bluuebunny/crossref_metadata_2025 huggingface dataset:
Serial colour flow duplex scanning of the veins of the lower limb throughout pregnancy
Authors: Sparey Colette , Sissons Guy , Haddad Nabil , Rosser Saskia , de Cossart Linda
Published: August 2005

Objective
To examine changes in diameter and reflux in normal veins of the lower limb throughout pregnancy.

Methods
Fifty‐seven women were recruited into the study and 43 completed the full assessment to six weeks postpartum. Thirteen had pre‐existing venous disease and are reported elsewhere. The veins were assessed in both lower limbs using colour flow duplex scanning. This was performed at a 75° tilt measuring vein diameter and the presence or absence of reflux. Measurements were made at 12, 20, 26, 34, 38 weeks of gestation and 6 weeks postpartum.

Results
No new reflux developed in any of the veins studied. In the superficial system the maximum change was seen in the long saphenous vein at 34 weeks, on the left side the vein diameter failed to return to baseline size. Significant change also occurred in the superficial femoral vein. Dilatation of the deep veins of the calf was observed being greater in the left posterior tibia1 and the left peroneal at the mid‐calf point.

Conclusion
Colour flow duplex scanning is an acceptable method of assessing the lower limb veins in pregnancy. Maximum diameter changes were seen in the long saphenous vein and in the deep veins at mid‐calf. No new reflux developed during the gestation period in veins which were previously normal.
Nonsurgical mid‐trimester termination of pregnancy: a review of 500 consecutive cases
Authors: Ashok Premila W. , Templeton Allan
Published: August 2005

Objective
To assess the effectiveness of a regimen comprising mifepristone followed by a combination of the vaginal and oral administration of misoprostol for mid‐trimester medical termination of pregnancy.

Design
Retrospective analysis of prospectively collected data in women undergoing mid‐trimester medical termination of pregnancy.

Setting
Aberdeen Royal Infirmary, Scotland.

Sample
A consecutive series of 500 women with pregnancies of 13–21 weeks of amenorrhea undergoing legally induced abortion in one Scottish NHS hospital.

Methods
Each woman received a single oral dose of mifepristone 200 mg and 36–48 h later vaginal misoprosto1800 pg. Three hours following the first dose of misoprostol, 400 yg doses were administered orally at three hourly intervals, to a maximum of four doses. Success was defined as abortion occurring with five doses of prostaglandin, or within 15 h of administration of the first dose of prostaglandin.

Results
Ninety‐seven percent aborted successfully. The median dose of misoprostol required was 1200 yg and the median induction‐toabortion interval after first prostaglandin administration was 6.5 h. The median number of doses of misoprostol required to induce abortion, and the induction‐toabortion interval, was statistically significantly higher among women at gestations 17–21 weeks than among those at 13–16 weeks (P= 0–0001). A total of 9.4% required surgical evacuation of the uterus under general anaesthesia and 66.4% of the women were managed as day cases.

Conclusions
The combination of oral mifepristone 200 mg followed by vaginally and orally administered misoprostol provides a noninvasive and effective regimen for second trimester termination of pregnancy.
The effect of oestrogen supplementation on post‐menopausal urinary stress incontinence: a double‐blind placebo‐controlled trial
Authors: Jackson Simon , Shepherd Angela , Brookes Sara , Abrams Paul
Published: August 2005

Objective
To investigate the effect of hormone replacement therapy on post‐menopausal urinary stress incontinence.

Design
Double‐blind, placebo‐controlled, randomised trial.

Setting
University associated teaching hospital.

Population
Post‐menopausal women with genuine stress incontinence, not taking hormone replacement therapy.

Methods
Randomisation to six months therapy with oestradiol valerate 2 mg daily or placebo. Assessment prior to treatment and upon study completion with the SF‐36 health status questionnaire, the Bristol Female Lower Urinary Tract Symptoms questionnaire, a one week urinary diary, one hour perheal pad test, cystometry and urethral profilometry.

Results
Sixty‐seven women consented to participate, 33 were randomised to receive oestradiol. Mean age was 63 years. Five women failed to undergo repeat assessment, three of whom were receiving oestrogen. Six women receiving oestradiol experienced breakthrough bleeding during the six months and were subsequently treated with additional monthly progestogen. No significant effect of oestrogen over placebo was observed for any subjective or objective clinical outcome.

Conclusions
This trial is one of the largest controlled studies yet reported, with the longest duration of treatment. No improvement in post‐menopausal stress incontinence was demonstrated after six months therapy with oestradiol. This concurs with another study reported recently; it seems unlikely that oestrogen has a significant role to play in this condition. incontinence.
Investigation of the cause of miscarriage and its influence on women's psychological distress
Authors: Nikcevic Ana V. , Tinkel Sarah A. , Kuczmierczyk Andrzej R. , Nicolaides Kypros H.
Published: August 2005

Objective
To determine whether knowledge of the possible cause of miscarriage reduces women's long term psychological distress.

Design
Prospective longitudinal study.

Setting
Harris Birthright Research Centre for Fetal Medicine, King's College Hospital Medical School, London.

Methods
In 143 women where a routine ultrasound scan at 10–14 weeks of gestation showed an anembryonic pregnancy or fetal death, investigations were carried out to help ascertain the cause of the pregnancy loss. The participants were divided into two groups according to whether the cause was identified or not, and the psychological conditions of the two groups were compared at four weeks and four months after the diagnosis of fetal loss. term psychological distress.

Main outcome measures
Anxiety, depression, grief, self‐blame, worry.

