bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surgery for sporadic primary hyperparathyroidism in the elderly
Authors: Öhryall Ulf , Åkerström Göran , Ljunghall Sverker , Lundgren Eva , Juhlin Claes , Rastad Jonas 
Published: October 2004

AbstractRetrospective analysis has been performed on 108 consecutive patients operated for primary hyperparathyroidism (HPT) at 75 to 85 years of age (mean 79 years). The preperative serum calcium value averaged 2.99 mM, and six patients had hypercalcemic crisis. Psychic disturbances were seen in 60 patients (56%), 40% of whom demonstrated dementia. Skeletal and muscular complaints were registered in 29% and 19%, respectively, and only 6% were overtly asymptomatic. Cardiovascular diseases were presented by 69% of the patients, 13% had diabetes mellitus, and 26% were institutionalized prior to surgery. Bilateral neck exploration disclosed a single adenoma in 69%, which was of the oxyphil cell type in 13%, and water‐clear (n=3) or chief cell hyperplasia in 27%. The total glandular weight averaged 1085 mg. Altogether 72 patients operated on after 1980 demonstrated a perioperative (30‐day) mortality of 1.4%; the corresponding morbidity of 8.7% mainly included infections as well as a vocal cord paralysis in one patient and two incisional hematomas. Analysis for mean 3.1 years postoperatively displayed reversal of hypercalcemia in 95% of the patients; 2.8% of those operated after 1980 had persistent disease. Symptoms seemed to be alleviated in 62%, with a similar rate attained in patients with dementia. Altogether 60 patients died from mainly cardiovascular diseases mean 4.2 years after the operation. Those succumbing the first postoperative year (n=21) showed overrepresentation of cardiac diseases and diabetes mellitus. The results demonstrate prevalent psychic disturcbances, oxyphil adenomas, and multiglandular parathyroid disease in elderly patients with primary HPT and favor rather liberal application of parathyroid surgery among these individuals.
Conserved Region 2.1 of
Escherichia coli
Heat Shock Transcription Factor σ
32
Is Required for Modulating both Metabolic Stability and Transcriptional Activity
Authors: Horikoshi Mina , Yura Takashi , Tsuchimoto Sachie , Fukumori Yoshihiro , Kanemori Masaaki 
Published: October 2004

ABSTRACT

Escherichia coli
heat shock transcription factor σ
32
is rapidly degraded in vivo, with a half-life of about 1 min. A set of proteins that includes the DnaK chaperone team (DnaK, DnaJ, GrpE) and ATP-dependent proteases (FtsH, HslUV, etc.) are involved in degradation of σ
32
. To gain further insight into the regulation of σ
32
stability, we isolated σ
32
mutants that were markedly stabilized. Many of the mutants had amino acid substitutions in the N-terminal half (residues 47 to 55) of region 2.1, a region highly conserved among bacterial σ factors. The half-lives ranged from about 2-fold to more than 10-fold longer than that of the wild-type protein. Besides greater stability, the levels of heat shock proteins, such as DnaK and GroEL, increased in cells producing stable σ
32
. Detailed analysis showed that some stable σ
32
mutants have higher transcriptional activity than the wild type. These results indicate that the N-terminal half of region 2.1 is required for modulating both metabolic stability and the activity of σ
32
. The evidence suggests that σ
32
stabilization does not result from an elevated affinity for core RNA polymerase. Region 2.1 may, therefore, be involved in interactions with the proteolytic machinery, including molecular chaperones.
The
Salmonella
Membrane Protein IgaA Modulates the Activity of the RcsC-YojN-RcsB and PhoP-PhoQ Regulons
Authors: Tierrez Alberto , García-del Portillo Francisco 
Published: October 2004

