bluuebunny/crossref_metadata_2025 huggingface dataset:
Robotic nephrectomy for the treatment of benign and malignant disease
Authors: Rogers Craig , Laungani Rajesh , Krane Louis Spencer , Bhandari Akshay , Bhandari Mahendra , Menon Mani
Published: July 2008

OBJECTIVES

To report our experience and describe our technique of robotic nephrectomy.

PATIENTS AND METHODS

We retrospectively evaluated 42 patients who underwent robotic nephrectomy at our institution from January 2004 to March 2008. Variables assessed included patient age, body mass index, operative duration, estimated blood loss (EBL), complications, hospital stay, analgesia requirements and specimen pathology. Radical nephrectomy (RN) was performed for suspected malignant disease and simple nephrectomy (SN) was performed for benign disease.

RESULTS

In all, 42 patients with a mean (range) age of 59.4 (17–38) years, underwent robotic nephrectomy (RN 35, SN seven) using a transperitoneal (39) or retroperitoneal (three) approach. The mean operative console time was 158 min, mean EBL was 223 mL, mean tumour size was 5.1 cm, and the mean hospital stay was 2.4 days. Renal hilar vessels were controlled using robotic suture ligation (25), robotic haemolock clips (12), or laparoscopic staplers (five). No patients required open conversion. One morbidly obese patient developed a wound dehiscience (complication rate 2.6%). On final tumour pathology, the RN specimens included 34 renal cell carcinomas (clear cell 23, papillary nine, chromophobe two) and an oncocytoma. The SN specimens showed chronic xanthogranulomatous pyelonephritis (four) and atrophic kidneys (three). All surgical margins were negative for malignancy with no evidence of tumour recurrence at a mean (range) follow‐up of 15.7 (1–51) months.

CONCLUSIONS

Robotic nephrectomy is a safe and feasible option for minimally invasive surgical removal of the kidney for benign and malignant conditions and can be performed through a transperitoneal or retroperitoneal approach.
Evaluation of pT2 subdivisions in the TNM staging system for prostate cancer
Authors: Hong Sung Kyu , Han Byung Kyu , Chung Jae Seung , Park Dong‐Soo , Jeong Seong Jin , Byun Seok‐Soo , Choe Gheeyoung , Lee Sang Eun
Published: July 2008

OBJECTIVE

To evaluate the subclassifications of pT2 diseases in tumour‐nodes‐metastases (TNM) staging system for prostate cancer.

PATIENTS AND METHODS

We retrospectively analysed the data of 372 patients who underwent radical retropubic prostatectomy (RRP) for pathologically organ‐confined prostate cancer at our institution. Pathological staging of all subjects were re‐evaluated using the 1997 and the 2002 TNM staging system for prostate cancer. Various clinicopathological features along with biochemical recurrence‐free survival (BRFS) of pT2 subgroups were assessed.

RESULTS

Using the 2002 TNM staging criteria, 87 of the tumours (23.4%) were pT2a, and 284 (76.3%) were pT2c. Of all subjects, there was only one (0.3%) pathological 2002 T2b tumour identified. When subjects were classified according to the 1997 versions of the T2 subclassification (pT2a vs pT2b), the 1997 pT2a and pT2b cases showed no significant difference regarding BRFS (log‐rank P = 0.645) among those who were followed‐up for >2 years after RRP. Also, pathological stage (1997 pT2a vs pT2b) was not a significant predictor of BRFS in either uni‐ or multivariate analysis (P = 0.289 and P = 0.241, respectively). Only preoperative serum PSA level and pathological Gleason score along with positive surgical margin were significant predictors of PSA outcome after RRP on multivariate analysis.

CONCLUSION

Our results suggest that two‐ or three‐tiered subclassification of pT2 organ‐confined prostate cancer via methods used in the previous or current TNM staging system may not be appropriate. Efforts should be made to upgrade the current TNM staging system for prostate cancer.
Comparison of potassium‐titanyl‐phosphate laser vaporization of the prostate and transurethral resection of the prostate: update of a prospective non‐randomized two‐centre study
Authors: Ruszat Robin , Wyler Stephen F. , Seitz Michael , Lehmann Kurt , Abe Constanze , Bonkat Gernot , Reich Oliver , Gasser Thomas C. , Bachmann Alexander
Published: July 2008

OBJECTIVES

To evaluate the intermediate‐term clinical efficacy and the rate of complications in 80 W photoselective vaporization of the prostate (PVP) with the potassium‐titanyl‐phosphate laser (GreenlightTM, (AMS, Minnetonka, MN, USA) compared with transurethral resection of the prostate (TURP) in a prospective non‐randomised two‐centre study.

PATIENTS AND METHODS

From December 2003 to August 2006, 396 patients (PVP 269, TURP 127) with lower urinary tract symptoms secondary to benign prostatic hyperplasia were included in the study. There was a significant difference in mean age (72 years for PVP vs 68 for TURP, P = 0.001). Patients were therefore stratified in age categories (<70, 70–80, >80 years) and compared for perioperative variables, functional outcome and complications, with a follow‐up of up to 24 months.