Results
The scores for all outcome variables were significantly lower at the four‐month compared with the four‐week post‐miscarriage assessment. A fetal chromosomal abnormality was the most commonly identified cause of miscarriage, and this group reported significantly less self‐blame than women in whom no cause was identified. There were no significant differences between the groups on any other outcome variables.

Conclusions
In women with a missed miscarriage, identification of the cause of fetal loss reduces the feelings of self‐blame.
The role of high resolution ultrasound with guided cytology of groin lymph nodes in the management of squamous cell carcinoma of the vulva: a pilot study
Authors: Moskovic E. C. , Shepherd J. H. , Barton D. P. J. , Trott P. A. , Nasiri N. , Thomas J. M.
Published: August 2005

The accuracy of high resolution ultrasound with guided fine needle aspiration cytology in detecting inguinal lymph node involvement was assessed in 24 women undergoing radical vulvectomy and groin node dissection for squamous cell vulval cancer. Of the 43 groins dissected, ultrasound correctly diagnosed the lymph node status in 36, with five false positive and two false negative results. Cytology in 40 groins showed no false positive and five false negative results. The sensitivity and specificity for the combined techniques were 83% and 82% respectively. Assessed together, the combined technique failed to detect metastatic disease in two groins; in both cases the extent of nodal metastatic involvement was a solitary focus < 3 mm in diameter. The ultrasound and fine needle aspiration procedure is safe and well tolerated and can be repeated as needed for surveillance. The authors suggest that this procedure should be evaluated further to determine whether a policy of individual selection for lymphadenectomy can be implemented based on this technique.
Estimation of fetal weight in twins: a new mathematical model
Authors: Ong Stephen , Smith Anne P. M. , Fitzmaurice Ann , Campbell Doris
Published: August 2005

Objectives
Evaluation of new mathematical formula (Femur 4) derived from a twin population to estimate fetal weight in twins using ultrasound. Comparison of Femur 4 is with conventional mathematical models.

Design
Retrospective analysis of ultrasonic measurements of 297 twin babies from 24 to 40 weeks of gestation who were born within 10 days of ultrasound examination.

Setting
Aberdeen Maternity Hospital.

Methods
With ultrasonic measurements obtained from twin babies, estimated fetal weight was calculated using the mathematical models of Campbell, Shepard and Hadlock. The calculations were repeated for the model of Femur 4. All models were compared against Femur 4.

Results
The coefficient of determination of the linear regression between the actual and predicted weight was highest for Femur 4 (0,852). Femur 4 had the highest proportion of babies with estimated weights within 10% of actual birth weight (71.4%). In babies who weighed between 2000 and 3000 g, Femur 4 had the least systematic and random error of −1.69 and 8.96, respectively. For babies below the 10th centile for weight, Femur 4 had comparable positive and negative predictive values of 76.0% and 92.3%, respectively. Femur 4 was equally poor at predicting growth discordancy with positive and negative predictive values of 70.0% and 86.5% only.

Conclusion
Femur 4 requires measurements of femur length and abdominal circumference only, hence avoiding the need to obtain difficult head measurements which is a common problem in twins. It is a good model for estimation of fetal weight in twins. However, prediction of growth discordancy remains problematic.
Are we prescribing multiple courses of antenatal corticosteroids? A survey of practice in the UK
Authors: Brocklehurst Peter , Gates Simon , McKenzie‐McHarg Kirstie , Alfirevic Zarko , Chamberlain Geoffrey
Published: August 2005

A postal questionnaire concerned with prescribing antenatal corticosteroids was sent to one named clinician at each of 279 obstetric units in the UK. They were asked whether their unit prescribed repeated courses, the indications for which these would be prescribed, the interval between courses, the drugs and regimens used and whether they would be willing to participate in a proposed randomised controlled trial. The response rate was 75%. Of the respondents, 98% prescribed repeated courses; the indications most commonly cited by units who prescribed steroids were prelabour spontaneous rupture of membranes (84.2%), and suspected preterm labour (81.8%). 70.6% of units were willing to participate in the proposed trial.
A Clinical Trial of a Rehabilitation Expert Clinician Versus Usual Care for Providing Manual Wheelchairs
Authors: Hoenig Helen , Landerman Lawrence R. , Shipp Kathy M. , Pieper Carl , Pieper Carl , Richardson Margaret , Pahel Nancy , George Linda
Published: August 2005

Objectives: To determine the effect of differing methods of dispensing wheelchairs.

Design: Quasi‐experimental by day of week.

Setting: Department of Veterans Affairs Medical Center.

Participants: Eighty‐four community‐dwelling, cognitively intact patients prescribed a standard manual wheelchair.

Intervention: A multifactorial intervention consisting of an expert physical/occupational therapist who used a scripted evaluation that included an evaluation based on medical record review and self‐reported and physical performance measures; individualization of the wheelchair and initiation of orders for additional occupational/physical therapy, equipment, or home modifications as needed; multimodal patient education; and telephone follow‐up at 3 and 6 weeks.

Measurements: The primary outcome was amount of wheelchair use. Secondary outcomes were shoulder pain, wheelchair comfort and confidence, and home modifications.

Results: The intervention group had significantly greater wheelchair use than usual care at 2 weeks, 3 months, and 6 months (P=.01). Wheelchair use declined monotonically over time for the entire study sample (P<.001). There were no significant differences between the two groups in shoulder pain, wheelchair comfort or confidence, or home modifications.

