bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation of a Minireplicon of the Virulence Plasmid pXO2 of
Bacillus anthracis
and Characterization of the Plasmid-Encoded RepS Replication Protein
Authors: Tinsley Eowyn , Naqvi Asma , Bourgogne Agathe , Koehler Theresa M. , Khan Saleem A. 
Published: April 2004

ABSTRACT

A minireplicon of plasmid pXO2 of
Bacillus anthracis
was isolated by molecular cloning in
Escherichia coli
and shown to replicate in
B. anthracis
,
Bacillus cereus
, and
Bacillus subtilis
. The pXO2 replicon included (i) an open reading frame encoding the putative RepS replication initiation protein and (ii) the putative origin of replication. The RepS protein was expressed as a fusion with the maltose binding protein (MBP) at its amino-terminal end and purified by affinity chromatography. Electrophoretic mobility shift assays showed that the purified MBP-RepS protein bound specifically to a 60-bp region corresponding to the putative origin of replication of pXO2 located immediately downstream of the RepS open reading frame. Competition DNA binding experiments showed that the 5′ and central regions of the putative origin were important for RepS binding. MBP-RepS also bound nonspecifically to single-stranded DNA with a lower affinity.
A Novel Tetrahydrofolate-Dependent
O
-Demethylase Gene Is Essential for Growth of
Sphingomonas paucimobilis
SYK-6 with Syringate
Authors: Masai Eiji , Sasaki Miyuki , Minakawa Yasunori , Abe Tomokuni , Sonoki Tomonori , Miyauchi Keisuke , Katayama Yoshihiro , Fukuda Masao 
Published: April 2004

ABSTRACT

Sphingomonas paucimobilis
SYK-6 degrades syringate to 3-
O
-methylgallate (3MGA), which is finally converted to pyruvate and oxaloacetate via multiple pathways in which protocatechuate 4,5-dioxygenase, 3MGA dioxygenase, and gallate dioxygenase are involved. Here we isolated the syringate
O
-demethylase gene (
desA
), which complemented the growth deficiency on syringate of a Tn
5
mutant of the SYK-6 derivative strain. The
desA
gene is located 929 bp downstream of
ferA
, encoding feruloyl-coenzyme A synthetase, and consists of a 1,386-bp open reading frame encoding a polypeptide with a molecular mass of 50,721 Da. The deduced amino acid sequence of
desA
showed 26% identity in a 325-amino-acid overlap with that of
gcvT
of
Escherichia coli
, which encodes the tetrahydrofolate (H
4
folate)-dependent aminomethyltransferase involved in glycine cleavage. The cell extract of
E. coli
carrying
desA
converted syringate to 3MGA only when H
4
folate was added to the reaction mixture. DesA catalyzes the transfer of the methyl moiety of syringate to H
4
folate, forming 5-methyl-H
4
folate. Vanillate and 3MGA were also used as substrates for DesA; however, the relative activities toward them were 3 and 0.4% of that toward syringate, respectively. Disruption of
desA
in SYK-6 resulted in a growth defect on syringate but did not affect growth on vanillate, indicating that
desA
is essential to syringate degradation. In a previous study the
ligH
gene, which complements the growth deficiency on vanillate and syringate of a chemical-induced mutant of SYK-6, DC-49, was isolated (S. Nishikawa, T. Sonoki, T. Kasahara, T. Obi, S. Kubota, S. Kawai, N. Morohoshi, and Y. Katayama, Appl. Environ. Microbiol. 64:836-842, 1998). Disruption of
ligH
resulted in the same phenotype as DC-49; its cell extract, however, was found to be able to convert vanillate and syringate in the presence of H
4
folate. The possible role of
ligH
is discussed.
Bdellovibrio bacteriovorusStrains Produce a Novel Major Outer Membrane Protein during Predacious Growth in the Periplasm of Prey Bacteria
Authors: Beck Sebastian , Schwudke Dominik , Strauch Eckhard , Appel Bernd , Linscheid Michael 
Published: April 2004

