bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transient Rise of Serum Testosterone Level After Single Sildenafil Treatment of Adult Male Rats
Authors: Janjic Marija M. , Stojkov Natasa J. , Bjelic Maja M. , Mihajlovic Aleksandar I. , Andric Silvana A. , Kostic Tatjana S. 
Published: March 2012

ABSTRACT

Introduction
Phosphodiesterase type 5 (PDE5) inhibitors have been established in therapy for a variety of physiological disorders including erectile dysfunction. Despite its popularity and wide usage in erectile dysfunction treatment, the short-term effect of PDE5 inhibition on Leydig cell functionality and testosterone dynamics is missing.

Aim
This study was designed to assess the acute in vivo effects of sildenafil citrate (Viagra) treatment on testosterone production.

Methods
Male adult rats were given sildenafil (1.25 mg/kg BW) per os, and testosterone production were analyzed 30, 60, 120, and 180 minutes after treatment. Additionally, in vitro effect of sildenafil extract on Leydig cell steroidogenesis was estimated.

Main Outcome Measures
The formation of testicular interstitial fluid (TIF), and testosterone, cyclic guanosine monophosphate (cGMP), cyclic adenosine monophosphate (cAMP) content was followed. Occurrence and phosphorylation of mature steroidogenic acute regulatory protein (StAR) and interaction with protein kinase G 1 (PRKG1) were assessed by immunoprecipitation and Western blot.

Results
Serum testosterone was increased 60 and 120 minutes after sildenafil treatment. In 60 minutes, TIF volume was doubled and stayed increased till the end of the experimental period. cGMP and testosterone content in TIF were increased 30 minutes after treatment, and cAMP decreased in 60 minutes. Further, sildenafil-induced stimulation of testosterone production was abolished by ex vivo addition of PRKG1 inhibitor but not by protein kinase A inhibitor. Sildenafil treatment increased the level of phosphorylated and total StAR protein. Moreover, co-immunoprecipitation of StAR and PRKG1 was increased following sildenafil treatment suggesting the active role of this kinase in initiation of testosterone synthesis. Additionally, sildenafil extract applied in vitro on primary Leydig cell culture increased cGMP accumulation and testosterone production in time- and dose-dependent manner without effect on cAMP level.

Conclusion
Acute sildenafil treatment enlarged TIF volume but also stimulated testosterone production which may be significant considering the positive testosterone effect in regulation of sexual activity.
Pandemic (H1N1) 2009 influenza in Canadian pediatric cancer and hematopoietic stem cell transplant patients
Authors: Tran Dat , Science Michelle , Dix David , Portwine Carol , Zelcer Shayna , Johnston Donna L. , Yanofsky Rochelle , Gassas Adam , Ethier Marie‐Chantal , Sung Lillian 
Published: March 2012

Please cite this paper as: Tran et al. (2012) Pandemic (H1N1) 2009 influenza in Canadian pediatric cancer and hematopoietic stem cell transplant patients. Influenza and Other Respiratory Viruses 6(601), e105–e113.Background  The impact of pandemic H1N1 influenza (pH1N1) virus in pediatric cancer is uncertain. The objectives of this study were to characterize the clinical course of pH1N1 and identify factors associated with severe outcomes.Methods  We conducted a Canadian multicenter retrospective review of children with cancer and stem cell transplant (SCT) recipients who were diagnosed with laboratory‐confirmed pH1N1 infection between May 1, 2009 and January 31, 2010.Results  We identified 100 (19 in wave 1 and 81 in wave 2) cases of pH1N1 infection. Median age was 8·7 years. 71% had a hematologic malignancy, and 20% received SCT. Median duration of fever and illness was 2 and 12·5 days, respectively. 51 (51·5%) were hospitalized for a median of 5 days, with no deaths and only 1 requiring admission to the intensive care unit. Radiologically confirmed pneumonia was diagnosed in 10 (10%). Interruption of chemotherapy or conditioning occurred in 43 patients. In multivariable analyses, age <5 years (relative to ≥10 years) and neutropenia were associated with hospitalization while neutropenia was associated with pneumonia. Despite oseltamivir use in 89%, viral shedding was prolonged (median, 46 days) and often persisted after symptom resolution. However, an extended treatment course (>5 days) correlated with shortened duration of viral shedding (P = 0·041).Conclusions  pH1N1 infection in pediatric cancer and SCT patients infrequently caused complications but commonly interrupted cancer treatment. Persistent shedding of virus after illness resolution was common. Further research is needed to verify this finding as it could have implications for treatment guidelines and infection control practices.
The use of prisms for vision rehabilitation after macular function loss: an evidence‐based review
Authors: Markowitz Samuel N. , Reyes Sophia V. , Sheng Li 
Published: March 2012

