bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevention of cardiac disease: lifestyle modification or pharmacotherapy?
Authors: Patel S. , Adams M. R.
Published: February 2008

Cardiovascular disease is still the leading cause of death in Australia. There have recently been significant advances in the management of acute coronary syndromes, as well as secondary prevention strategies; however, much of our resources are still directed towards treatment rather than prevention. Prevention of cardiovascular disease involves first, identifying patients at greatest risk of cardiovascular events and second, managing modifiable risk factors. Both pharmacotherapy and lifestyle modification are useful in modifying risk factors; however, the relative importance of each is often dictated by the risk factor profile of the individual. Although there is growing evidence that those at all levels of risk may benefit from lifestyle modification, pharmacotherapy is likely to be most useful in those at higher risk.
Prevalence of glucose‐6‐phosphate dehydrogenase deficiency in Northern Greece
Authors: Ntaios G. , Chatzinikolaou A. , Tomos C. , Manolopoulos C. , Karalazou P. , Nikolaidou A. , Alexiou‐Daniel S.
Published: February 2008

Glucose‐6‐phosphate dehydrogenase (G6PD) deficiency affects more than 400 million persons worldwide. Its distribution varies significantly among different geographic regions and different population groups. Purpose of our study was to estimate its prevalence in Northern Greece. The dataset comprised 5161 newborns and adults who were screened for G6PD deficiency between July 2001 and March 2007. G6PD deficiency was detected by the dye reduction method. In the screened group, 6.3% of subjects were G6PD deficient. Moderate enzyme deficiency was shown in 139 individuals (2.7%). Complete deficiency was identified in 3.7%. The prevalence of G6PD deficiency in Northern Greece is much higher compared with the general Greek population. Moreover, G6PD prevalence in the male sex is much higher – almost double – that in the female sex.
Sarcoidosis presenting with granulomatous uveitis induced by pegylated interferon and ribavirin therapy for hepatitis C
Authors: Yan K. K. L. , Dinihan I. , Freiman J. , Zekry A.
Published: February 2008

Sarcoidosis is a systemic granulomatous disease that is triggered by an autoimmune process, and is now a well recognized but uncommon complication of antiviral therapy for Hepatitis C virus (HCV) infection, likely related to its immunomodulatory effects. The clinical presentation of HCV related sarcoidosis is as varied as systemic sarcoidosis, but ocular presentation alone has not been reported previously. We present a 23 year‐old female who developed visual disturbances due to ocular sarcoidosis during the course of antiviral therapy for chronic HCV infection. Our case presentation is then followed by a review of the literature on the topic. We aim to stress the importance of screening for eye problems in following HCV patients undergoing antiviral therapy, and raise clinicians’ awareness of sarcoidosis as a possible cause for eye problems even in the absence of respiratory complaints.
The role of Variovorax and other Comamonadaceae in sulfur transformations by microbial wheat rhizosphere communities exposed to different sulfur fertilization regimes
Authors: Schmalenberger Achim , Hodge Sarah , Bryant Anna , Hawkesford Malcolm J. , Singh Brajesh K. , Kertesz Michael A.
Published: February 2008

Sulfonates are a key component of the sulfur present in agricultural soils. Their mobilization as part of the soil sulfur cycle is mediated by rhizobacteria, and involves the oxidoreductase AsfA. In this study, the effect of fertilization regime on rhizosphere bacterial asfA distribution was examined at the Broadbalk long‐term wheat experiment, Rothamsted, UK, which was established in 1843, and has included a sulfur‐free treatment since 2001. Direct isolation of desulfonating rhizobacteria from the wheat rhizospheres led to the identification of several Variovorax and Polaromonas strains, all of which contained the asfA gene. Rhizosphere DNA was isolated from wheat rhizospheres in plots fertilized with inorganic fertilizer with and without sulfur, with farmyard manure or from unfertilized plots. Genetic profiling of 16S rRNA gene fragments [denaturing gradient gel electrophoresis (DGGE)] from the wheat rhizospheres revealed that the level of inorganic sulfate in the inorganic fertilizer was correlated with changes in the general bacterial community structure and the betaproteobacterial community structure in particular. Community analysis at the functional gene level (asfA) showed that 40% of clones in asfAB clone libraries were affiliated to the genus Variovorax. Analysis of asfAB‐based terminal restriction fragment length polymorphism (T‐RFLP) fingerprints showed considerable differences between sulfate‐free treatments and those where sulfate was applied. The results suggest the occurrence of desulfonating bacterial communities that are specific to the fertilization regime chosen and that arylsulfonates play an important role in rhizobacterial sulfur nutrition.
Non‐linear increase in GLP‐1 levels in response to DPP‐IV inhibition in healthy adult subjects
Authors: Dai Haiqinq , Gustavson Stephanie M. , Preston Gregory M. , Eskra James D. , Calle Roberto , Hirshberg Boaz
Published: February 2008

Aim:  Dipeptidyl peptidase‐IV (DPP‐IV) inhibitors represent a new promising therapeutic intervention for the treatment of type 2 diabetes mellitus. The aim of this study was to investigate the effects of DPP‐IV inhibition by PF‐00734200, a potent competitive DPP‐IV inhibitor, on the dynamics of DPP‐IV activity and glucagon‐like peptide‐1 (GLP‐1) kinetics in healthy adult subjects.

