Severity of oEsophageal Anastomotic Leak in patients after oesophagectomy: the SEAL score

Background

Anastomotic leak (AL) is a common but severe complication after oesophagectomy. It is unknown how to determine the severity of AL objectively at diagnosis. Determining leak severity may guide treatment decisions and improve future research. This study aimed to identify leak-related prognostic factors for mortality, and to develop a Severity of oEsophageal Anastomotic Leak (SEAL) score.

Methods

This international, retrospective cohort study in 71 centres worldwide included patients with AL after oesophagectomy between 2011 and 2019. The primary endpoint was 90-day mortality. Leak-related prognostic factors were identified after adjusting for confounders and were included in multivariable logistic regression to develop the SEAL score. Four classes of leak severity (mild, moderate, severe, and critical) were defined based on the risk of 90-day mortality, and the score was validated internally.

Results

Some 1509 patients with AL were included and the 90-day mortality rate was 11.7 per cent. Twelve leak-related prognostic factors were included in the SEAL score. The score showed good calibration and discrimination (c-index 0.77, 95 per cent c.i. 0.73 to 0.81). Higher classes of leak severity graded by the SEAL score were associated with a significant increase in duration of ICU stay, healing time, Comprehensive Complication Index score, and Esophagectomy Complications Consensus Group classification.

Conclusion

The SEAL score grades leak severity into four classes by combining 12 leak-related predictors and can be used to the assess severity of AL after oesophagectomy.

Determinants of the Use of Health and Fitness Mobile Apps by Patients With Asthma: Secondary Analysis of Observational Studies

Background

Health and fitness apps have potential benefits to improve self-management and disease control among patients with asthma. However, inconsistent use rates have been reported across studies, regions, and health systems. A better understanding of the characteristics of users and nonusers is critical to design solutions that are effectively integrated in patients’ daily lives, and to ensure that these equitably reach out to different groups of patients, thus improving rather than entrenching health inequities.

Objective

This study aimed to evaluate the use of general health and fitness apps by patients with asthma and to identify determinants of usage.

Methods

A secondary analysis of the INSPIRERS observational studies was conducted using data from face-to-face visits. Patients with a diagnosis of asthma were included between November 2017 and August 2020. Individual-level data were collected, including age, gender, marital status, educational level, health status, presence of anxiety and depression, postcode, socioeconomic level, digital literacy, use of health services, and use of health and fitness apps. Multivariate logistic regression was used to model the probability of being a health and fitness app user. Statistical analysis was performed in R.

Results

A total of 526 patients attended a face-to-face visit in the 49 recruiting centers and 514 had complete data. Most participants were ≤40 years old (66.4%), had at least 10 years of education (57.4%), and were in the 3 higher quintiles of the socioeconomic deprivation index (70.1%). The majority reported an overall good health status (visual analogue scale [VAS] score>70 in 93.1%) and the prevalence of anxiety and depression was 34.3% and 11.9%, respectively. The proportion of participants who reported using health and fitness mobile apps was 41.1% (n=211). Multivariate models revealed that single individuals and those with more than 10 years of education are more likely to use health and fitness mobile apps (adjusted odds ratio [aOR] 2.22, 95%CI 1.05-4.75 and aOR 1.95, 95%CI 1.12-3.45, respectively). Higher digital literacy scores were also associated with higher odds of being a user of health and fitness apps, with participants in the second, third, and fourth quartiles reporting aORs of 6.74 (95%CI 2.90-17.40), 10.30 (95%CI 4.28-27.56), and 11.52 (95%CI 4.78-30.87), respectively. Participants with depression symptoms had lower odds of using health and fitness apps (aOR 0.32, 95%CI 0.12-0.83).

Conclusions

A better understanding of the barriers and enhancers of app use among patients with lower education, lower digital literacy, or depressive symptoms is key to design tailored interventions to ensure a sustained and equitable use of these technologies. Future studies should also assess users’ general health-seeking behavior and their interest and concerns specifically about digital tools. These factors may impact both initial engagement and sustained use.

