bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased serum interleukin‐1bT during treatment of zhyperthyroidism with antithyroid drugs
Authors: TSATSOULIS A. , VLACHOYIANNOPOULOS P. G. , DALEKOS G. N. , JOHNSON E. O. , MOUTSOPOULOS H. M.
Published: March 2008

Abstract. Serum interleukin‐1bT (IL‐1bT) and soluble interleukin‐2 receptor (sIL‐2R) levels were examined in patients with hyperthyroidism due to Graves' disease (GD) and toxic nodular goitre (TNG) before and during antithyroid drug therapy. A total of 32 patients were studied; 23 patients (14 with GD and nine with TNG) were in a hyperthyroid state (group A) and nine patients (four with GD and five with TNG) were in a euthyroid state, under carbimazole or methimazole treatment (group B). Ten hyperthyroid patients from group A (seven with GD and three with TNG) were also examined while euthyroid on treatment (Subgroup A). Serum was taken from all patients for the measurement of sIL‐2R, IL‐1bT, total T4 (TT4), total T3 (TT3) and TSH concentrations. The results were compared with those from 30 normal controls. Serum sIL‐2R levels were higher in Group A (671–3 pM 74–0 UmlT‐1, meaniSE), than in Group B (214–1 pM 61–8UmL‐1) and controls (149pm 14–8 Umr‐1), P< 0–001. Similarly, the subgroup of 10 patients had higher levels of sIL‐2R during the hyperthyroid phase than while euthyroid (P < 0001). There was a positive correlation between sIL‐2R values and levels of T4 and T3. In contrast, serum IL‐1bT levels were higher in Group B patients (197–5pM 39–2 pg mL‐1) compared with those in Group A (66–5pM17pgmL‐1 P<0–01). IL‐1bT levels were also higher in Subgroup A patients during the euthyroid than in the hyperthyroid phase of their disease (P<0005). In comparison with controls mean IL‐1bT levels were higher in both groups (A and B) of patients (P<005 and P<0002, respectively). It is concluded that serum IL‐1bT, as well as sIL‐2R is elevated in hyperthyroid patients. During treatment with antithyroid drugs sIL‐2R returns to normal, but IL‐1bT increases further. The latter changes may indicate a role for IL‐1bT in mediating antithyroid drug action.
Interferon‐γ and urine neopterin in attacks of the hyperimmunoglobulinaemia D and periodic fever syndrome
Authors: DRENTH J. P. H. , POWELL R. J. , BROWN N. S. , MEER J. W. M. VAN DER
Published: March 2008

Abstract. The hyperimmunoglobulinaemia D and periodic fever (hyper‐IgD) syndrome is typified by recurrent unpredictable febrile attacks with abdominal pain, joint involvement (arthralgias/arthritis), headache, skin lesions and a polyclonal elevation of serum IgD (> 100 Umr‐1). Interferon‐gamma (IFN‐γ) is a major proinflammatory cytokine which could play a role in the pathogenesis of the attacks. There is a need for parameters (if possible non‐invasive) to monitor disease activity. A potential candidate is neopterin which is released by monocytes/macrophages when stimulated with IFN‐γ, excreted unchanged in urine, and appears to be an early and sensitive marker for activation of the immune system. We measured rectal body temperature, serum IFN‐γ, and urine neopterin in 10 hyper‐IgD patients both during and between attacks. The body temperature rose to a mean of 38–9d̀C on the first day of the attack and normalized within 5 days. Serum IFN‐γ during the first day of the attack was 2.98 IUmL‐1 and was significantly lower during remissions. The urine neopterin excretion was 268 ± 170 μmolmol‐1 creatinine between attacks and was significantly increased to 638 ± 275 μmolmor‐1 creatinine on the first day of symptoms. Maximal urine neopterin values were reached on the fourth day of the attack (1051 ± 387 μmolmor‐1 creatinine) and excretion gradually declined and attained values below 400 μmolmol‐ ' creatinine after 9 days. There was a good correlation between serum IFN‐γ and urine neopterin. The increases in serum IFN‐γ and urine neopterin suggest activation of the cellular immunity during the febrile attacks of the hyper‐IgD syndrome. Furthermore, the activation of the cellular immune system appears to persist several days after normalization of the body temperature. The significant correlation between IFN‐γ; and urine neopterin in the hyper‐IgD syndrome accords with experimental data suggesting that IFN‐γ is the dominant factor in the release of neopterin. Our study shows that urinary neopterin is a good quantitative and qualitative parameter to monitor disease activity in patients with the hyper‐IgD syndrome
Neutrophil dysfunction and increased susceptibility to infection
Authors: OTTONELLO L. , DAPINO P. , PASTORINO G. , DALLEGRI F. , SACCHETTI C.
Published: March 2008

