bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Shortfall as a Risk Measure for Portfolios with Hedge Funds
Authors: Lucas André , Siegmann Arjen
Published: September 2007

Abstract:  Current research suggests that the large downside risk in hedge fund returns disqualifies the variance as an appropriate risk measure. For example, one can easily construct portfolios with nonlinear pay‐offs that have both a high Sharpe ratio and a high downside risk. This paper examines the consequences of shortfall‐based risk measures in the context of portfolio optimization. In contrast to popular belief, we show that negative skewness for optimal mean‐shortfall portfolios can be much greater than for mean‐variance portfolios. Using empirical hedge fund return data we show that the optimal mean‐shortfall portfolio substantially reduces the probability of small shortfalls at the expense of an increased extreme crash probability. We explain this by proving analytically under what conditions short‐put payoffs are optimal for a mean‐shortfall investor. Finally, we show that quadratic shortfall or semivariance is less prone to these problems. This suggests that the precise choice of the downside risk measure is highly relevant for optimal portfolio construction under loss averse preferences.
Capital Structure and Firm Efficiency
Authors: Margaritis Dimitris , Psillaki Maria
Published: September 2007

Abstract:  This paper investigates the relationship between firm efficiency and leverage. We consider both the effect of leverage on firm performance as well as the reverse causality relationship. In particular, we address the following questions: Does higher leverage lead to better firm performance? Does efficiency exert a significant effect on leverage over and above that of traditional financial measures of capital structure? Is the effect of efficiency on leverage similar across different capital structures? What is the signalling role of efficiency to creditors or investors? Using a sample of 12,240 New Zealand firms we find evidence supporting the theoretical predictions of the Jensen and Meckling (1976) agency cost model. Efficiency measured as the distance from the industry's ‘best practice’ production frontier is positively related to leverage over the entire range of observed data. The frontier is constructed using the non‐parametric Data Envelopment Analysis (DEA) method. Using quantile regression analysis we show that the reverse causality effect of efficiency on leverage is positive at low to mid‐leverage levels and negative at high leverage ratios. Firm size also has a non‐monotonic effect on leverage: negative at low debt ratios and positive at mid to high debt ratios. The effect of tangibles and profitability on leverage is positive while intangibles and other assets are negatively related to leverage.
Modeling CO2 generation, migration, and titration in sedimentary basins
Authors: CATHLES L. M. , SCHOELL M.
Published: September 2007

High mole fraction CO2 gases pose a significant risk to hydrocarbon exploration in some areas. The generation and movement of CO2 are also of scientific interest, particularly because CO2 is an important greenhouse gas. We have developed a model of CO2 generation, migration, and titration in basins in which a high mole fraction CO2 gas is generated by the breakdown of siderite (FeCO3) and magnesite (MgCO3) where parts of the basin are being heated above approximately 330°C. The CO2 reacts with Fe‐, Mg‐, and Ca‐silicates as it migrates upward and away from the generation zone (CO2‐kitchen). Near the kitchen, where the Fe‐, Mg‐, and Ca‐silicates have been titrated and destroyed by previous packets of migrating CO2, gas moves upward without lowering its CO2 mole fraction. Further on, where Fe‐ and Mg‐silicates are still present but Ca‐silicates are absent in the sediments, the partial pressure of CO2 is constrained to 0.1–30 bars and reservoirs contain a few mole percent CO2 as described by Smith & Ehrenberg (1989). Still further from the source, where Ca‐silicates have not been titrated, partial pressure of CO2 in migrating methane gas are orders of magnitude lower. A 2D numerical model of CO2 generation, migration, and titration quantifies these buffer relations and makes predictions of CO2 risk in the South China Sea that are compatible with exploration experience. Reactive CO2 transport models of the kind described could prove useful in determining how gases migrate in faulted sedimentary basins.
Human 2D (index) and 4D (ring) digit lengths: their variation and relationships during the menstrual cycle
Authors: Mayhew T. M. , Gillam L. , McDonald R. , Ebling F. J. P.
Published: September 2007

It is known that there are sexually dimorphic differences in relative and absolute lengths of the index (2nd) and ring (4th) fingers and that the sizes of laterally‐paired soft tissues (e.g. ears and fingers) show changes across the menstrual cycle. The aim of the present study was to determine whether cyclical changes in the digit lengths of the index and ring fingers also occur and, if so, to what extent these are related to changing patterns of circulating sex steroids. Digit lengths were assessed over two cycles in groups of right‐handed females (19–21 years of age) who were divided on the basis of whether or not they were taking oral contraceptive pills (n = 13 and n = 6 respectively). Using callipers, finger lengths were measured on photocopy images of both hands taken at 4‐day intervals for a total of 56 days. We tested the following null hypotheses: (1) digit length measurements do not exhibit fluctuations across the menstrual cycle; (2) there is no evidence of lateral asymmetry between measurements made on both hands; (3) the lengths of digits 2 and 4 do not differ in either hand. Null hypotheses were tested using Page's L trends test for related samples (cyclical fluctuations) and paired Student's t tests (left–right asymmetries and within‐hand digital differences). In those not taking oral contraceptives, finger lengths and 2D:4D digit ratios fluctuated across the cycle with values tending to increase in the pre‐ovulatory period and decline thereafter. Left–right asymmetries varied in a similar fashion with lengths generally being larger, and lateral asymmetries smaller, in the dominant hand. Although sample sizes were smaller, some of these patterns were retained but others were perturbed in those practising oral contraception. We conclude that finger lengths are cycle‐dependent and that account should be taken of this, and of oral contraceptive usage, in future studies on female digit lengths and their ratios.
Survival and recurrent disease after postoperative radiotherapy for early endometrial cancer: systematic review and meta‐analysis
Authors: Johnson N , Cornes P
Published: September 2007

Objective  To clarify the effect of postoperative (adjuvant) external‐beam pelvic radiotherapy (EBRT) for different grades of early endometrial cancer.

