First Extensive Microscopic Study of Butternut Defense Mechanisms Following Inoculation with the Canker Pathogen Ophiognomonia clavigignenti-juglandacearum Reveals Compartmentalization of Tissue Damage

Ophiognomonia clavigignenti-juglandacearum endangers the survival of butternut (Juglans cinerea) throughout its native range. While screening for disease resistance, we found that artificial inoculations of 48 butternut seedlings with O. clavigignenti-juglandacearum induced the expression of external symptoms, but only after a period of dormancy. Before dormancy, compartmentalized tissues such as necrophylactic periderms (NPs) and xylem reaction zones (RZs) contributed to limiting pathogen invasion. Phenols were regularly detected in RZs, often in continuity with NPs during wound closure, and confocal microscopy revealed their presence in parenchyma cells, vessel plugs and cell walls. Vessels were blocked with tyloses and gels, particularly those present in RZs. Suberin was also detected in cells formed over the affected xylem by the callus at the inoculation point, in a few tylosis walls, and in longitudinal tubes that formed near NPs. Following dormancy, in all inoculated seedlings but one, defensive barriers were breached by O. clavigignenti-juglandacearum and then additional ones were produced in response to this new invasion. The results of this histopathological study indicate that trees inoculated in selection programs to test butternut canker resistance should go through at least one period of dormancy and that asymptomatic individuals should be dissected to better assess how they defend themselves against O. clavigignenti-juglandacearum.

Intranasal fentanyl and inhaled nitrous oxide for fracture reduction: The FAN observational study

INTRODUCTION

Procedural sedation and analgesia (PSA) are frequently used for fracture reduction in pediatric emergency departments (ED). Combining intranasal (IN) fentanyl with inhalation of nitrous oxide (N₂O) allow for short recovery time and obviates painful and time-consuming IV access insertions.

METHODS

We performed a bicentric, prospective, observational cohort study. Patients aged 4-18years were included if they received combined PSA with IN fentanyl and N₂O for the reduction of mildly/moderately displaced fracture or of dislocation. Facial Pain Scale Revised (FPS-R) and Face, Leg, Activity, Cry, Consolability (FLACC) scores were used to evaluate pain and anxiety before, during and after procedure. University of Michigan Sedation Score (UMSS), adverse events, detailed side effects and satisfaction of patients, parents and medical staff were recorded at discharge. A follow up telephone call was made after 24-72h.

RESULTS

90 patients were included. There was no difference in FPS-R during the procedure (median score 2 versus 2), but the FLACC score was significantly higher as compared to before (median score 4 versus 0, Δ 2, 95% CI 0, 2). Median UMSS was 1 (95% CI 1, 2). We recorded no serious adverse events. Rate of vomiting was 12% (11/84). Satisfaction was high among participants responding to this question 85/88 (97%) of parents, 74/83 (89%) of patients and 82/85 (96%) of physicians would want the same sedation again.

CONCLUSION

PSA with IN fentanyl and N₂O is effective and safe for the reduction of mildly/moderately displaced fracture or dislocation, and has a high satisfaction rate.

The Fan Study: Intranasal Fentanyl and Inhaled Nitrous Oxide for Fracture Reduction

BACKGROUND: Recently, intranasal (IN) fentanyl and inhaled nitrous oxide/oxygen (N2O) mixture have been increasingly used for procedural sedation and analgesia (PSA) alone or in combination. There is a lack of data on the efficacy of these combined agents.

OBJECTIVES: To evaluate the efficacy of IN fentanyl and N2O as PSA for the reduction of mildly-to-moderately displaced fractures and dislocations.

DESIGN/METHODS: We performed a prospective, observational cohort study between September 2014 and October 2015. Patients were recruited at CHU Sainte Justine (Montréal, Canada) and Royal Children Hospital (Melbourne, Australia). Patients between the age of 4 and 18 years were eligible if PSA consisted of IN fentanyl and N2O for the reduction of mildly-to-moderately displaced fractures or dislocations. Patients received at least IN fentanyl 1.5 mcg/kg (100 mcg max) and at least a 50/50% mixture of N2O with oxygen. Primary outcome was the efficacy of PSA measured by the patient assigned Facial Pain Scale-Revised (FPS-R). The Face, Legs, Activity, Cry, Consolability (FLACC) scale was also recorded. Depth of sedation was evalu-ated using the University of Michigan Sedation Scale (UMSS). Adverse events were recorded following the criteria of the Consensus Panel on Sedation Research of PERC/PECARN. Additional data concerning satisfaction or discomfort were evaluated via questionnaires, and follow-up telephone calls were made to elicit information on adverse events after discharge.