ABSTRACTBdellovibrio bacteriovorusis a predatory bacterium that is capable of invading a number of gram-negative bacteria. The life cycle of this predator can be divided into a nonreproductive phase outside the prey bacteria and a multiplication phase in their periplasm. It was suggested that during the reproduction phase,B. bacteriovorusreutilizes unmodified components of the prey's cell wall. We therefore examined the outer membranes ofB. bacteriovorusstrains HD100 (DSM 50701) and HD114 (DSM 50705) by usingEscherichia coli,Yersinia enterocolitica, andPseudomonas putidaas prey organisms. The combined sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometric analyses revealed novel and innate major outer membrane proteins (OMPs) ofB. bacteriovorusstrains. An incorporation of prey-derived proteins into the cell wall ofB. bacteriovoruswas not observed. The corresponding genes of theB. bacteriovorusstrains were elucidated by a reverse-genetics approach, and a leader peptide was deduced from the gene sequence and confirmed by Edman degradation. The host-independent mutant strainB. bacteriovorusHI100 (DSM 12732) growing in the absence of prey organisms possesses an OMP similar to the major OMPs of the host-dependent strains. The similarity of the primary structure of the OMPs produced by the threeBdellovibriostrains is between 67 and 89%. The leader peptides of all OMPs have a length of 20 amino acids and are highly conserved. The molecular sizes of the mature proteins range from 34.9 to 37.6 kDa. Secondary-structure predictions indicate preferential α-helices and little β-barrel structures.
The θ Subunit ofEscherichia coliDNA Polymerase III: a Role in Stabilizing the ε Proofreading Subunit
Authors: Taft-Benz Sharon A. , Schaaper Roel M. 
Published: April 2004

ABSTRACTThe function of the θ subunit ofEscherichia coliDNA polymerase III holoenzyme is not well established. θ is a tightly bound component of the DNA polymerase III core, which contains the α subunit (polymerase), the ε subunit (3′→5′ exonuclease), and the θ subunit, in the linear order α-ε-θ. Previous studies have shown that the θ subunit is not essential, as strains carrying a deletion of theholEgene (which encodes θ) proved fully viable. No significant phenotypic effects of theholEdeletion could be detected, as the strain displayed normal cell health, morphology, and mutation rates. On the other hand, in vitro experiments have indicated the efficiency of the 3′-exonuclease activity of ε to be modestly enhanced by the presence of θ. Here, we report a series of genetic experiments that suggest that θ has a stabilizing role for the ε proofreading subunit. The observations include (i) defined ΔholEmutator effects in mismatch-repair-defectivemutLbackgrounds, (ii) strong ΔholEmutator effects in certain proofreading-impaireddnaQstrains, and (iii) yeast two- and three-hybrid experiments demonstrating enhancement of α-ε interactions by the presence of θ. θ appears conserved among gram-negative organisms which have an exonuclease subunit that exists as a separate protein (i.e., not part of the polymerase polypeptide), and the presence of θ might be uniquely beneficial in those instances where the proofreading 3′-exonuclease is not part of the polymerase polypeptide.
Molecular Evolution and Mosaicism of Leptospiral Outer Membrane Proteins Involves Horizontal DNA Transfer
Authors: Haake David A. , Suchard Marc A. , Kelley Melissa M. , Dundoo Manjula , Alt David P. , Zuerner Richard L. 
Published: April 2004

ABSTRACT

Leptospires belong to a genus of parasitic bacterial spirochetes that have adapted to a broad range of mammalian hosts. Mechanisms of leptospiral molecular evolution were explored by sequence analysis of four genes shared by 38 strains belonging to the core group of pathogenic
Leptospira
species:
L. interrogans
,
L. kirschneri
,
L. noguchii
,
L. borgpetersenii
,
L. santarosai
, and
L. weilii
. The 16S rRNA and
lipL32
genes were highly conserved, and the
lipL41
and
ompL1
genes were significantly more variable. Synonymous substitutions are distributed throughout the
ompL1
gene, whereas nonsynonymous substitutions are clustered in four variable regions encoding surface loops. While phylogenetic trees for the 16S,
lipL32
, and
lipL41
genes were relatively stable, 8 of 38 (20%)
ompL1
sequences had mosaic compositions consistent with horizontal transfer of DNA between related bacterial species. A novel Bayesian multiple change point model was used to identify the most likely sites of recombination and to determine the phylogenetic relatedness of the segments of the mosaic
ompL1
genes. Segments of the mosaic
ompL1
genes encoding two of the surface-exposed loops were likely acquired by horizontal transfer from a peregrine allele of unknown ancestry. Identification of the most likely sites of recombination with the Bayesian multiple change point model, an approach which has not previously been applied to prokaryotic gene sequence analysis, serves as a model for future studies of recombination in molecular evolution of genes.
Origin and Diversity of Alginate Lyases of Families PL-5 and -7 in
Sphingomonas
sp. Strain A1
Authors: Miyake Osamu , Ochiai Akihito , Hashimoto Wataru , Murata Kousaku 
Published: April 2004