Search strategy  Meta‐analysis of data from randomised trials stratified by histological risk factors supported by cohort studies.

Selection criteria  Cochrane methodology.

Data  Seven randomised trials were identified. Five were eligible for meta‐analysis. Homogeneity was confirmed (I2 < 25%).

Main outcome measures  Survival, site of recurrence and added complications.

Main results  EBRT after hysterectomy for low‐risk disease increases the odds of death (OR for overall survival 0.71; 95% CI 0.52–0.96). EBRT does not appear to alter survival for intermediate‐risk cancers (stage ICG1/2 and IBG3) (OR 0.97; 95% CI 0.69–1.35). In contrast, EBRT offers a significant disease‐free survival advantage for high‐risk cancer (OR 1.76; 95% CI 1.07–2.89). The survival advantage benefits one in ten women. The definition of high risk is variable across studies but focuses on ICG3 (deeply invasive, poorly differentiated) tumours. Pelvic EBRT reduces the risk of pelvic recurrent disease in all types of invasive endometrial cancer (OR 0.27; 95% CI 0.16–0.44), but local recurrence may respond to salvage treatment. The risk of distant metastasis appears to be increased significantly by prophylactic EBRT (OR 1.58; 95% CI 1.07–2.35), but this might be because pelvic relapse in untreated women alters reporting of metastatic disease.

Authors’ conclusions  Adjuvant EBRT should not be used for low‐ (IA, IBG1) or intermediate‐risk (IBG2) cancer, but it is associated with a 10% survival advantage for high‐risk (stage ICG3) endometrial cancer. This challenges the role of a staging lymphadenectomy.
An examination of the role of opportunistic smear taking in the NHS cervical screening programme using data from the CSEU cervical screening cohort study
Authors: Blanks RG , Moss SM , Coleman DA , Swerdlow AJ
Published: September 2007

Objective  The objective of this study was to study the prevalence of opportunistic smear taking in the NHS cervical screening programme between 1999 and 2003 and the relationship of this to screening interval policy.

Design  A cohort study of nearly 2 million women, with data on screening at ages 20–64 years from 1988 to 2003 has been constructed. Data from 1999 to 2003 have been used in this analysis. Screening episodes have been divided into those where the primary smear was initiated by the national call/recall system (invitational), normally at 3‐ or 5‐yearly intervals, and those initiated by the GP or woman (opportunistic). Opportunistic smears were further classified as routine (occurring within 6 months of 3 or 5 years) or sporadic (occurring at other times).

Setting  NHS cervical screening programme.

Population  Four Health Authorities in England (now Primary Care Trusts) with supplementary studies on national data.

Methods  Screening episodes have been defined. All episodes start with a primary smear defined as being invitational or opportunistic in origin.

Main outcome measure  Proportion of primary smear that were invitational or opportunistic.

Results  In total, 72% of incident screen primary smears were invitational and 28% were opportunistic. The proportion of opportunistic primary smears was 17 and 43% in 3‐ or 5‐yearly screening policy areas, respectively, resulting in a considerably reduced average screening interval for women aged 20–64 years in 5‐year policy areas.

Conclusion  The NHS cervical screening programme is strongly influenced by opportunistic smear taking. In particular, nominally 5‐year policy areas experienced much higher levels of opportunistic smear taking than those with a 3‐year policy, causing the average interval in the 5‐year areas to be much shorter than the policy would suggest. In future, with the change in national policy for inviting women aged 25–49 years every 3 years and those aged 50–64 years every 5 years, the level of opportunistic smear taking, particularly in the older group of women, needs to be carefully monitored. A lack of compliance may result in greater than predicted costs with little or no additional cancer prevention.
Is misoprostol a safe, effective and acceptable alternative to manual vacuum aspiration for postabortion care? Results from a randomised trial in Burkina Faso, West Africa
Authors: Dao B , Blum J , Thieba B , Raghavan S , Ouedraego M , Lankoande J , Winikoff B
Published: September 2007

Objectives  Previous research has demonstrated the effectiveness of misoprostol for treatment of incomplete abortion; however, few studies have systematically compared misoprostol’s effectiveness with that of standard surgical care. This study documents the effectiveness of a single 600 micrograms dose of oral misoprostol versus manual vacuum aspiration (MVA) for treatment of incomplete abortion in a developing country setting.

Design  Open‐label randomised controlled trial.

Setting  Two university teaching hospitals in Burkina Faso, West Africa.

Population  Women of reproductive age presenting with incomplete abortion.

Methods  From April 2004 through October 2004, 447 consenting women with incomplete abortion were randomised to either a single dose of 600 micrograms oral misoprostol or MVA for treatment of their condition.

Main outcome measure  Completed abortion following initial treatment.

Results  Regardless of treatment assigned, nearly all participants had a complete uterine evacuation (misoprostol = 94.5%, MVA = 99.1%; relative risk [RR] = 0.95 [95% CI 0.92–0.99]). Acceptability and satisfaction ratings were similar and high for both misoprostol and MVA, with three out of four women indicating that the treatment’s adverse effects were tolerable (misoprostol = 72.9%, MVA = 75.8%; RR = 0.96 [95% CI 0.86–1.07]). The majority of women were ‘satisfied’ or ‘very satisfied’ with the method they received (misoprostol = 96.8%, MVA = 97.7%; RR = 0.99 [95% CI 0.96–1.02]), expressed a desire to choose that method again (misoprostol = 94.5%, MVA = 86.6%; RR = 1.09 [95% CI 1.03–1.16]) and to recommend it to a friend (misoprostol = 94.5%, MVA = 85.2%; RR = 1.11 [95% CI 1.04–1.18]).