RESULTS: A total of 91 patients aged 9.7±3.0 years were enrolled. There was no difference between the median FPS-R score during the procedure compared to before: Median 2 and 2 (median difference 0 [95% CI 0, 0]), respectively. The FLACC score was higher during the procedure than before: Median 4 and 0 (median difference 2 [95% CI 1, 3]). UMSS was 1 (95% CI 1, 2) during the procedure. 42 (46%) patients had adverse events, all mild: vertigo (20%), nausea (16%)]or vomiting (12%). A total of 85/88 (97%) parents and 82/85 (96%) ED physicians would want the same sedation in another procedure.

CONCLUSION: PSA with IN fentanyl and N2O seems effective in our cohort study, as evaluated by patient assigned FPS-R. Patients were minimally sedated. Adverse events were frequent but mild. Overall, parents and medical staff would want the same agents used in another procedure. Thus, PSA with IN fentanyl and N2O appears to be an attractive option for reduction of mildly displaced fractures or dislocations.

Treating and Reducing Anxiety and Pain in the Paediatric Emergency Department (The Trapped 2 Survey): Time for Action – A Pediatric Emergency Research Canada (Perc) Project

BACKGROUND: Multiples barriers to appropriate analgesia provision are reported in the paediatric emergency department (PED), including limited accessibility to effective strategies.

OBJECTIVES: To evaluate the improvement in the accessibility of pain and anxiety management strategies in PEDs in Canada, after the creation of a national pediatric pain quality improvement collaborative, through Pediatric Emergency Research Canada.

DESIGN/METHODS: In 2013, the TRAPPED 1 survey was administered across Canadian PEDs, in order to evaluate the resources in place for pain and anxiety management. Subsequent to the TRAPPED 1, a pain Quality Improvement Collaborative was created to stimulate the implementation of new pain and anxiety management strategies through the sharing of information between PEDs. The TRAPPED 2 survey involved a cross sectional survey similar to TRAPPED 1, after a two year interval. Its main focus was to evaluate the improvement in the accessibility of specific, preferred strategies reported by each centre, after participating in this collaborative between December 2014 to November 2015, and then working to implement change within their own PEDs.

RESULTS: All 15/15 Canadian PEDs responded to TRAPPED 1 in 2013. In 2014, 11/15 agreed to participate in the national pain Quality Improvement Collaborative, with a goal of introducing new pain and anxiety management strategies within their own PEDs. An in-person meeting, email communication, and telephone meetings were employed for information sharing regarding experiences/challenges within each of the participating centres. Newly introduced strategies included education, distraction, nurse-initiated protocols, and policies/education to encourage the use of intranasal (IN) medications. 11/11 centres have responded to the interim follow up surveys in 2015. At the end of the project (Fall 2105), 15/15 Canadian PEDs agreed to complete the final TRAPPED 2 survey. When comparing the results of 2015 with 2013, an increased number of PEDs used face-based pain scales (14/15 vs 6/15) and behavioural scales (5/15 vs 1/15) for pain assessment of school-aged children and infants, respectively. Use of assessment room wall decoration for distraction increased from 7/15 to 11/15. Reminder posters for pain management at triage increased from 4/15 to 6/15. Availability of electronic distraction strategies (e.g. using tablets) increased from 4/15 to 10/15 centres. For skin-piercing procedure, nurses initiated protocols to use topical anesthetic creams and oral sucrose was available in 12/15 centres (compared to 10/15 in 2013), and 14/15 (compared to 12/15 in 2013) respectively. Availability of IN medications increased in the last two years: fentanyl 14/15 (9/15 in 2013) and midazolam in at least 10/15 (8/15 in 2013). 10/11 PEDS involved in the QI strategy reported the implementation of at least one of their strategies identified.

CONCLUSION: This study suggests that the use of a pain Quality Improvement Collaborative may improve the introduction of new strategies in multiple PEDs. It can help guide other centres when introducing new strategies to reduce pain and anxiety for children in community EDs. Future research can focus on the sustainability of the strategies, and as well the effect of the collaborative on the introduction of other pain treatment strategies.

