A molecular rheostat adjusts auxin flux to promote root protophloem differentiation.

Auxin influences plant development through several distinct concentration-dependent effects 1 . In the Arabidopsis root tip, polar auxin transport by PIN-FORMED (PIN) proteins creates a local auxin accumulation that is required for the maintenance of the stem-cell niche2-4. Proximally, stem-cell daughter cells divide repeatedly before they eventually differentiate. This developmental gradient is accompanied by a gradual decrease in auxin levels as cells divide, and subsequently by a gradual increase as the cells differentiate5,6. However, the timing of differentiation is not uniform across cell files. For instance, developing protophloem sieve elements (PPSEs) differentiate as neighbouring cells still divide. Here we show that PPSE differentiation involves local steepening of the post-meristematic auxin gradient. BREVIS RADIX (BRX) and PROTEIN KINASE ASSOCIATED WITH BRX (PAX) are interacting plasma-membrane-associated, polarly localized proteins that co-localize with PIN proteins at the rootward end of developing PPSEs. Both brx and pax mutants display impaired PPSE differentiation. Similar to other AGC-family kinases, PAX activates PIN-mediated auxin efflux, whereas BRX strongly dampens this stimulation. Efficient BRX plasma-membrane localization depends on PAX, but auxin negatively regulates BRX plasma-membrane association and promotes PAX activity. Thus, our data support a model in which BRX and PAX are elements of a molecular rheostat that modulates auxin flux through developing PPSEs, thereby timing PPSE differentiation.

Acute endometriosis-related sigmoid perforation in pregnancy- case report.

BACKGROUND: An acute abdomen is an emergency that requires accurate diagnosis and prompt treatment. In pregnancy, the process is even more challenging and sometimes the radiological findings are unclear. Moreover, endometriosis- related complications are rare, especially in previously unknown endometriosis. CASE PRESENTATION: We report on a case of acute endometriosis-related sigmoid perforation during pregnancy (34 weeks of gestation) due to a previously unknown deep intestinal infiltrating endometriosis with focal ulceration of the affected colonic mucosa. CONCLUSIONS: Despite the low relative risk, clinicians should be aware of possible endometriosis-associated complications in pregnancy with potentially life-threatening events, even in previously unknown endometriosis. Further studies should evaluate intestinal complications during pregnancy in relation to previous treatment of intestinal endometriosis (conservative vs. surgical).

Baseline characteristics and comorbidities in the CAnadian REgistry for Pulmonary Fibrosis.

BACKGROUND: The CAnadian REgistry for Pulmonary Fibrosis (CARE-PF) is a multi-center, prospective registry designed to study the natural history of fibrotic interstitial lung disease (ILD) in adults. The aim of this cross-sectional sub-study was to describe the baseline characteristics, risk factors, and comorbidities of patients enrolled in CARE-PF to date. METHODS: Patients completed study questionnaires and clinical measurements at enrollment and each follow-up visit. Environmental exposures were assessed by patient self-report and comorbidities by the Charlson Comorbidity Index (CCI). Baseline characteristics, exposures, and comorbidities were described for the overall study population and for incident cases, and were compared across ILD subtypes. RESULTS: The full cohort included 1285 patients with ILD (961 incident cases (74.8%)). Diagnoses included connective tissue disease-associated ILD (33.3%), idiopathic pulmonary fibrosis (IPF) (24.7%), unclassifiable ILD (22.3%), chronic hypersensitivity pneumonitis (HP) (7.5%), sarcoidosis (3.2%), non-IPF idiopathic interstitial pneumonias (3.0%, including idiopathic nonspecific interstitial pneumonia (NSIP) in 0.9%), and other ILDs (6.0%). Patient-reported exposures were most frequent amongst chronic HP, but common across all ILD subtypes. The CCI was ≤2 in 81% of patients, with a narrow distribution and range of values. CONCLUSIONS: CTD-ILD, IPF, and unclassifiable ILD made up 80% of ILD diagnoses at ILD referral centers in Canada, while idiopathic NSIP was rare when adhering to recommended diagnostic criteria. CCI had a very narrow distribution across our cohort suggesting it may be a poor discriminator in assessing the impact of comorbidities on patients with ILD.