Conclusion: New wheelchair owners used the wheelchair more often if they received it from an expert therapist using a multifactorial intervention.
Ethnic Differences in the Frequency and Circumstances of Falling in Older Community‐Dwelling Women
Authors: Faulkner Kimberly A. , Cauley Jane A. , Zmuda Joseph M. , Landsittel Douglas P. , Nevitt Michael C. , Newman Anne B. , Studenski Stephanie A. , Redfern Mark S.
Published: August 2005

Objectives: To examine ethnic differences in fall rates and fall circumstances in older community‐dwelling Caucasian and African‐American women.

Design: Prospective analysis of incident falls and a nested retrospective analysis of fall circumstances over 5.7 years.

Setting: Monongahela Valley, Pennsylvania.

Participants: A total of 1,821 Caucasian and African‐American women (mean age±standard deviation 76±5) enrolled in the Study of Osteoporotic Fractures and participating in 1993/94. Circumstances of 338 falls were collected on a subsample of 197 women who fell.

Measurements: Fall rates and fall circumstances.

Results: Women reported 4,547 falls in 9,508 person‐years, averaging 0.48 falls per woman annually (95% confidence interval (CI)=0.43–0.53). Age‐adjusted fall rates were nonsignificantly higher in Caucasians than African Americans (relative risk (RR)=1.30, 95% CI=0.93–1.83%). In women younger than 75, fall rates were similar in Caucasians and African Americans (RR=1.17, P=.46). In women aged 75 and older, fall rates were 50% higher in Caucasians than in African Americans (RR=1.50, 95% CI=0.90–2.49), although this difference was not significant (P=.12). Fall circumstances differed by ethnicity. Caucasian women were significantly more likely than African Americans to fall outdoors versus indoors (odds ratio (OR)=1.6, 95% CI =1.0–2.7) and laterally versus forward (OR=2.0, 95% CI =1.1–3.4) but less likely to fall on the hand/wrist (OR=0.6, 95% CI =0.3–1.0). Ninety‐eight percent of individuals falling on their hand/wrist reported that they extended their hand to attempt to break their fall.

Conclusion: Although the circumstances of falling differed for older Caucasian and African‐American women, there were no differences in the frequencies of falling. These findings suggest that ethnic differences in fracture risk in older women may be due in part to the different ways in which older Caucasian and African‐American women fall, rather than how often they fall. More information will be needed on fall circumstances to determine whether interventions need to be tailored by ethnic group.
Genomics in Nursing Education
Authors: Prows Cynthia A. , Glass Merlyn , Nicol M.J. (Nick) , Skirton Heather , Williams Janet
Published: August 2005

Purpose:

To review international efforts to incorporate genetics content into nursing education curricula.

Organizing Framework:

A discussion of the progress in nursing education programs in selected countries to educate students for genomics‐based health care. Information is based on review of the literature and curriculum change efforts by the authors.

Conclusions:

The lack of agreed‐upon minimum competencies impedes efforts to educate nurses for genomics‐based health care. Nationally and internationally recognized documents are useful for collaborative efforts to establish minimal competencies in knowledge, skills, and attitudes for nurses with basic and advanced education. Curriculum change that incorporates minimum competencies will require nursing faculty to improve their knowledge base in genomics‐based health care. Partnerships among nurses in different countries are needed for successful genomics education programs for faculty.
Design and Psychometric Evaluation of the Psychological Adaptation to Genetic Information Scale
Authors: Read Catherine Y. , Perry Donna J. , Duffy Mary E.
Published: August 2005

Purpose:To develop and psychometrically evaluate the Psychological Adaptation to Genetic Information Scale (PAGIS).

Design:A cross‐sectional, Web‐based survey of participants (n=323) recruited via Internet electronic mailing lists or Websites for people affected by genetic diseases.

Methods:Item analysis, confirmatory principal components analysis, and internal consistency reliability using Cronbach's alpha were used to construct the 26‐item PAGIS.

Findings:Five factors (nonintrusiveness, support, self‐worth, certainty, and self‐efficacy) explained 57.7% of the variance in psychological adaptation to genetic information. The internal consistency reliability of the total PAGIS was .90, and the subscale reliabilities ranged from .77 to .87.

Conclusions:Psychological adaptation to genetic information is a multidimensional phenomenon comprised of nonintrusiveness, support, self‐worth, certainty, and self‐efficacy. The PAGIS has initial reliability and validity for use in future research.
Cancer Risk Factors of Vietnamese Americans in Rural South Alabama
Authors: Xu Yu , Ross M. Candice , Ryan Rebecca , Wang Bin
Published: August 2005

Purpose:

To identify aggregate‐specific cancer risk factors of Vietnamese Americans in south Alabama and present a comparison with available national data and Healthy People 2010 targets.

Design:

Cross‐sectional survey.

Methods:

A convenience sample of 284 Vietnamese community residents 18 years and over completed an investigator‐designed questionnaire. Data were analyzed using descriptive correlational analysis.

Findings:

Aggregate‐specific cancer risk factors included high prevalence of hepatitis, high smoking and drinking rates in men, extended sun exposure without protection, knowledge deficit of cancer and cancer screenings, and low cancer screening rates. Educational level was significantly related to many cancer risk factors.