Cerebrovascular and blood-brain barrier impairments in Huntington's disease: Potential implications for its pathophysiology

OBJECTIVE

Although the underlying cause of Huntington's disease (HD) is well established, the actual pathophysiological processes involved remain to be fully elucidated. In other proteinopathies such as Alzheimer's and Parkinson's diseases, there is evidence for impairments of the cerebral vasculature as well as the blood-brain barrier (BBB), which have been suggested to contribute to their pathophysiology. We investigated whether similar changes are also present in HD.

METHODS

We used 3- and 7-Tesla magnetic resonance imaging as well as postmortem tissue analyses to assess blood vessel impairments in HD patients. Our findings were further investigated in the R6/2 mouse model using in situ cerebral perfusion, histological analysis, Western blotting, as well as transmission and scanning electron microscopy.

RESULTS

We found mutant huntingtin protein (mHtt) aggregates to be present in all major components of the neurovascular unit of both R6/2 mice and HD patients. This was accompanied by an increase in blood vessel density, a reduction in blood vessel diameter, as well as BBB leakage in the striatum of R6/2 mice, which correlated with a reduced expression of tight junction-associated proteins and increased numbers of transcytotic vesicles, which occasionally contained mHtt aggregates. We confirmed the existence of similar vascular and BBB changes in HD patients.

INTERPRETATION

Taken together, our results provide evidence for alterations in the cerebral vasculature in HD leading to BBB leakage, both in the R6/2 mouse model and in HD patients, a phenomenon that may, in turn, have important pathophysiological implications.

New lithium metal polymer solid state battery for an ultrahigh energy: nano C-LiFePO₄ versus nano Li1.2V₃O₈

Novel lithium metal polymer solid state batteries with nano C-LiFePO4 and nano Li1.2V3O8 counter-electrodes (average particle size 200 nm) were studied for the first time by in situ SEM and impedance during cycling. The kinetics of Li-motion during cycling is analyzed self-consistently together with the electrochemical properties. We show that the cycling life of the nano Li1.2V3O8 is limited by the dissolution of the vanadium in the electrolyte, which explains the choice of nano C-LiFePO4 (1300 cycles at 100% DOD): with this olivine, no dissolution is observed. In combination with lithium metal, at high loading and with a stable SEI an ultrahigh energy density battery was thus newly developed in our laboratory.

The morphological and molecular changes of brain cells exposed to direct current electric field stimulation

BACKGROUND

The application of low-intensity direct current electric fields has been experimentally used in the clinic to treat a number of brain disorders, predominantly using transcranial direct current stimulation approaches. However, the cellular and molecular changes induced by such treatment remain largely unknown.

METHODS

Here, we tested various intensities of direct current electric fields (0, 25, 50, and 100V/m) in a well-controlled in vitro environment in order to investigate the responses of neurons, microglia, and astrocytes to this type of stimulation. This included morphological assessments of the cells, viability, as well as shape and fiber outgrowth relative to the orientation of the direct current electric field. We also undertook enzyme-linked immunosorbent assays and western immunoblotting to identify which molecular pathways were affected by direct current electric fields.

RESULTS

In response to direct current electric field, neurons developed an elongated cell body shape with neurite outgrowth that was associated with a significant increase in growth associated protein-43. Fetal midbrain dopaminergic explants grown in a collagen gel matrix also showed a reorientation of their neurites towards the cathode. BV2 microglial cells adopted distinct morphological changes with an increase in cyclooxygenase-2 expression, but these were dependent on whether they had already been activated with lipopolysaccharide. Finally, astrocytes displayed elongated cell bodies with cellular filopodia that were oriented perpendicularly to the direct current electric field.

CONCLUSION

We show that cells of the central nervous system can respond to direct current electric fields both in terms of their morphological shape and molecular expression of certain proteins, and this in turn can help us to begin understand the mechanisms underlying the clinical benefits of direct current electric field.

