Correction to: Defining Polyamory: A Thematic Analysis of Lay People’s Definitions

Archives of Sexual Behavior - The article “Defining Polyamory: A Thematic Analysis of Lay People’s Definitions”, written by Daniel Cardoso, Patricia M. Pascoal, and Francisco...     

Effect of Paternal Diet on Spermatogenesis and Offspring Health: Focus on Epigenetics and Interventions with Food Bioactive Compounds

Infertility is a growing public health problem. Consumption of antioxidant bioactive food compounds (BFCs) that include micronutrients and non-nutrients has been highlighted as a potential strategy to protect against oxidative and inflammatory damage in the male reproductive system induced by obesity, alcohol, and toxicants and, thus, improve spermatogenesis and the fertility parameters. Paternal consumption of such dietary compounds could not only benefit the fathers but their offspring as well. Studies in the new field of paternal origins of health and disease show that paternal malnutrition can alter sperm epigenome, and this can alter fetal development and program an increased risk of metabolic diseases and breast cancer in adulthood. BFCs, such as ascorbic acid, α-tocopherol, polyunsaturated fatty acids, trace elements, carnitines, N-acetylcysteine, and coenzyme Q10, have been shown to improve male gametogenesis, modulate epigenetics of germ cells, and the epigenetic signature of the offspring, restoring offspring metabolic health induced by stressors during early life. This indicates that, from a father’s perspective, preconception is a valuable window of opportunity to start potential nutritional interventions with these BFCs to maximize sperm epigenetic integrity and promote adequate fetal growth and development, thus preventing chronic disease in adulthood.     

Young red blood cells; observations about the cytometric and morphologic alterations in the beginning of their life

Summary A recently described separation technique consisting of a combination of counterflow centrifugation and subsequent density (Percoll) scparation was tested for its ability to enrich red cell populations with young cells in comparison to either separation technique alone. The relative age of every fraction was determined by HbAlc measurements, resulting in the lowest HbAlc for the combination method. Conventional reticulocyte counting and floweytometric counting with thiazole orange indicated that in the youngest fractions the combination method showed the highest reticulocyte counts. There was a good correlation between manual and flowcytometric counting results. Radio-iron studies showed a two-fold enrichment with young cells in the fraction with the lowest HbAIc acquired by the combination technique in comparison to the other two methods. Cytometric measurements showed that the fractions with the lowest HbAlc were the ones with the highest MCV and MCH and the lowest MCHC. Besides loss of their RNA-material, young cells already seem to loose water and haemoglobin like older cells, resulting in a decrease of MCV and MCH and in increase in MCHC. It is concluded that combining counterflow centrifugation with subsequent density fractionation results in superior enrichment with young cells in comparison to the results of each method alone.     

Treatment of a second maxillary molar with six canals

Variations in the dental anatomy are found in all teeth. Knowledge of these variations, particularly concerning the location and treatment of all canals, is very important for the success of the endodontic therapy. The purpose of this study is to present a clinical case of a maxillary second molar with three palatal canals, two mesio-buccal and one disto-buccal canal. This report serves to remind clinicians that such anatomical variations should be taken into account during endodontic treatment of the maxillary molars.     

Maxillary Premolar with 4 Separate Canals

Introduction

Recognition of anatomic variations is a challenge for clinicians regardless of which tooth is treated. Maxillary premolars usually have 2 root canals, but the presence of 3 distinct root canals has been reported in 1%–6% of cases.

Methods and Results

This report describes the case of a maxillary right second premolar with 4 separate canals: 1 mesial, 1 palatal, and 2 distal canals. This was confirmed by using cone-beam computed tomography and was successfully treated with rotary files and obturated by using a warm vertical compaction technique.

Conclusions

The clinical significance of the present case is that this is the first report of 3 roots and 4 separate canals in a maxillary premolar. Precise knowledge of root canal morphology and its variation is also underlined. Cone-beam computed tomography examination and the operating microscope are excellent tools for identifying and managing these complex root canal systems.     

Can electronic zoom replace magnification in mammography? A comparative Monte Carlo study