Conclusions:

Significant cancer risk factors exist in the target population in comparison to available national data and Healthy People 2010 targets. More focused cancer prevention and early detection efforts should be initiated for this underserved population. Future research is needed to (a) determine the effect of acculturation on cancer risk factors and (b) develop culturally appropriate interventions to improve the effectiveness of cancer prevention and early detection interventions in this subgroup of Asian Americans.
Testing an Intervention to Reduce Negative Thinking, Depressive Symptoms, and Chronic Stressors in Low‐Income Single Mothers
Authors: Peden Ann R. , Rayens Mary Kay , Hall Lynne A. , Grant Elizabeth
Published: August 2005

Purpose:

To test the effectiveness of a cognitive‐behavioral group intervention in reducing depressive symptoms, negative thinking, and chronic stressors in low‐income, single mothers at risk for depression.

Design and Methods:

A randomized, controlled prevention trial was conducted with 136 low‐income, single mothers with children between the ages of 2 and 6 years. Each participant was screened before enrollment and was determined to be at risk for depression. Participants were randomly assigned to either the control or experimental group. The experimental group was invited to participate in a 4‐ to 6‐week cognitive‐behavioral group intervention. Data on depressive symptoms, negative thinking, and chronic stressors were collected via self‐report questionnaires from control and experimental groups at baseline, 1 month, and 6 months after the intervention to assess the effects of the intervention.

Findings:

Compared with those in the control group, women who received the intervention had a greater decrease in depressive symptoms, negative thinking, and chronic stressors; these beneficial effects were maintained over a 6‐month period.

Conclusions:

The findings indicate the effectiveness of this cognitive‐behavioral group intervention and show the beneficial effects of reducing negative thinking via the use of affirmations and thought‐stopping techniques.
Mechanical Properties of Thin Pyrolitic Carbon Interphase SiC–Matrix Composites Reinforced with Near‐Stoichiometric SiC Fibers
Authors: Katoh Yutai , Nozawa Takashi , Snead Lance L.
Published: August 2005

Tensile properties of Tyranno™‐SA near‐stoichiometric silicon carbide (SiC)‐fiber–reinforced chemically vapor‐infiltrated SiC‐matrix composites with pyrolytic carbon interphases were experimentally studied. The influence of interphase thickness in a range of 60–300 nm on the tensile properties of the materials appeared to be generally minor. Thin interphase (<100 nm) did not have a significant deteriorating effect on composite properties, which has commonly been reported for conventional SiC‐fiber composites. For very thin interphase (<60 nm) composites, a slight decrease in fracture strain and a substantial increase in interfacial sliding stress were noted. Increases in ultimate tensile strength and fracture strain were observed at a much thicker interphase (>600 nm) at the expense of composite stiffness.
Centrifugal Casting of Tubular Perovskite Membranes
Authors: Mertins Frédéric H. B. , Kruidhof Henk , Bouwmeester Henny J. M.
Published: August 2005

Dense tubular membranes were produced by centrifugal casting of an aqueous suspension, containing powder particles of the mixed‐conducting perovskite La0.5Sr0.5CoO3−δ and a dispersant. The resulting green bodies were dried and sintered to produce tubes with a maximum length of 12 cm, having a relative density higher than 92%. The particle morphology, the amount of dispersant and its burnout appeared to influence the quality of the final product. Oxygen permeation measurements were conducted in the temperature range 850°–950°C in Air/He gradients. Results were found to be consistent with data reported for disk‐type membranes.
A Synergistic Low‐Toxicity Gelcasting System by Using HEMA and PVP
Authors: Cai Kai , Huang Yong , Yang Jin‐long
Published: August 2005

A new low‐toxicity gelcasting system with a 2‐hydroxyethyl methacrylate (HEMA) monomer was applied for casting of alumina ceramics. Polyvinyl pyrrolidone (PVP) was adopted for modifying the homogeneity of the PHEMA (poly‐HEMA) gel. The rheological properties of alumina suspension in the HEMA–PVP premix solution were studied. After preparation of a concentrated alumina suspension, homogenous alumina green body with a relatively high strength of about 19 MPa could be formed through the PVP‐modified HEMA system. Dense complex‐shaped ceramic parts can be successfully produced through the system. Besides, the surface exfoliation phenomenon that seems inherent to the acrylamide gelcasting system could also be eliminated by using the PVP‐modified HEMA system. Analysis of the interaction of HEMA and PVP suggested that the improved microstructure and strength homogeneity, as well as the elimination of surface exfoliation in the new system, should be attributed to the intermolecular hydrogen bonding formed between PHEMA and PVP molecules.
Accuracy of image‐guided implantology
Authors: Brief Jakob , Edinger Dieter , Hassfeld Stefan , Eggers Georg
Published: August 2005

Objectives: The accuracy of two commercially available systems for image‐guided dental implant insertion based on infrared tracking cameras was compared with manual implantation.

Material and methods: Phantoms of partially edentulous mandibles were used. In a master phantom, pilot boreholes for dental implants were placed. These boreholes were reproduced in slave phantoms using either of the two image‐guided systems and manual implantation. The resulting positions were determined using a coordinate measurement machine and compared with the master model.

Results: In comparison with manual implantation, the difference of borehole positions to the master phantom was significantly lower using either of the systems for image‐guided implant insertion.

Conclusion: Image‐guided insertion of dental implants is significantly more accurate than manual insertion. However, the accuracy that can be achieved with manual implantation is sufficient for most clinical situations.
Partial generation of periodontal ligament on endosseous dental implants in dogs
Authors: Jahangiri Leila , Hessamfar Ramin , Ricci John L.
Published: August 2005

Objectives: The objective of this pilot study was to investigate the feasibility of periodontal ligament (PDL) generation on an implant surface by approximating a tooth‐to‐implant contact using orthodontics.

