bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of RpoS by a novel small RNA: the characterization of RprA
Authors: Majdalani Nadim , Chen SuAnn , Murrow Jonathan , St John Kristin , Gottesman Susan 
Published: February 2004

Translational regulation of the stationary phase sigma factor RpoS is mediated by the formation of a double‐stranded RNA stem–loop structure in the upstream region of the rpoS messenger RNA, occluding the translation initiation site. The interaction of the rpoS mRNA with a small RNA, DsrA, disrupts the double‐strand pairing and allows high levels of translation initiation. We screened a multicopy library of Escherichia coli DNA fragments for novel activators of RpoS translation when DsrA is absent. Clones carrying rprA (RpoS regulator RNA) increased the translation of RpoS. The rprA gene encodes a 106 nucleotide regulatory RNA. As with DsrA, RprA is predicted to form three stem–loops and is highly conserved in Salmonella and Klebsiella species. Thus, at least two small RNAs, DsrA and RprA, participate in the positive regulation of RpoS translation. Unlike DsrA, RprA does not have an extensive region of complementarity to the RpoS leader, leaving its mechanism of action unclear. RprA is non‐essential. Mutations in the gene interfere with the induction of RpoS after osmotic shock when DsrA is absent, demonstrating a physiological role for RprA. The existence of two very different small RNA regulators of RpoS translation suggests that such additional regulatory RNAs are likely to exist, both for regulation of RpoS and for regulation of other important cellular components.
The alien flowering plants of Mexico
Authors: Villaseñor Jose L. , J. Espinosa‐Garcia Francisco 
Published: February 2004

ABSTRACTA list of 618 species of alien flowering plants recorded for Mexico is presented; they are distributed in 355 genera and 87 families. The families with the largest number of species are Poaceae (171), Fabaceae sensu lato (57), Asteraceae (56), and Brassicaceae (45). The representation of most families with alien species in Mexico agrees with the average distribution frequencies estimated by Pysek (1998) for 26 floras throughout the World. Exceptions are an under‐representation of Asteraceae and an over‐representation of Poaceae. Most alien species (78.9%) in Mexico have their origin in the Old World; South America ranks second with 9.6%. As defined by Richardson et al. (2000), 19.8% of the alien species could be considered casual aliens and 80.2% of them naturalized. The proportion of alien species relative to the 22,968 native flowering plant species recorded for Mexico is 2.7%.
Place prioritization for biodiversity conservation using probabilistic surrogate distribution data
Authors: Sarkar Sahotra , Pappas Christopher , Garson Justin , Aggarwal Anshu , Cameron Susan 
Published: February 2004

ABSTRACTWe analyse optimal and heuristic place prioritization algorithms for biodiversity conservation area network design which can use probabilistic data on the distribution of surrogates for biodiversity. We show how an Expected Surrogate Set Covering Problem (ESSCP) and a Maximal Expected Surrogate Covering Problem (MESCP) can be linearized for computationally efficient solution. For the ESSCP, we study the performance of two optimization software packages (XPRESS and CPLEX) and five heuristic algorithms based on traditional measures of complementarity and rarity as well as the Shannon and Simpson indices of α‐diversity which are being used in this context for the first time. On small artificial data sets the optimal place prioritization algorithms often produced more economical solutions than the heuristic algorithms, though not always ones guaranteed to be optimal. However, with large data sets, the optimal algorithms often required long computation times and produced no better results than heuristic ones. Thus there is generally little reason to prefer optimal to heuristic algorithms with probabilistic data sets.
Impact of the invasive alien grass Melinis minutiflora at the savanna‐forest ecotone in the Brazilian Cerrado
Authors: Hoffmann William A. , Lucatelli Verusca M. P. C. , Silva Franciane J. , Azeuedo Isaac N. C. , Marinho Marcelo da S. , Albuquerque Ana Maria S. , Lopes Apoena de O. , Moreira Silvana P. 
Published: February 2004

