bluuebunny/crossref_metadata_2025_split huggingface dataset:
Respiratory function in pregnancy at sea level and at high altitude
Authors: McAuliffe Fionnuala , Kametas Nikos , Espinoza Jimmy , Greenough Anne , Nicolaides Kypros 
Published: March 2004

Objective  To determine the effect of pregnancy on respiratory function in a non‐Caucasian group and determine whether there was an interaction between pregnancy and altitude of residence.Design  Prospective cross sectional study.Setting  Antenatal clinics in Peru, at sea level in Lima and at high altitude in Cerro de Pasco.Sample  Peruvian women with singleton pregnancies; 122 living at sea level and 192 living at 4300 m altitude in the Peruvian Andes. At each location, 19 non‐pregnant women were also studied.Methods  Respiratory function was measured in pregnant and non‐pregnant women living at sea level and at 4300 m.Main outcome measures  Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow rate (PEFR), total lung capacity (TLC), inspiratory capacity (IC), residual volume (RV), expiratory residual volume (ERV) and functional residual capacity (FRC).Results  At sea level, RV and TLC were higher in the third compared with the first trimester (P < 0.05). At high altitude, FEV1 (P < 0.01), ERV (P < 0.01) and FRC (P < 0.01) were lower in the third compared with the first trimester. Pregnant and non‐pregnant women at high altitude were 4 cm shorter (P < 0.0001) and had larger lung volumes (P < 0.01); their total lung capacities were approximately 1 L greater than women living at sea level (P < 0.0001).Conclusion  These results suggest that the effect of pregnancy on the respiratory function of healthy women is influenced by altitude of residence.
Pain, quality of life and complications following the radical resection of rectovaginal endometriosis
Authors: Ford Jolyon , English James , Miles William A. , Giannopoulos Theo 
Published: March 2004

Objective  To determine the long term response, quality of life and levels of pain following the radical excision of rectovaginal endometriosis.Design  A cohort study.Setting  A tertiary referral centre for the management of advanced endometriosis.Sample  All patients who had undergone radical resection.Methods  Case note review and patient questionnaire.Main outcome measures  Surgical complications. Overall improvement. Dysmenorrhoea, dyspareunia, dyschezia and chronic pain were measured using a visual analogue scale. Quality of life was measured using the EQ‐5D questionnaire.Results  Twelve radical resections were performed by laparotomy, 48 by laparoscopy. Ten patients had a hysterectomy. Forty‐eight patients underwent shaving of the pre‐rectal fascia, two had a disc resection of the rectum, 10 had an anterior rectal resection. Two patients required a colostomy and two needed subsequent dilation of a stenosed anastomosis. Forty‐four of the first 46 patients replied. The median follow up period was 12 months (range 2 to 22 months) and 86% (38/44) reported an improvement or whom 27 (61%) had a good response (pain completely gone or greatly improved). Patients having a hysterectomy or a disc or segmental resection of the rectum reported a good response and had a normal quality of life. Quality of life scores in the study group overall were lower than the background population.Conclusions  Radical resection is an effective treatment for rectovaginal endometriosis. Hysterectomy and rectal resection were associated with a better response and quality of life.
Cross sectional study of automated blood pressure measurements throughout pregnancy
Authors: Ochsenbein‐Kölble N. , Roos M. , Gasser T. , Huch R. , Huch A. , Zimmermann R. 
Published: March 2004

Objective  To generate reliable new reference ranges for pregnancy blood pressure from a large population.Design  A prospective cross sectional study.Setting  Obstetric outpatient clinic, Zurich University Hospital.Sample  Accurately dateable singleton pregnancies (Caucasian: n= 3234; Asian [predominantly from Sri Lanka, Thailand and the Philippines]: n= 577; Black n= 212).Methods  Between January 1996 and February 2000 blood pressure was determined in 4023 pregnant women using an oscillometric automated device (Dinamap) according to British Hypertension Society recommendations. Women receiving antihypertensive medication were excluded.Main outcome measure  Blood pressure.Results  Only the means of duplicate measures at the booking visit (5–42 weeks) were used in the analysis. Mean blood pressure decreased from early to mid pregnancy before increasing to levels 4 mmHg higher at term than in early pregnancy. Values >130/80 and <90/50 mmHg were above the 95th and below the 5th centiles, respectively. Parity, age and body mass index were significant determinants in Caucasians. Blood pressure was slightly lower in Asians and Blacks.Conclusions  The current World Health Organisation definition of high diastolic blood pressure (≥90 mmHg on two occasions) reflects values >2 standard deviations from the mean. This may be too conservative as threshold for detecting women at risk of pre‐eclampsia. Further studies are required to determine the prognostic implications of gestational values ≥95th centile (≥130/80 mmHg) and ≤5th centile (≤90/50 mmHg).
Balance between microbial calcification and metazoan bioerosion in modern stromatolitic oncolites
Authors: Garcia‐Pichel Ferran , Al‐Horani Fuad A. , Farmer Jack D. , Ludwig Rebecca , Wade Brian D. 
Published: March 2004