Abstract. A critical evaluation of 3 years' experience using laboratory screening to detect neutrophil dysfunction is described. Neutrophil dysfunctions in patients with recurrent bacterial infections were investigated by using the following screening tests: (1) neutrophil chemotaxis towards N‐formylmethionyl peptides (FMLP) and the complement fragment C5a; (2) neutrophil production of superoxide anions (O2‐) in response to phorbol myristate acetate and opsonized zymosan particles; and (3) examination of May‐Griinwald and myeloperoxidase cytochemical staining of peripheral blood smears. These tests were carried out in 100 patients suffering from infections and suspected of having altered neutrophil functional competence. A minority of patients was found to have well defined neutrophil dysfunction syndromes: chronic granulomatous disease (four cases), Chediak Higashi disease (one case) and myeloperoxidase deficiency (one case). Of the remaining 94 patiens, in whom infections localized to airways and/or skin predominated, 53 cases were found to have impaired chemotaxis (41 cases) or partial defects of the O‐2 production. Defects of chemotaxis toward FMLP and those towards both FLMP and C5a were the most frequent abnormalities. No defect was found in the other 41 patients. Moreover, impaired neutrophil chemotaxis was found in some patients with selective IgA deficiency (five cases) or immotile cilia syndrome (seven cases). The results suggest that (a) additional screening tests are required to ameliorate the efficiency of the diagnostic work‐up of the patients suspected to have neutrophil dysfunction; and (b) further evaluation, also at the molecular level, should be considered at least in selected cases of non‐classified neutrophil dysfunction in order to clarify diagnosis and plan rational therapeutic strategies.
Direct assessment of extracellular water volume by the bromide‐dilution method in growth hormone‐deficient adults*
Authors: SNEL Y. E. M. , BRUMMER R.‐J. M. , BOL E. , DOERGA M. E. , ZELISSEN P. M. J. , ZONDERLAND M. L. , BOER P. , KOOMANS H. A. , KOPPESCHAAR H. P. F.
Published: March 2008

Abstract. Body composition and water content were assessed in 36 growth hormone deficient (GHD) patients (M:23, F:13) and 14 controls (M:7, F:7) using anthropometry, hydrodensitometry, bioelectri‐cal impedance measurement and the bromide‐dilution method, with which extracellular water volume can be measured directly. GHD patients, compared to controls, did not differ in extracellular water volume, in hydration state and water distribution. A higher BMI (P=0002) and a higher body fat mass (P < 0.0001) were found in the patients. Based on circumference measurements, the GHD patients had a higher waist/ hip ratio (P = 0.0001). This study shows that GHD patients, in comparison with healthy controls, have a normal extracellular water volume. The finding that extracellular water volume is within the normal range in GHD patients may be clinically relevant as it is well known that in the first months after initiating GH‐replacement therapy, most patients have signs and symptoms of excessive water retention.
Plasma noradrenaline and ageing: effects of smoking habits
Authors: JENSEN E. W. , ESPERSEN K. , KANSTRUP L‐L. , CHRISTENSEN N. J.
Published: March 2008

Abstract. We tested the hypothesis that long‐term smoking is responsible for increased plasma noradrenaline (NA) in elderly healthy subjects. Thirty‐nine subjects were studied both at rest and during exercise: 10 young non‐smokers (median age 24 years, range 21–33), 10 young smokers (30.5 years, 27–36), 10 elderly non‐smokers (64 years, 52–75) and nine elderly smokers (62 years, 56–68). The young and elderly subjects had smoked for an average of 15 years and 46.8 years respectively. Plasma NA was significantly elevated in elderly long‐term smokers compared with elderly non‐smokers, young non‐smokers and young smokers in both supine and sitting positions (supine: 1.06 ± 0.24 vs. 0.71 ± 0.22, 0.53 ± 0.12, and 0.70 ± 0.29 nmolL‐1 respectively; sitting: 3.01 ± 0.83 vs. 2.07 ± 0.77, 1.89 ± 0.52 and 2.25 ± 0.47 nmol L‐1 respectively). Plasma adrenaline did not differ among the groups. At submaximal exercise (60 W), plasma NA was significantly elevated in the elderly smokers compared with the other groups, owing to the elevated basal values. Increments in plasma NA at 60, 100 and 140 W were correlated with the relative exertion and not influenced by smoking. Plasma NA increased more in young subjects than in the elderly during maximal work load (21.7 ± 8.0 vs. 13.4 ± 5.4 nmol L‐1) and correlated with the peak O2 uptake. Total blood volume was not different among the four groups and correlated inversely with basal plasma NA. It is concluded that long‐term smoking may contribute to increased basal plasma NA concentrations and probably also increased sympathetic nerve activity in elderly healthy subjects, whereas smoking has little if any effect on plasma NA responses induced by exercise. Interindividual variability in basal plasma NA concentrations may in part be explained by differences in blood volume.
Iloprost effects on phagocytes in patients suffering from ischaemic diseases: in vivo evidence for down‐regulation of αMβ2 integrin
Authors: MAZZONE A. , MAZZUCCHELLI I. , FOSSATI G. , GRITTI D. , GIROLA S. , CANALE C. , CUSA C. , RICEVUTI G.
Published: March 2008

Abstract. This study has been designed to demonstrate the in vivo effects of iloprost therapy on expression of adhesion molecules on phagocytes. Sixty patients suffering from peripheral arterial occlusive disease (PAOD) and/or from skin ulcers due to secondary progressive systemic sclerosis (PSS) were enrolled in a double‐blind controlled parallel study. Thirty patients (group I) underwent iloprost infusion and 30 patients (group II) were treated with aspirin. Clinical assessment and measurement of phagocyte activation in vivo, using quantitative flow cytometry, were performed on entry and after 6 h on the first day of therapy. After 3 months of therapy, complete healing of all cutaneous lesions was observed in 84% of the patients treated with iloprost compared with the control patients (P < 0.001). Neutrophils and monocytes of PAOD and PSS patients showed a significant decrease in the expression of the αMβ2 integrin adhesion receptor after 6 h of iloprost infusion. Neutrophils and monocytes released a lower amount of anion superoxide (O2‐) after 6 h of iloprost treatment. These data confirm other clinical observations but demonstrate that in vivo this drug modifies the expression of the αMβ2 integrin of phagocytes that has a key role in leukocyte‐endothelium interactions in cases of inflammation and thrombosis.
Expression of nitric oxide synthase in ulcerative colitis
Authors: GODKIN A. J. , BELDER A. J. DE , VILLA L. , WONG A. , BEESLEY J. E. , KANE S. P. , MARTIN J. F.
Published: March 2008