ABSTRACT

The
Salmonella enterica
serovar Typhimurium membrane protein IgaA and the PhoP-PhoQ two-component system are used by this pathogen to attenuate the intracellular growth rate within fibroblasts. IgaA has also recently been shown to contribute to virulence by exerting tight repression of the RcsC-YojN-RcsB phosphorelay in host tissues. Here we show that loss of repression of the RcsC-YojN-RcsB system, linked to an R188H mutation in the IgaA protein (
igaA1
allele), is accompanied by altered expression of PhoP-PhoQ-activated (
pag
) genes. The changes in gene expression were different depending on the specific
pag
gene analyzed. Thus, transcription of
ugd
, which is required for lipopolysaccharide modification and colanic acid capsule synthesis, was enhanced in the
igaA1
mutant. RcsB and its coregulator RcsA promoted this alteration in a PhoP-PmrA-independent manner. Unlike
ugd
, activation of the RcsC-YojN-RcsB phosphorelay negatively affected the expression of all other
pag
genes tested. In this case, RcsB alone was responsible for this effect. We also found that PhoP, but not PmrA, negatively modulates the expression of
gmm
, a gene required for colanic acid synthesis that is regulated positively by RcsC-YojN-RcsB. Finally, it was observed that the fine regulation of
pag
genes exerted by RcsB requires the RpoS protein and that an active RcsB, but not RcsA, diminishes expression of the
phoP
gene. These data support the hypothesis that in
Salmonella
there is an intimate regulatory circuit between the PhoP-PhoQ and RcsC-YojN-RcsB phosphorelays, which is revealed only when the RcsC-YojN-RcsB signaling route is derepressed. Consistent with the phenotypes observed in fibroblast cells, IgaA is predicted to favor expression of the entire PhoP-PhoQ regulon based on its repression of the RcsC-YojN-RcsB phosphorelay.
Pyruvate Formate Lyase and Acetate Kinase Are Essential for Anaerobic Growth ofEscherichia colion Xylose
Authors: Hasona Adnan , Kim Youngnyun , Healy F. G. , Ingram L. O. , Shanmugam K. T. 
Published: October 2004

ABSTRACTDuring anaerobic growth of bacteria, organic intermediates of metabolism, such as pyruvate or its derivatives, serve as electron acceptors to maintain the overall redox balance. Under these conditions, the ATP needed for cell growth is derived from substrate-level phosphorylation. InEscherichia coli, conversion of glucose to pyruvate yields 2 net ATPs, while metabolism of a pentose, such as xylose, to pyruvate only yields 0.67 net ATP per xylose due to the need for one (each) ATP for xylose transport and xylulose phosphorylation. During fermentative growth,E. coliproduces equimolar amounts of acetate and ethanol from two pyruvates, and these reactions generate one additional ATP from two pyruvates (one hexose equivalent) while still maintaining the overall redox balance. Conversion of xylose to acetate and ethanol increases the net ATP yield from 0.67 to 1.5 per xylose. AnE. coli pflmutant lacking pyruvate formate lyase cannot convert pyruvate to acetyl coenzyme A, the required precursor for acetate and ethanol production, and could not produce this additional ATP.E. coli pflmutants failed to grow under anaerobic conditions in xylose minimal medium without any negative effect on their survival or aerobic growth. AnackAmutant, lacking the ability to generate ATP from acetyl phosphate, also failed to grow in xylose minimal medium under anaerobic conditions, confirming the need for the ATP produced by acetate kinase for anaerobic growth on xylose. Since arabinose transport by AraE, the low-affinity, high-capacity, arabinose/H+symport, conserves the ATP expended in pentose transport by the ABC transporter, bothpflandackAmutants grew anaerobically with arabinose. AraE-based xylose transport, achieved after constitutively expressingaraE, also supported the growth of thepflmutant in xylose minimal medium. These results suggest that a net ATP yield of 0.67 per pentose is only enough to provide for maintenance energy but not enough to support growth ofE. coliin minimal medium. Thus, pyruvate formate lyase and acetate kinase are essential for anaerobic growth ofE. colion xylose due to energetic constraints.
Role of CysE in Production of an Extracellular Signaling Molecule in
Providencia stuartii
and
Escherichia coli
: Loss of
cysE
Enhances Biofilm Formation in
Escherichia coli
Authors: Sturgill Gwen , Toutain Christine M. , Komperda John , O'Toole George A. , Rather Philip N. 
Published: October 2004