RESULTS

The mean prostate size was greater (overall, 62 vs 48 mL, P < 0.001) and mean operative duration longer (overall 72 vs 53 min; P = 0.001) for PVP in all age categories. The rate of intraoperative bleeding (3% vs 11%), blood transfusions (0% vs 5.5%) and capsule perforations (0.4% vs 6.3%), and early postoperative clot retention (0.4% vs 3.9%) was significantly lower for PVP. Hospitalization time was significantly shorter in the PVP group for patients aged <70 years (3.0 vs 4.7 days) and 70–80 years (4.0 vs 5.0 days; P = 0.001). The improvement of peak urinary flow rate was higher after TURP for any age category. The International Prostate Symptom Score and postvoid residual volume during the follow‐up showed no significant difference. After 12 months the overall prostate size reduction was 63% (−30 mL) after TURP and 44% (−27 mL) after PVP. The rate of repeat TURP/PVP was higher in the PVP group (6.7% vs 3.9%, not significant) within the follow‐up of up to 2 years. The incidence of urethral and bladder neck strictures was comparable.

CONCLUSIONS

PVP was more favourable in terms of perioperative safety. Although patients assigned for PVP were older and had larger prostates, PVP resulted in a similar functional outcome. Further follow‐up is needed to draw final conclusions about the long‐term efficacy of PVP.
Management of recurrent anastomotic stenosis following radical prostatectomy using holmium laser and steroid injection
Authors: Eltahawy Ehab , Gur Uri , Virasoro Ramon , Schlossberg Steven M. , Jordan Gerald H.
Published: July 2008

OBJECTIVE

To present our experience with the management of recurrent and resistant anastomotic stenosis following radical prostatectomy (RP) using transurethral laser incision of the stenotic area and injection of steroids.

PATIENTS AND METHODS

Between January 1999 and April 2006, we evaluated 24 patients with anastomotic stenosis that would not allow the passage of the flexible cystoscope (17 F). Using the paediatric 7.5 F Olympus scope and a 550‐µm fibre holmium laser, deep incisions were cut at the 3 and 9 o’clock positions at the bladder neck, and then triamcinolone was injected at the incision sites. Another session was then scheduled for office cystoscopy 6 weeks later, and if that showed evidence of annularity, another incision was made, as described above.

RESULTS

All 24 patients had RP for localized disease, 21 were retropubic and two were perineal, and one laparoscopic. Five patients had adjuvant radiotherapy. The mean patient age was 64 years. Nineteen (79%) patients had previous attempts to open the bladder neck: eight patients had dilatation, eight patients had internal urethrotomy, five patients underwent transurethral resection of the bladder neck, and six patients had open surgical intervention. The procedure was done once in 17 patients, and twice in seven patients. After a mean (range) follow up of 24 (6–72) months, 19 patients (83%) had a well‐healed and widely patent bladder neck. Of the 24 patients, 17 had urinary incontinence (UI) associated with the bladder neck contracture. An artificial urinary sphincter was implanted in 11 patients, three of which had to be explanted for malfunction in two, and erosion in one.

CONCLUSION

Holmium laser bladder neck incision and steroid injection for anastomotic stenosis after RP had a success rate of 83% in this small series. It can be used safely as a primary treatment, or in some cases, for resistant and recurrent stenosis. It appears that insertion of an artificial sphincter can be done in patients with UI when the bladder neck remains patent for at least 8 weeks.
The impact of maternal BMI status on pregnancy outcomes with immediate short‐term obstetric resource implications: a meta‐analysis
Authors: Heslehurst N. , Simpson H. , Ells L. J. , Rankin J. , Wilkinson J. , Lang R. , Brown T. J. , Summerbell C. D.
Published: July 2008

Obesity is rising in the obstetric population, yet there is an absence of services and guidance for the management of maternal obesity. This systematic review aimed to investigate relationships between obesity and impact on obstetric care. Literature was systematically searched for cohort studies of pregnant women with anthropometric measurements recorded within 16‐weeks gestation, followed up for the term of the pregnancy, with at least one obese and one comparison group. Two researchers independently data‐extracted and quality‐assessed each included study. Outcome measures were those that directly or indirectly impacted on maternity resources. Primary outcomes included instrumental delivery, caesarean delivery, duration of hospital stay, neonatal intensive care, neonatal trauma, haemorrhage, infection and 3rd/4th degree tears. Meta‐analysis shows a significant relationship between obesity and increased odds of caesarean and instrumental deliveries, haemorrhage, infection, longer duration of hospital stay and increased neonatal intensive care requirement. Maternal obesity significantly contributes to a poorer prognosis for mother and baby during delivery and in the immediate post‐partum period. National clinical guidelines for management of obese pregnant women, and public health interventions to help safeguard the health of mothers and their babies are urgently required.
Prevalence of overweight in the Seychelles: 15 year trends and association with socio‐economic status
Authors: Bovet P. , Chiolero A. , Shamlaye C. , Paccaud F.
Published: July 2008

We assessed the 15‐year trends in the distribution of body mass index (BMI) and the prevalence of overweight in the Seychelles (Indian Ocean, African Region) and the relationship with socio‐economic status (SES). Three population‐based examination surveys were conducted in 1989, 1994 and 2004. Occupation was categorized as ‘labourer’, ‘intermediate’ or ‘professional’. Education was also assessed in 1994 and 2004. Between 1989 and 2004, mean BMI increased markedly in all sex and age categories (overall: 0.16 kg m−2 per calendar year, which corresponds to 0.46 kg per calendar year). The prevalence of overweight (including obesity, BMI ≥ 25 kg m−2) increased from 29% to 52% in men and from 50% to 67% in women. The prevalence of obesity (BMI ≥ 30 kg m−2) increased from 4% to 15% in men and from 23% to 34% in women. Overweight was associated inversely with occupation in women and directly in men in all surveys. In multivariate analysis, overweight was associated similarly (direction and magnitude) to occupation and education. In conclusion, the increasing prevalence of overweight and obesity over time in all age, sex and SES categories suggests large‐scale changes in societal obesogenic factors. The sex‐specific association of SES with overweight suggests that prevention measures should be tailored accordingly.
Focused Information Criterion for Capture–Recapture Models for Closed Populations
Authors: BARTOLUCCI FRANCESCO , LUPPARELLI MONIA
Published: July 2008