Methods:  This was a prospective randomized, crossover, placebo‐controlled, ascending, single, oral dose study conducted at a clinical research centre. Twenty‐seven healthy adult subjects were randomized to receive placebo or PF‐00734200 with doses ranging from 0.3 to 300 mg (n = 9 per dose group). Pharmacokinetic and pharmacodynamic end points (DPP‐IV activity and GLP‐1) were measured prior to, and various times after, dosing.

Results:  PF‐00734200 was well tolerated in all subjects. Pharmacokinetics (PK) data indicate that the drug was rapidly absorbed and declined in a biphasic fashion. Mean maximum concentration and area under concentration curve appeared to increase with doses proportionally. DPP‐IV inhibition increased with PF‐00734200 concentrations, which can be described by an Emax model with EC50 approximately being 14 ng/ml. DPP‐IV inhibition led to greater GLP‐1 level accumulation compared with placebo. Plasma GLP‐1 levels stimulated by meals were augmented by DPP‐IV inhibition. However, the increase in GLP‐1 with DPP‐IV inhibition was non‐linear and maximized at 10 mg, a dose which resulted in about 75% weighted average DPP‐IV inhibition over 24 h and a 2.3‐fold increase in GLP‐1 over placebo. Moreover, even with near complete inhibition of DPP‐IV for over 24 h at the highest PF‐00734200 dose levels, the GLP‐1 levels actually declined during the night compared with postdinner levels.

Conclusion:  DPP‐IV inhibition by PF‐00734200 resulted in a non‐linear increase in plasma GLP‐1 level, suggesting GLP‐1 levels may be limited by meal stimulus or by production capacity. In addition, GLP‐1 level declined even during maximal DPP‐IV inhibition, suggesting that there may be additional pathways of GLP‐1 elimination other than DPP‐IV enzymatic breakdown.
Leptin and its metabolic interactions – an update
Authors: Anubhuti  , Arora Sarika
Published: February 2008

Obesity results from an abnormal accumulation of fat in the white adipose tissue. Recent research utilizing genetic models of obesity in rodents has implicated a major role of leptin as a controller of obesity. Leptin is a 167‐amino acid peptide hormone encoded by the obesity gene (ob), which is secreted by adipocytes and plays an important role in regulating food intake, energy expenditure and adiposity. Leptin receptors (OB‐R) are expressed in the central nervous system mainly in afferent satiety centres of hypothalamus and in peripheral organs such as adipose tissues, skeletal muscles, pancreatic β‐cells and liver, thus indicating the autocrine and paracrine role of leptin in energy regulation. In human beings, a highly organized circadian pattern of leptin secretion is observed with peak levels in the midnight probably resulting from cumulative hyperinsulinemia of entire day. Leptin has a dual role in weight maintenance. Leptin reflects total body adipose tissue mass whereas in conditions of negative and positive energy balance, the dynamic changes in plasma leptin concentration function as a sensor of energy balance and influence the efferent energy regulation pathways. Many effects of leptin on metabolism are mediated by interaction with Insulin and also by synergistic action with cholecystokinin. Besides physiological roles, leptin may influence pathological conditions like obesity‐ associated atherosclerosis, oxidative stress and cancers. The purpose of the present review is to summarize the important aspects of the biology, actions, and regulation of leptin and to serve as an update of new information.
Adiponectin and its response to thiazolidinediones are associated with insulin‐mediated glucose metabolism in type 2 diabetic patients and their first‐degree relatives
Authors: Hulstrøm V. , Højlund K. , Vinten J. , Beck‐Nielsen H. , Levin K.
Published: February 2008

Patients with type 2 diabetes (T2D) and their first‐degree relatives (FDRs) are characterized by hypoadiponectinaema and insulin resistance. In T2D patients, plasma adiponectin and insulin sensitivity (SI) increase in response to thiazolidinediones (TZDs). These findings suggest a role for adiponectin in the regulation of SI. We studied the relationship between plasma adiponectin and glucose and lipid metabolism and the effect of troglitazone (200 mg/day) for 12 weeks in 19 normoglycaemic, obese FDR and 20 obese T2D patients, using euglycaemic–hyperinsulinaemic clamps, glycolytic flux calculations and indirect calorimetry. Plasma adiponectin was similar in both groups, despite higher glucose disposal (Rd), glucose oxidation and glycolytic flux and lower lipid oxidation during insulin stimulation in FDR compared with T2D patients. Plasma adiponectin correlated with insulin‐stimulated Rd, non‐oxidative glucose disposal (NOGD), glucose storage and SI in both groups after adjustment for sex and body fat. The troglitazone‐mediated upregulation of plasma adiponectin was associated with increased insulin‐stimulated Rd, NOGD and glucose storage in both groups. No effect on endogenous glucose production was observed. In FDR, plasma adiponectin correlated with insulin‐stimulated glycogen synthase activity and the troglitazone‐induced increase in plasma adiponectin correlated with the improvement in insulin‐stimulated Rd and SI after adjustment for sex and body fat. In conclusion, plasma adiponectin in weight‐matched FDR and T2D patients is comparably low and correlates with insulin‐mediated glucose uptake and storage. Moreover, these data provide evidence for an adiponectin‐dependent insulin‐sensitizing effect of TZDs at an early stage before development of T2D and that this effect is exerted mainly on insulin‐mediated glucose metabolism.
Effects of vildagliptin on glucose control in patients with type 2 diabetes inadequately controlled with a sulphonylurea*
Authors: Garber A. J. , Foley J. E. , Banerji M. A. , Ebeling P. , Gudbjörnsdottir S. , Camisasca R.‐P. , Couturier A. , Baron M. A.
Published: February 2008

Aim:  To compare the efficacy and tolerability of vildagliptin vs. placebo in patients with type 2 diabetes mellitus (T2DM) who are inadequately controlled [haemoglobin A1c (HbA1c) 7.5 to 11%] with prior sulphonylurea (SU) monotherapy.