ABSTRACTExotic grasses are a serious threat to biodiversity in the cerrado savannas of central Brazil. Of particular concern is the possible role they may have in impeding tree regeneration at gallery (riverine) forest edges and increasing fire intensity, thereby driving gallery forest retreat. Here we quantify the effect of roads and distance from gallery forests on the abundance of the African grass Melinis minutiflora Beauv. and test for an effect of this species on woody plant regeneration and leaf area index. Melinis was present at approximately 70% of the sites near gallery forest edges, with its frequency declining sharply at greater distances from the edge. Melinis frequency was 2.8 times greater where roads were present nearby. Leaf area index (LAI) of the ground layer was 38% higher where Melinis was present than where it was absent. LAI was strongly correlated to fine fuel mass (r2 = 0.80), indicating higher fuel loads where Melinis was present. The abundance of tree and shrub species in the ground layer was negatively related to LAI and to the presence of Melinis. The greater fuel accumulation and reduced tree regeneration caused by Melinis may cause a net reduction in forest area by increasing fire intensity at the gallery forest edge and slowing the rate of forest expansion.
Latitudinal patterns in abundance and life‐history traits of the mole crabEmerita brasiliensison South American sandy beaches
Authors: Defeo Omar , Cardoso Ricardo S. 
Published: February 2004

ABSTRACTDemographic and life‐history attributes of the mole crabEmerita brasiliensiswere analysed along 2700 km of the Atlantic coast of South America, including sandy beaches at the southernmost limit (Uruguay) and at the core of its geographical range (Brazil). Population features varied markedly within this range and exhibited systematic geographical patterns of variation. Abundance significantly increased from temperate to subtropical beaches, and the same held true for the asymptotic weight of males. Conversely, length at maturity and asymptotic weight of females increased from subtropical to temperate beaches, being inversely related to sea water temperature. Macroecological patterns in abundance and body weight showed the first large‐scale evidence of scaling of population density to body size for a sandy beach population. Mortality rates (both sexes) followed a nonlinear increase from low‐density temperate beaches to high‐density subtropical beaches. The effect of habitat quality and availability could explain discontinuities in the species distribution within its range, and also differential responses in life‐history attributes at a local scale. Asymmetries and converse latitudinal trends between sexes suggest that there is not a single general factor determining large‐scale patterns in life‐history traits of this species. Our results reinforce the view that density‐dependent and environmental factors operating together regulate sandy beach populations. The need to develop macroecological studies in sandy beach ecology is highlighted, as knowledge acquired from local to large spatial scales throws light on population structure and regulation mechanisms.
Alien species reflecting history: medieval castles in Germany
Authors: Dehnen‐Schmutz Katharina 
Published: February 2004

ABSTRACTNinety‐seven alien plant species were found in habitats provided by rocks and walls around 56 castles in Germany. Compared to Central European agriophytes (i.e. alien species naturalised in natural vegetation), the flora adjacent to castles had more species introduced before 1500. More alien species introduced earlier were found at castles built earlier compared to castles built later. Fifty percent of the species introduced before and during the Middle Ages were usable plants at that time, compared to 20% of usable plants among the native species in the same habitats. Species introduced earlier were mainly used for medication and nutrition, whereas later introductions were used for ornamental purposes. Compared to the total alien flora of Germany, there were more useable species at the castles, nearly the same percentage of ornamentals and fewer plants without use. These results imply that the species composition of alien species growing in the vicinity of medieval castles today may be traced back to the historical reasons for their introduction to these places.
A simple C‐reactive protein measurement for the differentiation between tuberculous and malignant pleural effusion
Authors: Chierakul Nitipatana , Kanitsap Apichart , Chaiprasert Angkana , Viriyataveekul Ronnachai 
Published: February 2004

Objective:  The aim of this study was to determine the validity of pleural fluid C‐reactive protein (CRP) concentrations and/or pleural fluid to serum CRP ratio for differentiating tuberculous pleuritis (TBP) from malignant pleural effusion (MPE) in patients presenting with lymphocytic exudative pleural effusions.Methodology:  A cross‐sectional study was conducted on 161 patients with pleural effusion who underwent diagnostic evaluation at Siriraj Hospital, Bangkok, Thailand, between April 2001 and March 2002. The complete biochemical analysis of pleural fluid, cultures of pleural fluid, and pathological examinations of pleural fluid and pleural tissue were performed. The CRP concentrations were then measured in stored sera and pleural fluid samples from patients with a lymphocytic exudative pleural effusion and with a definite diagnosis.Results:  Among the 148 patients with lymphocytic exudative pleural effusions, 55 were diagnosed with TBP, 60 with MPE, and 33 with non‐specific pleuritis. Pleural fluid and serum CRP levels were significantly higher in the TBP group than in the MPE group (54.58 ± 4.50 mg/L and 106.93 ± 9.54 mg/L vs 12.66 ± 3.52 mg/L and 49.66 ± 8.84 mg/L, respectively, P < 0.001). The ratio of pleural fluid to serum CRP was significantly higher in the TBP group than in the MPE group (0.52 ± 0.18 vs 0.30 ± 0.16, P < 0.001). The optimum cut‐off value for pleural fluid CRP level of ≥30 mg/dL had a sensitivity of 72% with 93% specificity, and the pleural fluid to serum CRP ratio cut‐off value of 0.45 had a sensitivity of 60% with 89% specificity. A correlation between serum and pleural fluid CRP levels was observed in TBP patients but not in MPE patients.Conclusion:  In patients presenting with lymphocytic exudative pleural effusion, a simple marker of raised pleural fluid CRP level may be helpful in discriminating between TBP and MPE.
The effects of antioxidants on exercise‐induced lipid peroxidation in patients with COPD
Authors: Agacdiken Aysen , Basyigit Ilknur , Özden Meltem , Yildiz Fusun , Ural Dilek , Maral Hale , Boyaci Hasim , Ilgazli Ahmet , Komsuoglu Baki 
Published: February 2004