ABSTRACTStromatolites date back some 3.5 billion years and constitute the most common and conspicuous fossils through the Proterozoic. These organosedimentary structures decreased dramatically in diversity and abundance by the late Neoproterozoic, a phenomenon often ascribed to destructive grazing by newly evolved metazoans. We investigated the concurrent processes of microbial calcification and metazoan bioerosion in one of the few locations (Rio Mesquites, Cuatro Ciénegas, Coahuila, Mexico) where living freshwater stromatolites, formed by cyanobacteria and diatoms, coexist with significant populations of metazoan grazers. We used microsensor chemical profiling and monitoring of bulk water Ca2+concentrations to determine calcification rates and their dependence on microbial metabolism. The bioerosive impact resulting from grazing by endemic hydrobiid gastropods was assessed by gravimetric quantification of carbonaceous faecal pellet production. Calcification was clearly light‐dependent, reaching maximal rates (saturation) at low incident light intensity, and was surprisingly efficient, with O2/Ca2+exchange ratios well above unity, and with absolute rates similar to those found in corals. However, the erosive action of grazing snails removed most of these carbonate inputs from the oncolites. Thus, a precarious balance between constructive and destructive geobiological processes was at play in the system. The fact that accretion barely exceeded bioerosion in an environment highly conducive to calcification supports the potential impact of faunal grazing as causal agent in the demise of stromatolites in the late Proterozoic. Our findings indicate that a search for fossil evidence of bioerosive grazing in the form of carbonaceous faecal pellets associated with fossil stromatolites may provide a means to test that hypothesis directly.
Importance of clay size minerals for Fe(III) respiration in a petroleum‐contaminated aquifer
Authors: Shelobolina Evgenya S. , Anderson Robert T. , Vodyanitskii Yury N. , Sivtsov Anatolii V. , Yuretich Richard , Lovley Derek R. 
Published: March 2004

ABSTRACTThe availability of Fe(III)‐bearing minerals for dissimilatory Fe(III) reduction was evaluated in sediments from a petroleum‐contaminated sandy aquifer near Bemidji, Minnesota (USA). First, the sediments from a contaminated area of the aquifer, in which Fe(III) reduction was the predominant terminal electron accepting process, were compared with sediments from a nearby, uncontaminated site. Data from 0.5 m HCl extraction of different size fractions of the sediments revealed that the clay size fraction contributed a significant portion of the ‘bio‐available’ Fe(III) in the background sediment and was the most depleted in ‘bio‐available’ Fe(III) in the iron‐reducing sediment. Analytical transmission electron microscopy (TEM) revealed the disappearance of thermodynamically unstable Fe(III) and Mn(IV) hydroxides (ferrihydrite and Fe vernadite), as well as a decrease in the abundance of goethite and lepidocrocite in the clay size fraction from the contaminated sediment. TEM observations and X‐ray diffraction examination did not provide strong evidence of Fe(III)‐reduction‐related changes within another potential source of ‘bio‐available’ Fe(III) in the clay size fraction – ferruginous phyllosilicates. However, further testing in the laboratory with sediments from the methanogenic portion of the aquifer that were depleted in microbially reducible Fe(III) revealed the potential for microbial reduction of Fe(III) associated with phyllosilicates. Addition of a clay size fraction from the uncontaminated sediment, as well as Fe(III)‐coated kaolin and ferruginous nontronite SWa‐1, as sources of poorly crystalline Fe(III) hydroxides and structural iron of phyllosilicates respectively, lowered steady‐state hydrogen concentrations consistent with a stimulation of Fe(III) reduction in laboratory incubations of methanogenic sediments. There was no change in hydrogen concentration when non‐ferruginous clays or no minerals were added. This demonstrated that Fe(III)‐bearing clay size minerals were essential for microbial Fe(III) reduction and suggested that both potential sources of ‘bio‐available’ Fe(III) in the clay size fraction, poorly crystalline Fe(III) hydroxides and structural Fe(III) of phyllosilicates, were important sources of electron acceptor for indigenous iron‐reducing microorganisms in this aquifer.
Lipid biomarker and carbon isotopic signatures for stromatolite‐forming, microbial mat communities and Phormidium cultures from Yellowstone National Park
Authors: Jahnke Linda L. , Embaye Tsegereda , Hope Janet , Turk Kendra A. , Van Zuilen Mark , Des Marais David J. , Farmer Jack D. , Summons Roger E. 
Published: March 2004