Methods: Maxillary second premolars of six beagle dogs were extracted bilaterally. After 2 weeks of healing, hydroxyapatite (HA) coated titanium implants, 5 mm in length and 3.3 mm in diameter, were placed in the extraction sites. One side of the arch was used as control. Orthodontic tooth movement was initiated following implant placement to tip the first premolar roots into contact with the implant. This was achieved in 4–6 weeks as confirmed radiographically. Tooth‐to‐implant contact was maintained for further 6 weeks after which time, teeth were separated from implant contact orthodontically. After further 2 weeks of stabilization, the animals were sacrificed. Samples were analyzed by Faxitron radiographs before histology. Histology samples were prepared with Stevenel's Blue and Van Gieson stain and were subjected to polarized light microscopy.

Results: Histologic analysis revealed transfer and formation of PDL‐like structure with formation of cellular cementum on the implant surfaces, in four out of six animals, where tooth‐to‐implant contact had been achieved. Direct bone‐to‐implant contact was noted in the areas coronal to the PDL‐like tissue, an important sign to distinguish between PDL‐like tissue and connective tissue that could originate from the coronal portion of a failing implant. Additionally, at the site of contact, the implant surface revealed some resorption of the HA coating.

Conclusion: An animal model was established in which the proximity of tooth‐to‐implant contact lead to partial generation of PDL on a bioactive implant surface in four out of six animals.
The effect of platelet‐rich plasma upon implant stability measured by resonance frequency analysis in the lower anterior mandibles
Authors: Monov Gabriel , Fuerst Gabor , Tepper Gabor , Watzak Georg , Zechner Werner , Watzek Georg
Published: August 2005

Abstract: Using a one‐stage surgical protocol, a total of 34 Brånemark Mk‐III Ti‐Unite implants with a length of 13 mm and a diameter of 3.75 mm were inserted in 10 edentulous mandibles. Of these, seven patients received four and three patients two interforaminal implants. All implants were followed with repeated stability measurements by means of resonance frequency analysis at different time interval: 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44 days. In quadrant III platelet‐rich plasma (PRP) was instilled locally before implant placement, while no PRP was added in quadrant IV to serve as control group (split‐mouth design). Results showed no statistically significant difference between the two groups. Nonetheless, both groups (PRP+control) showed a highly significant reduction of the implant stability quotient (P<0.001) between days 0 and 4. However, no difference was noted between the two groups after day 4, it may be concluded that the instillation of PRP during implant placement in the lower anterior mandible did not add additional benefit.
Lichtschutz: Möglichkeiten und Grenzen
Authors: Elsner Peter , Beissert Stefan , Luger Thomas A.
Published: August 2005

Durch sinnvollen Lichtschutz gegen ultraviolette (UV) Strahlung können akute Hautschäden sowie chronische Hautveränderungen vermieden werden. Unter den verschiedenen Lichtschutzpräparaten wird besonders durch die Anwendung von Sonnencremes mit höherem Lichtschutzfaktor neben der Unterdrückung eines UV‐induzierten Erythems auch die UV‐induzierte Immunsuppression verhindert. Dieser Schutz wird teilweise durch die Hemmung der Freisetzung von mehreren immunsuppressiven Mediatoren aus der Epidermis erzielt. Besonders der Schutz vor Immunsuppression dürfte für die reduzierte Entwicklung von UV‐induzierten Hauttumoren nach regelmäßiger Anwendung von Sonnencremes mitverantwortlich sein. Neben Immunsuppression kann UV‐Strahlung auch DNS‐Mutationen induzieren, die häufig in Zellzyklus‐regulierenden Genen nachweisbar sind. Durch die topische Applikation von DNS‐Reparaturenzymen können diese DNS‐Schäden behoben werden und es entwickeln sich daher weniger Hautmalignome. Zukünftige Entwicklungen von effektiveren Lichtschutzpräparaten, die möglicherweise auch DNS‐Reparaturenzyme oder Substanzen enthalten, welche die endogene DNS‐Reparatur induzieren, werden weiterhin die Lichtschutzmöglichkeiten verbessern. Bis diese Entwicklungen in die Realität umgesetzt werden, bleibt ein der unterschiedlichen Komplexion entsprechender Lichtschutz vorrangiges Ziel.
Muscle spindle signals combine with the sense of effort to indicate limb position
Authors: Winter J. A. , Allen T. J. , Proske U.
Published: August 2005

Experiments were carried out to test the hypothesis that, in the absence of vision, position sense at the human forearm is generated by the combined input from muscle spindles in elbow flexor muscles and signals of central origin giving rise to a sense of effort. In a forearm position‐matching task, to remove a possible contribution from the sense of effort, the reference arm was held supported at the test angle. Subjects were less accurate in matching elbow position of the supported forearm than when it was unsupported. Adding a 2 kg weight to the unsupported reference arm led subjects to make matching errors consistent with an increase in the effort signal. Evidence of a contribution from muscle spindles was provided by showing that the direction of position matching errors could be systematically altered by flexion or extension conditioning of the reference arm before its placement at the test angle. Such changes in errors with conditioning could be shown to be present when the reference arm was supported, unsupported, or unsupported and weighted. It is concluded that both peripheral signals from muscle spindles and signals of central origin, associated with the motor command required to maintain arm position against the force of gravity, can provide information about forearm position.
A Mean-Value Model for Control of Homogeneous Charge Compression Ignition (HCCI) Engines
Authors: Rausen D. J. , Stefanopoulou A. G. , Kang J.-M. , Eng J. A. , Kuo T.-W.
Published: August 2005