Objective:  The oxidant–antioxidant balance plays an important role in the pathogenesis of COPD. The aim of the present study was to evaluate the effects of exercise, as an oxidative stress factor on the oxidant–antioxidant balance and to investigate whether short‐term antioxidant treatment affects lipid peroxidation products.Methodology:  Twenty‐one stable COPD patients and 10 control subjects were included in the study. Symptom‐limited exercise tests were performed by all subjects. Blood was collected before and 1 h after exercise in control subjects and before, 1 and 3 h after exercise in COPD patients, for analysis of malondialdehyde (MDA), reduced glutathione (GSH) and vitamin E (VE) levels. VE and vitamin C treatments were added to the regular bronchodilator therapy in 10 COPD patients for 1 month. After the treatment period, an exercise test was performed and blood was collected again for MDA, GSH and VE levels.Results:  Baseline GSH and VE levels were significantly lower in the COPD group when compared with the control subjects. There was no statistically significant difference in MDA levels between the two groups. In the COPD group, MDA levels 3 h after exercise were significantly higher than at baseline. In contrast there were no significant differences in MDA, VE and GSH levels in the control group after exercise. VE and MDA levels increased significantly after exercise in COPD patients but there was no difference in GSH levels. Baseline exercise time was significantly lower in the COPD group than in the controls. In 10 COPD patients who were given antioxidant therapy, their exercise time increased significantly and there was no increase in MDA and VE levels after the repeated exercise test.Conclusions:  Antioxidant levels were significantly lower in COPD patients than in control subjects. In these patients, exercise results in more significant oxidative stress and lipid peroxidation than in control subjects and antioxidant therapy may decrease lipid peroxidation following exercise and improve exercise capacity.
Hospital‐acquired pneumonia in general wards of a Japanese tertiary hospital
Authors: Ohi Hideo , Yanagihara Katsunori , Miyazaki Yoshitsugu , Hirakata Yoichi , Tomono Kazunori , Kadota Jun‐ichi , Tashiro Takayoshi , Kohno Shigeru 
Published: February 2004

Objective:  Hospital‐acquired pneumonia (HAP) is an important nosocomial disorder because both its mortality and morbidity are high. The Japanese Respiratory Society (JRS) has proposed a new guideline for the diagnosis and treatment of HAP. Clinical investigations of HAP were conducted to assess the current status of HAP in accordance with this guideline.Methodology:  Inpatients who developed HAP in the Second Department of Internal Medicine, Nagasaki University Hospital, a tertiary hospital in Japan, were evaluated. The incidence of HAP was 1.86% (59 cases in 3176 admissions) from 1996 to 2000. In particular, the severity rating of HAP for 46 patients in accordance with the JRS guidelines, was assessed.Results:  The mortality rate was 6.5% at this hospital, which is less than that reported by other investigators in the field. The frequency of bacteria isolated from clinical specimens was as follows: Haemophilus influenzae (20%), Pseudomonas aeruginosa (16.7%), and methicillin‐resistant Staphylococcus aureus (13.3%). Response rates were stratified by first‐line medications and the results were as follows: penicillins (33.3%), third‐generation cephems (44.4%), and carbapenems (66.7%).Conclusions:  Based on the results presented here, the severity rating proposed in this guideline for HAP appears reasonable, as the response rate for the first‐line antibiotic was better in Group II than in Groups III and IV. It will be important to analyse ‘clinical outcome’ in accordance with this guideline.
Blunted effect of the Kv channel inhibitor on pulmonary circulation in Tibetan sheep: A model for studying hypoxia and pulmonary artery pressure regulation
Authors: Ishizaki Takeshi , Sakai Akio , Koizumi Tomonori , Ruan Zonghai , Wang Zhan Gang 
Published: February 2004