Abstract. We propose a criterion for selecting a capture–recapture model for closed populations, which follows the basic idea of the focused information criterion (FIC) of Claeskens and Hjort. The proposed criterion aims at selecting the model which, among the available models, leads to the smallest mean‐squared error (MSE) of the resulting estimator of the population size and is based on an index which, up to a constant term, is equal to the asymptotic MSE of the estimator. Two alternative approaches to estimate this FIC index are proposed. We also deal with multimodel inference; in this case, the population size is estimated by using a weighted average of the estimates coming from different models, with weights chosen so as to minimize the MSE of the resulting estimator. The proposed model selection approach is compared with more common approaches through a series of simulations. It is also illustrated by an application based on a dataset coming from a live‐trapping experiment.
Adaptive Proposal Construction for Reversible Jump MCMC
Authors: EHLERS RICARDO S. , BROOKS STEPHEN P.
Published: July 2008

Abstract.  In this paper, we show how the construction of a trans‐dimensional equivalent of the Gibbs sampler can be used to obtain a powerful suite of adaptive algorithms suitable for trans‐dimensional MCMC samplers. These algorithms adapt at the local scale, optimizing performance at each iteration in contrast to the globally adaptive scheme proposed by others for the fixeddimensional problem. Our adaptive scheme ensures suitably high acceptance rates for MCMC and RJMCMC proposals without the need for (often prohibitively) time‐consuming pilot‐tuning exercises. We illustrate our methods using the problem of Bayesian model discrimination for the important class of autoregressive time series models and, through the use of a variety of prior and proposal structures, demonstrate their ability to provide powerful and effective adaptive sampling schemes.
4. A Relational Event Framework for Social Action
Authors: Butts Carter T.
Published: July 2008

Social behavior over short time scales is frequently understood in terms of actions, which can be thought of as discrete events in which one individual emits a behavior directed at one or more other entities in his or her environment (possibly including himself or herself). Here, we introduce a highly flexible framework for modeling actions within social settings, which permits likelihood-based inference for behavioral mechanisms with complex dependence. Examples are given for the parameterization of base activity levels, recency, persistence, preferential attachment, transitive/cyclic interaction, and participation shifts within the relational event framework. Parameter estimation is discussed both for data in which an exact history of events is available, and for data in which only event sequences are known. The utility of the framework is illustrated via an application to dynamic modeling of responder radio communications during the early hours of the World Trade Center disaster.
6. A Diagnostic Routine for the Detection of Consequential Heterogeneity of Causal Effects
Authors: Morgan Stephen L. , Todd Jennifer J.
Published: July 2008

Least squares regression estimates of causal effects are conditional-variance-weighted estimates of individual-level causal effects. In this paper, we extract from the literature on counterfactual causality a simple nine-step routine to determine whether or not the implicit weighting of regression has generated a misleading estimate of the average causal effect. The diagnostic routine is presented along with a detailed and original demonstration, using data from the 2002 and 2004 waves of the Education Longitudinal Study, for a contested but important causal effect in educational research: the effect of Catholic schooling, in comparison to public schooling, on the achievement of high school students in the United States.
THE LOGIC OF AUTHORITARIAN BARGAINS
Authors: DESAI RAJ M. , OLOFSGÅRD ANDERS , YOUSEF TARIK M.
Published: July 2008

Dictatorships do not survive by repression alone. Rather, dictatorial rule is often explained as an “authoritarian bargain” by which citizens relinquish political rights for economic security. The applicability of the authoritarian bargain to decision‐making in non‐democratic states, however, has not been thoroughly examined. We conceptualize this bargain as a simple game between a representative citizen and an autocrat who faces the threat of insurrection, and where economic transfers and political influence are simultaneously determined. Our model yields implications for empirical patterns that are expected to exist. Tests of a system of equations with panel data comprising 80 non‐democratic states between 1975 and 1999 generally confirm the predictions of the authoritarian‐bargain thesis, with some variation across different categories of dictatorship.
Call centres: A decade of research
Authors: Russell Bob
Published: July 2008

Call centres have, over the past decade, become a central element in the way information services are produced and delivered to the public. Much as automobile factories or textile mills were treated as both objects of curiosity and as metaphors for their age, call centres have garnered attention both in their own right as a new means of organizing particular types of work and as an important venue from which to undertake the study of other elements of management practice, including human resource management. This paper critically examines all aspects of research that has been undertaken on call centres, from the publication of the first novel pieces of research up to the most recent contributions. A good deal of effort has gone into classifying call centres, comparing the organization of work in them with other types of work and considering the extent of variation between call centres. Depending upon the theoretical lens that is used (e.g. labour process theory, high‐performance work systems theory, HR perspectives, gender theory, etc.) different aspects of call‐centre work are emphasized and different conclusions regarding call‐centre employment and its possibilities are reached. These contrasting results are compared and evaluated in this review. It is also the case that the study of call centres invites critical reflection upon theories of management, and this is also entered into in this paper. Additionally, the continuous spread of call centres into new realms of professional work activity and into new spaces of the global economy throws up challenges that are brought to the reader's attention for our understanding of this approach to managing informational work.
Unexpected distribution of surface hydration level of the lip
Authors: Caisey L , Gubanova E , Baras D , Lévêque JL
Published: July 2008

Background  The functional properties of human lips depend on their hydration level. Limited data are, however, available.