Profiling Persistent Asthma Phenotypes in Adolescents: A Longitudinal Diagnostic Evaluation from the INSPIRERS Studies

We aimed to identify persistent asthma phenotypes among adolescents and to evaluate longitudinally asthma-related outcomes across phenotypes. Adolescents (13–17 years) from the prospective, observational, and multicenter INSPIRERS studies, conducted in Portugal and Spain, were included (n = 162). Latent class analysis was applied to demographic, environmental, and clinical variables, collected at a baseline medical visit. Longitudinal differences in clinical variables were assessed at a 4-month follow-up telephone contact (n = 128). Three classes/phenotypes of persistent asthma were identified. Adolescents in class 1 (n = 87) were highly symptomatic at baseline and presented the highest number of unscheduled healthcare visits per month and exacerbations per month, both at baseline and follow-up. Class 2 (n = 32) was characterized by female predominance, more frequent obesity, and uncontrolled upper/lower airways symptoms at baseline. At follow-up, there was a significant increase in the proportion of controlled lower airway symptoms (p < 0.001). Class 3 (n = 43) included mostly males with controlled lower airways symptoms; at follow-up, while keeping symptom control, there was a significant increase in exacerbations/month (p = 0.015). We have identified distinct phenotypes of persistent asthma in adolescents with different patterns in longitudinal asthma-related outcomes, supporting the importance of profiling asthma phenotypes in predicting disease outcomes that might inform targeted interventions and reduce future risk.

Effect of different doses of inhaled ciclesonide on lung function, clinical signs related to airflow limitation and serum cortisol levels in horses with experimentally induced mild to severe airway obstruction

Background

Inhaled corticosteroids are effective for the treatment of equine asthma but they induce cortisol suppression with potential side effects.

Objectives

To study the efficacy of ciclesonide, an inhaled corticosteroid with an improved safety profile, on lung function, clinical signs related to airway obstruction, and serum cortisol levels in asthmatic horses exposed to a mouldy hay challenge.

Study design

Cross‐over placebo controlled, blinded, randomised experiment.

Methods

Sixteen horses were enrolled in three subsequent dose‐titration studies (8 horses/study) to investigate the effects of inhaled ciclesonide administered for 2 weeks at doses ranging from 450 to 2700 μg twice daily or 3712.5 μg once daily. Systemic dexamethasone (0.066 mg/kg per os) was our positive control. A placebo group was also studied. Lung function and clinical scores were blindly performed before and after 7 and 14 days of treatment. Serum cortisol was measured before and after 3, 5, 7, 10, 14 days of treatment as well as 3 and 7 days post treatment.

Results

After 7 days, dexamethasone induced a significant reduction in pulmonary resistance (from 2.5 ± 0.6 at day 0 to 1.1 ± 0.7 cm H₂O/L/s), pulmonary elastance (5.0 ± 2.6 to 1.2 ± 1.0 cm H₂O/L), and of the weighted clinical score (14.8 ± 4.7 to 8.0 ± 4.4). Similarly, ciclesonide 1687.5 μg twice daily significantly improved pulmonary resistance (2.7 ± 1.1 to 1.6 ± 0.8 cm H₂O/L/s), pulmonary elastance (5.2 ± 3.1 to 2.2 ± 1.3 cm H₂O/L), and weighted clinical score (13 ± 2.9 to 10.8 ± 4.2). Serum cortisol suppression (<50 nmol/L) systematically occurred with dexamethasone from day 3 of treatment up to day 3 post treatment, but not with ciclesonide at any tested doses. Placebo did not exert any significant beneficial effect.

Main limitations

Experimentally induced asthma exacerbations in horses might respond differently to treatment than naturally occurring exacerbations.

Conclusions

Inhaled ciclesonide is an effective treatment for horses with equine asthma. Serum cortisol was unaffected by treatment.