[DGP Interstitial Lung Disease Patient Questionnaire]. / Patientenfragebogen zur Erfassung der Ursachen interstitieller und seltener Lungenerkrankungen ­ klinische Sektion der DGP.

BACKGROUND: Interstitial lung diseases (ILD) encompass different heterogeneous, mainly chronic diseases of the pulmonary interstitium and/or alveoli with known and unknown reasons. The diagnostic of ILD is challenging and should be performed interdisciplinary. The medical history is of major importance and therefore, in German-speaking countries the Frankfurter Bogen (published in 1985) was utilised to scrutinise the medical history of the patient. This by now more than 30-years-old questionnaire requires a revision with regard to content and language. METHOD: Under the auspices of the clinical section of the DGP the new Interstitial Lung Disease Patient Questionnaire was developed in collaboration amongst pulmonologist, occupational medicine physicians and psychologists and supported by patient support groups. The questionnaire was finally optimised linguistically with the help of patients. RESULTS: The newly developed patient questionnaire for interstitial and rare lung diseases encompasses different domains: initial and current symptoms, medical history questions including prior drug treatments, previous pulmonary and extrapulmonary diseases, potential exposition at home, work and leisure time as well as family history and travelling. CONCLUSION: The newly developed questionnaire can facilitate the diagnosis in patients with suspicion on interstitial lung disease in clinical routine.

Higher rates of neuropsychiatric adverse events leading to dolutegravir discontinuation in women and older patients.

OBJECTIVES: Dolutegravir (DTG), a second-generation integrase strand transfer inhibitor (INSTI), is now among the most frequently used antiretroviral agents. However, recent reports have raised concerns about potential neurotoxicity. METHODS: We performed a retrospective analysis of a cohort of HIV-infected patients who had initiated an INSTI in two large German out-patient clinics between 2007 and 2016. We compared discontinuation rates because of adverse events (AEs) within 2 years of starting treatment with dolutegravir, raltegravir or elvitegravir/cobicistat. We also evaluated factors associated with dolutegravir discontinuation. RESULTS: A total of 1950 INSTI-based therapies were initiated in 1704 patients eligible for analysis within the observation period. The estimated rates of any AE and of neuropsychiatric AEs leading to discontinuation within 12 months were 7.6% and 5.6%, respectively, for dolutegravir (n = 985), 7.6% and 0.7%, respectively, for elvitegravir (n = 287), and 3.3% and 1.9%, respectively, for raltegravir (n = 678). Neuropsychiatric AEs leading to dolutegravir discontinuation were observed more frequently in women [hazard ratio (HR) 2.64; 95% confidence interval (CI) 1.23-5.65; P = 0.012], in patients older than 60 years (HR: 2.86; 95% CI: 1.42-5.77; P = 0.003) and in human leucocyte antigen (HLA)-B*5701-negative patients who initiated abacavir at the same time (HR: 2.42; 95% CI: 1.38-4.24; P = 0.002). CONCLUSIONS: In this large cohort, the rate of discontinuation of dolutegravir because of neuropsychiatric adverse events was significantly higher than for other INSTIs, at almost 6% within 12 months. Despite the limitations of this retrospective study, the almost three-fold higher discontinuation rates observed amongst women and older patients underscore the need for further investigation, especially in patient populations usually underrepresented in clinical trials.

Bleomycin induces pleural and subpleural fibrosis in the presence of carbon particles.

The pathological changes in idiopathic pulmonary fibrosis (IPF) typically start in subpleural lung regions, a feature that is currently not explained. IPF, as well as bleomycin-induced lung fibrosis, are more common in smokers. We hypothesised that carbon particles, which are major components of cigarette smoke that are transported to alveoli and pleural surface, might be involved in the development of subpleural fibrosis through interaction with pleural mesothelial cells. Carbon particles were administered to mice in combination with bleomycin through intratracheal and/or intrapleural injection and fibrosis was assessed using histomorphometry. Carbon administered to the chest cavity caused severe pleural fibrosis in the presence of bleomycin, whereas bleomycin alone had no fibrogenic effect. The pleural response was associated with progressive fibrosis in subpleural regions, similar to IPF in humans. Matrix accumulation within this area evolved through mesothelial-fibroblastoid transformation, where mesothelial cells acquire myofibroblast characteristics. In contrast, carbon did not exaggerate bleomycin-induced pulmonary fibrosis after combined intratracheal administration. This represents a novel approach to induce a robust experimental model of pleural fibrosis. It also suggests that carbon particles might be involved as a cofactor in the initiation and/or progression of (subpleural) pulmonary and pleural fibrosis. Mesothelial cells appear to be critical contributors to this fibrotic process.