Objective  To investigate water distribution through the lower lip surface.

Methods  Images from the surface of the lip were recorded using a new capacitance imaging technique. Capacitance and conductance measurements were also carried out in various points of lower lip and on adjacent skin.

Results  Data clearly show that the closest part of the mucosa of the lip is less hydrated than the external part. These unexpected findings could be related to the presence of a premucosa area whose structure is clearly different from that of vermilion zone.
THE POTENTIAL OF CARBONIZED GRAIN TO PRESERVE BIOGENIC 87SR/86SR SIGNATURES WITHIN THE BURIAL ENVIRONMENT*
Authors: HEIER A. , EVANS J. A. , MONTGOMERY J.
Published: July 2008

Carbonized grains survive for millennia in many archaeological contexts. Their stable structure raises the possibility that they preserve biogenic strontium isotope signatures. This hypothesis was investigated using short‐term, laboratory experiments with modern grain immersed in Chalk solution. HCl leaching removed > 95% of secondary alteration from charred grain, and isotope ratios close to the starting value were recovered. This could not be achieved with uncharred grains. HCl leaching of archaeological carbonized grains produced comparable levels of decontamination. Although preliminary, these results suggest that strontium isotope analysis of archaeological carbonized grains from calcareous burial contexts could be used to investigate ancient trade and agriculture.
GIS proximity analysis and environmental assessment of sugar beet transport in Scania, Sweden
Authors: Ness Barry , Brogaard Sara
Published: July 2008

Despite a heightened focus on sustainable transport and the increased use of biofuels, few studies have assessed the effects of such changes on a wider range of parameters. The aim of this study was to assess sugar beet transport in Scania, Sweden to determine how a switch to improved European vehicle standards and biodiesel impacts not only CO2 releases, but also the parameters of regional land use and air pollutants. The study estimated lorry travel distances by using a GIS‐based proximity analysis. It then calculated fuel use and air emissions from standard diesel fuel for 2003 and for the vehicle standard improvements or biodiesel alternatives. Proximity analysis results revealed that roughly 4.2M km were travelled in moving beets to sugar processing facilities, resulting in the use of 2200 m3 of diesel and release of 5700 tons CO2. The shift to newer vehicle types improved fuel use efficiency and emissions. The switch to the biodiesel alternatives resulted in general decreases in air emissions, but increased fuel use and NOX emissions. The regional land needed to grow the biodiesel feedstock for beet transport ranged from 270 to 2700 ha, which can be considered an important obstacle when a switch is made by the greater road transport system.
Is Neighborhood Access to Health Care Provision Associated with Individual‐Level Utilization and Satisfaction?
Authors: Hiscock Rosemary , Pearce Jamie , Blakely Tony , Witten Karen
Published: July 2008

Objective.To explore whether travel time access to the nearest general practitioner (GP) surgery (which is equivalent to U.S. primary care physician [PCP] office) and pharmacy predicts individual‐level health service utilization and satisfaction.

Data Sources.GP and pharmacy addresses were obtained from the New Zealand Ministry of Health in 2003 and merged with a geographic boundaries data set. Travel times derived from these data were appended to the 2002/03 New Zealand Health Survey (N=12,529).

Study Design.Multilevel logistic regression was used to model the relationship between travel time access and five health service outcomes: GP consultation, blood pressure test, cholesterol test, visit to pharmacy, and satisfaction with latest GP consultation.

Data Collection/Extraction.Travel times between each census meshblock centroid and the nearest GP and pharmacy were calculated using Geographical Information System.

Principal Findings.When travel times were long, blood pressure tests were less likely in urban areas (odds ratio [OR] 0.75 [0.59–0.97]), GP consultations were less likely in rural centers (OR 0.42 [0.22–0.78]) and pharmacy visits were less likely in highly rural areas (OR 0.36 [0.13–0.99]). There was some evidence of lower utilization in rural areas.

Conclusions.Locational access to GP surgeries and pharmacies appears to sometimes be associated with health service use but not satisfaction.
Better Sleep Quality and Less Daytime Symptoms in Patients on Evening Hemodialysis: A Questionnaire‐based Study
Authors: Hsu Chung‐Yao , Lee Chien‐Te , Lee Yue‐Joe , Huang Tiao‐Lai , Yu Ching‐Yi , Lee Lung‐Chih , Lam King‐Kwan , Chien Yu‐Shu , Chuang Feng‐Rong , Hsu Kao‐Tai
Published: July 2008

Abstract:  The aims of this study were to investigate the prevalence of sleep disorders in patients with end‐stage renal disease (ESRD), and to assess the effect of dialysis schedule on sleep quality and the presence of daytime symptoms. We prospectively selected 150 long‐term hemodialysis (HD) patients in three groups (morning, afternoon, and evening dialysis) and gave them a sleep questionnaire, the Epworth sleepiness scale and the Pittsburgh sleep quality index. Snoring was the most common complaint (56%), followed by insomnia (38%) and restless legs syndrome (22.7%). The evening dialysis group experienced more sleep time in bed (P = 0.02), required less hypnotic medication (P = 0.049), had fewer daytime symptoms (P < 0.01), and experienced less daytime sleepiness (P =  0.034). Our study confirms the high prevalence of sleep disorders in ESRD patients, and indicates a beneficial effect of evening HD on sleep quality and reduction of daytime symptoms.
Coated Carbon Hemoperfusion Provides Limited Clearance of Protein‐bound Solutes
Authors: Dinh Diana C. , Recht Natalie S. , Hostetter Thomas H. , Meyer Timothy W.
Published: July 2008