Variation in stem morphology and movement of amyloplasts in white spruce grown in the weightless environment of the International Space Station

One-year-old white spruce (Picea glauca) seedlings were studied in microgravity conditions in the International Space Station (ISS) and compared with seedlings grown on Earth. Leaf growth was clearly stimulated in space whereas data suggest a similar trend for the shoots. Needles on the current shoots of ground-based seedlings were more inclined towards the stem base than those of seedlings grown in the ISS. Amyloplasts sedimented in specialized cells of shoots and roots in seedlings grown on Earth while they were distributed at random in similar cells of seedlings tested in the ISS. In shoots, such amyloplasts were found in starch sheath cells located between leaf traces and cortical cells whereas in roots they were constituents of columella cells of the cap. Nuclei were regularly observed just above the sedimented amyloplasts in both organs. It was also frequent to detect vacuoles with phenolic compounds and endoplasmic reticulum (ER) close to the sedimented amyloplasts. The ER was mainly observed just under these amyloplasts. Thus, when amyloplasts sediment, the pressure exerted on the ER, the organelle that can for instance secrete proteins destined for the plasma membrane, might influence their functioning and play a role in signaling pathways involved in gravity-sensing white spruce cells.

A 6374 unigene set corresponding to low abundance transcripts expressed following fertilization in Solanum chacoense Bitt, and characterization of 30 receptor-like kinases

In order to characterize regulatory genes that are expressed in ovule tissues after fertilization we have undertaken an EST sequencing project in Solanum chacoense, a self-incompatible wild potato species. Two cDNA libraries made from ovule tissues covering embryo development from zygote to late torpedo-stage were constructed and plated at high density on nylon membranes. To decrease EST redundancy and enrich for transcripts corresponding to weakly expressed genes a self-probe subtraction method was used to select the colonies harboring the genes to be sequenced. 7741 good sequences were obtained and, from these, 6374 unigenes were isolated. Thus, the self-probe subtraction resulted in a strong enrichment in singletons, a decrease in the number of clones per contigs, and concomitantly, an enrichment in the total number of unigenes obtained (82%). To gain insights into signal transduction events occurring during embryo development all the receptor-like kinases (or protein receptor kinases) were analyzed by quantitative real-time RT-PCR. Interestingly, 28 out of the 30 RLK isolated were predominantly expressed in ovary tissues or young developing fruits, and 23 were transcriptionaly induced following fertilization. Thus, the self-probe subtraction did not select for genes weakly expressed in the target tissue while being highly expressed elsewhere in the plant. Of the receptor-like kinases (RLK) genes isolated, the leucine-rich repeat (LRR) family of RLK was by far the most represented with 25 members covering 11 LRR classes.

FOXO1 and c-jun transcription factors mRNA are modulated in endometriosis

Endometriosis is a polygenic gynaecological condition affecting 5-15% of women of childbearing age. Major symptoms of the disease are pelvic pain and infertility. No clear link has been established between symptoms and the stage of the disease. Although some aspects have begun to be clarified, clinical understanding of endometriosis remains partial at the molecular level. In this perspective, we targeted isolation of differentially expressed genes in the eutopic endometrial tissue. Our assumption was that the endometrial cells of patients presented an unusual gene expression profile, allowing their implantation and survival in an ectopic site, leading to endometriotic lesions. Here, we report that mRNA steady-state levels of two key transcription factors are modulated in endometriosis. FOXO1 (also known as FKHR) levels were 1.6-fold lower in endometriosis compared to the control group at the onset of the secretory phase (day 15-21), while c-jun mRNA was present at higher amounts in endometriosis (1.5-fold) at the proliferative phase of the menstrual cycle. These results were derived from a large sample composed of 157 control subjects and 209 patients with endometriosis. Gene profiling was conducted by real-time quantitative PCR, and data were quality controlled before statistical analysis. Whether protein levels are affected as well remains to be investigated.

Characterization of a WRKY transcription factor expressed in late torpedo-stage embryos of Solanum chacoense

A novel WRKY-like transcription factor was isolated from a screen for weakly expressed mRNAs in ovules in the self-incompatible wild potato species Solanum chacoense Bitt. This protein, named ScWRKY1, consisted of 525 amino acids and can be classified as a WRKY group-I member, having two WRKY domains. It is expressed at low levels in stems, roots, and petals, and expressed at much higher levels in leaves. Interestingly, although barely detectable in developing seeds, it is strongly and transiently expressed in fertilized ovules bearing late torpedo-staged embryos, suggesting a specific role during embryogenesis.