ABSTRACT

A mini-Tn
5Cm
insertion has been identified that significantly reduced the amount of an extracellular activating signal for a
lacZ
fusion (
cma37
::
lacZ
) in
Providencia stuartii
. The transposon insertion was located immediately upstream of an open reading frame encoding a putative CysE ortholog. The CysE enzyme, serine acetyltransferase, catalyzes the conversion of serine to
O
-acetyl-
l
-serine (OAS). This activating signal was also produced by
Escherichia coli
, and production was abolished in a strain containing a null allele of
cysE
. Products of the CysE enzyme (OAS,
N
-acetyl-
l
-serine [NAS],
O
-acetyl-
l
-threonine, and
N
-acetyl-
l
-threonine) were individually tested for the ability to activate
cma37
::
lacZ
. Only OAS was capable of activating the
cma37
::
lacZ
fusion. The ability of OAS to activate the
cma37
::
lacZ
fusion was abolished by pretreatment at pH 8.5, which converts OAS to NAS. However, the activity of the native signal in conditioned medium was not decreased by treatment at pH 8.5. In contrast, conditioned medium prepared from cells grown at pH 8.5 exhibited a 4- to 10-fold-higher activity, relative to pH 6.0. Additional genes regulated by the CysE-dependent signal and OAS were identified in
P. stuartii
and
E. coli
. The response to the extracellular signal in
E. coli
was dependent on CysB, a positive activator that requires NAS as a coactivator. In
E. coli
, a
cysE
mutant formed biofilms at an accelerated rate compared to the wild type, suggesting a physiological role for this extracellular signal.
Molecular Identification of the Urea Uptake System and Transcriptional Analysis of Urea Transporter- and Urease-Encoding Genes in
Corynebacterium glutamicum
Authors: Beckers Gabriele , Bendt Anne K. , Krämer Reinhard , Burkovski Andreas 
Published: October 2004

ABSTRACT

The molecular identification of the
Corynebacterium glutamicum
urea uptake system is described. This ABC-type transporter is encoded by the
urtABCDE
operon, which is transcribed in response to nitrogen limitation. Expression of the
urt
genes is regulated by the global nitrogen regulator AmtR, and an
amtR
deletion strain showed constitutive expression of the
urtABCDE
genes. The AmtR repressor protein also controls transcription of the urease-encoding
ureABCEFGD
genes in
C. glutamicum
. The
ure
gene cluster forms an operon which is mainly transcribed in response to nitrogen starvation. To confirm the increased synthesis of urease subunits under nitrogen limitation, proteome analyses of cytoplasmic protein extracts from cells grown under nitrogen surplus and nitrogen limitation were carried out, and five of the seven urease subunits were identified.
The CorA Mg
2+
Transporter Does Not Transport Fe
2+
Authors: Papp Krisztina M. , Maguire Michael E. 
Published: October 2004

ABSTRACT

corA
encodes the constitutively expressed primary Mg
2+
uptake system of most eubacteria and many archaea. Recently, a mutation in
corA
was reported to make
Salmonella enterica
serovar Typhimurium markedly resistant to Fe
2+
-mediated toxicity. Mechanistically, this was hypothesized to be from an ability of CorA to mediate the influx of Fe
2+
. Consequently, we directly examined Fe
2+
transport and toxicity in wild-type versus
corA
cells. As determined by direct transport assay, CorA cannot transport Fe
2+
and Fe
2+
does not potently inhibit CorA transport of
63
Ni
2+
. Mg
2+
can, relatively weakly, inhibit Fe
2+
uptake, but inhibition is not dependent on the presence of a functional
corA
allele. Although excess Fe
2+
was slightly toxic to
S. enterica
serovar Typhimurium, we were unable to elicit a significant differential sensitivity in a wild-type versus a
corA
strain. We conclude that CorA does not transport Fe
2+
and that the relationship, if any, between iron toxicity and
corA
is indirect.
A Novel Archaeal Alanine Dehydrogenase Homologous to Ornithine Cyclodeaminase and μ-Crystallin
Authors: Schröder Imke , Vadas Alexander , Johnson Eric , Lim Sierin , Monbouquette Harold G. 
Published: October 2004