Methods:  This 24‐week, multicentre, randomized, double‐blind, placebo‐controlled study assessed the effects of the dipeptidyl peptidase‐4 inhibitor vildagliptin (50 mg given once or twice daily) vs. placebo added to glimepiride (4 mg once daily) in 515 patients with T2DM. Adjusted mean changes from baseline to end‐point (AMΔ) in HbA1c, fasting plasma glucose, fasting lipids and body weight were compared by analysis of covariance.

Results:  The between‐group difference (vildagliptin − placebo) in AMΔ HbA1c was −0.6 ± 0.1% in patients receiving vildagliptin 50 mg daily and −0.7 ± 0.1% in those receiving 100 mg daily (p < 0.001 vs. placebo for both). Greater efficacy was seen in patients ≥65 years of age (−0.7 ± 0.1% and −0.8 ± 0.2% for 50 and 100 mg daily respectively) and in patients with baseline HbA1c > 9% (Δ = −1.0 ± 0.2% and −0.9 ± 0.2% for 50 and 100 mg daily respectively). Relative to placebo, patients receiving vildagliptin also had improvements in β‐cell function and postprandial glucose, with small changes in fasting lipids and body weight. The incidences of adverse events (AEs) (67.1, 66.3 and 64.2%) and serious AEs (2.9, 2.4 and 5.1%) were similar in patients receiving 50 mg vildagliptin, 100 mg vildagliptin or placebo respectively. The incidence of hypoglycaemic events was low but slightly higher in the group receiving vildagliptin 100 mg (3.6%) than in the group receiving vildagliptin 50 mg (1.2%) or placebo (0.6%).

Conclusions:  In patients with T2DM inadequately controlled with prior SU monotherapy, addition of vildagliptin (50 or 100 mg daily) to glimepiride (4 mg once daily) improves glycaemic control and is well tolerated. Addition of vildagliptin 50 mg daily to SU monotherapy may be a particularly attractive therapy in elderly patients.
How should patients with an overactive bladder manipulate their fluid intake?
Authors: Hashim Hashim , Abrams Paul
Published: February 2008

OBJECTIVE

To assess how the symptoms of overactive bladder (OAB) syndrome in adults are affected by decreasing or increasing fluid input, and the effect of fluid manipulation on quality of life.

PATIENTS AND METHODS

Adults with symptoms of OAB were randomized in a two‐group, prospective, cross‐over trial following a 4‐day screening period (to establish baseline values) using frequency/volume charts, if they had a mean of eight or more voids and one or more urgency and/or urgency incontinence episodes in 24‐h. Patients were asked to either increase or decrease their fluid intake, from baseline, as follows: group 1, 4 days drinking 25% less than baseline, and 2 days normal, then 4 days at 50% less than baseline, and 2 days normal, then 4 days at 25% more than baseline, and 2 days normal, and then 4 days at 50% more than baseline. Group 2 did the reverse. The primary endpoint was the change in the frequency of unwanted events during a 24‐h period.

RESULTS

In all, 67 patients were contacted, 40 recruited and 24 were eligible. There was a significant reduction in frequency, urgency and nocturia when patients decreased their fluid input by 25%. Increasing fluid input by 25% and 50% resulted in a worsening of daytime frequency. Overall there was no statistically significant improvement in quality of life but there was some subjective improvement in urgency and nocturia, as measured by a validated instrument, in the group that decreased their fluid input by 25%; ≈300 mL of daily fluid came from water‐containing foods.

CONCLUSIONS

Fluid manipulation is a cheap, noninvasive and easy way to help control the symptoms of OAB. Patients have difficulty in either decreasing or increasing their fluid input by 50%. Patients can now be told to expect a significant improvement in urgency, frequency and nocturia episodes if they reduce their fluid input by 25%.
A model of catheter‐associated urinary tract infection initiated by bacterial contamination of the catheter tip
Authors: Barford Jessica M.T. , Anson Ken , Hu Yanmin , Coates Anthony R.M.
Published: February 2008

OBJECTIVE

To examine the microbial colonization of urinary catheters that have been used by patients, to model catheter colonization in vitro and thus provide information about the way bacteria gain access to the bladder during catheterization.

MATERIALS AND METHODS

Microbial growth patterns from patients’ indwelling catheters and from catheters used in an in vitro model of the catheterized urinary tract were compared. Catheters were cut into short segments, microorganisms from the inside and outside of each segment of the catheters were removed by sonication, and viable bacteria counted. DNA was extracted from selected patient catheter isolates and the DNA fragment of 16S ribosomal RNA was amplified by polymerase chain reaction and confirmed by DNA sequencing. The DNA sequences from the isolates obtained from different catheter sections and from urine in the same patient were compared.