Objective:   The aim of this study was to assess the effect of 4‐aminopyridine, a Kv channel inhibitor, on the pulmonary circulation of Tibetan sheep. It has been reported that chronic hypoxia downregulates the 4‐aminopyridine (4AP)‐sensitive Kv channel (which governs the membrane potential (Em) of pulmonary vascular smooth muscle cells in pulmonary vessels) without a change in 4AP sensitivity.Methodology:   Pulmonary haemodynamic indices and blood gas analyses were measured in six young male animals in an altitude chamber that was adjusted to simulated altitudes of 0 m, 2260 m, and 4500 m. Drip infusion of 4AP, 10 mg/h for 3 h, was started and continued during the study.Results:   With the increase in altitude mean pulmonary artery pressure increased and mean Pao2 decreased. 4AP had no effect on the levels of mean PPA, mean pulmonary artery wedge pressure, cardiac output, and mean PaO2, mean PaCO2, and mean pH at any altitude but tended to alter heart rate and mean arterial pressure at altitudes of 2260 m and 4500 m.Conclusion:   It is concluded that the 4AP‐sensitive Kv channel does not play a role in pulmonary vascular tone in high‐altitude active Tibetan sheep. Their pulmonary vascular oxygen sensing appears not to involve Kv channels.
Prediction of the maximal voluntary ventilation in healthy adult Chinese subjects
Authors: Kor Ai Ching , Ong Kian Chung , Earnest Arul , Wang Yee Tang 
Published: February 2004

Objectives:  The aim of the present study was to investigate the relationship between the FEV1 and maximal voluntary ventilation (MVV) in healthy adult Chinese subjects, and to determine the validity of existing prediction equations of MVV for use in the Chinese population.Methodology:  Ninety‐five healthy subjects (48 male and 47 female) stratified into five age groups (from 20 to 70 years) for both sexes were recruited from the general population. The FEV1 and MVV of these subjects were measured with a clinical spirometer. The MVV was determined using the closed‐circuit technique. The MVV was assessed for 12 s and values were calculated to obtain L/min. Multiple regression analysis was used to develop equations to predict MVV with age, height, FEV1 as well as with FEV1 alone as predictor variables. One‐sample t‐tests were used to compare the actual values of MVV for the subjects with their predicted values using equations from previous studies of MVV in healthy subjects.Results:  Using FEV1 only, the following predictive equation was obtained: MVV = FEV1 × 45.12 − 15.85 (adjusted r2 = 0.792). Predicted MVV values using previously cited equations, including MVV = FEV1 × 35 or 40, were all significantly different from the actual MVV values of these subjects.Conclusions:  The relationship between MVV and FEV1 among healthy adult Chinese subjects is described. Previously cited equations describing the relationship between FEV1 and MVV cannot be applied to healthy adult Chinese subjects.
Determinants of BMI in patients with COPD
Authors: Karadag Fisun , Karul Aslihan B. , Cildag Orhan , Altun Cagatay , Gurgey Ozgur 
Published: February 2004

Objective:  COPD is characterized by significant chronic inflammation that is evident not only in the pulmonary compartment but also in the circulation. Peripheral blood features of COPD include markers of oxidative stress and altered circulating levels of inflammatory mediators and acute‐phase proteins. The presence of a systemic inflammatory response may influence quality of life by giving rise to weight loss, muscle wasting and tissue depletion. The aim of the present study was to evaluate the determinants of body mass and the value of serum tumour necrosis factor alpha (TNF‐α) as a marker of weight loss in COPD patients, and to correlate this with the burden of oxidative stress as measured by serum malonyldialdehyde (MDA) levels.Methodology:  Fifty‐two male COPD patients (mean age 62.55 ± 6.81 years) were studied. After anthropometric measurements and standard spirometry, serum TNF‐α concentration was measured by enzyme‐linked immunosorbent assay using an hTNF‐α kit, and MDA was studied spectrophotometrically using the Yoshioka‐Kawada method.Results:  The mean BMI was 24.82 ± 3.46. BMI was lower than normal (< 19) in six patients. Mean serum TNF‐α concentration was 14.99 ± 8.98 pg/mL and MDA was 0.93 ± 0.13 nmol/L. There was no significant correlation between serum MDA and TNF concentrations (P = 0.140). Serum TNF‐α and MDA concentrations were not correlated with severity of airflow obstruction or degree of hypoxaemia (P > 0.05 for all). BMI was negatively correlated with burden of smoking (pack‐years) (r = −0.392, P= 0.004); but not with pulmonary function, degree of hypoxaemia, serum TNF‐α or MDA levels. BMI was significantly lower in current smokers than ex‐smokers (P = 0.041); however, serum MDA and TNF levels were similar in both groups.Conclusion:  The results of this study indicate that body mass is related to smoking status (both pack‐years and continuance of smoking) in COPD; however, serum TNF‐α concentration does not seem to be a good marker of weight loss in these patients.
Sputum carcinoembryonic antigen, neuron‐specific enolase and cytokeratin fragment 19 levels in lung cancer diagnosis
Authors: Kalomenidis Ioannis , Dimakou Katerina , Kolintza Androniki , Vlami Katerina , Papadakis Manos , Sotiropoulou Cristina , Orphanidou Dora , Roussos Charis , Papiris Spyros 
Published: February 2004

