclonal anti-MRK antisera detects an 84-Kd polypeptide in COS cells transfected with an expression vector containing the MRK cDNA. Further studies of this novel RTK will provide potential insight into its role during hematopoiesis.

Expression of mRNA for the GATA-binding proteins in human eosinophils and basophils: potential role in gene transcription

The expression of the hematopoietic transcription factors GATA-1, GATA-2, and GATA-3 was studied in eosinophils and basophils. Eosinophils express mRNA for GATA-1, GATA-2, and GATA-3. Basophils express GATA-2 and GATA-3. Treatment of HL-60 eosinophilic sublines with either interleukin-5 or butyric acid increased the expression of GATA-1 mRNA concomitant with the expression of eosinophil-specific genes, whereas levels of GATA-2 mRNA remained relatively constant. The presence of mRNA for these proteins in eosinophils and basophils suggests that gene transcription in these lineages may be regulated by GATA-binding proteins.

Cytomegalovirus infection presenting as acute periodontal infection in a patient infected with the human immunodeficiency virus

During childhood, many people acquire primary infection with cytomegalovirus (CMV), one of the herpes viruses. If they later become immunosuppressed, such as occurs with human immunodeficiency virus (HIV) infection, CMV is likely to become reactivated. Severe disease caused by CMV is life-threatening in the HIV-infected population. CMV retinitis, gastritis, colitis, pneumonia, encephalitis and hepatitis have all been reported, but oral lesions due to infection with CMV are rarely reported. We report a case of oral CMV infection which at first was clinically indistinguishable from HIV-associated periodontal disease.

The role of thyroid hormone in the regulation of hepatic carbamyl phosphate synthetase activity in Rana catesbeiana

Both spontaneous and thyroid hormone (TH)-induced metamorphosis of Rana catesbeiana are accompanied by a marked increase in the activity of the urea cycle enzyme carbamyl phosphate synthetase (CPS). The increase induced by exogenous TH is de novo synthesis of enzyme and appears to be secondary to an increase in the CPS mRNA level resulting from the elevated plasma TH. Since endogenous TH levels rise sharply during spontaneous metamorphosis, a similar sequence of events would be anticipated. However, after midclimax, CPS activity continues to increase, while plasma TH levels steadily decline, suggesting that other factors are involved. To obtain insight into this problem, the changes in CPS mRNA level during spontaneous development were determined using a mammalian CPS cDNA probe and correlated with changes in CPS activity and plasma T3 concentration. CPS mRNA level and CPS activity were barely detectable until midprometamorphosis, but both increased rapidly during the latter half of this phase. CPS activity continued to rise, reaching a maximum in the adult frog. The CPS mRNA level, however, was highest during the first half of climax, but declined after midclimax and was relatively low in the adult frog. Studies were also performed in which the rise and fall in the plasma T3 concentration typical of metamorphic climax were induced by exposure of premetamorphic tadpoles to T3, followed by its withdrawal. Both CPS activity and CPS mRNA level were induced by T3, but when plasma T3 levels fell after removal of the exogenous T3, CPS mRNA level, but not CPS activity, also decreased. Additional studies indicated that the TH-induced increase in CPS mRNA was evident within 24 h, could be prevented by simultaneous injection of actinomycin-D, and could not be induced in tadpoles undergoing climax; in this phase the T3 receptors are fully occupied with endogenous TH. When premetamorphic tadpoles were immersed in T3-containing water (0-500 nM) for 6 days, CPS mRNA, CPS activity, and plasma T3 concentration increased in parallel, reaching a maximum at 50 nM. At 50 nM T3, the plasma T3 level was sufficient to saturate the receptors, and no additional increase in CPS mRNA level or CPS activity was obtained at higher concentrations of T3. These studies indicate that the CPS mRNA level during spontaneous development correlates with the plasma T3 concentration and suggest that it is a function of T3 receptor occupancy. The data are also consistent with an effect of TH on transcription of the CPS gene and with a relatively long half-life of its protein product, the CPS enzyme.

Decrease in polylactosaminoglycans associated with lysosomal membrane glycoproteins during differentiation of CaCo-2 human colonic adenocarcinoma cells

The proportion of labeled polylactosaminoglycans found in glycoproteins decreases during spontaneous differentiation of CaCo-2 human colonic adenocarcinoma cells to enterocytes in culture (A. Youakim and A. Herscovics, Biochem. J., 247: 299-306, 1987). To identify polylactosaminoglycan-containing glycoproteins, CaCo-2 cells were incubated with [3H]glucosamine or [3H]fucose, for 24 h, and membrane glycoproteins solubilized with 0.5% Nonidet P-40 were fractionated by affinity chromatography on Datura stramonium (DSA)-agarose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography showed that a restricted set of glycoproteins with a molecular weight of about 100,000 bound to DSA-agarose. These labeled glycoproteins were shown to contain polylactosaminoglycans by DSA-agarose chromatography and endo-beta-galactosidase digestion of Pronase-derived glycopeptides. Immunoprecipitation of the [3H]glucosamine-labeled Nonidet P-40 extract with polyclonal antibodies to the lysosomal membrane proteins h-lamp-1 and h-lamp-2 followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography also revealed a band with a molecular weight of about 100,000. The immunoprecipitates were digested with Pronase, and the resulting glycopeptides were first fractionated on Bio-Gel P-6 into excluded (Fraction I) and included (Fraction II) glycopeptides, and then by DSA-agarose affinity chromatography. A much greater proportion of labeled glycopeptides in undifferentiated cells (3 to 5 days in culture) than in differentiated cells (19 to 27 days in culture) was recovered in Fraction I; these glycopeptides were bound to DSA-agarose and were sensitive to endo-beta-galactosidase. This decrease in polylactosaminoglycans was associated primarily with h-lamp-1. These results indicate that h-lamp-1 of CaCo-2 cells contains polylactosaminoglycans and that it undergoes a change in glycosylation with differentiation.