Abstract.To determine the efficacy of prisms used for redirection of incoming images towards the peripheral retina in cases with macular function loss. Meta‐analysis of published work reporting outcomes from interventions using prisms was performed. The primary outcome measure selected for analysis was visual acuity (VA) used for viewing distance targets. Pooled data from 449 cases where prisms were prescribed for wearing in distance glasses were analysed. Visual acuity was better after using prisms (1.05 versus 0.89 logMAR units, p < 0.044). Mean effect size for improving VA was 79 bigger than the effect size calculated for the control group (0.158 versus 0.002). Most patients (76%) reported compliance with the therapy and also reported other benefits directly derived from the realized VA improvement. Published studies collectively offer positive evidence in support of using prisms for low vision rehabilitation after macular function loss. Further research is required to reach definitive binding conclusions.
Age‐related change in contrast sensitivity among Australian male adults: Florey Adult Male Ageing Study
Authors: Sia David I. T. , Martin Sean , Wittert Gary , Casson Robert J. 
Published: March 2012

Abstract.Purpose:  To describe the age‐related change in contrast sensitivity seen in 35‐ to 80‐year‐old men in an Australian population.Methods:  The Florey Adelaide Male Ageing Study (FAMAS) is a prospective population‐based study of men aged 35–80 years randomly selected from the north‐west suburbs of Adelaide. We conducted a nested ophthalmic substudy of these men. Contrast sensitivity (CS) was measured at four spatial frequencies (3, 6, 12 and 18 cycles/degree [cpd]) using the Vectorvision CSV‐1000 contrast sensitivity test chart (Vectorvision, Dayton, OH, USA), and results were statistically analysed relative to age and cataract type.Results:  There were 2650 eligible subjects in the FAMAS and 1195 participated (45.1%); 472 of those participated in the ophthalmic substudy. A statistically significant decrease in contrast sensitivity was seen with advancing age at each spatial frequency tested [Generalized estimating equations (GEE) multiple linear regression: p ≤ 0.01]. The decline with age was greatest in the highest spatial frequency (18 cpd) and least in the lowest spatial frequency (3 cpd). Posterior subcapsular cataract caused the greatest reduction in contrast sensitivity at all spatial frequencies, while nuclear cataract caused significant reduction only in the intermediate (12 cpd) and high (18 cpd) spatial frequencies. Cortical cataract failed to reach statistical significance in contrast sensitivity reduction at all spatial frequencies tested.Conclusion:  Contrast sensitivity declines with age in all spatial frequencies tested with a greater decline occurring in the higher spatial frequencies. Age and cataracts are independently associated with contrast sensitivity decline, and posterior subcapsular cataracts caused the greatest reduction at all spatial frequencies.
Large cell neuroendocrine carcinoma: retrospective analysis of 24 cases from four oncology centers in Turkey
Authors: Ustaalioglu Bala Başak Oven , Ulas Arife , Esbah Onur , Turan Nedim , Bilici Ahmet , Demirci Umut , Alkıs Necati , Seker Mesut , Oksuzoglu Berna , Gumus Mahmut ,   ASMO (Anatolian Society of Medical Oncology)
Published: March 2012