RESULTS

After 1 day of catheterization there was significant bacterial growth on the outside of all the segments of patient catheters; there was significant growth on the inside of all segments by 4 days. Higher viable counts and a wider spectrum of genera were found on the outside than on the inside of these catheters. The same strains of bacteria, as determined by ≥98% similarity of the 16S ribosomal DNA sequence, were found on the outside and inside of catheters and in the urine. In the in vitro model, when the distal urethra was inoculated before inserting the catheter, the viable counts after incubation were variable along the outside of the catheter and the inside counts were uniformly high. By contrast, there was a different pattern after inoculating the inside of the distal end of the catheter, leading to an ascending biofilm on the inside. A smaller inoculum delayed but did not prevent infection in the model.

CONCLUSION

The present results are consistent with the hypothesis that contamination of the tip of the catheter while it is being inserted is a possible means by which bacteria gain access to the bladder.
Human neural crest stem cells transplanted in rat penile corpus cavernosum to repair erectile dysfunction
Authors: Song Yun Seob , Lee Hong Jun , Park In Ho , Lim Ik Sung , Ku Ja Hyeon , Kim Seung U.
Published: February 2008

OBJECTIVE

To investigate the feasibility of applying neural crest stem cells (NCSCs), with multipotent capacity, to repair injury in the penile cavernosum, the HNC10.K10 (K10) immortalized NCSC line was transplanted into the penile cavernosum of adult rats, as one of the causes of erectile dysfunction is damaged penile cavernous smooth muscle cells and sinus endothelial cells.

MATERIALS AND METHODS

The K10 human NCSC line was generated via transfection of primary cultured NCSC with a retroviral vector encoding v‐myc. K10 NCSCs were transplanted into the cavernosum of adult rats. The expression of cell type‐specific markers for endothelial cells (CD31 and von Willebrand factor), and specific markers for smooth muscle cells (smooth muscle cell actin, calponin, and desmin) was determined immunohistochemically in the penile cavernosum of rats 2 weeks after transplantation.

RESULTS

In the rat cavernosum, transplanted K10 NCSCs identified by human nuclear antigen labelling expressed cell type‐specific markers for endothelial cells (CD31 and von Willebrand factor), and specific markers for smooth muscle cells (smooth muscle cell actin, calponin, and desmin) 2 weeks after transplantation. Human NCSCs transplanted into the rat penile corpus cavernosum differentiated into endothelial cells or smooth muscle cells, as shown by their expression of cell type‐specific markers for the cell types.

CONCLUSION

It appears that NCSCs are an ideal cell source for reconstructing endothelial and smooth muscle cells in the corpus cavernosum in cell therapy for patients with erectile dysfunction.
New classification of midline cysts of the prostate in adults via a transrectal ultrasonography‐guided opacification and dye‐injection study
Authors: Furuya Ryoji , Furuya Seiji , Kato Haruaki , Saitoh Nobuhito , Takahash Satoshi , Tsukamoto Taiji
Published: February 2008

OBJECTIVES

To reclassify midline cysts (MLCs) of the prostate according using the results from transrectal ultrasonography (TRUS)‐guided opacification and dye injection.

PATIENTS AND METHODS

Eighty‐six patients (mean age 60.9 years) who had MLCs detected in the pelvis by TRUS were investigated. In all patients the size of the MLC was measured and they had transperineal aspiration under TRUS guidance. After aspiration of the MLC a mixture of water‐soluble contrast medium and indigo carmine dye was injected to check for communication with the urethra or seminal tract by endoscopic and pelvic X‐ray examination.

RESULTS

We classified MLCs into four categories: (i) type 1 (nine cases), MLC with no communication into the urethra (traditional prostatic utricle cyst); (ii) type 2a (60 cases), MLC with communication into the urethra (cystic dilatation of the prostatic utricle, CDU); (iii) type 2b (14 cases), CDU which communicated with the seminal tract; (iv) type 3 (three cases), cystic dilation of the ejaculatory duct. The location, shape and volume of the MLC, and the prostate‐specific antigen level of MLC fluid, did not influence the classification.

CONCLUSIONS

The most common type of MLC was CDU. A new classification that depends on the communication with the urethra or seminal tract is proposed.
Impact of risk factors on the performance of the nuclear matrix protein 22 point‐of‐care test for bladder cancer detection
Authors: Lotan Yair , Shariat Shahrokh F. ,   the NMP22 Study Group
Published: February 2008

OBJECTIVES

To evaluate the impact of different risk factors and symptoms on the performance characteristics of the nuclear matrix protein 22 (NMP22) BladderChek® test (Matritech Inc., Newton, MA, USA) for the detection of bladder cancer, as this is a point‐of‐care assay that measures NMPs in voided urine.

PATIENTS AND METHODS

In all, 23 academic, private practice and veterans’ facilities in 10 states prospectively enrolled consecutive patients from September 2001 to May 2002. Participants included 1328 patients at elevated risk of bladder cancer from factors such as a history of smoking or symptoms including haematuria and/or dysuria. Patients at risk of malignancy of the urinary tract provided a voided urine sample for analysis of NMP22 protein and cytology before cystoscopy.