ABSTRACTThe molecular and isotopic compositions of lipid biomarkers from cultured filamentous cyanobacteria (Phormidium, also known as Leptolyngbya) have been used to investigate the community and trophic structure of photosynthetic mats from alkaline hot springs of the Lower Geyser Basin at Yellowstone National Park. We studied a shallow‐water coniform mat from Octopus Spring (OS) and a submerged, tufted mat from Fountain Paint Pots (FPP) and found that 2‐methylhopanepolyols and mid‐chain branched methylalkanes were diagnostic for cyanobacteria, whereas abundant wax esters were representative of the green non‐sulphur bacterial population. The biomarker composition of cultured Phormidium‐isolates varied, but was generally representative of the bulk mat composition. The carbon isotopic fractionation for biomass relative to dissolved inorganic carbon (DIC; ɛCO2) for cultures grown with 1% CO2 ranged from 21.4 to 26.1 and was attenuated by diffusion limitation associated with filament aggregation (i.e. cell clumping). Isotopic differences between biomass and lipid biomarkers, and between lipid classes, depended on the cyanobacterial strain, but was positively correlated with overall fractionation. Acetogenic lipids (alkanes and fatty acids) were generally more depleted than isoprenoids (phytol and hopanoids). The δ13CTOC for OS and FPP mats were somewhat heavier than for cultures (−16.9 and −23.6, respectively), which presumably reflects the lower availability of DIC in the natural environment. The isotopic dispersions among cyanobacterial biomarkers, biomass and DIC reflected those established for culture experiments. The 7‐methyl‐ and 7,11‐dimethylheptadecanes were from 9 to 11 depleted relative to the bulk organic carbon, whereas 2‐methylhopanols derived from the oxidation‐reduction of bacteriohopanepolyol were enriched relative to branched alkanes by approximately 5–7. These isotopic relationships survived with depth and indicated that the relatively heavy isotopic composition of the OS mat resulted from diffusion limitation. This study supports the suggestion that culture studies can establish valid isotopic relationships for interpretation of trophic structure in modern and ancient microbial ecosystems.
Stable and Noncompetitive RNA Internal Control for Routine Clinical Diagnostic Reverse Transcription-PCR
Authors: Dingle Kate E. , Crook Derrick , Jeffery Katie 
Published: March 2004

ABSTRACT
Clinical diagnostic tests based on nucleic acid amplification assist with the prompt diagnosis of microbial infections because of their speeds and extremely low limits of detection. However, the design of appropriate internal controls for such assays has proven difficult. We describe a reaction-specific RNA internal control for diagnostic reverse transcription (RT)-PCR which allows extraction, RT, amplification, and detection to be monitored. The control consists of a G+C-rich (60%) RNA molecule with an extensive secondary structure, based on a modified hepatitis delta virus genome. The rod-like structure of this RNA, with 70% intramolecular base pairing, provides a difficult template for RT-PCR. This ensures that the more favorable target virus amplicon is generated in preference to the control, with the control being detected only if the target virus is absent. The unusual structure of hepatitis delta virus RNA has previously been shown to enhance its stability and resistance to nucleases, an advantage for routine use as an internal control. The control was implemented in three nested multiplex RT-PCRs to detect nine clinically important respiratory viruses: (i) influenza A and B viruses, (ii) respiratory syncytial viruses A and B and human metapneumovirus, and (iii) parainfluenza virus types 1 to 4. The detection limits of these assays were not detectably compromised by the presence of the RNA control. During routine testing of 324 consecutive unselected respiratory samples, the presence of the internal control ensured that genuine and false-negative results were distinguishable, thus increasing the diagnostic confidence in the assay.
Comparison of PCR with the Routine Procedure for Diagnosis of Tuberculosis in a Population with High Prevalences of Tuberculosis and Human Immunodeficiency Virus
Authors: Kivihya-Ndugga Lydia , van Cleeff Maarten , Juma Ernest , Kimwomi Joseph , Githui Willie , Oskam Linda , Schuitema Anja , van Soolingen Dick , Nganga Lucy , Kibuga Daniel , Odhiambo Joseph , Klatser Paul 
Published: March 2004