AbstractBackground:  Large cell neuroendocrine carcinoma (LCNEC) of the lung is classified as a variant of large cell lung carcinoma by the World Health Organization, however, the clinical and biological behavior of LCNEC resembles small cell lung carcinoma (SCLC) with a high mitotic index and a positivity of tumor cells with neuroendocrine markers. As there have only been a small number of patients with LCNEC recorded in literature, there is no consensus about the management of this subset. In the present study, we evaluated the incidence and prognosis of LCNEC in four oncology centers in Turkey.Method:  We analyzed 24 patients with diagnoses of LCNEC from 3138 non‐small cell lung cancer patients who were diagnosed and treated between 2008 and 2010 in four different medical oncology centers in Turkey.Results:  The median age was 56 (range; 36–64) and most patients were male, with three women included in the study. Ten out of 24 patients (41.6%) had locally advanced or metastatic disease, therefore, surgery could not be performed. Five patients (20.8%) were staged with stage I, six (25%) with stage II, five (20.8%) with stage III, and eight (33.3%) with stage IV. All patients had a history of smoking. Nine patients received chemotherapy postoperatively. At the 14.4‐month follow‐up period (range; 3–59) the median overall survival (OS) and progression‐free survival (PFS) rates were 32.7 and 9.5 months respectively. Tumor, node, metastasis (TNM) stage, performance status (PS) and the performance of surgery were significantly related to rates of both OS and PFS (P < 0.05).Conclusion:  LCNEC was generally diagnosed postoperatively. Prognosis of LCNEC is poor and surgery has not proven an effective solution for long‐term survival, therefore, adjuvant chemotherapy has been suggested.
Comparison of four techniques of arthrocentesis of the lateral compartment of the femorotibial joint of the horse
Authors: Schumacher John , Schumacher Jim , Wilhite R. 
Published: March 2012

SummaryReasons for performing study:Clinical experiences indicate that centesis of the lateral compartment of the femorotibial joint is often unsuccessful.Objective:To determine the accuracy of 2 published and 2 unpublished techniques of centesis of the lateral compartment of the femorotibial joint.Hypothesis:It was hypothesised that a drug can be administered into the lateral compartment of the femorotibial joint via a diverticulum of this joint that surrounds the medial aspect of the long digital extensor tendon and that this technique is more accurate than described techniques of centesis of this compartment.Methods:Twenty‐four stifles of 12 horses were divided equally into 4 groups and a radiocontrast medium injected into the lateral compartment of the femorotibial joint of each group using a hypodermic needle inserted: 1) caudal to the lateral patellar ligament and proximal to the tibial plateau, 2) caudal to the long digital extensor tendon and proximal to the tibial plateau, 3) between the long digital extensor tendon and bone of the extensor groove of the tibia or 4) directly through the long digital extensor tendon until it contacted bone. Twelve veterinary students who had no experience using any of these techniques performed the injections. Accuracy of each technique was determined by examining radiographs obtained after injecting the contrast medium.Results:The most successful technique for arthrocentesis was by inserting a needle through the long digital extensor tendon. This approach was successful in all attempted cases, whilst other techniques had lower rates of success.Conclusions:The lateral compartment of the femorotibial joint can be accessed accurately by inserting a needle through the long digital extensor tendon as it lies within the extensor groove. Other techniques may not be as accurate for clinicians inexperienced in arthrocentesis of the lateral compartment of the femorotibial joint.
Development of a gastroretentive pulsatile drug delivery platform
Authors: Thitinan Sumalee , McConville Jason T 
Published: March 2012

Abstract

Objectives
To develop a novel gastroretentive pulsatile drug delivery platform by combining the advantages of floating dosage forms for the stomach and pulsatile drug delivery systems.

Methods
A gastric fluid impermeable capsule body was used as a vessel to contain one or more drug layer(s) as well as one or more lag-time controlling layer(s). A controlled amount of air was sealed in the innermost portion of the capsule body to reduce the overall density of the drug delivery platform, enabling gastric floatation. An optimal mass fill inside the gastric fluid impermeable capsule body enabled buoyancy in a vertical orientation to provide a constant surface area for controlled erosion of the lag-time controlling layer. The lag-time controlling layer consisted of a swellable polymer, which rapidly formed a gel to seal the mouth of capsule body and act as a barrier to gastric fluid ingress.

Key findings
By varying the composition of the lag-time controlling layer, it was possible to selectively program the onset of the pulsatile delivery of a drug.

Conclusions
This new delivery platform offers a new method of delivery for a variety of suitable drugs targeted in chronopharmaceutical therapy. This strategy could ultimately improve drug efficacy and patient compliance, and reduce harmful side effects by scaling back doses of drug administered.
Characterization of efflux transport of the PDE5 inhibitors, vardenafil and sildenafil
Authors: Choi Min-Koo , Song Im-Sook 
Published: March 2012

Abstract

Objectives
We aimed to characterize the efflux transport properties of vardenafil and sildenafil, and to compare the kinetics of these compounds via efflux transporters such as P-gp, BCRP and MRP2.