Overexpression of transforming growth factor-beta1 in fetal monkey lung results in prenatal pulmonary fibrosis.

Altered transforming growth factor (TGF)-ß expression levels have been linked to a variety of human respiratory diseases, including bronchopulmonary dysplasia and pulmonary fibrosis. However, a causative role for aberrant TGF-ß in neonatal lung diseases has not been defined in primates. Exogenous and transient TGF-ß1 overexpression in fetal monkey lung was achieved by transabdominal ultrasound-guided fetal intrapulmonary injection of adenoviral vector expressing TGF-ß1 at the second or third trimester of pregnancy. The lungs were then harvested near term, and fixed for histology and immunohistochemistry. Lung hypoplasia was observed where TGF-ß1 was overexpressed during the second trimester. The most clearly marked phenotype consisted of severe pulmonary and pleural fibrosis, which was independent of the gestational time point when TGF-ß1 was overexpressed. Increased cell proliferation, particularly in α-smooth muscle actin-positive myofibroblasts, was detected within the fibrotic foci. But epithelium to mesenchyme transdifferentiation was not detected. Massive collagen fibres were deposited on the inner and outer sides of the pleural membrane, with an intact elastin layer in the middle. This induced fibrotic pathology persisted even after adenoviral-mediated TGF-ß1 overexpression was no longer evident. Therefore, overexpression of TGF-ß1 within developing fetal monkey lung results in severe and progressive fibrosis in lung parenchyma and pleural membrane, in addition to pulmonary hypoplasia.

Role of STAT6 and SMAD2 in a model of chronic allergen exposure: a mouse strain comparison study.

BACKGROUND: Asthma is a disease characterized by variable and reversible airway obstruction and is associated with airway inflammation, airway remodelling (including goblet cell hyperplasia, increased collagen deposition and increased smooth muscle mass) and increased airway responsiveness. It is believed that airway inflammation plays a critical role in the development of airway remodelling, with IL-13 and TGF-beta1 pathways being strongly associated with the disease progression. Mouse models of asthma are capable of recapitulating some components of asthma and have been used to look at both IL-13 and TGF-beta1 pathways, which use STAT6 and SMAD2 signalling molecules, respectively. OBJECTIVES: Using brief and chronic models of allergen exposure, we utilized BALB/c and C57Bl/6 to explore the hypothesis that observed differences in responses to allergen between these mouse strains will involve fundamental differences in IL-13 and TGF-beta1 responses. METHODS: The following outcome measurements were performed: airway physiology, bronchoalveolar lavage cell counts/cytokine analysis, histology, immunoblots and gene expression assays. RESULTS: We demonstrate in BALB/c mice an IL-13-dependent phosphorylation of STAT6, nuclear localized in inflammatory cells, which is associated with indices of airway remodelling and development of airway dysfunction. In BALB/c mice, phosphorylation of SMAD2 is delayed relative to STAT6 activation and also involves an IL-13-dependent mechanism. In contrast, despite an allergen-induced increase in IL-4, IL-13 and eosinophils, C57Bl/6 demonstrates a reduced and distinct pattern of phosphorylated STAT6, no SMAD2 phosphorylation changes and fail to develop indices of remodelling or changes in airway function. CONCLUSION: The activation of signalling pathways and nuclear translocation of signalling molecules downstream of IL-13 and TGF-beta1 further support the central role of these molecules in the pathology and dysfunction in animal models of asthma. Activation of signalling pathways downstream from IL-13 and TGF-beta1 may be more relevant in disease progression than elevations in airway inflammation alone.