Magnification, which is considered to be a relatively high "dose cost" mammographic technique, is a complementary examination performed on women exhibiting breast complaints or abnormalities. Particular attention is given to the imaging procedure as the primary aim is to confirm the existence of suspected abnormalities, despite the additional dose. The introduction of post-processing capabilities and the widespread use of digital mammography promoted some controversy in the last decades on whether electronic zoom performed on the derived initial screening mammogram can effectively replace this technique. This study used Monte Carlo simulation methods to derive simulated screening mammograms produced under several exposure conditions, aiming to electronically magnify and compare them to the corresponding magnification mammograms. Comparison was based on quantitative measurements of image quality, namely contrast to noise ratio (CNR) and spatial resolution. Results demonstrated that CNR was higher for geometric magnification compared to the case of electronic zooming. The percentage difference was higher for lesions of smaller radius and achieved 29% for 0.10 mm details. Although spatial resolution is maintained high in the zoomed images, when investigating microcalcifications of 0.05 mm radius or less, only with geometric magnification can they be visualised.The carcinogenic risk associated with the delivery of high radiation doses such as those related to magnification views in mammography, in addition to the requirements for high image quality, have made it essential to optimise this technique. Although this radiation risk is considered to be relatively insignificant in the context of accurate diagnosis, work-up and treatment, an investigation has started for alternative techniques that could provide equivalent or improved characterisation of lesions and improved diagnostic information compared with that obtained from magnification views. The psychological “cost” of a woman being recalled for a second mammographic examination, the discomfort from the breast compression and the economic impact of an additional examination are also factors that have promoted research into alternative procedures that complement the information provided by standard mammography.For many decades, magnification mammographic images of selected breast regions have been considered the most effective diagnostic tool for enhancing the visibility of subtle suspicious breast lesions and microcalcifications, thus providing improved diagnostic sensitivity and specificity. To this end, screen-film radiography was the gold standard for many decades and has now been replaced with digital radiography, which can also be combined with digital post-processing methods. The enhancement of visibility in magnification views is attributed to the increase in contrast to noise ratio (CNR) caused by the increased fluence per irradiated area. The CNR increases with the degree of magnification, particularly for low degrees (increase of 75% between degrees 1.0 and 1.4) [5]. By contrast, a major disadvantage of magnification is the additional and significantly high dose of radiation delivered to the breast compared with the contact case. Owing to the fact that the breast is placed closer to the X-ray focal spot, both the entrance dose at the skin surface and the mean glandular dose (MGD) to the irradiated part of the breast are considerably higher than for the corresponding contact view. Typically, MGD is doubled at 1.5× magnification compared with a standard mammogram. Thus, there is an increased radiation risk [6, 7]. Regarding spatial resolution, this is significantly degraded as magnification increases owing to the finite dimensions of the focal spot and the detrimental penumbra effects [8, 9]. At the same time, however, spatial resolution is improved due to the effective detector resolution, which depends on the irradiated object''s size on the detector plane [9]. For the low degrees of magnification usually applied in clinical practice, the overall system resolution is improved with magnification. However, for higher degrees it is degraded owing to the dominant effect of the focal spot dimensions [9, 10].Among the new techniques introduced in the effort to replace magnification views, image post-processing, often facilitated by digital mammography, has become very popular [11–13]. Electronic magnification (zoom) of digital (or digitised) screening mammograms has recently come to the foreground of this research area and many authors are addressing this alternative. A question that arises is whether the image quality provided by electronic zoom is comparable to that provided by the (original) geometric magnification views. If not, another question arises – whether the dose-saving provided by electronic zooming can compensate for a potential detriment in image quality.Several studies have been performed, most involving observers, to evaluate the image quality provided by the two techniques. Perisinakis et al [4] demonstrated that the enhancement of image features through post-processing (zooming) of both digitised contact images and geometric magnification mammograms equally improved the visualisation of subtle microcalcifications that are only rarely identified in standard full-field screen-film mammograms. Similar results have been reported by Vyborny et al [11], Smathers et al [14] and Powell et al [15]. These authors also showed that lesion visualisation achieved with geometric magnification mammograms (without the application of further post-processing) was similar to that achieved by electronic magnification and processing of the contact full-field image. Chan et al [16] showed that geometric magnification combined with stereotactic imaging in mammography provides better results than electronic display zooming of the contact stereotactic images.Smith et al [17] included the radiologist''s experience in their study; the authors demonstrated that, when evaluating microcalcifications, radiologists less experienced in mammography should not replace digitised and enhanced contact mammograms for microfocal-spot magnified mammograms. Other studies in this area have been reported in recent years [18–23] and, despite the fact that their conclusions vary, most exhibit a common characteristic: they are based on subjective human perception and decision criteria, known to vary significantly, rather than on objective metrics of image quality such as CNR and spatial resolution. Moreover, to our knowledge, to date no studies have been published comparing the primary image for both techniques without the application of additional post-processing methods (e.g. denoising or enhancement), based only on objective metrics of image quality.In this study, a validated Monte Carlo model developed for producing simulated mammographic images under exposure conditions representative of clinical mammography was used. Sets of standard contact and geometrically magnified mammograms were produced using the same output. The contact mammograms were then electronically magnified (zoomed) and compared with the corresponding images produced with the geometric magnification with no further post-processing undertaken. The comparison was based on CNR (derived from signal and noise measured in the images and their background) and spatial resolution.