A Mean Value Model (MVM) for a Homogeneous Charge Compression Ignition (HCCI) engine is presented. Using a phenomenological zero-dimensional approach with five continuous and three discrete states we first model the effects of the Exhaust Gas Recirculation (EGR) valve, the exhaust Rebreathing Lift (RBL), and the fueling rate on the state of charge in the cylinder at intake valve closing. An Arrhenius integral is then used to model the start of combustion, θsoc. A series of simple algebraic relations that captures the combustion duration and heat release is finally used to model the state of charge after the HCCI combustion and the Location of Peak Pressure (LPP). The model is parametrized and validated using steady-state test data from an experimental gasoline engine at the General Motors Corporation. The simple model captures the temperature, pressure, air-to-fuel ratio, and inert gas fraction of the exhausted mass flow. This characterization is important for the overall HCCI dynamics because the thermodynamic state (pressure, temperature) and concentration (oxygen and inert gas) of the exhausted mass flow affect the next combustion event. The high dilution level in HCCI engines increases the significance of this internal feedback that generally exists to a smaller extent in conventional spark-ignition and compression-ignition internal combustion engines.
Controller Design for Flexible Systems With Friction: Pulse Amplitude Control
Authors: Kim Jae-Jun , Singh Tarunraj
Published: August 2005

Accounting for friction is important when designing controllers for precision motion control systems. However, the presence of the friction and the flexibility in the system yields undesirable behaviors such as residual vibration and stick-slip oscillation near the reference value. In the proposed development, a pulse amplitude modulated controller with user-specified pulse width, is used to initiate the motion so as to permit the system to coast to the desired final position after the final pulse, with zero residual vibrations. The proposed technique is illustrated on the floating oscillator benchmark problem, where friction acts on the first mass. Numerical simulation illustrates the effectiveness of the proposed technique.
Helicobacter hepaticus
Hydrogenase Mutants Are Deficient in Hydrogen-Supported Amino Acid Uptake and in Causing Liver Lesions in A/J Mice
Authors: Mehta Nalini S. , Benoit Stephane , Mysore Jagannatha V. , Sousa Renato S. , Maier Robert J.
Published: August 2005

Helicobacter hepaticus
, a causative agent of chronic hepatitis and hepatocellular carcinoma in mice, expresses a nickel-containing hydrogen-oxidizing hydrogenase enzyme. Growth of a
hyaB
gene-targeted mutant was unaffected by the presence of hydrogen, unlike the wild-type strain, which showed an enhanced growth rate when supplied with H
2
. Hydrogenase activities in
H. hepaticus
were constitutive and not dependent on the inclusion of H
2
during growth. Addition of nickel during growth significantly stimulated both urease (for wild-type and
hyaB
) and hydrogenase (for wild-type) activities. In a 5-h period, the extent of
14
C-labeled amino acid uptake by the wild type was markedly enhanced in the presence of hydrogen and was >5-fold greater than that of the
hyaB
mutant strain. In the presence of H
2
, the short-term whole-cell amino acid uptake
V
max
of the parent strain was about 2.2-fold greater than for the mutant, but the half-saturation affinity for amino acid transport was the same for the parent and mutant strain. The liver- and cecum-colonizing abilities of the strains was estimated by real-time PCR quantitation of the
H. hepaticus
-specific cytolethal distending toxin gene and showed similar animal colonization for the
hyaB
mutant and the wild type. However, at 21 weeks postinoculation, the livers from mice inoculated with wild type exhibited moderate lobular lymphoplasmacytic hepatitis with hepatocytic coagulative necrosis, but the hydrogenase mutants exhibited no histological evidence of lobular inflammation or necrosis.
Sequence Variation within Botulinum Neurotoxin Serotypes Impacts Antibody Binding and Neutralization
Authors: Smith T. J. , Lou J. , Geren I. N. , Forsyth C. M. , Tsai R. , LaPorte S. L. , Tepp W. H. , Bradshaw M. , Johnson E. A. , Smith L. A. , Marks J. D.
Published: August 2005

The botulinum neurotoxins (BoNTs) are category A biothreat agents which have been the focus of intensive efforts to develop vaccines and antibody-based prophylaxis and treatment. Such approaches must take into account the extensive BoNT sequence variability; the seven BoNT serotypes differ by up to 70% at the amino acid level. Here, we have analyzed 49 complete published sequences of BoNTs and show that all toxins also exhibit variability within serotypes ranging between 2.6 and 31.6%. To determine the impact of such sequence differences on immune recognition, we studied the binding and neutralization capacity of six BoNT serotype A (BoNT/A) monoclonal antibodies (MAbs) to BoNT/A1 and BoNT/A2, which differ by 10% at the amino acid level. While all six MAbs bound BoNT/A1 with high affinity, three of the six MAbs showed a marked reduction in binding affinity of 500- to more than 1,000-fold to BoNT/A2 toxin. Binding results predicted in vivo toxin neutralization; MAbs or MAb combinations that potently neutralized A1 toxin but did not bind A2 toxin had minimal neutralizing capacity for A2 toxin. This was most striking for a combination of three binding domain MAbs which together neutralized >40,000 mouse 50% lethal doses (LD50s) of A1 toxin but less than 500 LD50s of A2 toxin. Combining three MAbs which bound both A1 and A2 toxins potently neutralized both toxins. We conclude that sequence variability exists within all toxin serotypes, and this impacts monoclonal antibody binding and neutralization. Such subtype sequence variability must be accounted for when generating and evaluating diagnostic and therapeutic antibodies.
Biochemical Characterization and Functional Studies of
Acanthamoeba
Mannose-Binding Protein
Authors: Garate Marco , Cubillos Ibis , Marchant Jeffrey , Panjwani Noorjahan
Published: August 2005