Abstract. Nitric oxide (NO) is generated from L‐arginine by a family of enzymes called the NO synthases. Previous investigators have proposed that the expression of this inducible enzyme (iNOS) may account for the characteristic vasodilatation, oedema and impairment of gut motility seen in active ulcerative colitis. Using a specific antibody to iNOS, we have investigated the distribution of this enzyme in colonic tissue from patients with histologically proven ulcerative colitis. Eight patients with ulcerative colitis expressed calcium‐independent citrulline activity (9.96±2.34 pmol citrulline mg‐1 protein min‐1) and showed immunoreactivity to the iNOS antibody within the inflammatory infiltrate of the lamina propria, and also within the cytoplasm of the epithelial cells lining the colon. Five age‐matched controls showed no calcium‐independent citrulline activity (0.2 ±0.08 pmol citrulline mg‐1 protein min‐1) and no immunoreaction to the antibody. We conclude that this enzyme is present in colonic tissue including the epithelium from patients with active colitis. Inhibition of this enzyme may provide a novel therapeutic option for patients with active ulcerative colitis.
Effects of N‐acetylcysteine on bacterial clearance
Authors: KOCH T. , HELLER S. , HEIßLER S. , BREIL I. , SCHIEFER H. G. , ACKERN K. VAN , NEUHOF H.
Published: March 2008

Abstract. The aim of this study was to investigate whether the oxygen radical scavenger N‐acetylcysteine (N‐AC) impairs bacterial clearance, thus predisposing the host to increased risk of disease. Blood clearance of Escherichia coli and organ colonization were investigated in anaesthetized rabbits after pretreatment with N‐AC (250 mg kg‐1 body weight, n= 16) and in sham‐operated animals (n= 12). To enable quantification of the clearance process, defined numbers of exogenous E. coli [1.3 times 108 colony‐forming units (CFUs)] were injected intravenously. Parameters monitored were kinetics of bacterial elimination from the blood, and polymorphonuclear leucocyte (PMN) oxidative burst activity. Samples of liver, kidney, spleen and lung were collected for bacterial counts. Compared with controls, pretreatment with N‐AC resulted in delayed bacterial elimination from blood and higher organ colonization with increased numbers of E. coli in liver, lung and kidney (P < 0.05). N‐AC treatment was associated with a suppressed PMN oxidative burst activity. Impaired bacterial clearance and enhanced organ colonization in N‐AC‐treated animals correlated with reduced oxidative burst activity, suggesting impaired granulocyte‐dependent bacterial killing due to N‐AC application.
Carrier detection by microsatellite haplotyping in 10 properdin type 1‐deficient families
Authors: FIJEN C. A. P. , BOGAARD R. VAN DEN , DAHA M. R. , DANKERT J. , MANNENS M. , KUIJPER E. J.
Published: March 2008

Abstract. Properdin deficiency carrier identification is relevant, because properdin‐deficient persons have an increased risk of contracting meningococcal disease. Vaccination against meningococcal disease at a young age may provide protection. Accurate detection of this deficiency is needed. Microsatellite haplotyping with the PFC1 and PFC2 markers closely linked to the properdin gene locus at Xp11.3‐Xp.11.23 may offer an easy and accurate identification of carriers of the properdin deficiency gene. The chance to study 91 relatives belonging to 10 families with complete (type 1) properdin deficiency offered a unique opportunity to assess whether properdin type 1 deficiency is associated with a distinct microsatellite haplotype. Haplotyping with the closely linked PFC1 and 2 markers yielded five different haplotypes, which did not support the concept of a founder effect. Among the 28 women carriers, two had normal properdin levels and in five the PFC1,2 polymorphism was not informative owing to homozygosity. Extending the microsatellite haplotyping with three additional markers (DXS1126, DXS426 and DXS7) yielded informative haplotypes in all meioses. We concluded that microsatellite haplotyping using five markers in close proximity to the properdin gene locus is an accurate method of detecting carriers of the properdin deficiency gene and of properdin‐deficient persons within a family at a young age.
Red blood cell ghosts are affected by adrenoleucodystrophy
Authors: ARIENTI G. , CARLINI E. , LAURETI S. , BRUNETTI P. , SANTEUSANIO F.
Published: March 2008

Abstract. X‐linked adrenoleucodystrophy is a disorder occurring in different clinical forms, characterized by adrenal, gonadal and nervous system dysfunction. The basis of the illness is a derangement of the peroxisomal system necessary to oxidize very long‐chain fatty acids that accumulate in various tissues. The diagnosis relies on clinical signs and symptoms and on biochemical findings. The six reported cases presented idiopathic adrenal insufficiency. We measured the lipid composition of red blood cell (RBC) ghosts of patients and control subjects. The distribution of phosphorus among phospholipid classes was unaffected; we could not demonstrate any differences between the fatty acid patterns of RBC membrane, either in total lipid extracts or in separated lipid classes. However, we found an increase in total lipid (both phospholipid and cholesterol), in membrane viscosity and in the Na+/K+‐dependent ATPase. Therefore, we report four main findings on ghosts in adrenoleucodystrophy patients: (a) very long‐chain fatty acids do not accumulate; (b) the lipid‐protein ratio increases; (c) fluidity decreases; and (d) the activity of ATPase increases. The last finding is proposed as a possible biochemical marker of the illness. We conclude that adrenoleucodystrophy affects deeply RBC membranes.
HIV‐1 viraemia changes in patients with and without syncytium‐inducing phenotype treated with nucleoside analogues: a case‐control study
Authors: LEAL M. , TORRES Y. , MEDRANO F. J. , REY C. , CARUZ A. , SÁNCHEZ‐QUIJANO A. , LISSEN E.
Published: March 2008