Fertilization induces strong accumulation of a histone deacetylase (HD2) and of other chromatin-remodeling proteins in restricted areas of the ovules

Fertilization triggers a unique and complex developmental program leading to embryogenesis and seed set. Recently, mutations affecting chromatin-remodeling enzymes in plants have shown their key roles in development as demonstrated before in animal cells. Using a negative selection screen to isolate genes expressed in ovary tissues upon fertilization, we have identified a histone deacetylase gene (named ScHD2a ) of the plant-specific HD2 family, which is predominantly expressed in ovaries of the self-incompatible species Solanum chacoense. The ScHD2a is the probable orthologue of the Arabidopsis thaliana AtHD2a gene, which upon antisense suppression leads to aborted seeds formation. Transcription of the ScHD2a gene is strongly triggered by fertilization and transcripts accumulate predominantly in the micropylar region of the ovule's integument. Interestingly, this fertilization-induced accumulation pattern was also observed for other genes involved in transcriptional repression but not for a MYST-family histone acetyltransferase. The strong increase in ScHD2a mRNA levels in ovules after fertilization suggests an important and localized role for transcriptional repression in seed development, and indicates why silencing of the AtHD2a gene leads to aborted seed formation.

Large scale validation of human N-myc Downstream-Regulated Gene (NDRG)-1 expression in endometrium during the menstrual cycle

A major challenge in the comprehension of the endometrial transformations leading to the completion of each menstrual cycle in humans is in the identification of specific molecular pathways underlying these monthly turnovers. Towards this goal we compared, by the differential display technique, the relative expression of mRNA in endometrial biopsies harvested in individuals (n = 48) either at the proliferative or the secretory phase of the menstrual cycle. We isolated a cDNA fragment homologous to NDRG1 (N-myc Downstream-Regulated Gene-1) that is present in markedly higher amounts in the secretory phase. Northern blot analysis and quantitative real time PCR experiments confirmed this result in distinct cohorts of individuals (44 and 560 respectively). A closer examination of data showed that the highest mRNA levels were found during the range of 25-28 days of the uterine cycle. Consistent with the mRNA data, the temporal profile of the NDRG1 protein showed a 15-fold increase during the secretory phase, as demonstrated by using semi-quantitative dot blot analyses (n = 92). Immunohistochemical localization revealed that NDRG1 was expressed both in epithelial and stromal cells. This large scale validation of the NDRG1 mRNA and protein increase in endometrium during the secretory phase is consistent with its differentiation-related function described in other tissues and its potential involvement in the window of implantation of the human endometrium, as suggested by previous chip-based evidence.

Genomic organization of the X-linked inhibitor of apoptosis and identification of a novel testis-specific transcript

Here we report the genomic organization and mapping of the X-linked inhibitor of apoptosis gene (BIRC4, also known as XIAP and hILP) and the identification of a closely related transcript. BIRC4 is located on Xq25 and is composed of seven exons. The intron/exon structure is highly conserved between the mouse homologue and its human counterpart. Four bands cross-react with a BIRC4 coding region probe on a genomic Southern blot. One of these cross-reactive bands encodes an intronless gene that expresses a 2.2-kb transcript solely in the testis. This testis-specific transcript contains a putative open reading frame (ORF) that is homologous to the carboxy-terminal end of BIRC4; overexpression of this ORF shows protective effects against BAX-induced apoptosis.

The palmitoylation state of the beta(2)-adrenergic receptor regulates the synergistic action of cyclic AMP-dependent protein kinase and beta-adrenergic receptor kinase involved in its phosphorylation and desensitization