Measurement of Dysprosium Stark Width and the Electron Impact Width Parameter

In this work, we suggest a methodology to determine the impact parameter for neutral dysprosium emission lines from the characterization of the plasma generated by laser ablation in a sealed chamber filled with argon. The procedure is a combination of known consistent spectroscopic methods for plasma temperature determination, electron density, and species concentration. With an electron density of 3.1 × 10¹⁸cm^-3 and temperature close to 10⁴ K, we estimated the impact electron parameter for nine spectral lines of the neutral dysprosium atom. The gaps in the impact parameter data in the literature, mainly for heavy elements, stress the importance of the proposed method.

Efficacy of inhaled budesonide for the treatment of severe equine asthma

Background

Corticosteroids are the most potent drugs for the control of severe equine asthma, but adverse effects limit their chronic systemic administration. Inhaled medications allow for drug delivery directly into the airways, reducing the harmful effects of these drugs.

Objectives

To evaluate the efficacy of inhaled budesonide specifically formulated for the equine use and administered by a novel inhalation device in horses with severe asthma.

Study design

Experimental studies in horses with naturally occurring asthma with cross‐over, randomised, blinded experimental designs.

Methods

In Study 1, budesonide (1800 μg twice daily) administered using a novel Respimat^® based inhaler was compared to i.v. dexamethasone (0.04 mg/kg). In Study 2, 3 doses of budesonide (450, 900, and 1800 μg) were compared to oral dexamethasone (0.066 mg/kg). Lung function, bronchoalveolar fluid cytology (Study 1), CBC, serum chemistry, and serum cortisol and adrenocorticotropic hormone (ACTH) values were evaluated.

Results

In Study 1, there was a marked and significant improvement in the lung function of all horses treated with budesonide and dexamethasone. Neutrophil percentages in bronchoalveolar fluid decreased in all horses treated with dexamethasone and in four of six horses treated with budesonide. Serum cortisol and blood ACTH concentrations decreased with both treatments. In Study 2, there was a significant improvement in the lung function with all dosages of budesonide, and the effects of higher dosages were comparable to those of dexamethasone. Dexamethasone and budesonide at the two higher dosages induced a significant decrease of cortisol concentrations.

Main limitations

The Respimat^® based inhaler is not currently commercially available.

Conclusions

Administration of budesonide with the Respimat^® based inhaler provided dose‐dependent relief of airway obstruction in horses with severe asthma, but also a suppression of serum cortisol.

Serum Magnesium and Related Factors in Long-Term Renal Transplant Recipients: An Observational Study

BACKGROUND

Low serum magnesium (MgS) is a known risk factor for cardiovascular and mineral bone disease. In renal transplant recipients (RTRs), low MgS levels have been related to higher glomerular filtration rates (GFR) and with calcineurin inhibitors, particularly tacrolimus. We aimed to evaluate MgS in renal transplant recipients with over 1 year of follow-up to establish related risk factors and the impact of the use of cyclosporine versus tacrolimus.

METHODS

Cross-sectional study of 94 RTRs with more than 12 months of follow-up. Hypomagnesemia was defined as serum magnesium level <1.5 mg/dL.

RESULTS

Hypomagnesemia was found in 5.3% of patients. MgS showed a negative correlation with creatinine clearance. A positive correlation between MgS with urinary magnesium and phosphorus was found. Cyclosporine versus tacrolimus analysis did not show a significant difference regarding MgS when considering all the population and the subgroup of patients with GFR >45 mL/min/1.73 m². On the subgroup with GFR <45 mL/min/1.73 m², those on tacrolimus had lower MgS than those on cyclosporine, but those same patients presented with significantly different GFR, higher in the tacrolimus subgroup.

CONCLUSIONS

Hypomagnesemia has a low prevalence in RTRs with more than 1 year of follow-up. MgS levels evidenced a strong correlation with GFR. A significant difference on MgS levels between patients on tacrolimus and cyclosporine was found only when considering GFR <45 mL/min/1.73 m², in which patients on tacrolimus had significantly higher GFR than patients on cyclosporine, which may explain these results.