Abstract. The objective of the present study was to investigate the effect of the nucleoside analogue treatment on serum viraemia, CD4+ cell count and disease progression in patients with and without syncytium‐inducing (SI) HIV‐I variants. To achieve this in a case‐control study, 11 nucleoside‐naive patients harbouring SI variants who started treatment with zidovudine or zidovudine plus didanosine were matched with 11 control patients who never formed SI variants during a follow‐up of 48 weeks. The matching criteria were age, CD4+ cell count and CDC clinical category at the start of the study and exposure to the same antiretroviral treatment. During the follow‐up there were no significant differences in the changes of serum HIV‐I RNA viral load and CD4+ cell counts between the two groups. In contrast, AIDS or new AIDS‐defining events were observed in five SI cases but in none of the non‐SI controls (P= 0.002). The emergence of a zidovudine‐resistant mutation at codon 215 was observed in all the patients harbouring SI strains and in six of the subjects with non‐SI variants (P= 0.03). The results of the present study show that in patients carrying SI virus, measurements of CD4+ count or RNA viral burden are neither related to the virulence of the virus strains nor able to predict the clinical course of the disease, at least under antiretroviral drug conditions. Thus, determination of SI phenotype should be considered in the evaluation and monitoring of HIV‐I therapies.
Peripancreatic lymphoadenopathy and extrahepatic immunological manifestations in chronic hepatitis C
Authors: NERI S. , BRUNO C. M. , D'ANGELO G. , RUSSO S.
Published: March 2008

Abstract. The aim of the study was to determine the role of peripancreatic lymph node swelling in systemic immunological alterations during chronic hepatitis C (HC). The prospective study was carried out as a clinical study in a university hospital. Clinical, haematochemical and ultrasonographic findings in 182 patients were studied. Ultrasonography was performed by the same operator and the findings were evaluated blind without the operator knowing the clinical and haematochemical parameters. Hepatitis B virus (HBV) markers, anti‐HCV antibodies. LKMl, cryoglobulinaemia, rheumatoid factor and anti‐tissue antibodies were determined. Liver biopsy was carried out in 43 of the 182 patients. One or two pathological peripancreatic lymph nodes (PLNs) were present in 30 of the 182 patients and, of the 30, 28 were anti‐HC positive. Only one patient in the non‐PLN group was positive for anti‐HCV, there being statistical significance (P<0.0001) between the PLN and non‐PLN groups. In HCV‐positive patients, extrahepatic immunological manifestations were observed (cryoglobulinaemia; positivity to anti‐smooth muscle, antinuclear and antimitochondrial antibodies; positivity to rheumatoid factor and LKMl). In five patients the presence of focal lymphocytic aggregates was detected by biopsy, whereas one patient presented typical ocular lesion of Mikulicz's syndrome. Our results may confirm the marked lymphotropism shown by the HC virus and indicate more complex immune system involvement, especially in view of the coexisting signs of immune system involvement related to the presence of intrahepatic cellular aggregates detected in our study. We believe that the peripancreatic adenopathy in chronic HCV hepatitis is an important diagnostic sign and may indicate an involvement of the C virus in the still unexplained extrahepatic immunological disorders.
Elevation of plasminogen activator inhibitor 1 in borderline hypertension is linked to concomitant metabolic disturbances
Authors: LEMNE C. , FAIRE U. DE
Published: March 2008

Abstract. In the present study we investigated plasma levels of plasminogen activator inhibitor 1 (PAI‐1), fibrinogen and von Willebrand factor (vWF) in borderline hypertensive (BHT) men [diastolic blood pressure (DBP) 85–94 mmHg, n= 75] and age‐matched normotensive (NT) control subjects (DBP ≤80 mmHg, n= 75), in relation to smoking, body mass index (BMI) and fasting lipoprotein and insulin levels. PAI‐1 levels were elevated in the BHT group [16.3 vs. 13.7 arbitrary units (AU), P= 0.032], whereas levels of fibrinogen and vWF were similar in the two groups. The PAI‐1 elevation was even more pronounced in dyslipidaemic BHT subjects than in normolipidaemic NT subjects (20.0 vs. 10.3 arbitrary units (AU), P= 0.001). PAI‐1 levels showed strong correlations with insulin, lipoproteins and BMI (P < 0.01‐0.001), but not with DBP. The results show that disturbances in the fibrinolytic system appear even in borderline hypertension. The elevation of PAI‐1 levels seems to be more strongly linked to concomitant metabolic disturbances than to blood pressure levels.
Vegetation and flow regime in lowland streams
Authors: RIIS TENNA , SUREN ALASTAIR M. , CLAUSEN BENTE , SAND‐JENSEN KAJ
Published: March 2008

1. The hydrological regime is important to the distribution of benthic organisms in streams. The objective of this study was to identify relationships between hydrological variables, describing the flow regime, and macrophyte cover, species richness, diversity and community composition in Danish lowland streams.