ABSTRACT

Sphingomonas
sp. strain A1 has three endotype alginate lyases (A1-I, A1-II [family PL-7], and A1-III [family PL-5]), each of which is encoded by a single gene. In addition to those of these lyases, a gene (the A1-II′ gene) showing significant identity with the A1-II gene was present in the bacterial genome and coded for an alginate lyase with broad substrate specificity. Since no expression of A1-II′ was observed even in bacterial cells grown on alginate, the A1-II′ gene was thought to be a silent gene derived from the A1-II gene, presumably through duplication, modification, and translocation.
Preferential Reduction of Fe(III) over Fumarate by
Geobacter sulfurreducens
Authors: Esteve-Núñez Abraham , Núñez Cinthia , Lovley Derek R. 
Published: April 2004

ABSTRACT

The presence of Fe(III), but not that of Fe(II), resulted in ca. 20-fold-lower levels of mRNA for fumarate reductase, inhibiting fumarate reduction and favoring utilization of fumarate as an electron donor in chemostat cultures of
Geobacter sulfurreducens
, despite the fact that growth yield with fumarate was 3-fold higher than with Fe(III).
Employment retention after moderate-severe traumatic brain injury (TBI) in the British Army 1989–98
Authors: McLeod A , Wills A , Etherington J 
Published: April 2004

Aims:To examine retention in employment of subjects with moderate-severe traumatic brain injury (TBI) in the British Army.Methods:Comparative groups study of retention in Army employment after TBI using 564 TBI, 368 lower limb fracture, and 25 575 healthy subjects. Kaplan-Meier survival analysis was used to examine, stratifying for age, continuation in Army employment for six years after TBI.Results:Subjects in the younger groups (mean ages 23 years and 27 years respectively) with either TBI or lower limb fracture remained in employment longer than healthy peers (median time for TBI, 3.91 years, lower limb fracture, 4.39 years, and healthy, 1.74 years). This trend changed through age stratification and for older subjects the reverse pattern was seen. In group 4 (mean age 41 years), median retention time for TBI was 3.33 years, for lower limb fracture, 3.75 years, healthy 5.55 years. Older subjects also showed a marked drop out rate at one year after injury; 32.7% of those with TBI in group 3 (mean age 31 years) had left Army employment at the end of year one compared with 19% in age group 1 (mean age 23 years).Conclusions:Younger soldiers with either TBI or lower limb fracture are retained in Army employment longer than their healthy peers. This may be due to sheltered employment, the availability of ongoing support, or transience of the healthy population. Since these results were drawn from incidence data on moderate and severe TBI it may be that those who serve on after TBI will do so with some degree of disability which affects occupational performance. There may be a significant unmet rehabilitation need for this group which is the focus of ongoing research.
Risk of upper aerodigestive tract cancers in a case-cohort study of autoworkers exposed to metalworking fluids
Authors: Zeka A , Eisen E A , Kriebel D , Gore R , Wegman D H 
Published: April 2004

Aims:To re-examine aerodigestive cancer risk in a cohort of autoworkers exposed to metal working fluids (MWF), using improved case definition and more recently diagnosed cases.Methods:The autoworker cohort included 31 100 hourly workers alive on 1 January 1985 who worked at three automobile plants in Michigan. A case-cohort design was carried out that included incident cases of cancers of the larynx, oesophagus, and stomach, and a 10% sample of the cohort. A Cox proportional hazards model was used to estimate MWF exposure effects. The smoothing method of penalised splines was used to explore the shape of the underlying exposure-response curves.Results:The most important finding was the association between larynx cancer incidence and cumulative straight MWF exposure. The results for oesophageal cancer were less consistent. For stomach cancer there was no evidence of excess risk.Conclusion:This association between larynx cancer and straight MWF exposures was consistent with a previous finding in this cohort, providing further support for a causal relation.
Oral contraceptive exposure of amenorrheic women with and without prolactinomas
Authors: Jones James R. , Kemmann Ekkehard , Norwood Paula K. 
Published: April 2004