The genetic contribution to sex determination and number of sex chromosomes vary among populations of common frogs (Rana temporaria)

The patterns of sex determination and sex differentiation have been shown to differ among geographic populations of common frogs. Notably, the association between phenotypic sex and linkage group 2 (LG2) has been found to be perfect in a northern Swedish population, but weak and variable among families in a southern one. By analyzing these populations with markers from other linkage groups, we bring two new insights: (1) the variance in phenotypic sex not accounted for by LG2 in the southern population could not be assigned to genetic factors on other linkage groups, suggesting an epigenetic component to sex determination; (2) a second linkage group (LG7) was found to co-segregate with sex and LG2 in the northern population. Given the very short timeframe since post-glacial colonization (in the order of 1000 generations) and its seemingly localized distribution, this neo-sex chromosome system might be the youngest one described so far. It does not result from a fusion, but more likely from a reciprocal translocation between the original Y chromosome (LG2) and an autosome (LG7), causing their co-segregation during male meiosis. By generating a strict linkage between several important genes from the sex-determination cascade (Dmrt1, Amh and Amhr2), this neo-sex chromosome possibly contributes to the 'differentiated sex race' syndrome (strictly genetic sex determination and early gonadal development) that characterizes this northern population.

High-density linkage maps fail to detect any genetic component to sex determination in a Rana temporaria family

Sex chromosome differentiation in Rana temporaria varies strikingly among populations or families: whereas some males display well-differentiated Y haplotypes at microsatellite markers on linkage group 2 (LG2), others are genetically undistinguishable from females. We analysed with RADseq markers one family from a Swiss lowland population with no differentiated sex chromosomes, and where sibship analyses had failed to detect any association between the phenotypic sex of progeny and parental haplotypes. Offspring were reared in a common tank in outdoor conditions and sexed at the froglet stage. We could map a total of 2177 SNPs (1123 in the mother, 1054 in the father), recovering in both adults 13 linkage groups (= chromosome pairs) that were strongly syntenic to Xenopus tropicalis despite > 200 My divergence. Sexes differed strikingly in the localization of crossovers, which were uniformly distributed in the female but limited to chromosome ends in the male. None of the 2177 markers showed significant association with offspring sex. Considering the very high power of our analysis, we conclude that sex determination was not genetic in this family; which factors determined sex remain to be investigated.

A simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions

We present a simple electron time of flight spectrometer for time resolved photoelectron spectroscopy of liquid samples using a vacuum ultraviolet (VUV) source produced by high-harmonic generation. The field free spectrometer coupled with the time-preserving monochromator for the VUV at the Artemis facility of the Rutherford Appleton Laboratory achieves an energy resolution of 0.65 eV at 40 eV with a sub 100 fs temporal resolution. A key feature of the design is a differentially pumped drift tube allowing a microliquid jet to be aligned and started at ambient atmosphere while preserving a pressure of 10(-1) mbar at the micro channel plate detector. The pumping requirements for photoelectron (PE) spectroscopy in vacuum are presented, while the instrument performance is demonstrated with PE spectra of salt solutions in water. The capability of the instrument for time resolved measurements is demonstrated by observing the ultrafast (50 fs) vibrational excitation of water leading to temporary proton transfer.

Within-population polymorphism of sex-determination systems in the common frog (Rana temporaria)

In sharp contrast with birds and mammals, the sex chromosomes of ectothermic vertebrates are often undifferentiated, for reasons that remain debated. A linkage map was recently published for Rana temporaria (Linnaeus, 1758) from Fennoscandia (Eastern European lineage), with a proposed sex-determining role for linkage group 2 (LG2). We analysed linkage patterns in lowland and highland populations from Switzerland (Western European lineage), with special focus on LG2. Sibship analyses showed large differences from the Fennoscandian map in terms of recombination rates and loci order, pointing to large-scale inversions or translocations. All linkage groups displayed extreme heterochiasmy (total map length was 12.2 cM in males, versus 869.8 cM in females). Sex determination was polymorphic within populations: a majority of families (with equal sex ratios) showed a strong correlation between offspring phenotypic sex and LG2 paternal haplotypes, whereas other families (some of which with female-biased sex ratios) did not show any correlation. The factors determining sex in the latter could not be identified. This coexistence of several sex-determination systems should induce frequent recombination of X and Y haplotypes, even in the absence of male recombination. Accordingly, we found no sex differences in allelic frequencies on LG2 markers among wild-caught male and female adults, except in one high-altitude population, where nonrecombinant Y haplotypes suggest sex to be entirely determined by LG2. Multifactorial sex determination certainly contributes to the lack of sex-chromosome differentiation in amphibians.