RESULTS

Of the 1328 patients: no urinary disease, benign disease and malignancy were found in 545 (41%), 704 (53%) and 79 (6%) patients, respectively. Overall, the positive predictive value (PPV) for detection of bladder cancer was 20.3% (45/222) and negative predictive value (NPV) was 96.9% (1072/1106). The PPV was higher in men (24.0%) than women (13.2%). In men, the PPV increased with smoking (35.4%), gross haematuria (51.2%) and a combination of both factors (70.6%). The impact on the PPV of smoking (9.7%) and gross haematuria (28.6%) was less dramatic in women. The PPV increased from 16.8% in patients aged <65 years to 23.5% in those aged >65 years. The NPV remained almost always >95% except in men with gross haematuria where it decreased to 77% in smokers and 94% in non‐smokers.

CONCLUSION

The PPV of the BladderChek test improves in patients at higher risk of bladder cancer reaching 77% in men presenting with gross haematuria who are aged >65 years and smoke. The NPV is highest in women aged <65 years, up to 100%.
Comparison of biochemistry and diet in patients with enterocystoplasty who do and do not form stones
Authors: Hamid Rizwan , Robertson William G. , Woodhouse Christopher R.J.
Published: February 2008

OBJECTIVE

To evaluate patients with a history of urinary stones in intestinal reservoirs and compare them with similar patients who have never formed stones.

PATIENTS AND METHODS

One consequence of storing urine in an intestinal reservoir is urolithiasis, and there are several theories on its cause, all based on limited evidence. There are many factors predisposing to stone formation, and dietary and biochemical factors might be useful to distinguish those who form stones from those who do not. In a prospective study (with ethical committee approval) we identified 15 patients (six male and six female, mean age 29 years) who had formed stones after an enterocystoplasty (group 1), and another 10 (three male and seven female, mean age 44 years) with no history of urolithiasis after enterocystoplasty (group 2). The respective mean (range) follow‐up was 14.6 (8–24) and 15.2 (6–23) years. They were investigated using our stone‐screening protocol described previously and the results compared between the groups using an unpaired Student’s t‐test, with statistically significance indicated at P < 0.05.

RESULTS

There was a statistically significant difference in almost all the variables assessed. The mean 24‐h urine output was 41% higher (P = 0.009) and the mean citrate excretion 173% higher (P = 0.002) in group 2. The mean (range) urinary pH was 6.46 (6.0–7.0) and 6.93  (6.3–7.8) in groups 2 and 1, respectively (P = 0.005). Of the stone‐forming elements, only the excretion of calcium was significant (2.78 vs 5.2 mmol/day, P < 0.001). The biochemical risk of stone formation was significantly higher for both calcium oxalate and calcium phosphate stones in group 1 than group 2 (P < 0.001 in both). From the dietary diaries there was a 24% higher fluid intake in group 2 (P = 0.04). The difference between group 2 and group 1 for the intake of magnesium (18.2 vs 12.38 mmol/day) and phosphate (49 vs 37.8 mmol/day) was statistically significant (P = 0.04 and 0.02, respectively).

CONCLUSIONS

Apparently the use of bowel in the urinary tract does not alone increase the risk of urolithiasis. Patients in group 1 were more prone due to the constituents of urine and possibly their dietary habits. This implies that with adequate fluid intake and eating a healthy balanced diet, the risk of urolithiasis can be reduced in patients with enterocystoplasty, as with idiopathic stone formers.
‘Cutting for the stone’: the ancient art of lithotomy
Authors: Herr Harry W.
Published: February 2008

OBJECTIVE

Bladder stone was a common ailment plaguing mankind from antiquity to the 20th century. Largely forgotten today, lithotomy relieved the anguish of bladder stones and identified urology as a medical specialty nearly 2500 years ago.

METHODS

The historical literature pertaining to lithotomy was reviewed. Translated and original documents describing operative techniques and developments pertaining to the history of lithotomy were obtained through the internet and library sources.

RESULTS

The ancient art of lithotomy was first recorded by the Greeks and evolved through five phases: the Celsian method, or ‘lesser operation’; the Marian, or ‘greater operation’; the lateral operation; suprapubic cystotomy, or ‘high operation’, and proctocystotomy. The practice of open lithotomy ceased to exist owing to better minimally invasive alternative methods and most notably by the virtual disappearance of bladder stones in modern man.

CONCLUSIONS

The history of lithotomy is a fascinating story of how early surgeons forced by the culture and customs of the time dealt with common but devastating bladder stones. Out of their efforts, urology was born.
Recovery of erectile function after nerve‐sparing radical prostatectomy: improvement with nightly low‐dose sildenafil
Authors: Bannowsky Andreas , Schulze Heiko , Van Der Horst Christof , Hautmann Stefan , Jünemann Klaus‐Peter
Published: February 2008

OBJECTIVE

To evaluate the effect of low‐dose sildenafil for rehabilitating erectile function after nerve‐sparing radical prostatectomy (NSRP), as the delay to recovery of erectile function after NSRP remains under debate.

PATIENTS AND METHODS

Forty‐three sexually active patients had a NSRP; at 7–14 days after surgery they had a Rigiscan® (Dacomed Corporation, Minneapolis, MN, USA) measurement of nocturnal penile tumescence and rigidity (NPTR). To support the recovery of spontaneous erectile function, 23 patients with preserved nocturnal erections received sildenafil 25 mg/day at night. A control group of 18 patients were then followed but had no phosphodiesterase‐5 inhibitors. The International Index of Erectile Function (IIEF)‐5 questionnaire was completed 6, 12, 24, 36 and 52 weeks after NSRP.