ABSTRACT

A novel alanine dehydrogenase (AlaDH) showing no significant amino acid sequence homology with previously known bacterial AlaDHs was purified to homogeneity from the soluble fraction of the hyperthermophilic archaeon
Archaeoglobus fulgidus
. AlaDH catalyzed the reversible, NAD
+
-dependent deamination of
l
-alanine to pyruvate and NH
4
+
. NADP(H) did not serve as a coenzyme. The enzyme is a homodimer of 35 kDa per subunit. The
K

m

values for
l
-alanine, NAD
+
, pyruvate, NADH, and NH
4
+
were estimated at 0.71, 0.60, 0.16, 0.02, and 17.3 mM, respectively. The
A. fulgidus
enzyme exhibited its highest activity at about 82°C (203 U/mg for reductive amination of pyruvate) yet still retained 30% of its maximum activity at 25°C. The thermostability of
A. fulgidus
AlaDH was increased by more than 10-fold by 1.5 M KCl to a half-life of 55 h at 90°C. At 25°C in the presence of this salt solution, the enzyme was ∼100% stable for more than 3 months. Closely related
A. fulgidus
AlaDH homologues were found in other archaea. On the basis of its amino acid sequence,
A. fulgidus
AlaDH is a member of the ornithine cyclodeaminase-μ-crystallin family of enzymes. Similar to the μ-crystallins,
A. fulgidus
AlaDH did not exhibit any ornithine cyclodeaminase activity. The recombinant human μ-crystallin was assayed for AlaDH activity, but no activity was detected. The novel
A. fulgidus
gene encoding AlaDH, AF1665, is designated
ala
.
The
bcr1
DNA Repeat Element Is Specific to the
Bacillus cereus
Group and Exhibits Mobile Element Characteristics
Authors: Økstad Ole Andreas , Tourasse Nicolas J. , Stabell Fredrik B. , Sundfær Cathrine K. , Egge-Jacobsen Wolfgang , Risøen Per Arne , Read Timothy D. , Kolstø Anne-Brit 
Published: October 2004

ABSTRACT

Bacillus cereus
strains ATCC 10987 and ATCC 14579 harbor a ∼155-bp repeated element,
bcr1
, which is conserved in
B. cereus
,
B. anthracis
,
B. thuringiensis
, and
B. mycoides
but not in
B. subtilis
and
B. licheniformis
. In this study, we show by Southern blot hybridizations that
bcr1
is present in all 54
B. cereus
group strains tested but absent in 11
Bacillus
strains outside the group, suggesting that
bcr1
may be specific and ubiquitous to the
B. cereus
group. By comparative analysis of the complete genome sequences of
B. cereus
ATCC 10987,
B. cereus
ATCC 14579, and
B. anthracis
Ames, we show that
bcr1
is exclusively present in the chromosome but absent from large plasmids carried by these strains and that the numbers of full-length
bcr1
repeats for these strains are 79, 54, and 12, respectively. Numerous copies of partial
bcr1
elements are also present in the three genomes (91, 128, and 53, respectively). Furthermore, the genomic localization of
bcr1
is not conserved between strains with respect to chromosomal position or organization of gene neighbors, as only six full-length
bcr1
loci are common to at least two of the three strains. However, the intergenic sequence surrounding a specific
bcr1
repeat in one of the three strains is generally strongly conserved in the other two, even in loci where
bcr1
is found exclusively in one strain. This finding indicates that
bcr1
either has evolved by differential deletion from a very high number of repeats in a common ancestor to the
B. cereus
group or is moving around the chromosome. The identification of
bcr1
repeats interrupting genes in
B. cereus
ATCC 10987 and ATCC 14579 and the presence of a flanking TTTAT motif in each end show that
bcr1
exhibits features characteristic of a mobile element.
Responses of the
Rhodobacter sphaeroides
Transcriptome to Blue Light under Semiaerobic Conditions
Authors: Braatsch Stephan , Moskvin Oleg V. , Klug Gabriele , Gomelsky Mark 
Published: October 2004