Methods
We measured the basal-to-apical and apical-to-basal transport of vardenafil and sildenafil within the concentration range of 1–100 µm using MDCKII cells overexpressing P-gp, BCRP and MRP2, and Caco-2 cells.

Key findings
Vardenafil had a much greater basal-to-apical than apical-to-basal transport rate in MDCKII cells overexpressing P-gp, BCRP and MRP2. Sildenafil showed P-gp- and BCRP-mediated efflux transport, but did not seem to be pumped out via MRP2 transporters. Consequently, the absorptive transport of vardenafil and sildenafil in Caco-2 cells increased linearly over the concentration range of 1–100 µm, whereas the secretory transport of these drugs was saturable and inhibited by the presence of specific inhibitors of P-gp and BCRP. MK571, a representative MRP2 inhibitor, inhibited the basal-to-apical transport of vardenafil, but not of sildenafil.

Conclusion
The involvement of P-gp, BCRP and MRP2 for vardenafil and the involvement of P-gp and BCRP for sildenafil in the secretory transport with linear absorptive transport may contribute to the limited intestinal absorption of these drugs.
The effect of voxel size on high‐resolution peripheral computed tomography measurements of trabecular and cortical bone microstructure
Authors: Tjong Willy , Kazakia Galateia J. , Burghardt Andrew J. , Majumdar Sharmila 
Published: March 2012

Purpose:Accurate quantification of bone microstructure plays a significant role in understanding bone mechanics and response to disease or treatment. High‐resolution peripheral quantitative computed tomography (HR‐pQCT) allows for the quantification of trabecular and cortical structurein vivo, with the capability of generating images at multiple voxel sizes (41, 82, and 123 μm). The aim of this study was to characterize the effect of voxel size on structural measures of trabecular and cortical bone and to determine accuracy in reference to micro‐CT (µCT), the gold standard for bone microstructure quantification.Methods:Seventeen radii from human cadaver specimens were imaged at each HR‐pQCT voxel size and subsequently imaged using µCT. Bone density and microstructural assessment was performed in both the trabecular and cortical compartments, including cortical porosity quantification. Two distinct analysis techniques were applied to the 41 μm HR‐pQCT data: the standard clinical indirect analysis and a direct analysis requiring no density or structural model assumptions. Analysis parameters were adjusted to enable segmentation and structure extraction at each voxel size.Results:For trabecular microstructural measures, the 41 μm HR‐pQCT data displayed the strongest correlations and smallest errors compared to µCT data. The direct analysis technique applied to the 41 μm data yielded an additional improvement in accuracy, especially for measures of trabecular thickness. The 123 μm data performed poorly, with all microstructural measures either having moderate or nonsignificant correlations with µCT data. Trabecular densitometric measures showed strong correlations to µCT data across all voxel sizes. Cortical thickness was strongly correlated with µCT values across all HR‐pQCT voxel sizes. The accuracy of cortical porosity parameters was highly dependent on voxel size; again, the 41 μm data was most strongly correlated. Measures of cortical density and pore diameter at all HR‐pQCT voxel sizes had either weak or nonsignificant correlations.Conclusions:This study demonstrates the effect of voxel size on the accuracy of HR‐pQCT measurements of trabecular and cortical microstructure and presents parameters for HR‐pQCT analysis at nonstandard resolutions. For all parameters measured, correlations were strongest at 41 μm. Weak correlations for porosity measures indicate that a better understanding of pore structure and resolution dependence is needed.
Image‐based spectral distortion correction for photon‐counting x‐ray detectors
Authors: Ding Huanjun , Molloi Sabee 
Published: March 2012