2. We quantified macrophyte vegetation in 44 Danish streams during summer by cover, species richness and diversity. Flow regime was characterized by 18 non‐intercorrelated variables describing magnitude, frequency and duration of low and high flow events, timing or predictability of flow and general flow variability.

3. We found support in the stepwise multiple regressions analysis for our expectation that macrophyte cover is lowest in streams with high flow variability and highest in streams with long duration of low flow and low flow variability. We found support for the intermediate disturbance hypothesis as there were significant quadratic relationships between species richness and diversity as functions of disturbance frequency. There was poor discrimination in a detrended correspondence analysis (DCA) analysis of macrophyte community composition between four twinspan groups separating streams with different hydrological properties. Moreover, we did not find any relationship between the presence of disturbance‐tolerant species and hydrological disturbance, suggesting that plant community composition developed independently of stream hydrology.
East meets west: adaptive evolution of an insect introduced for biological control
Authors: Phillips C. B , Baird D. B , Iline I. I , McNeill M. R , Proffitt J. R , Goldson S. L , Kean J. M
Published: March 2008

A possible explanation for low success rates when introducing natural enemies to new regions for biological control of insect pests is that they fail to adapt to their new conditions. Therefore it has been widely recommended that biological control practitioners increase the probability of local adaptation by maximizing the genetic variation released. An alternative recommendation is to use climate matching to identify native populations that may already possess traits suited to the new region. However, support for these recommendations is weak through lack of empirical evidence that local adaptation is important to biological control.

This study examined how genetic drift and selection influenced the population frequencies of two asexually reproducing, genetically differentiated parasitoid biotypes that were introduced to New Zealand from South America for biological control. Other than by mutation, the biotypes were genetically fixed due to the absence of recombination both within and between biotypes. This meant that adaptive evolution could occur only if selection acted on any traits that varied between the biotypes introduced from South America.

The two parasitoid biotypes were released simultaneously at 14 sites and their frequencies were monitored for up to 10 years. Changes in biotype frequency were consistent with strong directional selection favouring one of the South American biotypes, thus generating established parasitoid populations that were better adapted to New Zealand conditions than those that had originally been released. This local adaptation of the control agent contributed to greater mortality of the pest.

Synthesis and applications. This study provides the first clear demonstration of the importance of releasing natural enemy genetic variation in new regions to foster adaptive evolution and improve success rates in classical biological control. However, the benefit to biological control of maximizing the genetic variation released needs to be balanced against possible risks to non‐target species. The results do not support the concept of choosing sampling sites for putative biological control agents based solely on climatic similarities between the source location and the intended region of introduction.
A novel gene, phcA from Pseudomonas syringae induces programmed cell death in the filamentous fungus Neurospora crassa
Authors: Wichmann Gale , Sun Jianping , Dementhon Karine , Glass N. Louise , Lindow Steven E.
Published: March 2008

The phytopathogen Pseudomonas syringae competes with other epiphytic organisms, such as filamentous fungi, for resources. Here we characterize a gene in P. syringae pv. syringae B728a and P. syringae pv. tomato DC3000, termed phcA, that has homology to a filamentous fungal gene called het‐c. phcA is conserved in many P. syringae strains, but is absent in one of the major clades, which includes the P. syringae pathovar phaseolicola. In the filamentous fungus Neurospora crassa, HET‐C regulates a conserved programmed cell death pathway called heterokaryon incompatibility (HI). Ectopic expression of phcA in N. crassa induced HI and cell death that was dependent on the presence of a functional het‐c pin‐c haplotype. Further, by co‐immunoprecipitation experiments, a heterocomplex between N. crassa HET‐C1 and PhcA was associated with phcA‐induced HI. P. syringae was able to attach and extensively colonize N. crassa hyphae, while an Escherichia coli control showed no association with the fungus. We further show that the P. syringae is able to use N. crassa as a sole nutrient source. Our results suggest that P. syringae has the potential to utilize phcA to acquire nutrients from fungi in nutrient‐limited environments like the phyllosphere by the novel mechanism of HI induction.
An isochromosome confers drug resistance in vivo by amplification of two genes, ERG11 and TAC1
Authors: Selmecki Anna , Gerami‐Nejad Maryam , Paulson Carsten , Forche Anja , Berman Judith
Published: March 2008

Acquired azole resistance is a serious clinical problem that is often associated with the appearance of aneuploidy and, in particular, with the formation of an isochromosome [i(5L)] in the fungal opportunist Candida albicans. Here we exploited a series of isolates from an individual patient during the rapid acquisition of fluconazole resistance (FluR). Comparative genome hybridization arrays revealed that the presence of two extra copies of Chr5L, on the isochromosome, conferred increased FluR and that partial truncation of Chr5L reduced FluR. In vitro analysis of the strains by telomere‐mediated truncations and by gene deletion assessed the contribution of all Chr5L genes and of four specific genes. Importantly, ERG11 (encoding the drug target) and a hyperactive allele of TAC1 (encoding a transcriptional regulator of drug efflux pumps) made independent, additive contributions to FluR in a gene copy number‐dependent manner that was not different from the contributions of the entire Chr5L arm. Thus, the major mechanism by which i(5L) formation causes increased azole resistance is by amplifying two genes: ERG11 and TAC1.
TtsI regulates symbiotic genes in Rhizobium species NGR234 by binding to tts boxes
Authors: Wassem Roseli , Kobayashi Hajime , Kambara Kumiko , Le Quéré Antoine , Walker Graham C. , Broughton William J. , Deakin William J.
Published: March 2008