Objective:  The aim of the present study was to examine the impact of sputum carcinoembryonic antigen (CEA), neuron‐specific enolase (NSE) and cytokeratin fragment 19 (CYFRA 21‐1) levels in lung cancer diagnosis and to compare the diagnostic usefulness of sputum assays with that of serum assays.Methodology:  Forty‐seven patients with lung cancer and 62 with benign lung disease were studied. Tumour marker levels in sputum (sp.) and serum (ser) were measured by immunoradiometric assays.Results:  Sputum and serum tumour marker levels were significantly higher in lung cancer than in benign disease. When the specificity was 95%, the sensitivity was 57%, 43%, 36%, 30%, 28% and 19%, for spCEA, serCYFRA 21‐1, spCYFRA 21‐1, serCEA, serNSE, and spNSE, respectively. Bayesian analysis showed that the best predictive values correspond to spCEA and serCYFRA 21‐1. The maximum overall gain was obtained in pretest probability of 0.35 for both spCEA and serCYFRA 21‐1, with predictive values of 84% and 80% for spCEA and serCYFRA 21‐1, respectively.Conclusion:  Sputum tumour marker levels were no more useful than the serum levels in lung cancer diagnosis. SpCEA offered the best predictive values but these were still not sufficiently satisfactory for spCEA to be proposed for routine use.
Impact of coping and socioeconomic factors on quality of life in adults with asthma
Authors: Adams Robert J. , Wilson David , Smith Brian J. , Ruffin Richard E. 
Published: February 2004

Objective:  The socioeconomic variables of income, race and employment status have been shown to influence health‐related quality of life (HRQL) scores in persons with asthma. However, little is known about the impact of other psychological factors or perceptions of economic hardship on HRQL in asthma, despite the known influence these have on general activity levels and emotional perceptions. The aim of the present study was to assess the relationships between psychological and socioeconomic factors and HRQL and on subsequent changes to HRQL over 12 months.Methodology:  Consecutive adult patients with moderate or severe asthma attending outpatient clinics, emergency departments or who were inpatients at two teaching hospitals, completed surveys of clinical status, psychological and socioeconomic variables, and HRQL instruments (SF‐36 and Modified Marks Asthma Quality of Life Questionnaire [MAQLQ‐M]), at baseline and over 12‐months follow‐up.Results:  Of 343 eligible subjects, survey responses were received from 293 at baseline and 232 at 12‐months. Mean age was 42 years (SD 18), 67% were female, 42% had moderate, and 58% severe current asthma clinical status according to the National Asthma Education and Prevention Program guidelines criteria. In random‐effects multiple regression models, after adjusting for age, gender, education, income and hospital, significant independent variables associated with each of total MAQLQ‐M, SF‐36 Physical Component Summary (PCS) and SF‐36 Mental Component Summary (MCS) scores were avoidance coping, perceived recent financial difficulties and clinical asthma status. Additional independent associations were, for total MAQLQ‐M, patient concerns about costs delaying them from seeking care (overall model r2 = 0.69); for PCS, active coping (r2 = 0.69) and for MCS, positive evaluations/satisfaction with illness (r2 = 0.54).Conclusion:  Psychological factors, particularly coping styles, need to be taken into account when considering HRQL scores as outcome measures in asthma. Interventions to improve the coping capabilities of individuals with moderate‐to‐severe asthma may be potentially important areas for improvement of asthma‐related HRQL.