AbstractThe purpose of this study was to determine the extent of oral contraceptive (OC) exposure of women with secondary amenorrhea of hypothalamic‐pituitary etiology. In 93 of 126 women with secondary amenorrhea sufficient data were obtained regarding menstrual history and OC exposure: 26 patients had evidence of a prolactinoma, an additional 26 patients had idiopathic hyperprolactinemia without evidence of a pituitary tumor, and 41 had “pure” dysfunction hypothalamicpituitary amenorrhea. After stratification by age at diagnosis and parity the estimated odds ratio for past oral contraceptive usage showed no differences among the three groups (odds ratios between 0.74 and 1.48). Using the chisquare test the proportion of subjects who had regular menses before oral contraceptive intake and developed anovulation immediately after discontinuance (“post pill amenorrhea”) in the three groups also showed no difference (χ2 = 0.60, P = 0.74). These data indicate that non‐ovulatory patients are likely to have been exposed to OC, and do not indicate that patients with prolactinomas differ in the extent of their OC exposure from other specified groups of patients with secondary amenorrhea.
Pituitary and placental hormone levels in pseudocyesis
Authors: Osotimehin B.O. , Ladipo O.A , Adejuwon C.A. , Otolorin E.O. 
Published: April 2004

AbstractTwelve patients with clinical features of pseudocyesis were divided into two groups according to the presence or absence of galactorrhea. The mean serum prolactin level of patients with galactorrhea was significantly higher than the normal values of the patients without galactorrhea. The mean serum levels of luteinizing hormone and follicle‐stimulating hormone were markedly elevated in patients without galactorrhea. This was especially true of luteinizing hormone. Serum levels of human chorionic gonadotropin were undetectable in all patients. The significance of these observations is discussed.
Cesarean section in four Rio de Janeiro hospitals
Authors: Lins Fernando Estellita , Fortney Judith A. 
Published: April 2004

AbstractData collected on maternity patients at four hospitals in Rio de Janeiro, Brazil, show that their rates of cesarean section vary considerably, ranging from less than 15% of all deliveries at the hospital serving women from the lowest socioeconomic group to over 80% at the one restricted to private patients. Virtually none of the conditions usually considered as indication for cesarean delivery were universally managed in this manner. On the other hand, in many instances, there was no recorded indication for abdominal delivery. While mortality and morbidity rates were low, exposure of mothers and infants to the additional risks associated with surgery for no apparently valid reason is unwarranted.
Simultaneous in situ squamous cell carcinoma and microinvasive adenocarcinoma of the cervix
Authors: Wolk Barry M. , Kime Warson , Albites Victor 
Published: April 2004

AbstractA case of simultaneously occurring carcinoma in situ of the cervix, and adenocarcinoma of the endometrium is presented. The diagnosis was made by examination of the pathological specimen, but was suspected pre‐operatively because of Pap smear findings. A review of the recent literature is discussed.
The first abortion ‐ and the last? A study of the personality factors underlying repeated failure of contraception
Authors: Niemelä Pirkko , Lehtinen Päivi , Rauramo Lauri , Hermansson Ralf , Karjalainen Rauni , Mäki Hannele , StorÅ Clas‐Åke 
Published: April 2004

AbstractThe causes leading to a second abortion were outlined in a psychological study comparing 30 women expecting a second abortion with 29 women who had successfully prevented conception after a first abortion. It was found that both groups improved their contraceptive practices after the first abortion. However, while the latter group continued with their improved practices, the former group went back to the earlier inefficient or non‐existent contraceptive behavior. The inability to improve contraception in the long run was not related to differences in educational level or knowledge about contraceptive techniques but to the developmental level of personality structures. The women expecting their second abortion rated lower in control of impulsivity, emotional balance, realism, self‐esteem and stability of life as well as capacity for more integrated personal relationships. The differences in personality development and consequently in the capacity for long‐term contraception were found to be due to growth conditions in childhood.
Postpartum sterilization by operating‐room nurses in Thailand
Authors: Koetsawang Suporn , Varakamin Somsak , Satayapan Suvanee , Srisupandit Suwanee , Apimas Supanee J. 
Published: April 2004

AbstractA training project to assess the performance of experienced operating room nurses as operators in postpartum sterilization was conducted in 1977–1978. The results for over 1000 nurse‐operated clients and a comparison group of approximately 300 physician‐sterilized clients show that nurses achieved comparable success with physicians in postpartum sterilization, as judged by clinical and attitudinal follow‐up. No serious complications were recorded in either group. Minor infections in both groups were treated routinely. A stitch obcess for one nurse‐operated client resulted in hospitalization; the client was released after 3 days. The clients in both groups returned to routine chores at home rapidly, and client satisfaction with the procedure was virtually unanimous in each group. This study lends support to the use of nurses in performing contraceptive surgery. The need for increased service coverage in this area is of high priority, and nurses provide a readily available and easily trained cadre of support staff.
Ultrastructural alterations in human endometrium caused by intrauterine contraceptive devices
Authors: Verma Vinod 
Published: April 2004