Purpose:To investigate the feasibility of using an image‐based method to correct for distortions induced by various artifacts in the x‐ray spectrum recorded with photon‐counting detectors for their application in breast computed tomography (CT).Methods:The polyenergetic incident spectrum was simulated with the tungsten anode spectral model using the interpolating polynomials (TASMIP) code and carefully calibrated to match the x‐ray tube in this study. Experiments were performed on a Cadmium‐Zinc‐Telluride (CZT) photon‐counting detector with five energy thresholds. Energy bins were adjusted to evenly distribute the recorded counts above the noise floor. BR12 phantoms of various thicknesses were used for calibration. A nonlinear function was selected to fit the count correlation between the simulated and the measured spectra in the calibration process. To evaluate the proposed spectral distortion correction method, an empirical fitting derived from the calibration process was applied on the raw images recorded for polymethyl methacrylate (PMMA) phantoms of 8.7, 48.8, and 100.0 mm. Both the corrected counts and the effective attenuation coefficient were compared to the simulated values for each of the five energy bins. The feasibility of applying the proposed method to quantitative material decomposition was tested using a dual‐energy imaging technique with a three‐material phantom that consisted of water, lipid, and protein. The performance of the spectral distortion correction method was quantified using the relative root‐mean‐square (RMS) error with respect to the expected values from simulations or areal analysis of the decomposition phantom.Results:The implementation of the proposed method reduced the relative RMS error of the output counts in the five energy bins with respect to the simulated incident counts from 23.0%, 33.0%, and 54.0% to 1.2%, 1.8%, and 7.7% for 8.7, 48.8, and 100.0 mm PMMA phantoms, respectively. The accuracy of the effective attenuation coefficient of PMMA estimate was also improved with the proposed spectral distortion correction. Finally, the relative RMS error of water, lipid, and protein decompositions in dual‐energy imaging was significantly reduced from 53.4% to 6.8% after correction was applied.Conclusions:The study demonstrated that dramatic distortions in the recorded raw image yielded from a photon‐counting detector could be expected, which presents great challenges for applying the quantitative material decomposition method in spectral CT. The proposed semi‐empirical correction method can effectively reduce these errors caused by various artifacts, including pulse pileup and charge sharing effects. Furthermore, rather than detector‐specific simulation packages, the method requires a relatively simple calibration process and knowledge about the incident spectrum. Therefore, it may be used as a generalized procedure for the spectral distortion correction of different photon‐counting detectors in clinical breast CT systems.
A novel curvilinear approach for prostate seed implantation
Authors: Podder Tarun K. , Dicker Adam P. , Hutapea Parsaoran , Darvish Kurosh , Yu Yan 
Published: March 2012

Purpose:A new technique called “curvilinear approach” for prostate seed implantation has been proposed. The purpose of this study is to evaluate the dosimetric benefit of curvilinear distribution of seeds for low‐dose‐rate (LDR) prostate brachytherapy.Methods:Twenty LDR prostate brachytherapy cases planned intraoperatively with VariSeed planning system and I‐125 seeds were randomly selected as reference rectilinear cases. All the cases were replanned by using curved‐needle approach keeping the same individual source strength and the volume receiving 100% of prescribed dose 145 Gy (V100). Parameters such as number of needles, seeds, and the dose coverage of the prostate (D90, V150, V200), urethra (D30, D10) and rectum (D5, V100) were compared for the rectilinear and the curvilinear methods. Statistical significance was assessed using two‐tailed student's t‐test.Results:Reduction of the required number of needles and seeds in curvilinear method were 30.5% (p < 0.001) and 11.8% (p < 0.49), respectively. Dose to the urethra was reduced significantly; D30 reduced by 10.1% (p < 0.01) and D10 reduced by 9.9% (p < 0.02). Reduction in rectum dose D5 was 18.5% (p < 0.03) and V100 was also reduced from 0.93 cc in rectilinear to 0.21 cc in curvilinear (p < 0.001). Also the V150 and V200 coverage of prostate reduced by 18.8% (p < 0.01) and 33.9% (p < 0.001), respectively.Conclusions:Significant improvement in the relevant dosimetric parameters was observed in curvilinear needle approach. Prostate dose homogeneity (V150, V200) improved while urethral dose was reduced, which might potentially result in better treatment outcome. Reduction in rectal dose could potentially reduce rectal toxicity and complications. Reduction in number of needles would minimize edema and thereby could improve postimplant urinary incontinence. This study indicates that the curvilinear implantation approach is dosimetrically superior to conventional rectilinear implantation technique.