Treatment of hepatitis C virus infection in kidney transplant recipients: case report

Chronic hepatitis C virus (HCV) infection exists in a large proportion of patients undergoing renal transplantation. Nowadays it is not considered to be an absolute contraindication to transplantation; however, it is associated with an increased risk for the patient and accounts for a shorter half-life of the renal allograft. We present three transplant recipients who displayed serious hepatic dysfunction after renal transplantation due to an HCV infection. In two of these cases, the liver biopsies established the diagnosis of FCH. In the third case, the liver biopsy was compatible with the early stages of FCH. All patients were started on peg-interferon alfa 2-b and ribavirin with subsequent normalization of hepatic function and early complete viral responses.

Environmental vulnerability assessment in the vicinity of an industrial site in the frame of ARAMIS European project

This work has been carried out in the framework of the ARAMIS project, which aims at developing a comprehensive procedure for assessing the risk level associated to an industrial site with respect to the surrounding environment. To this end, an index is defined which consists of the contribution of three terms, expressing the severity of the scenario consequences, the efficiency of the safety management and the vulnerability of the surrounding environment. The present work focuses on this last aspect concerning the determination of the vulnerability, of the area in the vicinity of an industrial site, of human, environmental (or natural) and material stakes. The applied methodology consists in identifying and quantifying the targets by the means of a geographical information system (GIS) and in assessing the contribution of each target on the basis of a multicriteria decision approach (Saaty method). The result is an operational tool allowing competent authorities, industrialists and risk experts to assess the vulnerability of the area surrounding an industrial site.

Transforming growth factor beta 1 mediates cell-cycle arrest of primitive hematopoietic cells independent of p21(Cip1/Waf1) or p27(Kip1)

The regulation of stem cell proliferation is a poorly understood process balancing rapid, massive blood cell production in times of stress with maintenance of a multipotent stem cell pool over decades of life. Transforming growth factor beta 1 (TGF-beta 1) has pleiotropic effects on hematopoietic cells, including the inhibition of primitive cell proliferation. It was recently demonstrated that the cyclin-dependent kinase inhibitors, p21(Cip1/Waf1) (p21) and p27(Kip1) (p27), can inhibit the proliferation of hematopoietic stem cells and progenitor cells, respectively. The relation of TGF-beta 1 stimulation to p21 and p27 was examined using a fine-mapping approach to gene expression in individual cells. Abundant TGF-beta 1 expression and p21 expression were documented in quiescent, cytokine-resistant hematopoietic stem cells and in terminally differentiated mature blood cells, but not in proliferating progenitor cell populations. TGF-beta 1 receptor (T beta R II) was expressed ubiquitously without apparent modulation. Cell- cycle-synchronized 32D cells exposed to TGF-beta 1 demonstrated a marked antiproliferative effect of TGF-beta 1, yet neither the level of p21 mRNA nor the protein level of either p21 or p27 was altered. To corroborate these observations in primary cells, bone marrow mononuclear cells derived from mice engineered to be deficient in p21 or p27 were assessed. Progenitor and primitive cell function was inhibited by TGF-beta 1 equivalently in -/- and +/+ littermate controls. These data indicate that TGF-beta 1 exerts its inhibition on cell cycling independent of p21 and p27 in hematopoietic cells. TGF-beta 1 and p21 or p27 participate in independent pathways of stem cell regulation, suggesting that targeting each may provide complementary strategies for enhancing stem or progenitor cell expansion and gene transduction.

Development and use of a new medium to detect yeasts of the genera Dekkera/Brettanomyces

AIMS

The objectives of this work were to develop a selective and/or differential medium able to efficiently recover Dekkera/Brettanomyces sp. from wine-related environments and to determine the relationship between these yeasts and the 4-ethylphenol content in a wide range of wines.