Although palmitoylation of the beta(2)-adrenergic receptor (beta(2)AR), as well as its phosphorylation by the cyclic AMP-dependant protein kinase (PKA) and the beta-adrenergic receptor kinase (beta ARK), are known to play important roles in agonist-promoted desensitization, their relative contribution and mutual regulatory influences are still poorly understood. In this study, we investigated the role that the carboxyl tail PKA site (Ser(345,346)) of the beta(2)AR plays in its rapid agonist-promoted phosphorylation and desensitization. Mutation of this site (Ala(345,346)beta(2)AR) significantly reduced the rate and extent of the rapid desensitization promoted by sustained treatment with the agonist isoproterenol. The direct contribution of Ser(345,346) in desensitization was then studied by mutating all other putative PKA and beta ARK phosphorylation sites (Ala(261,262)beta ARK(-)beta(2)AR). We found this mutant receptor to be phosphorylated upon receptor activation but not following direct activation of PKA, suggesting a role in receptor-specific (homologous) but not heterologous phosphorylation. However, despite its phosphorylated state, Ala(261,262)beta ARK(-)beta(2)AR did not undergo rapid desensitization upon agonist treatment, indicating that phosphorylation of Ser(345,346) alone is not sufficient to promote desensitization. Taken with the observation that mutation of either Ser(345,346) or of the beta ARK phosphorylation sites prevented both the hyper-phosphorylation and constitutive desensitization of a palmitoylation-less mutant (Gly(341)beta(2)AR), our data suggest a concerted/synergistic action of the two kinases that depends on the palmitoylation state of the receptor. Consistent with this notion, in vitro phosphorylation of Gly(341)beta(2)AR by the catalytic subunit of PKA facilitated further phosphorylation of the receptor by purified beta ARK. Our study therefore allows us to propose a coordinated mechanism by which sequential depalmitoylation, and phosphorylation by PKA and beta ARK lead to the functional uncoupling and desensitization of the ss(2)AR.

The late expression factors 8 and 9 and possibly the phosphoprotein p78/83 of Autographa californica multicapsid nucleopolyhedrovirus are components of the virus-induced RNA polymerase

Attempts were made to identify some of the subunits of the baculovirus-induced RNA polymerase following purification of its enzymatic activity by conventional chromatography. Polymerase activity was extracted from lysates of insect cells infected with Autographa californica multicapsid nucleopolyhedrovirus by polyethylenimine precipitation and subsequently purified by phosphocellulose, anion exchange, poly(A) Sepharose affinity, and gel filtration chromatography. The presence of the polymerase was monitored by its alpha-amanitin-resistant activity in in vitro transcription assays. A number of polypeptides associated with the enzymatic activity were identified. Peptide-specific antibodies were generated against a variety of late-expression factors (LEFs) and these antibodies, along with antisera directed against several other baculovirus proteins, were used in an immunoblot analysis of the purified polymerase. The results revealed that both the viral helicase (p143) and the virogenic stroma protein, pp31, copurify with the baculovirus-induced RNA polymerase activity through several chromatographic steps and may be loosely associated with the RNA polymerase. LEF8, LEF9 and p78/83, a nucleocapsid-associated phosphoprotein, were found to associate with the viral-induced polymerase activity. LEF8 and LEF9 contain regions of sequence homology with components of other DNA-directed RNA polymerases, while a portion of p78/83 exhibits some homology to the sigma factor of bacterial RNA polymerase, the RAP30 protein found in the mammalian transcription complex TFIIF, and the RAP94 polypeptide associated with vaccinia virus RNA polymerase. The p78/83 protein has previously been shown by our laboratory to be a capsid protein, but it may also play some role with the RNA polymerase. These results represent a first attempt to identify specific components of the RNA polymerase associated with infections of insect cells by A. californica nucleopolyhedrovirus.

Activation of the beta(2)-adrenergic receptor-Galpha(s) complex leads to rapid depalmitoylation and inhibition of repalmitoylation of both the receptor and Galpha(s)

Palmitoylation is unique among lipid modifications in that it is reversible. In recent years, dynamic palmitoylation of G protein alpha subunits and of their cognate receptors has attracted considerable attention. However, very little is known concerning the acylation/deacylation cycle of the proteins in relation to their activity status. In particular, the relative contribution of the activation and desensitization of the signaling unit to the regulation of the receptors and G proteins palmitoylation state is unknown. To address this issue, we took advantage of the fact that a fusion protein composed of the stimulatory alpha subunit of trimeric G protein (Galpha(s)) covalently attached to the beta(2)-adrenergic receptor (beta(2)AR) as a carboxyl-terminal extension (beta(2)AR-Galpha(s)) can be stimulated by agonists but does not undergo rapid inactivation, desensitization, or internalization. When expressed in Sf9 cells, both the receptor and the Galpha(s) moieties of the fusion protein were found to be palmitoylated via thioester linkage. Stimulation with the beta-adrenergic agonist isoproterenol led to a rapid depalmitoylation of both the beta(2)AR and Galpha(s) and inhibited repalmitoylation. The extent of depalmitoylation induced by a series of agonists was correlated (0.99) with their intrinsic efficacy to stimulate the adenylyl cyclase activity. However, forskolin-stimulated cAMP production did not affect the palmitoylation state of beta(2)AR-Galpha(s), indicating that the agonist-promoted depalmitoylation is linked to conformational changes and not to second messenger generation. Given that, upon activation, the fusion protein mimics the activated receptor-G protein complex but cannot undergo desensitization, the data demonstrate that early steps in the activation process lead to the depalmitoylation of both receptor and G protein and that repalmitoylation requires later events that cannot be accommodated by the activated fusion protein.