Conclusion  Six hundred micrograms of oral misoprostol is as safe and acceptable as MVA for the treatment of incomplete abortion. Operations research is needed to ascertain the role of misoprostol within postabortion care programmes worldwide.
Detection of acute myocardial infarction using the 12‐lead ECG plus inverted leads versus the 16‐lead ECG (with additional posterior and right‐sided chest electrodes)
Authors: Trägårdh Elin , Claesson Mikaela , Wagner Galen S. , Zhou Sophia , Pahlm Olle
Published: September 2007

Background:  The electrocardiographic (ECG) diagnosis of acute myocardial infarction (MI) should be improved. This might be done either by regarding all 24 aspects (both positive and negative leads), or a subset hereof (e.g. 19‐lead ECG), of the conventional 12‐lead ECG or by using additional electrodes. The purpose of this study was to investigate the accuracy of the different ECG methods in diagnosing acute ST‐elevation MI.

Methods:  The study population consisted of 479 patients admitted to Lund University Hospital with acute chest pain. One conventional ECG plus leads V4R, V5R, V8 and V9 were recorded for each patient within 24 h of admittance. Biochemical markers were used as the ‘gold standard’ for diagnosis of MI. We measured ST‐segment elevations in the 12‐, 16‐ and 24‐lead postadmission ECGs as well as in the 12‐, 19‐ and 24‐lead admission ECGs.

Results:  The sensitivity for detecting acute MI was 28% for the postadmission 12‐lead ECG, 33% for the 16‐lead ECG and 37% for the 24‐lead ECG. The specificities were 97%, 93% and 95%, respectively. For admission ECGs, the sensitivity was 33% for the 12‐lead ECG, 45% for the 19‐lead ECG and 49% for the 24‐lead ECG, with specificities of 97%, 96% and 94%, respectively.

Conclusions:  The sensitivity for detecting acute MI was higher for the 16‐, 19‐ and 24‐lead ECGs than for the conventional 12‐lead ECGs. Their specificity, however, was slightly lower. If increased sensitivity for detecting MI is desired, the 24‐lead or 19‐lead should be used as no additional electrodes are required.
Comparison of three methods for detection of the lactate threshold
Authors: Davis James A. , Rozenek Ralph , DeCicco Derek M. , Carizzi Michael T. , Pham Patrick H.
Published: September 2007

The lactate threshold (LT) represents the onset of a metabolic acidosis during graded exercise testing (GXT). It is a valuable measurement in clinical exercise testing and correlates well with endurance performance. Our purpose was to compare three LT detection methods, namely, Inspection (work rate at onset of a systematic increase in blood lactate concentration determined by inspection of blood lactate versus work rate plot), 0·5 mM (work rate which just precedes a rise in blood lactate concentration of >0·5 mM) and log–log (work rate at the intersection of two linear lines in plot of log lactate versus log work rate where the residual sum of squares for both lines added together is minimized). Fourteen subjects underwent cycle ergometer GXT with blood samples obtained at the end of each 3‐min work rate increment and analysed for lactate concentration. The mean ± 95% confidence limits of work rates at LT for the Inspection, 0·5 mM and log–log methods were 104·5 ± 28·0, 103·2 ± 28·1 and 105·1 ± 27·3 W, respectively. Repeated‐measures analysis of variance yielded a non‐significant F ratio. The Bland–Altman bias ± 95% limits of agreement for Inspection versus 0·5 mM, Inspection versus log‐log and 0·5 mM versus log–log were 1·3 ± 20·6, −0·6 ± 12·5 and −1·9 ± 20·5 W, respectively. The intraclass correlation coefficients for Inspection versus 0·5 mM, Inspection versus log–log and 0·5 mM versus log–log were 0·978, 0·992 and 0·977, respectively. The results of this study suggest that all three methods detect the LT at the same work rate.
Antihypertensive Medications and Anemia
Authors: Sica Domenic A. , Mannino Rosemarie
Published: September 2007

Antihypertensive medication use can be associated with a reduction in hemoglobin concentration. The magnitude of such a change is generally small, but in certain instances it can be extreme enough to produce a clinically significant degree of anemia. The mechanistic basis for antihypertensive medication‐related changes in hemoglobin concentration include hemodilution, hemolytic anemia, and suppression of red blood cell production, as this occurs most commonly with angiotensin‐converting enzyme inhibitors and angiotensin receptor blockers. A reduction in hemoglobin concentration in a patient who is receiving treatment for hypertension and does not have an obvious source of blood loss should account for potential antihypertensive therapy involvement.
Linear Relationship Between Blood Pressure and Stroke: The Jichi Medical School Cohort Study
Authors: Ishikawa Shizukiyo , Kario Kazuomi , Kayaba Kazunori , Gotoh Tadao , Nago Naoki , Nakamura Yosikazu , Tsutsumi Akizumi , Kajii Eiji
Published: September 2007