METHODS AND RESULTS

The selectivity of the developed medium was provided by the addition of ethanol, as single carbon source, and cycloheximide. The inclusion of bromocresol green evidenced acid-producing strains. The inclusion of p-coumaric acid, substrate for the production of 4-ethylphenol, enabled the differentiation by smell of Dekkera/Brettanomyces sp. from all other yeast species growing in the medium. The medium was used either by plating after membrane filtration or by the Most Probable Number (MPN) technique. In 29 white and 88 red randomly collected wines, these yeasts were found only in red wines at levels up to 2500 MPN ml-1, but constituted less than 1% of the total microbial flora. In red wines, 84% showed detectable amounts of 4-ethylphenol up to 4430 microg l-1 while 28% of the white wines showed detectable levels up to 403 microg l-1.

CONCLUSION

The use of the medium proposed in this work evidenced the presence of low relative populations of Dekkera/Brettanomyces sp. even in wines contaminated by fast-growing yeasts and moulds.

SIGNIFICANCE AND IMPACT OF THE STUDY

Further ecological studies on Dekkera/Brettanomyces sp. should take into account the use of highly specific culture media in order to establish their true occurrence in nature.

Stem cell repopulation efficiency but not pool size is governed by p27(kip1)

Sustained blood cell production requires preservation of a quiescent, multipotential stem cell pool that intermittently gives rise to progenitors with robust proliferative potential. The ability of cells to shift from a highly constrained to a vigorously active proliferative state is critical for maintaining stem cells while providing the responsiveness necessary for host defense. The cyclin-dependent kinase inhibitor (CDKI), p21(cip1/waf1) (p21) dominates stem cell kinetics. Here we report that another CDKI, p27(kip1) (p27), does not affect stem cell number, cell cycling, or self-renewal, but markedly alters progenitor proliferation and pool size. Therefore, distinct CDKIs govern the highly divergent stem and progenitor cell populations. When competitively transplanted, p27-deficient stem cells generate progenitors that eventually dominate blood cell production. Modulating p27 expression in a small number of stem cells may translate into effects on the majority of mature cells, thereby providing a strategy for potentiating the impact of transduced cells in stem cell gene therapy.

Hematopoietic stem cell quiescence maintained by p21cip1/waf1

Relative quiescence is a defining characteristic of hematopoietic stem cells, while their progeny have dramatic proliferative ability and inexorably move toward terminal differentiation. The quiescence of stem cells has been conjectured to be of critical biologic importance in protecting the stem cell compartment, which we directly assessed using mice engineered to be deficient in the G1 checkpoint regulator, cyclin-dependent kinase inhibitor, p21cip1/waf1 (p21). In the absence of p21, hematopoietic stem cell proliferation and absolute number were increased under normal homeostatic conditions. Exposing the animals to cell cycle-specific myelotoxic injury resulted in premature death due to hematopoietic cell depletion. Further, self-renewal of primitive cells was impaired in serially transplanted bone marrow from p21-/- mice, leading to hematopoietic failure. Therefore, p21 is the molecular switch governing the entry of stem cells into the cell cycle, and in its absence, increased cell cycling leads to stem cell exhaustion. Under conditions of stress, restricted cell cycling is crucial to prevent premature stem cell depletion and hematopoietic death.

Syntenic organization of the mouse distal chromosome 7 imprinting cluster and the Beckwith-Wiedemann syndrome region in chromosome 11p15.5