Infection of legumes by Rhizobium sp. NGR234 and subsequent development of nitrogen‐fixing nodules are dependent on the coordinated actions of Nod factors, proteins secreted by a type III secretion system (T3SS) and modifications to surface polysaccharides. The production of these signal molecules is dependent on plant flavonoids which trigger a regulatory cascade controlled by the transcriptional activators NodD1, NodD2, SyrM2 and TtsI. TtsI is known to control the genes responsible for T3SS function and synthesis of a symbiotically important rhamnose‐rich lipo‐polysaccharide, most probably by binding to cis elements termed tts boxes. Eleven tts boxes were identified in the promoter regions of target genes on the symbiotic plasmid of NGR234. Expression profiles of lacZ fusions to these tts boxes showed that they are part of a TtsI‐dependent regulon induced by plant‐derived flavonoids. TtsI was purified and demonstrated to bind directly to two of these tts boxes. DNase I footprinting revealed that TtsI occupied not only the tts box consensus sequence, but also upstream and downstream regions in a concentration‐dependent manner. Highly conserved bases of the consensus tts box were mutated and, although TtsI binding was still observed in vitro, gfp fusions were no longer transcribed in vivo. Random mutagenesis of a tts box‐containing promoter revealed more nucleotides critical for transcriptional activity outside of the consensus.
Oxidant‐dependent switching between reversible and sacrificial oxidation pathways for Bacillus subtilis OhrR
Authors: Soonsanga Sumarin , Lee Jin‐Won , Helmann John D.
Published: March 2008

The Bacillus subtilis OhrR protein functions as a transcriptional repressor of the inducible peroxidase, OhrA. Derepression is mediated by the organic‐peroxide selective oxidation of an active site cysteine (C15). In the presence of cumene hydroperoxide (CHP), oxidation of OhrR leads to a sulphenic acid intermediate which reacts to form either a mixed‐disulphide or a protein sulphenamide. These inactive forms of OhrR can be reactivated by thiol–disulphide exchange reactions allowing restoration of repression. Here, we demonstrate that linoleic acid hydroperoxide (LHP) is a potent oxidant for OhrR and even low levels lead to overoxidation of OhrR to cysteine sulphinic (and sulphonic) acid derivatives. Kinetic competition experiments indicate that further oxidation of the initial OhrR sulphenate product occurs at least 100‐fold more rapidly with LHP than with CHP. Thus, depending on the oxidant, OhrR can be either reversibly oxidized or can instead function as a sacrificial regulator.
Mini‐III, an unusual member of the RNase III family of enzymes, catalyses 23S ribosomal RNA maturation in B. subtilis
Authors: Redko Yulia , Bechhofer David H. , Condon Ciarán
Published: March 2008

The late steps of both 16S and 5S ribosomal RNA maturation in the Gram‐positive bacterium Bacillus subtilis have been shown to be catalysed by ribonucleases that are not present in the Gram‐negative paradigm, Escherichia coli. Here we present evidence that final maturation of the 5′ and 3′ extremities of B. subtilis 23S rRNA is also performed by an enzyme that is absent from the Proteobacteria. Mini‐III contains an RNase III‐like catalytic domain, but curiously lacks the double‐stranded RNA binding domain typical of RNase III itself, Dicer, Drosha and other well‐known members of this family of enzymes. Cells lacking Mini‐III accumulate precursors and alternatively matured forms of 23S rRNA. We show that Mini‐III functions much more efficiently on precursor 50S ribosomal subunits than naked pre‐23S rRNA in vitro, suggesting that maturation occurs primarily on assembled subunits in vivo. Lastly, we provide a model for how Mini‐III recognizes and cleaves double‐stranded RNA, despite lacking three of the four RNA binding motifs of RNase III.
Characterization of the PvdS‐regulated promoter motif in Pseudomonas syringae pv. tomato DC3000 reveals regulon members and insights regarding PvdS function in other pseudomonads
Authors: Swingle Bryan , Thete Deepti , Moll Monica , Myers Christopher R. , Schneider David J. , Cartinhour Samuel
Published: March 2008

Bacteria that survive under variable conditions possess an assortment of genetic regulators to meet these challenges. The group IV or extracytoplasmic function (ECF) sigma factors regulate gene expression in response to specific environmental signals by altering the promoter specificity of RNA polymerase. We have undertaken a study of PvdS, a group IV sigma factor encoded by Pseudomonas syringae pv. tomato DC3000 (DC3000), a plant pathogen that is likely to encounter variations in nutrient availability as well as plant host defences. The gene encoding PvdS was previously identified by sequence similarity to the Pseudomonas aeruginosa orthologue, which directs transcription of genes encoding the biosynthesis of pyoverdine, a siderophore involved in iron acquisition, and is responsible for the characteristic fluorescence of the pseudomonads. We identified 15 promoters regulated by PvdS in DC3000 and characterized the promoter motif using computational analysis. Mutagenesis of conserved nucleotides within the motif interfered with promoter function and the degree of the effect was different depending on which region of the motif was mutated. Hidden Markov models constructed from alignments of sequence motifs extracted from DC3000 and PAO1 were used to query genomes of DC3000 and other fluorescent pseudomonads for similar motifs. We conclude that the role of PvdS as a regulator of pyoverdine synthesis is conserved among the fluorescent pseudomonads, but the promoters recognized by PvdS orthologues may differ subtly from species to species.
Delayed activation of Xer recombination at dif by FtsK during septum assembly in Escherichia coli
Authors: Kennedy Sean P. , Chevalier Fabien , Barre François‐Xavier
Published: March 2008