RESULTS

Of the 43 patients, 41 (95%) had one to five erections during the first night after catheter removal. In the group using daily sildenafil the mean IIEF‐5 score decreased from 20.8 before NSRP to 3.6, 3.8, 5.9, 9.6 and 14.1 at 6, 12, 24, 36 and 52 weeks after NSRP, respectively. In the control group the respective scores were 21.2, decreasing to 2.4, 3.8, 5.3, 6.4 and 9.3. There was a significant difference in IIEF‐5 score and time to recovery of erectile function between the groups (P < 0.001), with potency rates of 86% vs 66%.

CONCLUSION

The measurement of NPTR after NSRP showed erectile function even the ‘first’ night after catheter removal. In cases of early penile erection, daily low‐dose sildenafil leads to a significant improvement in the recovery of erectile function.
Laparoscopic anatrophic nephrolithotomy for managing large staghorn calculi
Authors: Simforoosh Nasser , Aminsharifi Alireza , Tabibi Ali , Noor‐Alizadeh Akbar , Zand Saeed , Radfar Mohammad‐Hadi , Javaherforooshzadeh Ahmad
Published: February 2008

OBJECTIVES

To evaluate the efficacy of a laparoscopic approach for managing large staghorn renal calculi.

PATIENTS AND METHODS

Laparoscopic transperitoneal anatrophic nephrolithotomy was used to duplicate open anatrophic nephrolithotomy in five patients (three men) with large staghorn renal stones unsuitable for percutaneous nephrolithotomy. Only the renal artery was clamped, using a bulldog clamp. The stone was removed through a nephrotomy incision on the Brodel line, which was closed using 3/0 polyglactin continuous sutures, and sutures were buttressed by haemostatic clips instead of knots. Intraoperative ultrasonography was used in the last two patients to evaluate residual stones.

RESULTS

The mean (range) stone size was 53  (45–65) mm, the patient age was 53  (45–58) years, and the warm ischaemia and operative duration were 32 (29–35) and 170 (120–225) min, respectively. No blood transfusion was needed during or after surgery. All of the procedures were uneventful and there was no urine leakage after surgery. Only an 8‐mm and a 6‐mm residual stone remained in the first and third patients, in the lower and middle calyces, respectively. Both of them were subsequently treated with shock wave lithotripsy. An intravenous pyelogram after surgery showed a functional corresponding renal unit, with a significant improvement in obstruction in all patients.

CONCLUSION

Laparoscopic anatrophic nephrolithotomy is a promising alternative for patients who are candidates for open surgery, with an acceptable stone‐free rate. While offering a minimally invasive approach, it can minimize the need for secondary invasive interventions. Further patients and a longer follow‐up are needed before this is suggested as the preferred method in selected patients in the future.
How day of posting affects level of critical discourse in asynchronous discussions and computer‐supported collaborative argumentation
Authors: Jeong Allan , Frazier Sue
Published: February 2008

In asynchronous threaded discussions, messages posted near the end of the week provide less time for students to critically examine and respond to ideas presented in the messages than messages posted early in the week. This study examined how the day in which messages are posted (early, midweek and weekend) in computer‐supported collaborative argumentation affect the number of responses elicited by arguments and challenges, and how its effects differ across the four types of exchanges (argument–challenge, challenge–counterchallenge, challenge–explain, challenge–evidence) that serve as indicators of critical discourse. This study found that the day of posting had a significant effect on the number of responses elicited per message, with the greatest to smallest effect on argument–challenge, challenge–counterchallenge, challenge–explain and challenge–evidence exchanges respectively. These findings highlight some of the limitations of asynchronous discussions, and suggest alternative ways to implement and design discussion environments to promote higher levels of critical discourse.
Mutual feedback in e‐portfolio assessment: an approach to the netfolio system
Authors: Barbera Elena
Published: February 2008

This paper presents an alternative application of e‐portfolio in a university student assessment context. A concept based on student collaboration (called netfolio) is developed, that differs from the classical e‐portfolio concept. The use of a netfolio, a network of student e‐portfolios, in a virtual classroom is explained through an exploratory study. A netfolio is more than a group of e‐portfolios because it offers students a better understanding of learning objectives and promotes self‐revision through participation in assessment of other students' learning, as indicated through their portfolios. Class student e‐portfolios are interconnected in a unique netfolio such that each student assesses their peers' work and at the same time is being assessed. This process creates a chain of co‐evaluators, facilitating a mutual and progressive improvement process. Results about teachers' and students' mutual feedback are presented and the benefits of the process in terms of academic achievements are analysed.
Cowboys with cameras: an interactive expedition
Authors: Robert Kenny , Lenz Adam
Published: February 2008

Utilizing the same technologies pioneered by the embedded journalists in Iraq, the University of Central Florida (UCF) teamed up with TracStar, Inc to create a small‐scale, satellite‐based expedition transmission package to accompany a university film and digital media professor into parts of Utah and the Moab Desert that had a historical significance to American Western Films. The expedition took the group to many locations where scenes from John Wayne and John Ford movies were filmed. Students along on the trip camped out and suffered similar tough conditions as did the original film crews, experienced the wilderness, and participated in lectures and interviews with locals, who supported the films and acted as extras and stunt persons. The project brought a live experience back to the university campus in which students personally interact firsthand with the people, places, things in as real a manner as what the remote travelers encountered.