TGF-beta receptor II in epithelia versus mesenchyme plays distinct roles in the developing lung.

Transforming growth factor (TGF)-beta signalling plays important roles in regulating lung development. However, the specific regulatory functions of TGF-beta signalling in developing lung epithelial versus mesenchymal cells are still unknown. By immunostaining, the expression pattern of the TGF-beta type II receptor (TbetaRII) was first determined in the developing mouse lung. The functions of TbetaRII in developing lung were then determined by conditionally knocking out TbetaRII in the lung epithelium of floxed-TbetaRII/surfactant protein C-reverse tetracycline transactivator/TetO-Cre mice versus mesenchyme of floxed-TbetaRII/Dermo1-Cre mice. TbetaRII was expressed only in distal airway epithelium at early gestation (embryonic day (E)11.5), but in both airway epithelium and mesenchyme from mid-gestation (E14.5) to post-natal day 14. Abrogation of TbetaRII in mouse lung epithelium resulted in retardation of post-natal lung alveolarisation, with markedly decreased type I alveolar epithelial cells, while no abnormality in prenatal lung development was observed. In contrast, blockade of TbetaRII in mesoderm-derived tissues, including lung mesenchyme, resulted in mildly abnormal lung branching and reduced cell proliferation after mid-gestation, accompanied by multiple defects in other organs, including diaphragmatic hernia. The primary lung branching defect was verified in embryonic lung explant culture. The novel findings of the present study suggest that transforming growth factor-beta type II receptor-mediated transforming growth factor-beta signalling plays distinct roles in lung epithelium versus mesenchyme to differentially control specific stages of lung development.

Transient expression of IL-1beta induces acute lung injury and chronic repair leading to pulmonary fibrosis.

IL-1beta is one of a family of proinflammatory cytokines thought to be involved in many acute and chronic diseases. Although it is considered to participate in wound repair, no major role has been attributed to IL-1beta in tissue fibrosis. We used adenoviral gene transfer to transiently overexpress IL-1beta in rat lungs after intratracheal administration. The high expression of IL-1beta in the first week after injection was accompanied by local increase of the proinflammatory cytokines IL-6 and TNF-alpha and a vigorous acute inflammatory tissue response with evidence of tissue injury. The profibrotic cytokines PDGF and TGF-beta1 were increased in lung fluid samples 1 week after peak expression of IL-1beta. Although PDGF returned to baseline in the third week, TGF-beta1 showed increased concentrations in bronchoalveolar lavage fluid for up to 60 days. This was associated with severe progressive tissue fibrosis in the lung, as shown by the presence of myofibroblasts, fibroblast foci, and significant extracellular accumulations of collagen and fibronectin. These data directly demonstrate how acute tissue injury in the lung, initiated by a highly proinflammatory cytokine, IL-1beta, converts to progressive fibrotic changes. IL-1beta should be considered a valid target for therapeutic intervention in diseases associated with fibrosis and tissue remodeling.

Assessment of the environmental impact of landfill sites with open combustion located in arid regions by combined chemical and ecotoxicological studies.

Two different waste disposal sites in Jordan were investigated in order to determine the environmental situation in context with waste disposal techniques. One landfill, located at Marka/Amman, had been closed about 25 years ago and covered with soil. Here, the waste had been actively open combusted and openings in the cover, still emitting smoke, indicated that waste was still smoldering inside the landfill's body. The second disposal site close to Ekeeder/Irbid is still operated. On this ground, the solid waste is not intentionally burned, although spontaneous fires frequently come up. Samples of waste, soil, and entrained dust were collected and analyzed. From the solid samples, respectively, their eluates, sum parameters, ecotoxicological effects as well as contents of elements/heavy metals and organic pollutants (PAH, PCDD/F) were determined. In general, the Ekeeder-samples were low-contaminated. The investigation of the Marka-samples showed higher contamination of the site's center, clearly being influenced by combustion processes. A significant contamination of the landfill's vicinity by its emissions could not be derived from the analytical data. Ecotoxicological investigations, applying a bio-test battery, revealed correlations with the sum parameters but not with the trace pollutants. Thus, the Marka-samples with the highest measured values of sum parameters caused adverse effects on three different test species, whereas other samples from Marka and Ekeeder had small or no effects. The results of these investigations depict the influence of different disposal techniques on the contamination situation of a landfill and they shall contribute to assess the conditions of other disposal sites in (semi)arid regions.