Biliopancreatic Diversion with a New Type of Gastrectomy: Some Previous Conclusions Revisited

BACKGROUND: In 1990, we modified Scopinaro's billopancreatic diversion (BPD); instead of a distal gastrectomy and gastroileal anastomosis, a parietal gastrectomy was performed with nutrients diverted through a duodenal switch. Also, the length of the common channel (50 cm) was doubled to 100 cm, while the nutrient limb remained 250 cm. In 1991, we reported initial results after 16 months, weight loss was as expected following BPD, but patients reported fewer side-effects and the prevalence of excessive malabsorption was less. This cohort of patients had their duodenum stapled shut to construct the duodenal switch. This staple-line failed insidiously in some patients, allowing the duodenum to recanalize partially or completely. This resulted in an incomplete BPD. METHODS: Since 1992, the duodenal switch has been constructed with a complete transaction of the duodenum to prevent recanalization. We report here on the first 61 patients who underwent this definitive procedure. RESULTS: At 16 months, we observed a mean weight loss of 84% of initial excess weight, the number of daily stools at 2.9 +/- 1.6 and the prevalence of diarrhea at 10%. Twenty per cent of patients experienced mild anemia, hypocalcemia, or hypoalbuminemia, which required added supplements. CONCLUSIONS: BPD with parietal gastrectomy, duodenal switch and longer common channel improved weight loss and decreased gastrointestinal side-effects without an increased prevalence of excessive malabsorption. The parietal gastrectomy may contribute to weight loss by increasing satiety, and decreasing side-effects by regulating gastric emptying.

Biliopancreatic Diversion, with Distal Gastrectomy, 250 cm and 50 cm Limbs: Long-term Results

BACKGROUND: Since 1984, biliopancreatic diversion (BPD) has been our procedure of choice in the treatment of morbid obesity. Better understanding of long-term outcome following BPD is needed. METHODS: We report the results of our first consecutive 92 patients who underwent BPD more than 5 years ago. Of these 92, only 82 were available for a recent formal evaluation after a mean of 79 months. RESULTS: Weight loss, was maintained over the years at 62% of initial excess weight; the success rate for losing more than 50% of initial excess weight was 72%. The gastrointestinal side-effects decreased with time, but diarrhea was still present in 13%. The average number of daily stools was 3 +/- 1.0. Of the patients, 76% were free from any gastrointestinal side-effects, taking normal diet and having normal stools. Malabsorption, however, was still present. A third of patients had laboratory values slightly below normal levels for hemoglobin, albumin and calcium. These values were mostly without clinical manifestation and were well tolerated by the patients. Regarding associated diseases, 75% were cured or improved following BPD. In 14 patients, reoperation was required to improve diarrhea or serum albumin. In these patients, the common channel was lengthened from 50 to 100 cm. The revision was successful in 11 and did not cause significant weight gain. CONCLUSIONS: BPD, as proposed by Scopinaro, was an efficient surgical treatment of morbid obesity that allowed normal eating habits and despite malabsorption was well tolerated by the great majority of patients.