Hypertension is a major risk for stroke; a linear or J‐shaped relationship between blood pressure (BP) and stroke have been reported. The authors examined the relationship between systolic and diastolic BP and risk of stroke in the general population in Japan. The study included 11,097 men and women who were divided into quintiles by systolic BP and diastolic BP in each sex. Follow‐up duration was 10.7 years. In men, risks of second to fifth quintiles of systolic BP for all stroke were 1.5 (95% confidence interval [CI], 0.7–3.0), 2.2 (CI, 1.2–4.2), 3.0 (CI, 1.7–5.5), and 4.2 (CI, 2.4–7.6) compared with a reference of the first quintile using Cox's proportional hazard model, respectively. In women, risk of second to fifth quintiles of systolic BP for all stroke were 1.2 (95% CI, 0.6–2.4), 1.5 (CI, 0.8–2.9), 2.2(CI, 1.2–4.1), and 3.1 (CI, 1.7–5.6), respectively. Systolic BP and diastolic BP were related to stroke incidence linearly in the general Japanese population. Systolic BP was slightly more predictive of the risk of stroke than diastolic BP.
Prevalence and Characteristics of Left Ventricular Noncompaction in a Community Hospital Cohort of Patients with Systolic Dysfunction
Authors: Sandhu Roopinder , Finkelhor Robert S. , Gunawardena Diyana R. , Bahler Robert C.
Published: September 2007

Background: Left ventricular noncompaction (LVNC) is felt to be a rare form of cardiomyopathy, although its prevalence in a nonreferred population is unknown. We examined the prevalence and clinical characteristics of LVNC in a community hospital cohort of adult patients with echocardiographic evidence of left ventricular (LV) systolic dysfunction. Methods: All adult echocardiograms with global LV dysfunction and an LVEF ≤ 45% over a 1‐year period were reviewed for signs of LV noncompaction. Its presence was confirmed by the consensus of at least 2/3 readers specifically searching for this using standard criteria for noncompaction. Results: A 3.7% prevalence of definite or probable LVNC was found in those with LVEF≤ 45% and a 0.26% prevalence for all patients referred for echocardiography during this period. This is appreciably higher than prior reports from tertiary centers. Conclusion: Noncompaction may not be a rare phenomenon and is comparable to other more widely recognized but less common causes of heart failure such as peripartum myopathy, connective tissue diseases, chronic substance abuse and HIV disease.
Influence of Aging, Tidal Volume, and Respiratory Rate on Doppler Echocardiographic Indices of Diastolic Function in Normal Male Subjects: A Quantitative Evaluation
Authors: Romano Minna Moreira Dias , Pazin‐Filho Antônio , Crescêncio Júlio César , Schmidt André , Almeida‐Filho Oswaldo César , Gallo‐Júnior Lourenço , Marin‐Neto José Antonio , Maciel Benedito Carlos
Published: September 2007

Background: Although the influence of respiration on ventricular filling, as evaluated by Doppler technique, and the evaluation of diastolic velocities of mitral valve annulus (MVA), as measured by Doppler tissue imaging (DTI), can provide valuable information for the study of left ventricular (LV) diastolic function, the concomitant effects of aging, tidal volume (TV), and respiratory rate (RR) on these velocities have not been quantitatively investigated. Methods: We evaluated 12 normal male volunteers (Group I) aged 20–26 years (mean: 22.8) and 8 normal subjects aged 41 to 54 years old (mean: 45.9) (Group II). Using DTI we measured peak early (Ea) and late (Aa) velocities of longitudinal axis expansion at lateral and medial MVA. Doppler mitral and tricuspid flow velocities were measured: peak early (E) and late (A) inflow velocity, early (Ei) and late (Ai) flow integral, and deceleration time of peak early mitral flow velocity (DT). Respiratory cycles were simultaneously recorded at RR of 9, 12, 15, and 18 cycles/min and TV of 600 and 900 mL during respiration (RESP). Results and conclusions: (1) E, A, and Ai in MV had negligible change during respiration, but Ei was significantly reduced during inspiration; (2) DT reduced slightly with inspiration, but the change was significant only with TV of 900 mL; (3) an important increase of E in right ventricular flow was observed during inspiration; (4) variations of RR and TV did not significantly influence right and left ventricular inflow in normal subjects, in the conditions of this investigation; (5) a significant increase of Ea at medial MVA was documented during inspiration only in young subjects; (6) a significant decrease of Aa at medial MVA was observed during inspiration in both groups of volunteers; (7) RR and TV did not influence MVA velocities in young and adult subjects; (8) a consistent reduction in Ea and a significant increase in Aa were observed with increasing age; (9) these changes were more conspicuous and consistent than those documented in ventricular filling when young and middle‐age men are compared, suggesting that the DTI is more sensitive to detect changes in diastolic function; and (10) in addition, these data suggest that, for evaluation of diastolic function, in clinical context, it is not necessary to control rigorously RR or TV.
Coronary Stents, Hypersensitivity Reactions, and the Kounis Syndrome
Authors: KOUNIS NICHOLAS G. , HAHALIS GEORGE , THEOHARIDES THEOHARIS C.
Published: September 2007

The use of drug‐eluting stents (DES) for the treatment of coronary stenosis has increased sharply and now accounts for more than 75% of all coronary stents utilized. However, concern has been increasing that DES could be associated with stent thrombosis, paradoxical coronary vasoconstriction, and hypersensitivity reactions. Components of currently used DES have been reported to induce, either separately or synergistically, hypersensitivity reactions and possibly lead to cardiac events. DES‐activated intracoronary mast cells could release histamine, arachidonic acid metabolites, proteolytic enzymes, as well as a variety of cytokines, chemokines, and platelet‐activating factor (PAF) leading to local inflammation and thrombosis. These events may be more common than suspected because it is hard to document them, unless they become systemic, in which case they manifest themselves as the “Kounis syndrome,” characterized by the concurrence of acute coronary events with hypersensitivity reactions. Recognition of this problem may lead to better vigilance, as well as new DES with mast cell blocking molecules that may also be disease modifying.
Quantifying the Effect of the Surrogate Marker by Information Gain
Authors: Qu Yongming , Case Michael
Published: September 2007