ABSTRACT

Exposure to blue light of the facultative phototrophic proteobacterium
Rhodobacter sphaeroides
grown semiaerobically results in repression of the
puc
and
puf
operons involved in photosystem formation. To reveal the genome-wide effects of blue light on gene expression and the underlying photosensory mechanisms, transcriptome profiles of
R. sphaeroides
during blue-light irradiation (for 5 to 135 min) were analyzed. Expression of most photosystem genes was repressed upon irradiation. Downregulation of photosystem development may be used to prevent photooxidative damage occurring when the photosystem, oxygen, and high-intensity light are present simultaneously. The photoreceptor of the BLUF-domain family, AppA, which belongs to the AppA-PpsR antirepressor-repressor system, is essential for maintenance of repression upon prolonged irradiation (S. Braatsch et al., Mol. Microbiol. 45:827-836, 2002). Transcriptome data suggest that the onset of repression is also mediated by the AppA-PpsR system, albeit via an apparently different sensory mechanism. Expression of several genes, whose products may participate in photooxidative damage defense, including deoxypyrimidine photolyase, glutathione peroxidase, and quinol oxidoreductases, was increased. Among the genes upregulated were genes encoding two σ factors: σ
E
and σ
38
. The consensus promoter sequences for these σ factors were predicted in the upstream sequences of numerous upregulated genes, suggesting that coordinated action of σ
E
and σ
38
is responsible for the upregulation. Based on the dynamics of upregulation, the anti-σ
E
factor ChrR or its putative upstream partner is proposed to be the primary sensor. The identified transcriptome responses provided a framework for deciphering blue-light-dependent signal transduction pathways in
R. sphaeroides
.
Global Transcriptome Analysis of the Heat Shock Response of
Shewanella oneidensis
Authors: Gao Haichun , Wang Yue , Liu Xueduan , Yan Tingfen , Wu Liyou , Alm Eric , Arkin Adam , Thompson Dorothea K. , Zhou Jizhong 
Published: October 2004

ABSTRACT

Shewanella oneidensis
is an important model organism for bioremediation studies because of its diverse respiratory capabilities. However, the genetic basis and regulatory mechanisms underlying the ability of
S. oneidensis
to survive and adapt to various environmentally relevant stresses is poorly understood. To define this organism's molecular response to elevated growth temperatures, temporal gene expression profiles were examined in cells subjected to heat stress by using whole-genome DNA microarrays for
S. oneidensis
. Approximately 15% (
n
= 711) of the total predicted
S. oneidensis
genes (
n
= 4,648) represented on the microarray were significantly up- or downregulated (
P
< 0.05) over a 25-min period after shift to the heat shock temperature. As expected, the majority of the genes that showed homology to known chaperones and heat shock proteins in other organisms were highly induced. In addition, a number of predicted genes, including those encoding enzymes in glycolysis and the pentose cycle, serine proteases, transcriptional regulators (MerR, LysR, and TetR families), histidine kinases, and hypothetical proteins were induced. Genes encoding membrane proteins were differentially expressed, suggesting that cells possibly alter their membrane composition or structure in response to variations in growth temperature. A substantial number of the genes encoding ribosomal proteins displayed downregulated coexpression patterns in response to heat stress, as did genes encoding prophage and flagellar proteins. Finally, a putative regulatory site with high conservation to the
Escherichia coli
σ
32
-binding consensus sequence was identified upstream of a number of heat-inducible genes.
Long-Term Effect of Mutagenic DNA Repair on Accumulation of Mutations in
Pseudomonas syringae
B86-17
Authors: Zhang Shouan , Sundin George W. 
Published: October 2004