Acanthamoebae produce a painful, sight-threatening corneal infection. The adhesion of parasites to the host cells is a critical first step in the pathogenesis of infection. Subsequent to adhesion, the parasites produce a potent cytopathic effect (CPE) leading to target cell death. Recent studies showing that acanthamoebae express a mannose-binding protein (MBP) and that free α-mannose (α-Man) specifically inhibits the adhesion of parasites to host cells suggest that the MBP plays a key role in the pathogenesis of
Acanthamoeba
infection by mediating host-parasite interactions. However, direct evidence showing that
Acanthamoeba
MBP is a virulence protein has been lacking. In this study, we demonstrate that the polyclonal immunoglobulin Y (IgY) antibodies prepared against affinity-purified
Acanthamoeba
MBP markedly inhibit the adhesion of parasites to host cells. The antibody also inhibited the
Acanthamoeba
-induced CPE on host cells. In contrast, preimmune IgY did not influence either the adhesion of the parasites to host cells or the amoeba-induced CPE. Using a variety of approaches, including affinity chromatography on an α-Man gel, electrophoresis under native and denaturing conditions, biotinylation of cell surface proteins, and immunostaining, it was conclusively established that
Acanthamoeba
MBP is located on the surface membranes of the parasites. Neutral-sugar analysis and lectin binding experiments using succinylated concanavalin A, a plant lectin with high affinity for mannose, revealed that
Acanthamoeba
MBP is itself a mannose-containing glycoprotein.
N
-Glycanase treatment to remove N-linked oligosaccharides shifted the subunit molecular mass of MBP from 130 kDa to 110 kDa. Hexosamine analysis revealed that
Acanthamoeba
MBP lacks detectable levels of GalNAc, suggesting the absence of O-linked oligosaccharides. In summary, we have characterized
Acanthamoeba
MBP and have shown that it is a major virulence protein responsible for host-parasite interactions and the parasite-induced target cell destruction.
Toward a Novel Experimental Model of Infection To Study American Cutaneous Leishmaniasis Caused byLeishmania braziliensis
Authors: de Moura Tatiana R. , Novais Fernanda O. , Oliveira Fabiano , Clarêncio Jorge , Noronha Almério , Barral Aldina , Brodskyn Claudia , de Oliveira Camila I.
Published: August 2005

Leishmaniaspp. cause a broad spectrum of diseases collectively known as leishmaniasis.Leishmania braziliensisis the main etiological agent of American cutaneous leishmaniasis (ACL) and mucocutaneous leishmaniasis. In the present study, we have developed an experimental model of infection that closely resembles ACL caused byL. braziliensis. In order to do so, BALB/c mice were infected in the ear dermis with 105parasites and distinct aspects of the infection were evaluated. Following inoculation, parasite expansion in the ear dermis was accompanied by the development of an ulcerated dermal lesion which healed spontaneously, as seen by the presence of a scar. Histological analysis of infected ears showed the presence of a mixed inflammatory infiltrate consisting of both mononuclear and polymorphonuclear cells. In draining lymph nodes, parasite replication was detected throughout the infection. In vitro restimulation of draining lymph node cells followed by intracellular staining showed an up-regulation in the production of gamma interferon (IFN-γ) and in the frequency of IFN-γ-secreting CD4+and CD8+T cells. Reverse transcription-PCR of ears and draining lymph node cells showed the expression of CC chemokines. The dermal model of infection withL. braziliensisherein is able to reproduce aspects of the natural infection, such as the presence of an ulcerated lesion, parasite dissemination to lymphoid areas, and the development of a Th1-type immune response. These results indicate that this model shall be useful to address questions related to the concomitant immunity to reinfection and parasite persistence leading to mucocutaneous leishmaniasis.
Sex-Dependent Susceptibility toListeria monocytogenesInfection Is Mediated by Differential Interleukin-10 Production
Authors: Pasche Bastian , Kalaydjiev Svetoslav , Franz Tobias J. , Kremmer Elisabeth , Gailus-Durner Valérie , Fuchs Helmut , Hrabé de Angelis Martin , Lengeling Andreas , Busch Dirk H.
Published: August 2005

It is well documented that sex-dependent factors affect susceptibility to infection, with most mouse models demonstrating higher resistance in females. We made the unexpected observation that infection with the intracellular bacteriumListeria monocytogenesshowed an opposite pattern in several commonly used inbred mouse strains: female C57BL/6J, BALB/c, C3H/HeN, and CBA/J mice were significantly more susceptible toListeriainfection. The pronounced sensitivity of females toListeria, which was revealed by significantly higher lethality rates, correlated also with increased bacterial numbers in organ tissues (spleen and liver) and several immunological changes in peripheral blood samples. Surprisingly, increased severity of infection in females was associated with elevated interleukin-10 (IL-10) levels in plasma. Experiments usingIl10knockout mice, for which no differences between the susceptibilities of males and females toListeriainfection could be detected, confirmed the important role of this immunosuppressive cytokine for the outcome of disease. Our findings are likely to have clinical relevance, since similar sex differences with regard to infection withListeria monocytogenesand other intracellular pathogens have been reported for humans.
Identification of Virulence Determinants for Endocarditis in
Streptococcus sanguinis
by Signature-Tagged Mutagenesis
Authors: Paik Sehmi , Senty Lauren , Das Sankar , Noe Jody C. , Munro Cindy L. , Kitten Todd
Published: August 2005