This article presents details about the experiences of the first implementation of the live broadcasts from the remote desert and the reactions of focus groups to the experience. One group watched archived broadcast, convinced that they were live. Their impressions and reactions were recorded and analyzed and compared to those who were part of a control group. Conclusions and recommendations for future trips are introduced.
Frameworks of educational technology*
Authors: Ely Donald
Published: February 2008

This paper, written from a 20th‐century perspective, traces the development of, and influences on, the field of instructional technology and attempts to describe a framework within which we can better understand the field.
Innovation Intermediaries: Why Internet Marketplaces for Technology Have Not Yet Met the Expectations
Authors: Lichtenthaler Ulrich , Ernst Holger
Published: February 2008

A few years ago, internet marketplaces for technology, e.g., yet2.com, received great attention. In the light of open innovation processes, it was assumed that they could be an appropriate means to overcome the imperfections in the markets for technology. Little is known about the performance of these innovation intermediaries, and very limited information is provided by the firms that run the marketplaces. Therefore, we have interviewed intellectual property and technology managers in 25 medium‐sized and large industrial companies, who represent the potential licensees and licensors in the internet exchanges. The results show relatively limited success rates of internet marketplaces regarding the number of technology transactions that have been initiated, particularly in comparison with the hopes that had initially been placed in these tools. Moreover, important problems and recent trends in these web‐enabled exchanges are identified, and propositions are developed regarding major consequences for initiating and managing technology transactions.
Organizational Output Innovativeness: A Theoretical Exploration, Illustrated by a Case of a Popular Music Festival
Authors: Paleo Iván Orosa , Wijnberg Nachoem M.
Published: February 2008

Different interpretations of innovation and innovativeness lead to different approaches and different methods to measure organizational output innovativeness. Two indicators of innovativeness are derived from two divergent approaches: the Referent Innovativeness Index and the Classification Innovativeness Index. The article uses the case of the popular music festival to discuss how these indexes can be operationalized and calculated, as well as to outline the implications of the differences between the methods.
Creative Potential and Practised Creativity: Identifying Untapped Creativity in Organizations
Authors: DiLiello Trudy C. , Houghton Jeffery D.
Published: February 2008

This study examines the construct validity of creative potential and practised creativity, two overlooked aspects of creativity that may be useful for identifying untapped creative resources in organizations. Results of an exploratory factor analysis (EFA) and a confirmatory factor analysis (CFA) utilizing structural equation modelling techniques provide some initial evidence in support of the construct validity of these concepts. These findings appear to have important managerial implications for increasing creativity and overall organizational effectiveness. The results presented here also suggest some directions for future research aimed at examining the relationships between creative potential, practised creativity and other variables of interest.
The Politics of Creativity™: Four Domains for Inquiry and Action by Leaders in R&D1
Authors: Boehlke Steve
Published: February 2008

Leaders in R&D functions today face increasingly challenging environments in which to foster creativity and promote innovation. While organizational systems and management processes impact productivity, relationships between and among scientists and engineers must be nurtured to sustain competitive advantage. Initiating conversations about organizational dynamics that are otherwise difficult for R&D professionals is a critical task of leaders. This paper, based on practitioner work in the field, identifies four domains of inquiry and action in which focused dialogue and leadership initiative promises more engaged and motivated professionals: (1) pacing productivity; (2) capitalizing on failure; (3) managing connections; and (4) paying the price. As a result of working intentionally in these domains, leaders in R&D make it possible for their organizations to work explicitly with the ‘Politics of Creativity™’ in a way that encourages trust and fosters more creativity.
A Social Network Perspective of Lead Users and Creativity: An Empirical Study among Children
Authors: Kratzer Jan , Lettl Christopher
Published: February 2008

Generating ideas at the ‘fuzzy front end’ of new product development is risky and has serious consequences for all preceding development stages. One of the currently most prominent techniques in supporting this idea‐generation stage is the lead user approach. Involving lead users in idea generation closely correlates to individual creativity, and both, in turn, to the provision of information in social networks. This study, guided by lead user theory, creativity research and network theory, investigates 16 school‐groups of children examining the relationship between the children's social networks and their resulting creativity and lead userness. In addition, the interplay between lead userness and creativity is discussed and empirically tested. The main result of this study is that children who are positioned as bridging links between different groups in social networks reveal both a high degree of lead userness and a high level of creativity.
Employee Creativity and R&D: A Critical Review
Authors: Chen Ming‐Huei , Kaufmann Geir
Published: February 2008

Employee creativity is one of the most important components to measure a company's human capital, particularly in knowledge‐intensive companies. However, the complexity of the conception of creativity means that the measurement of employee creativity has become difficult. Reflecting discussions and contributions on Creativity in R&D as presented at the 2006 R&D Management Conference held in Taiwan, this short thematic paper reviews four different and critical approaches to creativity, namely the evolutionary approach, the cross‐disciplinary science approach, the social system approach and the social network approach. This paper concludes that the four approaches provide complementary contributions in understanding the measurement of creativity in an R&D context, but that the interaction of the socio‐cultural context with employee creativity needs to be taken into account.
Pooling data for the analysis of dynamic marketing systems
Authors: Horváth Csilla , Wieringa Jaap E.
Published: February 2008