Synthesis and biochemical properties of chemically stable product analogues of the reaction catalyzed by S-adenosyl-L-methionine decarboxylase.

Structural analogues of decarboxylated S-adenosyl-L-methionine (dc-SAM), product of the reaction catalyzed by S-adenosyl-L-methionine decarboxylase (SAM-DC), with modifications in the side-chain portion of the molecule have been synthesized, and their ability to inhibit SAM-DC has been investigated. Mainly, compounds with a nitrogen atom in place of the sulfur were investigated. The data from these inhibition studies have resulted in a delineation of the structural features required for binding on SAM-DC. It was concluded that a terminal primary amino group, a terminal carboxyl group, and the sulfonium functionality are not required for binding on SAM-DC. It was also found that analogues of dc-SAM in which replacement of the sulfur by nitrogen was the only modification were still able to form an azomethine with the enzyme. As found for SAM and dc-SAM, these compounds also caused a time-dependent inactivation of SAM-DC.

2,2-Difluoro-5-hexyne-1,4-diamine: a potent enzyme-activated inhibitor of ornithine decarboxylase.

2,2-Difluoro-5-hexyne-1,4-diamine was prepared in an eight-step sequence from ethyl 2,2-difluoro-4-pentenoate and tested as an inhibitor of mammalian ornithine decarboxylase. It produces a time-dependent inhibition of the enzyme in vitro which shows saturation kinetics, with KI = 10 microM and tau 1/2 = 2.4 min. In rats, it produces a rapid, long-lasting, and dose-dependent decrease of ornithine decarboxylase activity in the ventral prostate, testis, and thymus. In contrast with the nonfluorinated analogue 5-hexyne-1,4-diamine (Danzin et al. Biochem. Pharmacol. 1983, 32, 941), 2,2-difluoro-5-hexyne-1,4-diamine is not a substrate of mitochondrial monoamine oxidase.

Synthesis and evaluation of mono-, di-, and trifluoroethenyl-GABA derivatives as GABA-T inhibitors.

The syntheses of four derivatives of gamma-vinyl-GABA, in which vinylic hydrogen atoms were replaced by fluorine, are described. With use of 5-ethenyl-2-pyrrolidinone as starting material, the E and Z isomers of 4-amino-6-fluoro-5-hexenoic acid were prepared. The 6,6-difluoro and 5,6,6-trifluoro analogues could be synthesized from 4-oxobutanoic acid tert-butyl ester and (2,2-difluoroethenyl)- and (trifluoroethenyl)lithium correspondingly. The compounds were tested as inhibitors of GABA-T, and their in vitro and in vivo biochemistry is reported. The most active derivative was (Z)-4-amino-6-fluoro-5-hexenoic acid; the structure-activity relationship in the series is discussed.

Synthesis of peptidyl fluoromethyl ketones and peptidyl alpha-keto esters as inhibitors of porcine pancreatic elastase, human neutrophil elastase, and rat and human neutrophil cathepsin G.

Comparison of MeO-Suc-Val-Pro-Phe-CO2Me (29) and MeO-Suc-Ala-Ala-Pro-Phe- CO2Me (25) with their corresponding trifluoromethyl ketones 9a and 9b, respectively, in rat and human neutrophil cathepsin G assays showed the alpha-keto esters to be more potent inhibitors. Likewise, Ac-Pro-Ala-Pro-Ala-CO2Me (21) was more potent than its corresponding trifluoromethyl ketone (9c) in both porcine pancreatic elastase and human neutrophil elastase assays. Within a set of Ala-Ala-Pro-Val-CF3 elastase inhibitors, the carbobenzyloxy (Cbz) N-protecting group conferred greater potency as a P5 site recognition unit for elastase than did dansyl, methoxysuccinyl, or tert-butyloxycarbonyl. Initial inhibition of elastase was greater when trifluoromethyl ketone 9f was added from a stock solution of dimethyl sulfoxide than when it had been buffer-equilibrated prior to assay, which suggests that the nonhydrated ketone is the more effective form of the inhibitor. The most potent elastase inhibitor we report is Na-(Ad-SO2)-N epsilon-(MeO-Suc)Lys-Pro-Val-CF3 (16) which has a Ki of 0.58 nM.