Abstract:  This study assessed the capacity of a cartridge containing coated granular carbon to clear protein‐bound solutes. Clearances for test solutes were measured while an albumin solution representing plasma was pumped from a 10 L reservoir through the cartridge at a rate of 200 mL/min for 5 h. Clearance values for phenol red, phenytoin, and indican were well below the limit imposed by the plasma flow and declined with time. The clearance of phenol red, which was the most tightly bound solute, fell from 38 ± 12 to 17 ± 2 mL/min. Additional studies revealed that the cartridge contained enough carbon to absorb all the protein‐bound test solutes, but that the rate of their clearance was limited by the inability of granular carbon to take up solutes rapidly at a low concentration. The rate of solute uptake at low concentration was shown to be much greater when carbon was in powdered rather than granular form. A device in which approximately 50 g of powdered carbon was recirculated in the dialysate compartment of hollow fiber kidneys cleared phenol red and phenytoin more rapidly than the hemoperfusion cartridge containing 300 g of coated granular carbon. These results indicate that hemoperfusion over coated granular carbon provides limited clearance of protein‐bound solutes.
Elective Bridging to Recovery After Repair: The Surgical Approach to Ventricular Reverse Remodeling
Authors: Pitsis Antonis A. , Visouli Aikaterini N. , Ninios Vlasis , Bougioukas Georgios , Filippatos Gerasimos , Kremastinos Dimitrios , Burkhoff Daniel , Long James W.
Published: July 2008

Abstract:  We described our “surgical approach to reverse ventricular remodeling” in advanced chronic heart failure, based on the unique idea that “downstaging” class IV heart failure by supporting patients with left ventricular assist devices (LVADs) allows treatments mainly indicated for class III patients. The types of surgeries include mitral valve repair, surgical ventricular remodeling, coronary artery bypass grafting, and cardiac resynchronization. This approach has been applied to two patients with class IV chronic heart failure due to idiopathic dilated cardiomyopathy who were supported with the magnetically levitated Levacor LVAD. These were the first in‐human implantations of this device. Sustained short‐ to medium‐term recovery has been achieved in both patients.
A Hybrid System for Upper Limb Movement Restoration in Quadriplegics
Authors: Varoto Renato , Barbarini Elisa Signoreto , Cliquet Jr Alberto
Published: July 2008

Abstract:  Generally, quadriplegic individuals have difficulties performing object manipulation. Toward satisfactory manipulation, reach and grasp movements must be performed with voluntary control, and for that, grasp force feedback is essential. A hybrid system aiming at partial upper limb sensory‐motor restoration for quadriplegics was built. Such device is composed of an elbow dynamic orthosis that provides elbow flexion/extension (range was approximately from 20° to 120°, and average angular speed was approximately 15°/s) with forearm support, a wrist static orthosis and neuromuscular electrical stimulation for grasping generation, and a glove with force sensors that allows grasping force feedback. The glove presents two user interface modes: visual by light emitting diodes or audio emitted by buzzer. Voice control of the entire system (elbow dynamic orthosis and electrical stimulator) is performed by the patient. The movements provided by the hybrid system, combined with the scapular and shoulder movements performed by the patient, can aid quadriplegic individuals in tasks that involve reach and grasp movements.
The Human Umbilical Vein: A Novel Scaffold for Musculoskeletal Soft Tissue Regeneration
Authors: Abousleiman Rita I. , Reyes Yuliana , McFetridge Peter , Sikavitsas Vassilios
Published: July 2008

Abstract:  The umbilical cord is a biological tissue that is readily available and is usually discarded. In this study, we investigate the potential of making use of part of the human umbilical cord, in particular the umbilical vein, as a functional tissue engineering scaffold. Previous studies suggested the use of the human umbilical vein (HUV) as an acellular vascular grafting material. We propose taking advantage of the longitudinal mechanical properties of the HUV to use it as a scaffold material for musculoskeletal soft tissue regeneration. HUVs were mechanically dissected from 8.5‐cm sections of fresh human umbilical cords. The sections were inverted such that the luminal side formed the exterior surface. HUVs were then decellularized, and filled with mesenchymal stem cells (MSCs) suspended in a type I collagen hydrogel. Seeded HUVs were cultured for periods of up to 2 weeks. After 2 weeks of culture, results showed a significant increase in cell number reaching almost three times the original inoculation density. Histological analysis revealed cell integration and migration into the HUV scaffold and extensive remodeling of extracellular matrix. Mechanically, the ultimate tensile stress doubled, and elastic modulus values were almost 2.7‐fold higher. Given the differentiation capacity of the MSCs, along with the appropriate biochemical and biomechanical environment, the seeded HUV has a potential for ligament or tendon regeneration.
The Complementarity of the Technical Tools of Tissue Engineering and the Concepts of Artificial Organs for the Design of Functional Bioartificial Tissues
Authors: Lenas Petros , Moreno Angel , Ikonomou Laertis , Mayer Joerg , Honda Hiroyuki , Novellino Antonio , Pizarro Camilo , Nicodemou‐Lena Eleni , Rodergas Silvia , Pintor Jesus
Published: July 2008