ABSTRACT

Direct smear examination with Ziehl-Neelsen (ZN) staining for the diagnosis of tuberculosis (TB) as employed in most low-income countries is cheap and easy to use, but its low sensitivity is a major drawback. The low specificity of chest X-rays, used for the diagnosis of smear-negative TB, risks high levels of overdiagnosis. Major advances in molecular techniques, which rapidly identify mycobacterial DNA in sputa, may overcome these obstacles. In this study, the AMPLICOR PCR system was used to diagnose pulmonary TB in a developing country with high prevalences of both TB and human immunodeficiency virus (HIV). The sensitivity and specificity of this technique were compared to those of the usual diagnostic techniques. Sputum specimens were collected from 1,396 TB suspects attending the Rhodes Chest Clinic, Nairobi, Kenya. The specimens were analyzed for the presence of
Mycobacterium tuberculosis
by PCR; culture on Löwenstein-Jensen medium was used as the “gold standard.” All culture-positive samples were genotyped to identify the mycobacterial species. The sensitivity and specificity of PCR were 93 and 84%, respectively. HIV status did not affect the sensitivity of PCR. A total of 99.7% of the true smear-positive and 82.1% of the true smear-negative TB patients were correctly identified by PCR. PCR detected
M. tuberculosis
in 11.7% of the culture-negative suspects, 60% of which had one or two PCR-positive sputum specimens. Of the 490 positive cultures, 486 were identified as
M. tuberculosis
. The high sensitivity of Amplicor PCR merits usage in a clinical setting with high TB and HIV burdens. Thus, PCR can be considered as an alternative to ZN staining in combination with chest X-ray for diagnosis of TB; however, cost-effectiveness studies and operational studies are required to support an evidence-based decision of introducing PCR for TB control in high-burden environments.
Temperature-Mediated Heteroduplex Analysis for Detection of
pncA
Mutations Associated with Pyrazinamide Resistance and Differentiation between
Mycobacterium tuberculosis
and
Mycobacterium bovis
by Denaturing High- Performance Liquid Chromatography
Authors: Mohamed Amr M. , Bastola Dhundy R. , Morlock Glenn P. , Cooksey Robert C. , Hinrichs Steven H. 
Published: March 2004

ABSTRACT

The goal of this study was to apply temperature-mediated heteroduplex analysis using denaturing high-performance liquid chromatography to identify pyrazinamide (PZA) resistance in
Mycobacterium tuberculosis
isolates and simultaneously differentiate between
M. tuberculosis
and
Mycobacterium bovis
. Features that contributed to an optimal assay included the use of two different reference probes for the
pncA
gene targets from wild-type
M. tuberculosis
and wild-type
M. bovis
, optimization of the column temperature, increasing the starting concentration of the elution buffer, and reducing the rate of elution buffer increase (slope). A total of 69 strains were studied, including 48 wild-type
M. tuberculosis
strains (13 were PZA-resistant strains) and 21
M. bovis
strains (8 were BCG strains). In all isolates tested, wild-type
M. tuberculosis
generated a single-peak pattern when mixed with the
M. tuberculosis
probe and a double-peak pattern with the
M. bovis
probe. In contrast, all
M. bovis
isolates generated a double-peak pattern when mixed with the
M. tuberculosis
probe and a single-peak pattern with the
M. bovis
probe. PZA-resistant mutant
M. tuberculosis
isolates generated characteristic patterns that were easily distinguishable from both wild-type
M. tuberculosis
and
M. bovis
isolates. Chromatographic patterns generated by the two reference probes allowed the rapid detection of PZA resistance with the simultaneous ability to distinguish between
M. tuberculosis
and
M. bovis
. This approach may allow the detection of drug resistance-associated mutations, with potential application to clinical and epidemiological aspects of tuberculosis control.
Human β-Defensins 2 and 3 Demonstrate Strain-Selective Activity against Oral Microorganisms
Authors: Joly Sophie , Maze Connie , McCray Paul B. , Guthmiller Janet M. 
Published: March 2004