Marked and prolonged inhibition of mammalian ornithine decarboxylase in vivo by esters of (E)-2-(fluoromethyl)dehydroornithine.

(E)-2-(fluoromethyl)dehydroornithine, a new enzyme-activated irreversible inhibitor of ornithine decarboxylase (ODC) is no more effective than alpha-difluoromethylornithine (DFMO) at inhibiting polyamine biosynthesis in rat hepatoma tissue culture (HTC) cells and in rat organs even though its potency is over 15 times higher than that of DFMO in vitro. The methyl, ethyl, octyl and benzyl esters of (E)-2-(fluoromethyl)dehydroornithine were synthesized as potential prodrugs of the amino acid. When tested at concentration equivalent to the Ki value of the amino acid, they are devoid of ODC-inhibitory property. When measured 6 hr after its addition to the HTC cell culture medium, the absorption of methyl ester was 20 times higher than that of the parent amino acid or that of DFMO, and was accompanied by a more marked intracellular accumulation of (E)-2-(fluoromethyl)dehydroornithine than that achieved by the addition of the parent amino acid. The methyl ester used at 10 times lower concentrations is as effective as its parent amino acid or as DFMO at inhibiting polyamine biosynthesis in HTC cells. Similarly, the methyl and the ethyl esters of (E)-2-(fluoromethyl)dehydroornithine used at 10 times lower doses are as effective as the parent amino acid and as DFMO at inhibiting ODC in the ventral prostate of rat, 6 hr after oral administration. All the esters of (E)-2-(fluoromethyl)dehydroornithine produce a particularly long duration of ODC inhibition in the ventral prostate and in the testes. Repeated administration (25 mg/kg given once a day by gavage) of the methyl ester of (E)-2-(fluoromethyl)dehydroornithine for 8 days to rats results in a constant 80% inhibition of ODC over a 24-hr period, accompanied by a 90% decrease of putrescine and spermidine concentrations in the ventral prostate.

Case reports. Intrauterine echovirus type II infection.

The case described herein represents the first laboratory-confirmed case indicating intrauterine infection due to echovirus type II. The virus was recovered from the vagina of the mother and from the blood from the umbilical cord and nasopharynx of an apathetic newborn (all cultures were taken within 60 minutes of birth in the delivery room) with a generalized maculopapular exanthem. When the infant was 15 days of age, results of all laboratory tests and physical examinations were normal.

Variation in ophthalmic testing before cataract surgery. Results of a national survey of ophthalmologists.

Little information is available either for the clinical value of many ophthalmic tests performed preoperatively in the evaluation of patients for cataract surgery or for variation in ophthalmologists' use of such tests. To assess variation in ophthalmologists' use of ophthalmic tests, we conducted a national survey of American Academy of Ophthalmology members. Thirty-three percent, 17%, 37%, and 19% of the respondents reported that they "frequently" or "always" perform glare testing, contrast sensitivity testing, potential acuity measurement, and specular microscopy, respectively, in patients being considered for cataract surgery who have no history of eye disease other than cataract. In contrast, 27%, 54%, 24%, and 48% of respondents reported that they never perform each of these four tests in such patients. Two ophthalmologist characteristics--a surgical volume of greater than 200 cataract extractions per year and performance of surgery in an ambulatory surgical center or private office (as opposed to a hospital)--were independently associated with an increased probability of performing each of these four tests frequently or always. Ten percent or less of the respondents reported that they frequently or always perform electroretinography, visual evoked response testing, photography of fundus or anterior segment, B-scan ultrasonography, formal color vision testing, and formal visual field testing in such patients. Thus, there is considerable variation in ophthalmologists' use of glare testing, contrast sensitivity testing, potential acuity measurement, and specular microscopy. A small percentage of ophthalmologists may be overusing several other tests in the evaluation of patients being considered for cataract surgery.