Abstract:  Although tissue engineering uses powerful biological tools, it still has a weak conceptual foundation, which is restricted at the cell level. The design criteria at the cell level are not directly related with the tissue functions, and consequently, such functions cannot be implemented in bioartificial tissues with the currently used methods. On the contrary, the field of artificial organs focuses on the function of the artificial organs that are treated in the design as integral entities, instead of the optimization of the artificial organ components. The field of artificial organs has already developed and tested methodologies that are based on system concepts and mathematical‐computational methods that connect the component properties with the desired global organ function. Such methodologies are needed in tissue engineering for the design of bioartificial tissues with tissue functions. Under the framework of biomedical engineering, artificial organs and tissue engineering do not present competitive approaches, but are rather complementary and should therefore design a common future for the benefit of patients.
Development of a Composite Degradable/Nondegradable Tissue‐engineered Vascular Graft
Authors: Tschoeke Beate , Flanagan Thomas C. , Cornelissen Anne , Koch Sabine , Roehl Anna , Sriharwoko Marvi , Sachweh Jörg S. , Gries Thomas , Schmitz‐Rode Thomas , Jockenhoevel Stefan
Published: July 2008

The present study aimed to determine the feasibility of constructing a reinforced autologous vascular graft by combining the advantages of fibrin gel as an autologous cell carrier material with the inherent mechanical strength of an integrated mesh structure. It was hypothesized that the mesh and dynamic culture conditions could be combined to generate mechanically stable and implantable vascular grafts within a shorter cultivation period than traditional methods. A two‐step moulding technique was developed to integrate a polyvinylidene fluoride (PVDF) mesh (pore size: 1–2 mm) in the wall of a fibrin‐based vascular graft (I.D. 5 mm) seeded with carotid myofibroblasts. The graft was cultured under increasing physiological flow conditions for 2 weeks. Histology, burst strength, and suture retention strength were evaluated. Cell growth and tissue development was excellent within the fibrin gel matrix surrounding the PVDF fibers, and tissue structure demonstrated remarkable similarity to native tissue. The grafts were successfully subjected to physiological flow rates and pressure gradients from the outset, and mechanical properties were enhanced by the mesh structure. Mean suture retention strength of the graft tissue was 6.3 N and the burst strength was 236 mm Hg. Using the vascular composite graft technique, the production of tissue engineered, small‐caliber vascular grafts with good mechanical properties within a conditioning period of 14 days is feasible.
BACTERIA‐INDUCED MOTILITY REDUCTION IN LINGULODINIUM POLYEDRUM (DINOPHYCEAE)1
Authors: Mayali Xavier , Franks Peter J. S. , Tanaka Yuji , Azam Farooq
Published: July 2008

Biotic factors that affect phytoplankton physiology and behavior are not well characterized but probably play a crucial role in regulating their population dynamics in nature. We document evidence that some marine bacteria can decrease the swimming speed of motile phytoplankton through the release of putative protease(s). Using the dinoflagellate Lingulodinium polyedrum (F. Stein) J. D. Dodge as a model system, we showed that the motility‐reducing components of bacterial‐algal cocultures were mostly heat labile, were of high molecular weight (>50 kDa), and could be partially neutralized by incubations with protease inhibitors. We further showed that additions of the purified protease pronase E decreased dinoflagellate swimming speed in a concentration‐dependent manner. We propose that motility can be used as a marker for dinoflagellate stress or general unhealthy status due to proteolytic bacteria, among other factors.
GROWTH DYNAMICS OF ULVA ROTUNDATA (CHLOROPHYTA) IN A FISH FARM: IMPLICATIONS FOR BIOMITIGATION AT A LARGE SCALE1
Authors: Hernández Ignacio , Pérez‐Pastor Abraham , Mateo Juan J. , Megina Cesar , Vergara Juan J.
Published: July 2008

Changes in biomass of several macroalgae [Ulva rotundata Bliding; Gracilariopsis longissima (S. G. Gmel.) Steentoft, L. M. Irvine et Farnham; Ulva intestinalis L.; and Cladophora sp.] and marine plants (Zostera noltii and Ruppia cirrhosa) growing naturally in earthen ponds of a fish farm (Acuinova, San Fernando, Southern Spain) were recorded during a year. The farm is mainly devoted to the culture of gilthered seabream (Sparus aurata). The most conspicuous algal species thriving in the ponds was U. rotundata, which reached densities up to 600 g dry mass · m−2 and produced up to 20.45 g C · m−2 · d−1. Dissolved nutrients (phosphate and ammonium), tissue nutrient content, and growth rates of this species were estimated during 2001 and 2002. Evidence of natural biomitigation by U. rotundata when water circulates throughout the fish farm is presented. Due to the fish cultivation, both phosphate and ammonium increased as water circulated from the preculture ponds to the postculture ponds. As a consequence, U. rotundata tissue nitrogen (N) and phosphorus (P) increased from algae growing in preculture ponds to algae growing in the outflow channel, so that mean C:N:P ratio varied from 773:57:1 in preculture ponds to 567:64:1 in the outflow channel. Phosphorus limited growth of U. rotundata during the spring. As growth rates increased as a function of tissue P, data were fitted to the Droop equation. From this equation, the estimated maximal growth rate was 0.295 ± 0.041 d−1, the subsistence quota was 0.05 ± 0.01% P of dry mass, and the critical quota was 0.215% P of dry mass. The results suggest that management of the fish farm based on a large‐scale integrated mariculture system of fish and macroalgae may increase the total ecological and economic benefits, both for the farm and for the environment.
ORIGIN OF APOMICTIC RED ALGAE: OUTCROSSING STUDIES OF DIFFERENT STRAINS IN CALOGLOSSA MONOSTICHA (CERAMIALES, RHODOPHYTA)1
Authors: Kamiya Mitsunobu , West John A.
Published: July 2008