The co‐ordination and synchronization of DNA replication, chromosome partitioning and cell division in bacteria are critical to survival. In Escherichia coli, the septal protein FtsK links cell division and chromosome segregation through its integral membrane N‐terminal and cytoplasmic C‐terminal domains. FtsK is responsible for promoting decatenation and dimer resolution in the later stages of chromosome segregation by activating recombination at dif by the site‐specific Xer recombinases. Here, we formally demonstrate, using novel assay based on real‐time quantitative polymerase chain reaction, that dif recombination depends not only on proteins upstream of FtsK in the septum assembly pathway, but also on the activity of downstream proteins. Work in synchronized cell cultures further showed that even though FtsK is recruited early to the septum, dif recombination only occurs shortly before cell division and this activity requires a closing septum. We propose a model whereby septum localization and concentration of FtsK co‐ordinate its various roles in chromosome segregation and cell division.
How obligatory is anaerobiosis?
Authors: Imlay James A.
Published: March 2008

Historically many bacteria have been classified as obligate anaerobes. They have been construed as wholly intolerant of oxygen, a feature that was originally ascribed to their lack of superoxide dismutases and catalases. Clostridial species were regarded as classic examples. We now know that this view is quite wrong: enzymes that scavenge superoxide, hydrogen peroxide and even oxygen itself abound in anaerobes. In the current issue of Molecular Microbiology, Hillmann et al. demonstrate that full production of these proteins can allow Clostridium acetobutylicum to survive and even grow in oxygenated culture medium. Evidently, oxidative defences in anaerobes can be robust. In all likelihood, they are critical for the movement of bacteria through aerobic environments to new anaerobic habitats.
Location and architecture of the Caulobacter crescentus chemoreceptor array
Authors: Briegel Ariane , Ding H. Jane , Li Zhuo , Werner John , Gitai Zemer , Dias D. Prabha , Jensen Rasmus B. , Jensen Grant J.
Published: March 2008

A new method for recording both fluorescence and cryo‐EM images of small bacterial cells was developed and used to identify chemoreceptor arrays in cryotomograms of intact Caulobacter crescentus cells. We show that in wild‐type cells preserved in a near‐native state, the chemoreceptors are hexagonally packed with a lattice spacing of 12 nm, just a few tens of nanometers away from the flagellar motor that they control. The arrays were always found on the convex side of the cell, further demonstrating that Caulobacter cells maintain dorsal/ventral as well as anterior/posterior asymmetry. Placing the known crystal structure of a trimer of receptor dimers at each vertex of the lattice accounts well for the density and agrees with other constraints. Based on this model for the arrangement of receptors, there are between one and two thousand receptors per array.
A versatile strategy to define the phosphorylation preferences of plant protein kinases and screen for putative substrates
Authors: Vlad Florina , Turk Benjamin E. , Peynot Philippe , Leung Jeffrey , Merlot Sylvain
Published: March 2008

Most signaling networks are regulated by reversible protein phosphorylation. The specificity of this regulation depends in part on the capacity of protein kinases to recognize and efficiently phosphorylate particular sequence motifs in their substrates. Sequenced plant genomes potentially encode over than 1000 protein kinases, representing 4% of the proteins, twice the proportion found in humans. This plethora of plant kinases requires the development of high‐throughput strategies to identify their substrates. In this study, we have implemented a semi‐degenerate peptide array screen to define the phosphorylation preferences of four kinases from Arabidopsis thaliana that are representative of the plant calcium‐dependent protein kinase and Snf1‐related kinase superfamily. We converted these quantitative data into position‐specific scoring matrices to identify putative substrates of these kinases in silico in protein sequence databases. Our data show that these kinases display related but nevertheless distinct phosphorylation motif preferences, suggesting that they might share common targets but are likely to have specific substrates. Our analysis also reveals that a conserved motif found in the stress‐related dehydrin protein family may be targeted by the SnRK2‐10 kinase. Our results indicate that semi‐degenerate peptide array screening is a versatile strategy that can be used on numerous plant kinases to facilitate identification of their substrates, and therefore represents a valuable tool to decipher phosphorylation‐regulated signaling networks in plants.
Effect ofβ‐casein,κ‐casein andβ‐lactoglobulin genotypes on concentration of milk protein variants
Authors: Hallén E. , Wedholm A. , Andrén A. , Lundén A.
Published: March 2008

Individual mid‐lactation milk samples were collected from 116 cows of the Swedish Red and Swedish Holstein breeds with known genotypes ofβ‐casein,κ‐casein andβ‐lactoglobulin. Detailed milk protein composition and allele‐specific expression ofβ‐casein,κ‐casein andβ‐lactoglobulin proteins in milk were analysed using reversed‐phase high‐performance liquid chromatography. Aggregateβ‐/κ‐casein genotype was significantly associated with theκ‐casein concentration in milk. The lowestκ‐casein concentration was found in milk of cows with genotypes includingκ‐casein E (A1A2/AE, A1A1/AE) and also A2A2/AA milk, whereas highest levels were associated with genotypes includingκ‐casein B. Casein number was positively and concentration ofβ‐lactoglobulin negatively associated with theβ‐lactoglobulin BB genotype. In heterozygote cows,β‐casein A1andβ‐lactoglobulin A proteins were found at higher concentrations in milk compared with the protein variant encoded by the alternative allele at these loci, whereasκ‐casein A and B variants were found at similar concentrations in heterozygote AB cows.
Genetic characterization of the Burlina cattle breed using microsatellites markers
Authors: Dalvit C. , De Marchi M. , Dal Zotto R. , Zanetti E. , Meuwissen T. , Cassandro M.
Published: March 2008