Summary Statistical validation of a surrogate marker has been studied for more than a decade. Recently, Alonso et al. (2004, Biometrics 60, 724–728) proposed a quantity called the likelihood reduction factor (LRF) to evaluate the validity of a surrogate marker. However, as pointed out in the present article, the LRF may not correctly validate a surrogate marker. Therefore, a new quantity, the proportion of information gain (PIG) using the Kullback–Leibler information, is proposed. Simulations show that under some model assumptions, the PIG precisely reflects the role of a surrogate marker.
Cognitive impairment in schizoaffective disorder: a comparison with non‐psychotic bipolar and healthy subjects
Authors: Torrent C. , Martínez‐Arán A. , Amann B. , Daban C. , Tabarés‐SeisDedos R. , González‐Pinto A. , Reinares M. , Benabarre A. , Salamero M. , McKenna P. , Vieta E.
Published: September 2007

Objective:  Only a few studies have examined specifically the neuropsychological performance of schizoaffective patients.

Method:  The sample consisted of 34 euthymic DSM‐IV schizoaffective patients, who were compared with 41 euthymic bipolar patients without history of psychotic symptoms and 35 healthy controls. Euthymia was defined by a score of 6 or less at the Young Mania Rating Scale and a score of 8 or less at the Hamilton Depression Rating Scale for at least 6 months. Patients were compared with several clinical, occupational, and neuropsychological variables such as executive function, attention, verbal and visual memory and the two groups were contrasted with 35 healthy controls on cognitive performance. The three groups were compared using mancova after checking the potential role of several co‐variables.

Results:  Schizoaffective patients showed greater impairment than controls and bipolar patients, in several domains, including verbal memory, executive function, and attentional measures. Bipolar patients without history of psychosis performed similar to the controls except for verbal fluency.

Conclusion:  Schizoaffective disorder carries more neurocognitive impairment than non‐psychotic bipolar disorder and more occupational difficulties.
Evaluation of periodontal parameters in patients undergoing peritoneal dialysis or hemodialysis
Authors: Bayraktar G , Kurtulus I , Kazancioglu R , Bayramgurler I , Cintan S , Bural C , Bozfakioglu S , Besler M , Trablus S , Issever H , Yildiz A
Published: September 2007

Objective:  To analyze and compare periodontal parameters in chronic renal failure (CRF) patients undergoing peritoneal dialysis (PD) therapy with a group of patients on hemodialysis (HD) treatment and healthy controls (C).

Participants:  Seventy‐five PD patients (mean age: 44 ± 12 years) were matched with 41 HD patients (mean age: 46 ± 15 years) and 61 C (mean age: 46 ± 18 years).

Methods:  Plaque (PI) and calculus (CSI) accumulation and gingival bleeding (GI) were recorded with the appropriate indices. Periodontal condition was assessed using the probing pocket depth (PPD). One‐way anova test, Pearson chi‐squared test, Mann–Whitney U‐test and Kruskal–Wallis test were performed to compare PD patients with HD patients and healthy C.

Results:  Plaque Index values were significantly higher (P < 0.001) in the PD and HD groups than the C group. GI values were significantly higher (P < 0.01) in the HD group than the PD group. Finally, CSI values in the PD and HD groups were also significantly higher (P < 0.001) than the C group.

Conclusions:  Chronic renal failure patients on PD treatment are more susceptible to periodontal diseases like HD patients. Thus, it is very important to maintain an optimal oral hygiene level. Further studies on periodontal parameters of only PD patients are needed to get more information on the oral health status of this patient group.
Statistical analysis of six STR loci located in MHC region in Iranian population for preimplantation genetic diagnosis
Authors: Korzebor A. , Zamani M. , Nouri K. , Modarressi M. H.
Published: September 2007

We studied allele frequency and other statistical parameters of six short‐tandem repeat (STR) loci: D6S265, D6S439, D6S105, D6S82‐1, MICA, and MOGd, which are located in major histocompatibility complex (MHC) region (6p21.3) in 101 Iranian individuals. STR polymorphisms were analysed by PCR and polyacrylamide gel electrophoresis and subsequent comparison with standard (allelic) ladders. Exact tests of Hardy–Weinberg equilibrium were performed for the six loci. All loci, except the MOGd (P = 0.4291), were in Hardy–Weinberg equilibrium. These data may be useful in PGD‐HLA matching and forensic science.
Immune response to Newcastle disease virus in chicken lines divergently selected for cutaneous hypersensitivity
Authors: Ahmed K. A. , Saxena V. K. , Ara A. , Singh K. B. , Sundaresan N. R. , Saxena M. , Rasool T. J.
Published: September 2007