Various red algae lack sexual reproduction and propagate by spore recycling, but it is still unknown how apomixis originates. In previous crossing experiments, we obtained an unusual hybrid of Caloglossa monosticha M. Kamiya through the outcrossing between a male from Australia and a female from Indonesia. This hybrid was morphologically identical to a normal tetrasporophyte, but its tetraspores grew into tetrasporophytes and repeated tetraspore recycling. During 5 years of culture, no sexual reproductive structures have formed on the tetrasporelings from this hybrid or its progenies. Further hybridization experiments revealed that all the five female strains from Indonesia successfully crossed with the male strain from the East Alligator River, Australia, and most of the F1 sporophytes demonstrated tetraspore recycling, though the germination rates of these tetraspores were quite low. The ploidy level of the hybrid tetrasporophyte was similar to the normal tetrasporophyte, rather than the parental gametophyte, based on the comparison of relative DNA contents of their nuclei. Single strand conformation polymorphism (SSCP) and sequence analyses of the internal transcribed spacer 1 (ITS1) region indicated that the alleles from both parents were present in all the hybrid tetrasporophytes examined. These results suggest that this hybrid does not carry out meiosis during sporogenesis, and heterozygous diploid sporophytes arose from tetraspores. Therefore, we believe that obligate apomixis was generated through outcrossing between genetically different entities of C. monosticha.
GRACILARIOPSIS MCLACHLANII SP. NOV. AND GRACILARIOPSIS PERSICA SP. NOV. OF THE GRACILARIACEAE (GRACILARIALES, RHODOPHYCEAE) FROM THE INDIAN OCEAN1
Authors: Bellorin Alexis M. , Buriyo Amelia , Sohrabipour Jelveh , Oliveira Mariana C. , Oliveira Eurico C.
Published: July 2008

Two new species of Gracilariopsis from the Indian Ocean are proposed—Gracilariopsis (Gp.) mclachlanii Buriyo, Bellorin et M. C. Oliveira sp. nov. from Tanzania and Gracilariopsis persica Bellorin, Sohrabipour et E. C. Oliveira sp. nov. from Iran—based on morphology and DNA sequence data (rbcL gene and SSU rDNA). Both species fit the typical features of Gracilariopsis: axes cylindrical throughout, freely and loosely ramified up to four orders, with an abrupt transition in cell size from medulla to cortex, cystocarps lacking tubular nutritive cells and superficial spermatangia. Nucleotide sequence comparisons of rbcL and SSU rDNA placed both species into the Gracilariopsis clade as distinct species from all the accepted species for this genus, forming a deeply divergent lineage together with some species from the Pacific. The new species are very difficult to distinguish on morphological grounds from other species of Gracilariopsis, stressing the importance of homologous molecular marker comparisons for the species recognition in this character‐poor genus.
OXIDATIVE STRESS RESPONSES IN THE MARINE ANTARCTIC DIATOM CHAETOCEROS BREVIS (BACILLARIOPHYCEAE) DURING PHOTOACCLIMATION1
Authors: Janknegt Paul J. , Van De Poll Willem H. , Visser Ronald J. W. , Rijstenbil Jan W. , Buma Anita G. J.
Published: July 2008

The enzyme superoxide dismutase (SOD) holds a key position in the microalgal antioxidant network. The present research focused on oxidative stress responses in the Antarctic diatom Chaetoceros brevis F. Schütt during transition to excess (including ultraviolet radiation [UVR]) and limiting irradiance conditions. Over a 4 d period, cellular responses of thiobarbituric acid reactive substances (TBARS, a general oxidative stress indicator), SOD activity, photosynthetic and xanthophyll cycle pigments, PSII efficiency, and growth were determined. In addition, oxidative responses were measured during a daily cycle. Changing irradiance conditions significantly affected growth rates of C. brevis. PSII efficiency decreased significantly during periodic excess irradiance and increased under low irradiance conditions. Transition to excess irradiance increased the ratio of xanthophyll to light‐harvesting pigments, whereas the opposite was observed for cultures transferred to low irradiance. This acclimation process was completed after 2 d in the new irradiance environment. SOD activity increased significantly after the first day regardless of the new irradiance environment but returned to preexposure values on the fourth day. We hypothesize that SOD activity may be temporarily elevated in C. brevis after irradiance shifts, thereby reducing oxidative stress when photoacclimation is in progress.
PHYLOGENETIC RELATIONSHIPS AMONG LINEAGES OF THE CERAMIACEAE (CERAMIALES, RHODOPHYTA) BASED ON NUCLEAR SMALL SUBUNIT rDNA SEQUENCE DATA1
Authors: Choi Han‐Gu , Kraft Gerald T. , Kim Hyung‐Seop , Guiry Michael D. , Saunders Gary W.
Published: July 2008