AbstractBiopsies of endometrium from women using intrauterine contraceptive devices (IUDs) were examined by electron microscopy to elucidate the possible cause of IUD‐associated uterine hemorrhage. The findings reveal the presence of degenerated, shrunken cells in the endometrial glands of IUD users. These cells, termed pyknotic or apoptotic, are more prevalent in tissue from women with complaints of excessive bleeding than in cases without such complaints. The pyknotic cells often show discontinuities of the plasma membrane at their luminal pole, from which cell contents stream into the lumen. Sometimes erythrocytes are also observed in the lumen. A second alteration in the ultrastructure of the endometrium is an abnormal increase in microfilaments in the epithelial cells.These two changes, a large number of pyknotic cells on the one hand and increase in microfilaments on the other, are correlated with excessive bleeding but they do not explain in simple terms the outflow of erythrocytes. Probably some inflammatory mechanism is involved. The increased number of microfilaments might be helping the movement of fluid from healthy to pyknotic cells.
Endocrinologic and psychologic aspects of galactorrhea associated with normal menstrual cycles
Authors: Naguib Y.A. , Darwish N.A. , Shaarawy M. , Nagui A.R. , Thabet S.M. , Abdel Azim S. 
Published: April 2004

AbstractTwelve cases of galactorrhea in women with normal menstrual cycles who were radiologically free of any pituitary adenomas were investigated. Determinations were made for serum thyroid‐stimulating hormone (TSH), T3 resin uptake (T3RU), total thyroxine by radioimmunoassay (T4), free thyroxine index (FT4I), norepinephrine, epinephrine, prolactin and urinary luteinizing hormone, total estrogens, pregnanediol and total catecholamines. Psychologic evaluation and assessment were also done using the Middlesex Hospital Questionnaire and the Eysenk, manual dexterity. Bender Gestalt and trial‐making scales. Hypothyroidism associated with moderate hyperprolactinemia and anovulation were the main features in eight cases. Associated psychologic disturbances were reported. The other four cases showed significant elevations in serum epinephrine, norepinephrine and urinary total catecholamines with concomitant pathologic scales of anxiety and neuroticism. Thyroxine replacement and psychotherapy are recommended in the treatment of such cases.
Triplet pregnancy in Nigeria: Socio‐biologic aspects
Authors: Sogbanmu M.O. 
Published: April 2004

AbstractA retrospective analysis of 20 triplet pregnancies not stimulated by clomiphene or gonadotrophins revealed a perinatal mortality of 26.3%. There were greater losses recorded in the case of mothers who had received no antenatal care than for those who had been seen before the babies' births. Triplet pregnancy in this series was associated with anemia, hypertension, postpartum hemorrhage and hydramnios. In Nigeria, where there is a high incidence of such pregnancy, it should be suspected more often than elsewhere. The authors recommend amnioscopy, amniocentesis and early resort to cesarean section as part of the antenatal regimen, with careful management of the third stage of labor to prevent postpartum hemorrhage.
Laparoscopic sterilizations (16,803) without vaginal manipulation
Authors: Mehta P.V. 
Published: April 2004

AbstractLaparoscopic sterilization is usually done after viewing the fallopian tubes brought into the laparoscopic field by a uterine manipulator introduced through the vagina. The orthodox rural Indian women, however, resent vaginal manipulation exposing their genitalia. Therefore, the author developed a single‐puncture technique for performing laparoscopic sterilization with a Falope‐Ring®, which dispenses with a uterine manipulator. Experience with 16,803 cases is presented. This technique is recommended for mass sterilizations because it eliminates the risks involved in vaginal manipulation and enhances acceptability and popularity of the procedure. Nonetheless, the risks of bowel injury are augmented, and the method is not for the inexperienced or occasional operator.
Sinusoidal fetal heart rate pattern in severe fetal anemia from feto‐maternal transfusion
Authors: Treisser A. , Vige P. , Maria B. , Lebrun F. , Sureau C. 
Published: April 2004

AbstractA case is reported where a sinusoidal fetal heart rate pattern was found in a fetus at 34 weeks. This pattern, at first isolated and later persistent for several hours, during a normal pregnancy became progressively transformed into a silent pattern. Cesarean delivery then performed resulted in the birth of an infant affected by a severe anemia due to a major feto‐maternal transfusion and it died aged 36 h. The authors enquire into the significance of this pattern when found in apparently normal pregnancies, not involving rhesus iso‐immunization, and they suggest a possible management when confronted with a sinusoidal fetal heart pattern.