This paper describes for the first time the differential immune response to virulent Newcastle disease virus (NDV) in birds differing in cell‐mediated immunity, as measured by response to phytohaemagglutinin‐P. To explore potential host–pathogen interactions, peripheral blood mononuclear cells (PBMC) were collected from 40 extreme responder birds (20 birds each from high and low cell‐mediated immunity lines). PBMC cultures were stimulated by virulent NDV and temporal expression profiles of interferon‐gamma (IFN‐γ), and inducible nitric oxide synthase (iNOS) mRNA was evaluated by semiquantitative reverse transcription polymerase chain reaction (PCR). To further explore the correlation of iNOS mRNA expression and nitric oxide (NO) production, we assayed the culture supernatants for NO. NO production, as well as iNOS and IFN‐γ mRNA expression, was significantly (P < 0.05) higher in the line with higher cell‐mediated immunity. In our study, a significant (P < 0.05) difference was observed between the lines for IFN‐γ promoter polymorphism for theTspEI site. The high cell‐mediated immunity line mostly revealed the genotype (GG) with a 168‐bp fragment. On the other hand, this genotype was not predominant in the low cell‐mediated immunity line. Later, quantitative real‐time PCR demonstrated higher (P < 0.01) IFN‐γ mRNA transcription in the genotype GG in response to NDV. This difference in promoter region may be responsible for differential IFN‐γ mRNA transcription in chicken lines. Furthermore, birds of high cell‐mediated immunity line showed better adaptive immunity to booster NDV vaccination as revealed by an enhanced antibody titre. Thus, this study provides baseline data on the effect of phytohaemagglutinin‐P response‐based selection on immune responses to virulent NDV and the data could be of immense importance to poultry geneticist and immunologist attempting to breed poultry for disease resistance.
Performance evaluation of Abbott CELL‐DYN Ruby for routine use
Authors: LEHTO T. , HEDBERG P.
Published: September 2007

CELL‐DYN® Ruby™ is a new automated hematology analyzer suitable for routine use in small laboratories and as a back‐up or emergency analyzer in medium‐ to high‐volume laboratories. The analyzer was evaluated by comparing the results from the CELL‐DYN® Ruby™ with the results obtained from CELL‐DYN® Sapphire™. Precision, linearity, and carryover between patient samples were also assessed. Precision was good at all levels for the routine cell blood count (CBC) parameters, CV% being ≤2.6, except for platelet count (PLT) at the low level with CV% of ≤6.9%. The CV% for reticulocyte percentage was highest at the low level (10.4). In a comparative study, the CELL‐DYN Ruby results showed a good correlation (R2 ≥ 0.98) with CELL‐DYN Sapphire for the CBC parameters. For the absolute reticulocyte count, R2 was 0.82. In the white blood cell (WBC) differentials, the between‐days precision was good for all parameters (CV%: ≤8.0), except basophil percentage and absolute basophil count (CV%: ≤31.8 and 31.3, respectively). Additionally, in the commercial control sample with the low WBC count (2.5 × 109/l), the precisions in the WBC differentials were ≤16.9%. The cell types that occur in low numbers showed higher CVs, as expected. The methodological comparison of the WBC differential parameters of neutrophils, lymphocytes, and eosinophils showed excellent correlations (R2 ≥ 0.97), and the correlation coefficient for absolute monocyte count and monocyte percentage were 0.91 and 0.87, respectively. For absolute basophil count and basophil percentage the correlations were weaker (R2 = 0.46 and 0.34, respectively). Carryover was minimal for all the parameters studied. The linearities of WBC, red blood cell, PLTs, and hemoglobin were acceptable within the tested ranges. In conclusion, the results of the evaluation showed the performance of CELL‐DYN Ruby to be good.
Immunoproteomic Assay of Membrane‐associated Proteins ofStreptococcus suisType 2 China Vaccine Strain HA9801
Authors: Zhang W. , Lu C. P.
Published: September 2007

Immunoproteomic approaches were undertaken to study the immunogenicity of the membrane‐associated proteins of theStreptococcus suistype 2 (SS2) China vaccine strain HA9801. The membrane‐associated proteins were enriched using the Triton X‐114 extraction protocol and were analysed by two‐dimensional gel electrophoresis (2‐DE) and subsequent immunoblotting using the hyperimmune serum of SS2‐HA9801‐immunized specific pathogen free (SPF) minipigs. A total of 11 proteins were recognized, and the corresponding spots on a duplicate gel were excised and identified by MALDI‐TOF MS.
Dermatophytosis caused by Trichophyton mentagrophytes in the Southern Chamois (Rupicapra pyrenaica) in the Eastern Pyrenees
Authors: Marco I. , Lopez‐Olvera J. R. , Gibert P. , Abarca L. , Gauthier D. , Lavín S.
Published: September 2007

Two free‐ranging southern chamois (Rupicapra pyrenaica) – one 4‐year‐old male and one 3‐year‐old male – were diagnosed with clinical dermatophytosis in the French and Spanish Eastern Pyrenees respectively. Skin samples were collected for microbiological studies, Trichophyton mentagrophytes being isolated and identified in both animals. The first chamois was found dead at the base of a cliff, and presented with alopecia and scaling on the dorsum and left forelimb. The second chamois showed grey‐yellow, rough to raised scaling and crusting skin lesions at the base of the horns, around the eyes, dorsum of the nose, sternum, tail and limbs. Histological examination was carried out only on the second animal. The main lesions were orthokeratotic hyperkeratosis with focal parakeratosis, irregular to papillary epidermal hyperplasia, intracorneal neutrophilic pustules, perivascular to diffuse dermatitis with neutrophilic folliculitis and furunculosis. In those follicles with folliculitis and/or furunculosis, fungal hyphae and arthrospores associated with the follicular keratin and hair shafts were seen.
Variation in the Immuno‐pathological Responses of Lambs after Experimental Infection with Different Strains ofMycobacterium aviumsubsp.paratuberculosis
Authors: Verna A. E. , Garcia‐Pariente C. , Muñoz M. , Moreno O. , García‐Marin J. F. , Romano M. I. , Paolicchi F. , Pérez V.
Published: September 2007