In human and mouse, most imprinted genes are arranged in chromosomal clusters. Their linked organization suggests co-ordinated mechanisms controlling imprinting and gene expression. The identification of local and regional elements responsible for the epigenetic control of imprinted gene expression will be important in understanding the molecular basis of diseases associated with imprinting such as Beckwith-Wiedemann syndrome. We have established a complete contig of clones along the murine imprinting cluster on distal chromosome 7 syntenic with the human imprinting region at 11p15.5 associated with Beckwith-Wiedemann syndrome. The cluster comprises approximately 1 Mb of DNA, contains at least eight imprinted genes and is demarcated by the two maternally expressed genes Tssc3 (Ipl) and H19 which are directly flanked by the non-imprinted genes Nap1l4 (Nap2) and Rpl23l (L23mrp), respectively. We also localized Kcnq1 (Kvlqt1) and Cd81 (Tapa-1) between Cdkn1c (p57(Kip2)) and Mash2. The mouse Kcnq1 gene is maternally expressed in most fetal but biallelically transcribed in most neonatal tissues, suggesting relaxation of imprinting during development. Our findings indicate conserved control mechanisms between mouse and human, but also reveal some structural and functional differences. Our study opens the way for a systematic analysis of the cluster by genetic manipulation in the mouse which will lead to animal models of Beckwith-Wiedemann syndrome and childhood tumours.

The mitogen-activated protein kinase phosphatase-3 N-terminal noncatalytic region is responsible for tight substrate binding and enzymatic specificity

We have reported recently that the dual specificity mitogen-activated protein kinase phosphatase-3 (MKP-3) elicits highly selective inactivation of the extracellular signal-regulated kinase (ERK) class of mitogen-activated protein (MAP) kinases (Muda, M., Theodosiou, A., Rodrigues, N., Boschert, U., Camps, M., Gillieron, C., Davies, K., Ashworth, A., and Arkinstall, S. (1996) J. Biol. Chem. 271, 27205-27208). We now show that MKP-3 enzymatic specificity is paralleled by tight binding to both ERK1 and ERK2 while, in contrast, little or no interaction with either c-Jun N-terminal kinase/stress activated protein kinase (JNK/SAPK) or p38 MAP kinases was detected. Further study revealed that the N-terminal noncatalytic domain of MKP-3 (MKP-3DeltaC) binds both ERK1 and ERK2, while the C-terminal MKP-3 catalytic core (MKP-3DeltaN) fails to precipitate either of these MAP kinases. A chimera consisting of the N-terminal half of MKP-3 with the C-terminal catalytic core of M3-6 also bound tightly to ERK1 but not to JNK3/SAPKbeta. Consistent with a role for N-terminal binding in determining MKP-3 specificity, at least 10-fold higher concentrations of purified MKP-3DeltaN than full-length MKP-3 is required to inhibit ERK2 activity. In contrast, both MKP-3DeltaN and full-length MKP-3 inactivate JNK/SAPK and p38 MAP kinases at similarly high concentrations. Also, a chimera of the M3-6 N terminus with the MKP-3 catalytic core which fails to bind ERK elicits non selective inactivation of ERK1 and JNK3/SAPKbeta. Together, these observations suggest that the physiological specificity of MKP-3 for inactivation of ERK family MAP kinases reflects tight substrate binding by its N-terminal domain.

Evidence for compound heterozygosity causing mild and severe forms of autosomal recessive spinal muscular atrophy

Spinal muscular atrophy is an autosomal recessive disease of motor neurone degeneration which shows a variable phenotype. Two candidate genes show deletions in affected subjects but with no distinction between different forms of the disease. We report an unusual family in which mild and severe SMA coexists and patients are deleted for the SMN gene. The father is affected with late onset SMA; therefore this family shows pseudodominant inheritance. When typed using closely linked flanking markers the severely affected son does not share the same haplotype as his sib, who is deleted for SMN but shows no signs yet of SMA. This supports the hypothesis that differences in SMA phenotype can be explained by a multiple allele model.