ABSTRACT

Forty replicate lineages of
Pseudomonas syringae
B86-17 cells expressing the
rulAB
mutagenic DNA repair (MDR) determinant or the
rulB
::Km MDR-deficient mutant GWS242 were passaged through single-cell bottlenecks (60 cycles), with a UV radiation (UVR) exposure given to half of the lineages at the beginning of each cycle. After every 10th bottleneck cycle, single-colony isolates from all 80 lineages were subjected to 39 phenotypic screens, with newly arising mutations detected in 60 and 0% of UVR-exposed or non-UVR-exposed B86-17 lineages, respectively, by the 60th cycle. Cellular fitness, measured as growth rate in a minimal medium, of UVR-exposed lineages of both B86-17 and GWS242 after 60 cycles was not significantly different from that of the ancestral strains. Although UVR exposure and MDR activity increased the occurrence of mutations in cells, a significant reduction in overall fitness was not observed.
In Vivo Production of Active Nickel Superoxide Dismutase from
Prochlorococcus marinus
MIT9313 Is Dependent on Its Cognate Peptidase
Authors: Eitinger Thomas 
Published: October 2004

ABSTRACT

Metal-dependent superoxide dismutases (SODs) with a specific requirement for a manganese or iron ion for catalytic activity and copper- and zinc-dependent enzymes are essential for detoxification of superoxide anion radicals. Genome sequence analyses predict the existence of a nickel-dependent enzyme (NiSOD) as the unique SOD in oxygen-evolving marine cyanobacteria. NiSOD activity was observed in
Escherichia coli
when
sodN
and
sodX
(encoding a putative peptidase) from
Prochlorococcus marinus
MIT9313 were coexpressed.
Nasal nitric oxide is low early in life: case study of two infants with primary ciliary dyskinesia: Fig. 1.—
Authors: Baraldi E. , Pasquale M.F. , Cangiotti A.M. , Zanconato S. , Zacchello F. 
Published: October 2004

Nasal nitric oxide levels are low in patients with primary ciliary dyskinesia, but it is not known whether this defect is already present in the first months of life.The current authors measured nasal nitric oxide in two infants withsitus inversusand primary ciliary dyskinesia, diagnosed by electron microscopy at 4 and 6 months of age, and in five healthy control infants.Nasal nitric oxide values in the primary ciliary dyskinesia infants (85 and 115 parts per billion (ppb)) were markedly lower than in the healthy controls (mean: 295 ppb, range: 225–379 ppb).This is the first report to show that nasal nitric oxide values are already low in early life in primary ciliary dyskinesia children, supporting the hypothesis that a reduced production of nasal nitric oxide is an intrinsic feature of this disease. The current authors suggest that the nasal nitric oxide test may be a useful, noninvasive method for screening young children for primary ciliary dyskinesia in clinical practice.
Course of illness in depressive and bipolar disorders
Authors: Kessing Lars Vedel , Hansen Mette Gerster , Andersen Per Kragh 
Published: October 2004

BackgroundNewer antidepressants have increasingly been used during the past decade. These drugs may increase compliance and reduce the risk of cycle acceleration in affective disorders.AimsTo investigate the naturalistic longitudinal course of illness in patients with depressive or bipolar disorder following the use of recently introduced drugs.MethodThe rates of relapse leading to hospitalisation after successive episodes were calculated in a case register study including all hospital admissions of patients with primary affective disorder in Denmark during 1994–1999. Altogether, 9417 patients had a diagnosis of depressive disorder and 1106 patients had a diagnosis of mania or bipolar disorder, at first-ever discharge.ResultsThe rate of relapse leading to hospitalisation increased with the number of previous episodes in both depressive and bipolar disorders. However, the effect of episodes was not significant for men. The rate of relapse did not decline during the study period.ConclusionsThe course of severe depressive and bipolar disorders has remained roughly the same despite introduction of new treatments.