Ruminant infection byMycobacterium aviumsubsp.paratuberculosis(MAP) causes a granulomatous inflammatory response in the intestine and associated lymph nodes. Differences either in the affected organs or in the inflammatory infiltrate were observed between species and individuals. Such differences are usually attributed to variations in host immune responses or to inconsistent effects among different MAP strains. To evaluate if different MAP strains induce different immuno‐pathological responses in lambs, 28 one‐month‐old individuals were divided into six groups and inoculated with different MAP strains. Groups 1 and 2 were inoculated with two bovine strains isolated in Argentina that showed different genetic patterns afterBstEII‐IS900‐RFLP (hereafter strains E and A respectively). Group 3 was inoculated with a bovine strain isolated in Spain obtained after a previous step of culture (patterns C1). Group 4 was inoculated with a homogenate of intestinal mucosa of a clinical case affected by the same bovine strain as that of group 3. Group 5 was inoculated with an ovine strain that was directly purified from the intestinal mucosa of a clinical case, and group 6 was kept as control (i.e. no inoculation). Peripheral immune responses were assessed until 150 days post‐infection (dpi), when lambs were humanely killed. Pathological studies were performed in tissues from the intestine and lymph nodes. Lesion types and inflammatory infiltrates were examined as indicators of pathogenicity. All the lambs infected with bovine MAP strains showed a common lesion pattern regardless of the strain type. Such pattern was characterized by focal lesions mainly in the mesenteric lymph nodes, the presence of fibrous tissue, and, occasionally, necrosis in the granulomas as well as the presence of numerous giant cells. Differences in lesion severity were observed among groups: lambs from groups 1 and 2 had the highest number of granulomas and the largest lymph node area affected. Lesions in animals from group 5 (infected with an ovine strain) were more severe and occurred mostly in the intestinal lymphoid tissue; necrosis, fibrosis or giant cells were never detected in this group. These results indicate that the MAP strain type induces different pathological responses in lambs.
Chlamydophila psittaci DNA Detection in the Faeces of Cage Birds
Authors: Sareyyupoglu B. , Cantekin Z. , Bas B.
Published: September 2007

In this study, we investigated the shedding of Chlamydophila psittaci in faecal samples from cage birds using PCR testing. A total of 47 faeces samples were collected from four different aviaries. Main symptoms determined after clinical investigation and owner histories of the birds showed that the birds had respiratory system problems changing from mild to severe. They also showed conjunctivitis, diarrhoea or no symptoms at all. DNA extractions from faeces were performed with the QIAamp DNA Stool Mini Kit. Following PCR with Cp. psittaci specific primers, 43 (91.5%) samples were determined to harbour‐specific DNA. Only one bird from each aviary was found to be negative by PCR. As all the samples from birds showing clinical signs were PCR positive, these signs could be correlated to psittacosis in these birds. Cp. psittaci shedding in faeces was detected in all the aviaries. After restriction analysis of PCR amplicons with AluI enzyme, all the isolates showed the same RFLP (Restriction Fragment Length Polymorphism) patterns with the control Cp. psittaci DNA. PCR following QIAamp DNA stool mini kit extraction of faecal samples was found to be a rapid, specific, sensitive, reproducible test, which did not need additional nested PCR of samples.
Detection and Identification of Salmonella Typhimurium in Bovine Diarrhoeic Fecal Samples by Immunomagnetic Separation and Multiplex PCR Assay
Authors: Zahraei Salehi T. , Tadjbakhsh H. , Atashparvar N. , Nadalian M. G. , Mahzounieh M. R.
Published: September 2007

The aim of this study was to use the immunomagnetic separation (IMS) test plus a multiplex polymerase chain reaction (m‐PCR) assay to detect Salmonella at genus level and also for the identification of Salmonella enterica serovar Typhimurium in bovine diarrhoeic fecal samples. In all, 400 bovine diarrhoeic fecal specimens were examined by conventional bacterial culture, IMS, and m‐PCR. For m‐PCR assay, four set primers were selected: 139‐141, specific for inv‐A gene of Salmonella spp and the RfbJ, FliC and FljB, specific for the rfbJ, FliC and fljB genes of Salmonella Typhimurium or other Salmonella serovars with similar antigenic properties. Thirty‐three (8.25%) out of the 400 fecal samples were culture positive for Salmonella serovars. Of these, 66.7% (22 of 33) were Salmonella enterica serovar Typhimurium, and 9.1% (three of 33) were serovar Dublin. In the IMS + m‐PCR, four amplified product (663, 526, 284 and 183 bp) were found in all specimens that had serovar Typhimurium (4,5,12:i:1,2), they corresponded, respectively, to the rfbJ, fljB, inv‐A and Flic genes of this serovar. In serovar Dublin (1,9,12:g,p:‐), Georgia (6,7:b:e,n,z15) and, Enteritidis (1,9,12;g,m:‐) only one PCR product (284 bp) was amplified from the inv‐A gene. In serovars Augustenborg (6,7:i:1,2) and Lindenburg (6,8:i:1,2) three positive bands (526, 284 and 183 bp) were amplified corresponding to the fljB, inv‐A and Flic genes, respectively. In serovar Virchow (6,7:r:1,2) two amplified products (284 and 526 bp) from the inv‐A and FliC genes were observed. In serovar Gloucster (1,4,12(27):i:1,w) three fragments (183, 284 and 663) from the FliC, inv‐A and, rfbJ genes respectively, were observed. In the positive control as expected, four PCR products were amplified corresponding to the FliC, inv‐A, fljB and rfbJ genes, respectively. In conclusion, the results of this study showed that detection of Salmonella at genus level with universal ST139‐141 primers and identification of Salmonella Typhimurium by using specific primers of O4, H2:1, 2 and H1 antigens can potentially permit to more readily evaluate fecal and other types of samples for the presence of these organisms. Compared to bacteriological culture the combination of IMS and m‐PCR resulted a faster method for the detection and identification of Salmonella at genus and serovar level by using of universal and specific primers.
Activity of an Antimicrobial Peptide Mimetic against Planktonic and Biofilm Cultures of Oral Pathogens
Authors: Beckloff Nicholas , Laube Danielle , Castro Tammy , Furgang David , Park Steven , Perlin David , Clements Dylan , Tang Haizhong , Scott Richard W. , Tew Gregory N. , Diamond Gill
Published: September 2007