Streptococcus sanguinis
is a gram-positive, facultative anaerobe and a normal inhabitant of the human oral cavity. It is also one of the most common agents of infective endocarditis, a serious endovascular infection. To identify virulence factors for infective endocarditis, signature-tagged mutagenesis (STM) was applied to the SK36 strain of
S. sanguinis
, whose genome is being sequenced. STM allows the large-scale creation, in vivo screening, and recovery of a series of mutants with altered virulence. Screening of 800 mutants by STM identified 38 putative avirulent and 5 putative hypervirulent mutants. Subsequent molecular analysis of a subset of these mutants identified genes encoding undecaprenol kinase, homoserine kinase, anaerobic ribonucleotide reductase, adenylosuccinate lyase, and a hypothetical protein. Virulence reductions ranging from 2-to 150-fold were confirmed by competitive index assays. One putatively hypervirulent strain with a transposon insertion in an intergenic region was identified, though increased virulence was not confirmed in competitive index assays. All mutants grew comparably to SK36 in aerobic broth culture except for the homoserine kinase mutant. Growth of this mutant was restored by the addition of threonine to the medium. Mutants containing an insertion or in-frame deletion in the anaerobic ribonucleotide reductase gene failed to grow under strictly anaerobic conditions. The results suggest that housekeeping functions such as cell wall synthesis, amino acid and nucleic acid synthesis, and the ability to survive under anaerobic conditions are important virulence factors in
S. sanguinis
endocarditis.
Therapeutic Efficacy of High-Dose Intravenous Immunoglobulin inMycobacterium tuberculosisInfection in Mice
Authors: Roy Eleanor , Stavropoulos Evangelos , Brennan John , Coade Stephen , Grigorieva Elena , Walker Barry , Dagg Belinda , Tascon Ricardo E. , Lowrie Douglas B. , Colston M. Joseph , Jolles Stephen
Published: August 2005

Intravenous immunoglobulin (IVIg) is used to treat patients with primary antibody deficiencies and, at high doses, to treat a range of autoimmune and inflammatory disorders. With high-dose IVIg (hdIVIg), immunomodulatory mechanisms act on a range of cells, including T cells, B cells, and dendritic cells. Here, we demonstrate that the treatment ofM. tuberculosis-infected mice with a single cycle of hdIVIg resulted in substantially reduced bacterial loads in the spleen and lungs when administered at either an early or late stage of infection. Titration of the IVIg showed a clear dose-response effect. There was no reduction in bacterial load when mice were given equimolar doses of another human protein, human serum albumin, or maltose, the stabilizing agent in the IVIg preparation. HdIVIg in vitro had no inhibitory effect on the growth ofM. tuberculosisin murine bone marrow-derived macrophages. In addition, the effect of hdIVIg on bacterial loads was not observed in nude mice, suggesting the involvement of conventional T cells. Analysis of T cells infiltrating the lungs revealed only small increases in CD8+but not CD4+T-cell numbers in hdIVIg-treated mice. The mechanism of action of hdIVIg against tuberculosis in mice remains to be determined. Nevertheless, since hdIVIg is already widely used clinically, the magnitude and long duration of the therapeutic effect seen here suggest that IVIg, or components of it, may find ready application as an adjunct to therapy of human tuberculosis.
Horizontally Acquired Genes for Purine Salvage in
Borrelia
spp. Causing Relapsing Fever
Authors: Barbour Alan G. , Putteet-Driver Adrienne D. , Bunikis Jonas
Published: August 2005

Unlike
Borrelia burgdorferi
, the relapsing fever agent
Borrelia hermsii
and the related
Borrelia miyamotoi
had
purA
and
purB
genes of the purine salvage pathway. These were located among the rRNA genes. Phylogenetic analysis indicated that these genes had a different evolutionary history than those of orthologs in other spirochetes.
Noninvasive Bilevel Positive Pressure Ventilation in Patients with Blunt Thoracic Trauma
Authors: Xirouchaki N. , Kondoudaki E. , Anastasaki M. , Alexopoulou C. , Koumiotaki S. , Georgopoulos D.
Published: August 2005

Background: Noninvasive bilevel positive pressure ventilation (N-BiPAP) has an established role in providing respiratory support in patients with acute respiratory failure. The significant advantage of N-BiPAP is to avoid endotracheal intubation and its complications. Currently there are no data that support N-BiPAP as first-line treatment in patients with blunt thoracic trauma. Objective: To evaluate the safety and efficacy of N-BiPAP in patients with acute respiratory failure due to blunt thoracic trauma. Methods: Prospective observational study. Twenty-two patients with blunt chest trauma (mean injury severity score 26 ± 9) were studied. N-BiPAP was applied via a tight-fitting full or total-face mask, combined with regional anesthesia in all patients. Results:N-BiPAP resulted in significant changes in blood gasses, heart rate and breathing frequency at 1 h. Eighteen out of 22 patients avoided intubation and were discharged from the ICU (success group). Four patients met predefined criteria and required intubation (failure group) within 24 h after N-BiPAP. Three of the patients in the failure group survived while 1 developed septic shock and died. The acute response of oxygenation to N-BiPAP differed significantly between groups, being higher in the success group. Complications related to N-BiPAP were minor, consisting of nose bridge injury (1 patient) and gastric distention (1 patient). Conclusions: N-BiPAP administration could be a safe and effective method to improve the gas exchange in patients with acute respiratory failure due to blunt thoracic trauma.