The dual specificity phosphatases M3/6 and MKP-3 are highly selective for inactivation of distinct mitogen-activated protein kinases

The mitogen-activated protein (MAP) kinase family includes extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) and p38/RK/CSBP (p38) as structurally and functionally distinct enzyme classes. Here we describe two new dual specificity phosphatases of the CL100/MKP-1 family that are selective for inactivating ERK or JNK/SAPK and p38 MAP kinases when expressed in COS-7 cells. M3/6 is the first phosphatase of this family to display highly specific inactivation of JNK/SAPK and p38 MAP kinases. Although stress-induced activation of p54 SAPKbeta, p46 SAPKgamma (JNK1) or p38 MAP kinases is abolished upon co-transfection with increasing amounts of M3/6 plasmid, epidermal growth factor-stimulated ERK1 is remarkably insensitive even to the highest levels of M3/6 expression obtained. In contrast to M3/6, the dual specificity phosphatase MKP-3 is selective for inactivation of ERK family MAP kinases. Low level expression of MKP-3 blocks totally epidermal growth factor-stimulated ERK1, whereas stress-induced activation of p54 SAPKbeta and p38 MAP kinases is inhibited only partially under identical conditions. Selective regulation by M3/6 and MKP-3 was also observed upon chronic MAP kinase activation by constitutive p21(ras) GTPases. Hence, although M3/6 expression effectively blocked p54 SAPKbeta activation by p21(rac) (G12V), ERK1 activated by p21(ras) (G12V) was insensitive to this phosphatase. ERK1 activation by oncogenic p21(ras) was, however, blocked totally by co-expression of MKP-3. This is the first report demonstrating reciprocally selective inhibition of different MAP kinases by two distinct dual specificity phosphatases.

Multiple signaling pathways control the activation of the CEF-4/9E3 cytokine gene by pp60v-src

The CEF-4/9E3 cytokine gene is expressed aberrantly in chicken embryo fibroblasts (CEF) transformed by the Rous sarcoma virus. The expression of CEF-4 is dependent on both transcriptional and post-transcriptional mechanisms of regulation. The characterization of the promoter region indicated that three distinct regulatory elements corresponding to an AP-1 binding site (or TRE), a PRDII/kappaB domain, and a CAAT box are involved in the activation by pp60(v-)src. In this report we investigate the signaling pathways controlling the expression of the TRE and PRDII domain. The expression of a dominant negative mutant of p21(ras) reduced the activity of both elements. In contrast a similar mutant of c-Raf-1 affected modestly the activation dependent on the TRE but not PRDII. The stress-activated protein kinase (SAPK)/Jun N-terminal kinase (JNK) pathway was important for the activity of PRDII and the TRE but was not markedly stimulated by pp60(v-)src. The addition of calphostin C and the inhibition of protein kinase C (PKC) diminished the accumulation of the CEF-4 mRNA and reduced the activity of a TRE-controlled promoter. Likewise, the depletion of PKC by chronic treatment with phorbol esters inhibited the activation of the TRE. Rous sarcoma virus-transformed CEF treated with calphostin C were also flatter, did not display a high degree of criss-crossing, and appeared morphologically normal. Hence PKC was important for the activation of AP-1 and the morphological transformation of CEF. The constitutive expression of CEF-4 was correlated with transformation only when dependent on the TRE. This was not true for PRDII, which was the only element required for the constitutive activation to the CEF-4 promoter in nontransformed cells treated chronically with phorbol esters.

Novel transcribed sequences represented in the complex genomic region 5q13

YACs from the complex repetitive human genomic region 5q13, spanning the spinal muscular atrophy (SMA) locus, have been searched for transcribed sequences using the method of End Ligation Coincident Sequence Cloning. Six transcripts (PT1-6) have been identified, three of which (PT4, PT5 and PT6) are novel. Five of these elements hybridise to multiple loci in 5q13, but PT5 is single copy and maps very close to markers that show linkage disequilibrium with SMA.

Further characterization, isolation and identification of the epithelial cell-surface antigen defined by monoclonal antibody AUA1

The human epithelial antigen recognized monoclonal antibody (MAb) AUA1 has been characterized as a cell-surface glycoprotein. It has been isolated from human colonic mucosa by AUA1 affinity separation. N-terminal peptide sequence of this purified material has revealed a 17 amino acid sequence which identifies it with one of a group of similar epithelial/tumor-associated glycoproteins defined by a variety of MAbs. Using the polymerase chain reaction to map the gene encoding this antigen, our previous AUA1 antigen assignment to chromosome 2 has been confirmed.