Phylogenetic relationships among 69 species of the Ceramiales (51 Ceramiaceae, six Dasyaceae, seven Delesseriaceae, and five Rhodomelaceae) were determined based on nuclear SSU rDNA sequence data. We resolved five strongly supported but divergent lineages among the included Ceramiaceae: (i) the genus Inkyuleea, which weakly joins other orders of the Rhodymeniophycidae rather than the Ceramiales in our analyses; (ii) the tribe Spyridieae, which is sister to the remainder of the included ceramialean taxa; (iii) the subfamily Ceramioideae, weakly including the tribe Warrenieae; (iv) the subfamily Callithamnioideae; and (v) the subfamily Compsothamnioideae, which emerges as sister to the Dasyaceae/Delesseriaceae/Rhodomelaceae complex, thus rendering the Ceramiaceae sensu lato unequivocally paraphyletic, as has been argued separately on anatomical grounds by Kylin and Hommersand. Our data support a restricted concept of the Ceramiaceae that includes only one of the five lineages (Ceramioideae) that we have resolved. In addition to failing to ally with the Ceramiales in our molecular analyses, species of Inkyuleea differ substantially from other Ceramiaceae sensu lato in details of pre‐ and postfertilization development. The genus Inkyuleea is here assigned to the Inkyuleeaceae fam. nov., which we provisionally retain in the Ceramiales. Species of Spyridia also differ from the remaining Ceramiaceae in their postfertilization development, and, in light of our molecular data, the genus Spyridia is assigned to the Spyridiaceae. The Callithamnioideae is strongly monophyletic (100% in all analyses), which, in combination with key anatomical differences, supports elevation to family status for this lineage as the Callithamniaceae. Similarly, the Compsothamnioideae is solidly monophyletic in our molecular trees and has a unique suite of defining anatomical characters that supports family status for a complex that we consider to include the tribes Compsothamnieae, Dasyphileae, Griffithsieae, Monosporeae, Ptiloteae, Spermothamnieae, Sphondylothamnieae, Spongoclonieae, and Wrangelieae, for which the reinstated family name Wrangeliaceae is available.
Intermittent Access to 20% Ethanol Induces High Ethanol Consumption in Long–Evans and Wistar Rats
Authors: Simms Jeffrey A. , Steensland Pia , Medina Brian , Abernathy Kenneth E. , Chandler L. Judson , Wise Roy , Bartlett Selena E.
Published: July 2008

Background:  There has been some difficulty getting standard laboratory rats to voluntarily consume large amounts of ethanol without the use of initiation procedures. It has previously been shown that standard laboratory rats will voluntarily consume high levels of ethanol if given intermittent‐access to 20% ethanol in a 2‐bottle‐choice setting [Wise, Psychopharmacologia 29 (1973), 203]. In this study, we have further characterized this drinking model.

Methods:  Ethanol‐naïve Long–Evans rats were given intermittent‐access to 20% ethanol (three 24‐hour sessions per week). No sucrose fading was needed and water was always available ad libitum. Ethanol consumption, preference, and long‐term drinking behaviors were investigated. Furthermore, to pharmacologically validate the intermittent‐access 20% ethanol drinking paradigm, the efficacy of acamprosate and naltrexone in decreasing ethanol consumption were compared with those of groups given continuous‐access to 10 or 20% ethanol, respectively. Additionally, ethanol consumption was investigated in Wistar and out‐bred alcohol preferring (P) rats following intermittent‐access to 20% ethanol.

Results:  The intermittent‐access 20% ethanol 2‐bottle‐choice drinking paradigm led standard laboratory rats to escalate their ethanol intake over the first 5 to 6 drinking sessions, reaching stable baseline consumption of high amounts of ethanol (Long–Evans: 5.1 ± 0.6; Wistar: 5.8 ± 0.8 g/kg/24 h, respectively). Furthermore, the cycles of excessive drinking and abstinence led to an increase in ethanol preference and increased efficacy of both acamprosate and naltrexone in Long–Evans rats. P‐rats initiate drinking at a higher level than both Long–Evans and Wistar rats using the intermittent‐access 20% ethanol paradigm and showed a trend toward a further escalation in ethanol intake over time (mean ethanol intake: 6.3 ± 0.8 g/kg/24 h).

Conclusion:  Standard laboratory rats will voluntarily consume ethanol using the intermittent‐access 20% ethanol drinking paradigm without the use of any initiation procedures. This model promises to be a valuable tool in the alcohol research field.
Impact of donor deferrals for malaria on blood availability in the United States
Authors: Leiby David A. , Nguyen Megan L. , Notari Edward P.
Published: July 2008

BACKGROUND: US blood availability is negatively impacted by residence or travel‐related deferrals designed to prevent transmission of human immunodeficiency virus type 1 group O, variant Creutzfeldt‐Jakob disease, Leishmania, and malaria. Generally, travel and residence deferrals lack sensitivity and specificity to identify infected donors, particularly for malaria. This study evaluated trends in malaria deferrals and their impact on blood availability from 2000 through 2006.

STUDY DESIGN AND METHODS: An American Red Cross (ARC) research database was used to monitor trends in deferrals for exposure to Plasmodium spp., the causative agents of malaria. Annual deferral rates were classified as travel, residence, and history of malaria during 2000 through 2006. Overall yearly donation rates for acceptable donors were determined and used to estimate donations lost due to malaria‐related deferrals.

RESULTS: Approximately 29 million donors presented at ARC collection sites and 316,495 (1.1%) were deferred for malaria risk. More than 91 percent of malaria deferrals were for travel to endemic countries; travel deferrals showed a significant increase (p < 0.001) throughout the study period. Calculations of yearly donation rates suggested that more than 540,000 potential ARC blood donations were lost to malaria deferrals during the 7‐year period.

CONCLUSIONS: The vast majority of malaria deferrals were for travel to endemic areas; however, few US donors visit those areas associated with most US cases of malaria or transfusion‐transmitted malaria. Current interventions fail to capture many semi‐immune donors, those at greatest risk for transmitting infection. Considerations should be given to selective screening and permanent deferral of donors with a history of malaria.