Vector autoregressive (VAR) models have become popular in marketing literature for analyzing the behavior of competitive marketing systems. One drawback of these models is that the number of parameters can become very large, potentially leading to estimation problems. Pooling data for multiple cross‐sectional units (stores) can partly alleviate these problems. An important issue in such models is how heterogeneity among cross‐sectional units is accounted for. We investigate the performance of several pooling approaches that accommodate different levels of cross‐sectional heterogeneity in a simulation study and in an empirical application. Our results show that the random coefficients modeling approach is an overall good choice when the estimated VAR model is used for out‐of‐sample forecasting only. When the estimated model is used to compute Impulse Response Functions, we conclude that one should select a modeling approach that matches the level of heterogeneity in the data.
Method‐of‐moment view of linear simultaneous equation systems
Authors: Lee Myoung‐jae
Published: February 2008

In this paper, we review the modern method‐of‐moment‐based approaches to identification and estimation of linear simultaneous equation systems. First, we present the rank condition for the structural form (SF) parameter identification. The rank condition comes naturally and is much easier to understand than that in the conventional reduced‐form‐based indirect approach. Then, we show how to estimate all SF parameters jointly (in a single step) with method‐of‐moment estimators. As it turns out, using only unconditional moments, but not any conditional moments, greatly simplifies the identification and estimation issues, and makes light work of conveying the essential ideas involved.
Information loss for 2 × 2 tables with missing cell counts: binomial case
Authors: Eisinga Rob
Published: February 2008

We formulate likelihood‐based ecological inference for 2 × 2 tables with missing cell counts as an incomplete data problem and study Fisher information loss by comparing estimation from complete and incomplete data. In so doing, we consider maximum‐likelihood (ML) estimators of probabilities governed by two independent binomial distributions and obtain simplified expressions for their covariance. These expressions reflect well the additional uncertainty arising from the unobserved data compared to complete data tables. We also discuss an approximation to the expected conditional variance of the unobserved entries and ML parameter bias correction. An empirical example is used to demonstrate the results.
Detection of drug‐resistant HIV minorities in clinical specimens and therapy failure
Authors: Louvel S , Battegay M , Vernazza P , Bregenzer T , Klimkait T , Hamy F ,   the Swiss HIV Cohort Study
Published: February 2008

Objective

Particularly for therapy‐experienced patients, resistance assessment by genotypic or phenotypic methods produces discordances. This study seeks proof that differences may arise from the fact that genotyping produces a single summary sequence whereas replicative phenotyping (rPhenotyping) functionally detects and assigns resistances in mixed HIV populations.

Methods

For validation, defined mixes of wild‐type and M184V mutant were analysed by rPhenotyping or standard genotyping. Allele‐specific and quantitative polymerase chain reaction (PCR) set detection and quantification limits for minor virus populations in vitro and in authentic clinical samples showing geno‐/pheno‐discrepant lamivudine resistance.

Results

Allele‐specific and real‐time PCR methods detected down to 0.3% of mutant M184V. The functional assessment was sensitive enough to reveal <1% of mutant M184V in mixed samples. Also in discordant samples from the diagnostic routine, in which rPhenotyping had identified drug resistance, real‐time PCR confirmed minute amounts of mutant M184V.

Conclusion

By utilizing the replication dynamics of HIV under drug pressure, a rPhenotyping format potently reveals relevant therapy‐resistant minority species, even of HIV known to possess reduced replicative fitness. With its rapid turnaround of 8 days and its high sensitivity, our rPhenotyping system may be a valuable diagnostic tool for detecting the early emergence of therapy‐threatening HIV minorities or the persistence of residual resistant virus.
Right and left cardiac function in HIV‐infected patients investigated using radionuclide ventriculography and brain natriuretic peptide: a 5‐year follow‐up study
Authors: Kristoffersen US , Lebech AM , Gerstoft J , Hesse B , Petersen CL , Gutte H , Kjær A
Published: February 2008

Objective

The aim of the study was to determine the incidence of myocardial dysfunction in an HIV‐infected population receiving state‐of‐the‐art treatment.

Methods

Between April 2001 and July 2002, 91 HIV‐infected patients had a radionuclide ventriculography performed with determination of right ventricular ejection fraction (RVEF) and left ventricular ejection fraction (LVEF), as well as measurement of brain natriuretic peptide (BNP). Between July 2005 and January 2007, 63 patients (69%) agreed to participate in a follow‐up study with a mean follow‐up of 4.5 years.

Results

All patients had normal LVEF at both examinations. A minimal increase in mean LVEF of 0.02 was observed at follow‐up (P=0.01). At the initial visit, four patients [6%; 95% confidence interval (CI) 2–15%] had a reduced RVEF, and at follow‐up two patients (3%; 95% CI 0–11%) had slightly reduced RVEF. No significant change in mean RVEF was found. No patients had increased BNP and no change in mean plasma BNP was found.

Conclusions

HIV‐related cardiomyopathy appears not to constitute a problem in closely monitored, well‐treated HIV‐infected patients. Compared with pre‐highly active antiretroviral therapy (HAART) studies, it seems that the improvement in immunocompetency and viral load has removed the problem of HIV‐related cardiomyopathy. Although HAART has been suggested as a possible new cause of cardiomyopathy, we did not find any evidence of this.