Antimicrobial peptides (AMPs) are naturally occurring, broad-spectrum antimicrobial agents that have recently been examined for their utility as therapeutic antibiotics. Unfortunately, they are expensive to produce and are often sensitive to protease digestion. To address this problem, we have examined the activity of a peptide mimetic whose design was based on the structure of magainin, exhibiting its amphiphilic structure. We demonstrate that this compound,
meta
-phenylene ethynylene (mPE), exhibits antimicrobial activity at nanomolar concentrations against a variety of bacterial and
Candida
species found in oral infections. Since
Streptococcus mutans
, an etiological agent of dental caries, colonizes the tooth surface and forms a biofilm, we quantified the activity of this compound against
S. mutans
growing under conditions that favor biofilm formation. Our results indicate that mPE can prevent the formation of a biofilm at nanomolar concentrations. Incubation with 5 nM mPE prevents further growth of the biofilm, and 100 nM mPE reduces viable bacteria in the biofilm by 3 logs. Structure-function analyses suggest that mPE inhibits the bioactivity of lipopolysaccharide and binds DNA at equimolar ratios, suggesting that it may act both as a membrane-active molecule, similar to magainin, and as an intracellular antibiotic, similar to other AMPs. We conclude that mPE and similar molecules display great potential for development as therapeutic antimicrobials.
Isoxyl Activation Is Required for Bacteriostatic Activity against
Mycobacterium tuberculosis
Authors: Korduláková Jana , Janin Yves L. , Liav Avraham , Barilone Nathalie , Dos Vultos Tiago , Rauzier Jean , Brennan Patrick J. , Gicquel Brigitte , Jackson Mary
Published: September 2007

Isoxyl (ISO), a thiourea derivative that was successfully used for the clinical treatment of tuberculosis during the 1960s, is an inhibitor of the synthesis of oleic and mycolic acids in
Mycobacterium tuberculosis
. Its effect on oleic acid synthesis has been shown to be attributable to its inhibitory activity on the stearoyl-coenzyme A desaturase DesA3, but its enzymatic target(s) in the mycolic acid pathway remains to be identified. With the goal of elucidating the mode of action of ISO, we have isolated a number of spontaneous ISO-resistant mutants of
M. tuberculosis
and undertaken their genotypic characterization. We report here the characterization of a subset of these strains carrying mutations in the monooxygenase gene
ethA
. Through complementation studies, we demonstrate for the first time that the EthA-mediated oxidation of ISO is absolutely required for this prodrug to inhibit its lethal enzymatic target(s) in
M. tuberculosis
. An analysis of the metabolites resulting from the in vitro transformation of ISO by purified EthA revealed the occurrence of a formimidamide allowing the formulation of an activation pathway in which the oxidation of ISO catalyzed by EthA is followed by chemical transformations involving extrusion or elimination and, finally, hydrolysis.
Identification of 16S rRNA Methylase-Producing
Acinetobacter baumannii
Clinical Strains in North America
Authors: Doi Yohei , Adams Jennifer M. , Yamane Kunikazu , Paterson David L.
Published: September 2007

Five highly amikacin-resistant
Acinetobacter baumannii
isolates were collected at a medical center in Pennsylvania. The aminoglycoside resistance was due to the production of the 16S rRNA methylase ArmA. Two of the isolates coproduced OXA-23 β-lactamase and were highly resistant to carbapenems as well. The isolates were genetically closely related by pulsed-field gel electrophoresis.
Characterization of an Immunogenic Outer Membrane Autotransporter Protein, Arp, of
Bartonella henselae
Authors: Litwin Christine M. , Rawlins Mindy L. , Swenson Erica M.
Published: September 2007

Bartonella henselae
is a recently recognized pathogenic bacterium associated with cat scratch disease, bacillary angiomatosis, and bacillary peliosis. This study describes the cloning, sequencing, and characterization of an antigenic autotransporter gene from
B. henselae
. A cloned 6.0-kb BclI-EcoRI DNA fragment expresses a 120-kDa
B. henselae
protein immunoreactive with 21.2% of sera from patients positive for
B. henselae
immunoglobulin G antibodies by indirect immunofluorescence, with 97.3% specificity and no cross-reactivity with antibodies against various other organisms. DNA sequencing of the clone revealed one open reading frame of 4,320 bp with a deduced amino acid sequence that shows homology to the family of autotransporters. The autotransporters are a group of proteins that mediate their own export through the outer membrane and consist of a passenger region, the α-domain, and an outer membrane transporter region, the β-domain. The passenger domain shows homology to a family of pertactin-like adhesion proteins and contains seven, nearly identical 48-amino-acid repeats not found in any other bacterial or
Bartonella
DNA sequences. The passenger α-domain has a calculated molecular mass of 117 kDa, and the transporter β-domain has a calculated molecular mass of 36 kDa. The clone expresses a 120-kDa protein and a protein that migrates at approximately 38 kDa exclusively in the outer membrane protein fraction, suggesting that the 120-kDa passenger protein remains associated with the outer membrane after cleavage from the 36-kDa transporter.