The present study was a contribution on the genetic characterization of the Burlina local cattle breed, and an approach to understanding the relationships between Burlina, Holstein Friesian and Brown Swiss which represent the majority of the dairy cattle reared nowadays in North‐East Italy. The obtained results helped to clarify the genetic diversity and distinctiveness of Burlina population. In particular, the low genetic distance between Burlina and Holstein Friesian and the assignment of a moderate percentage of Burlina animals to Holstein Friesian suggested that crosses between them took place in the past, while crosses with Brown Swiss seemed to be less frequent. However, analyses of marker genotypes, showed a cluster with only Burlina individuals, which demonstrates the genetic distinctness of this breed. The Burlina breed showed the highest variability among the analysed breeds and its inbreeding coefficient was low. The data contribute to the feasibility of a conservation and selection programme for this breed and the results are useful for the implementation of a conservation strategy that should aim to conserve animals where the contribution from foreign breeds is as small as possible.
Neonatal maternal separation and enhancement of the inspiratory (phrenic) response to hypoxia in adult rats: disruption of GABAergic neurotransmission in the nucleus tractus solitarius
Authors: Kinkead Richard , Balon Norbert , Genest Sophie‐Emmanuelle , Gulemetova Roumiana , Laforest Sylvie , Drolet Guy
Published: March 2008

Neonatal maternal separation (NMS) alters respiratory control development. Adult male rats previously subjected to NMS show a hypoxic ventilatory response 25% greater than controls. During hypoxia, γ‐aminobutyric acid (GABA) release within the nucleus tractus solitarius (NTS) modulates the magnitude of the ventilatory response. Because development of GABAergic receptors is sensitive to NMS, we tested the hypothesis that in adults, a change in responsiveness to GABA within the NTS contributes to NMS‐related enhancement of the inspiratory (phrenic) response to hypoxia. Pups subjected to NMS were placed in an incubator for 3 h/day for 10 consecutive days [postnatal days 3 to 12]. Controls were undisturbed. Adult (8–10 weeks old) rats were anaesthetized (urethane; 1.6 g/kg), paralysed and artificially ventilated to record phrenic activity. Rats either received a 50‐nL microinjection of GABA (5 µm) or phosphate‐buffered saline (sham) within the caudal NTS, or no injection prior to being exposed to hypoxia (FiO2 = 0.12; 5 min). NMS enhanced both the frequency and amplitude components of the phrenic response to hypoxia vs controls. GABA microinjection attenuated the phrenic responses in NMS rats only. This result is supported by ligand binding autoradiography results showing that the number of GABAAreceptors within the NTS was 69% greater in NMS vs controls. Despite this increase, the phrenic response to hypoxia of NMS rats is larger than controls, suggesting that the higher responsiveness to GABA microinjection within the NTS is part of a mechanism that aims to compensate for: (i) a deficient GABAergic modulation; (ii) enhancement of excitatory inputs converging onto this structure; or (iii) both.
Recruiting new neurons from the subventricular zone to the rat postnatal cortex: an organotypic slice culture model
Authors: Dayer A. G. , Jenny B. , Potter G. , Sauvain M. O. , Szabó G. , Vutskits L. , Gascon E. , Kiss J. Z.
Published: March 2008

The neurogenic subventricular zone (SVZ) of the lateral ventricle is a potential source for neuronal replacement in the postnatal or adult neocortex after injury. Here we present a novel model system to directly explore the cellular mechanisms of this process. In order to visualize directed migration from the SVZ towards the cortex, we transplanted green fluorescent protein‐labeled progenitor/stem cells into the SVZ of newborn rats. At 2 days after transplantation, we generated organotypic slice cultures and applied fluorescent time‐lapse imaging to explore directly the migration and integration of donor cells into the host tissue for up to 2 weeks. Our studies revealed that subventricular grafts provide a significant number of immature neurons to neocortical regions. In the cortex, immature neurons first migrate radially towards the pial surface and then differentiate into GABAergic interneurons. We conclude that our model system presents a novel and effective experimental paradigm to evaluate the recruitment of SVZ‐derived neurons into the postnatal cortex, a phenomenon that may represent a potential route for cortical repair.
Activation of transient receptor potential ankyrin 1 by hydrogen peroxide
Authors: Sawada Yosuke , Hosokawa Hiroshi , Matsumura Kiyoshi , Kobayashi Shigeo
Published: March 2008

Hydrogen peroxide (H2O2), which is contained in industrial products, is also generated within cells. H2O2 causes pain but it has not been elucidated how it activates sensory neurons in the pain pathway. Here we show that transient receptor potential ankyrin 1 (TRPA1), expressed by sensory neurons in the pain pathway, is a receptor for H2O2. H2O2 activated mouse TRPA1 to induce Ca2+ influx and elicit non‐selective cation currents. These effects of H2O2 were mimicked by both reactive oxygen species and reactive nitrogen species. Cysteine‐reducing agents suppressed H2O2‐induced TRPA1 activation, whereas cysteine‐oxidizing agents activated TRPA1. H2O2 caused Ca2+ influx in a subset of dorsal root ganglia neurons, which responded to allyl isothiocyanate, a TRPA1 ligand. These results suggest that TRPA1 might be involved in the sensation of pain caused by H2O2.