ABSTRACT

Human β-defensins 2 and 3 (HBD-2 and HBD-3) are inducible peptides present at sites of infection in the oral cavity. A few studies have reported broad-spectrum antimicrobial activity for both peptides. However, no comprehensive study has thoroughly investigated their potential against oral pathogens. The purpose of this study was to test the effectiveness of HBD-2 and HBD-3 against a collection of oral organisms (
Actinobacillus actinomycetemcomitans
,
Fusobacterium nucleatum
,
Porphyromonas gingivalis
,
Peptostreptococcus micros
,
Actinomyces naeslundii
,
Actinomyces israelii
,
Streptococcus sanguis
,
Streptococcus mutans
,
Candida tropicalis
,
Candida parapsilosis
,
Candida krusei
,
Candida glabrata
, and
Candida albicans
). Radial diffusion assays were used to test HBD-2 and HBD-3 activities against at least three strains of each species. There was significant variability in MICs, which was strain specific rather than species specific. MICs ranged from 3.9 to >250 μg/ml for HBD-2 and from 1.4 to >250 μg/ml for HBD-3. HBD-3 demonstrated greater antimicrobial activity and was effective against a broader array of organisms. Overall, aerobes were 100% susceptible to HBD-2 and HBD-3, whereas only 21.4 and 50% of the anaerobes were susceptible to HBD-2 and HBD-3, respectively. HBD-2 and HBD-3 also demonstrated strain-specific activity against the
Candida
species evaluated. Interestingly, an association between HBD-2 and HBD-3 activities was noted. This suggests that the two peptides may have similar mechanisms yet utilize distinct pathways. The lack of activity against specific anaerobic strains and
Candida
warrants further investigation of the potential resistance mechanisms of these organisms. Finally, the significant variability between strains underlies the importance of testing multiple strains when evaluating activities of antimicrobial peptides.
Multicenter Evaluation of the MB/BACT System for Susceptibility Testing of
Mycobacterium tuberculosis
Authors: Bemer Pascale , Bodmer Thomas , Munzinger Juerg , Perrin Monique , Vincent Véronique , Drugeon Henri 
Published: March 2004

ABSTRACT

The reliability of the MB/BACT system for susceptibility testing of
Mycobacterium tuberculosis
to pyrazinamide, rifampin, isoniazid, streptomycin, and ethambutol was compared to the BACTEC 460TB system. The proportion method was used to resolve discrepant results by an independent arbiter. Two interpretative methods were used, with an undiluted control (direct control) and a diluted control (10
−1
control). As no significant difference was observed between the two controls, the method with the direct control was adopted as the most accurate one. One hundred sixty-six strains were tested, with an overall agreement of 98.3%. After resolution of the 18 discrepant results by the proportion method, the sensitivity and specificity of the MB/BACT system were 100% for rifampin, isoniazid, and pyrazinamide. For ethambutol, sensitivity was 92.3% at the critical concentration and 33% at the high concentration, and specificity was 100% at both concentrations. For streptomycin, sensitivity was 100% at the critical concentration and 80% at the high concentration, and specificity was 98.6% at the critical concentration and 100% at the high concentration. The rifampin, isoniazid, streptomycin, and ethambutol susceptibility test results were obtained in 6.6 days with the MB/BACT versus 5 days with the BACTEC 460TB. The pyrazinamide susceptibility test results were obtained in 7.8 days with the MB/BACT, versus 6.7 days with the BACTEC 460TB. These data demonstrate that the fully automated MB/BACT system is a very reliable method for rapid susceptibility testing of
M. tuberculosis
against rifampin, isoniazid, and pyrazinamide. Sensitivity results have to be improved for ethambutol and streptomycin, especially at the high concentration.