Factors interacting with the rat carbamyl phosphate synthetase promoter in expressing and nonexpressing tissues

The proximal promoter of the rat carbamyl phosphate synthetase-encoding gene (CPS) contains at least six potential cis-acting regulatory elements (sites I-VI), as judged by DNase I footprint analysis using rat liver nuclear extracts; all six regions bind proteins with DNA recognition properties similar to those of CAAT and enhancer-binding protein alpha (C/EBP alpha) [Lagacé et al., Gene 118 (1992) 231-238]. In contrast, nuclear extracts from kidney, brain and spleen contain proteins that recognize CPS promoter sites II, V and VI, but not sites I, III and IV. Mutation of the octameric sequence (5'-GTTGCAAC) within site II, which is a recognition element for C/EBP alpha, abolished binding of nuclear proteins to site II oligodeoxyribonucleotides (oligos) in all tissues. As well, the site II mutation reduced the level of in vitro transcription from the CPS promoter by about 50% in liver and spleen nuclear extracts, but had a negligible effect in brain and kidney extracts. The fact that promoter activity was observed in extracts of tissues that do not express the endogenous CPS gene (i.e., brain, kidney and spleen) indicates that these tissues, nevertheless, contain factors with the potential to activate transcription through a limited number of CPS promoter elements. Tissue-specific regulation, therefore, must involve steps to prevent these factors from acting on the endogenous CPS promoter in situ.

The carbamyl phosphate synthetase promoter contains multiple binding sites for C/EBP-related proteins

The promoter of the gene (CPS) encoding rat carbamyl phosphate synthetase I has been mapped 5' to a segment of about 525 nucleotides upstream from the transcription start point and, when analyzed in liver nuclear extracts, contained six well-defined protein-recognition elements, designated CPS sites I-VI. All six elements were recognized, with varying affinities, by CAAT and enhancer-binding protein (C/EBP alpha) produced in bacteria. Oligodeoxyribonucleotides corresponding to CPS site II or to the C/EBP alpha-recognition element of the ALB promoter, site D, competed with the six CPS-promoter elements in footprinting assays. However, mutagenesis of the C/EBP alpha-recognition element, 5'-GTTGCAAC, at the core of site II was sufficient to abolish transactivation of the CPS promoter by C/EBP alpha in co-transfected HepG2 cells. These findings indicate that the CPS promoter contains multiple recognition elements for factors with DNA-binding specificities similar to C/EBP proteins. Activation by C/EBP alpha, however, requires promoter site II.

Activity of the carbamyl phosphate synthetase I promoter in liver nuclear extracts is dependent on a cis-acting C/EBP recognition element

We have identified an essential cis element in the proximal promoter region of the rat carbamyl phosphate synthetase I (CPSI) gene that is requisite for promoter activity in liver nuclear extracts. Excess synthetic oligonucleotides specifying this region abolished promoter-dependent in vitro transcription. We show that C/EBP, a nuclear factor enriched in liver but found as well in other tissues, such as gut, fat, and lung, interacts with an inverted repeat, GTTGCAAC, at the core of the essential cis element. In brain, a tissue that did not express CPSI or contain significant levels of C/EBP, a different factor was capable of binding at or near the C/EBP recognition element. Activity of the CPSI promoter in liver nuclear extracts was also dependent on sequences 5' to the C/EBP motif; presumably, factors binding to elements within this upstream region are instrumental in restricting CPSI gene expression to liver and intestinal mucosa.

Rat carbamyl-phosphate synthetase I gene. Promoter sequence and tissue-specific transcriptional regulation in vitro

The region flanking the 5'-end of the rat gene encoding the cytoplasmic precursor of carbamyl-phosphate synthetase I, a mitochondrial matrix enzyme, has been cloned and partially characterized. S1 nuclease and primer extension analyses position the starts of transcription 138-140 nucleotides upstream of the translation initiation codon. Exon 1 contains this untranslated sequence and extends downstream to include the coding region for the pre-enzyme signal peptide (38 amino acids) plus 4 amino acids from the amino terminus of the mature protein. The 5'-flanking sequence contains typical promoter elements, including putative TATA and CAAT motifs at -21 and -82 nucleotides, respectively. In addition, several copies of consensus sequences corresponding to the H4TF-1 recognition element, GATTTC, together with the enhancer-like octamer, ATTTGCAT, are also present. Carbamyl-phosphate synthetase I is a cell-type specific enzyme, being expressed only in hepatocytes and epithelial cells of the intestinal mucosa. It is also synthesized at relatively high levels in the hepatoma cell line, Hep G2. Employing pCPS2.1, a minigene containing the promoter and part of exon 1, we show that nuclear extracts from Hep G2 support accurate carbamyl-phosphate synthetase I gene transcription in vitro. No such activity was observed, however, in extracts from HeLa, a cell line which does not express carbamyl-phosphate synthetase I.