Prospective evaluation of ultrasound features of magnesium-based bioabsorbable screw resorption in pediatric fractures

OBJECTIVE

Bioabsorbable magnesium-based alloy screws release gas upon resorption. The resulting findings in the adjacent soft tissues and joints may mimic infection. The aim of the study was to evaluate the ultrasound (US) findings in soft tissues and joints during screw resorption.

METHODS

Prospectively acquired US studies from pediatric patients treated with magnesium screws were evaluated for screw head visibility, posterior acoustic shadowing, twinkling artifact, foreign body granuloma, gas (soft tissue, intra-articular), alterations of the skin and subcutaneous fat, perifascial fluid, localized fluid collections, hypervascularization, and joint effusion.

RESULTS

Sixty-six US studies of 28 pediatric patients (nfemale = 9, nmale = 19) were included. The mean age of the patients at the time of surgery was 10.84 years; the mean time between surgery and ultrasound was 128.3 days (range = 6-468 days). The screw head and posterior acoustic shadowing were visible in 100% of the studies, twinkling artifact in 6.1%, foreign body granuloma in 92.4%, gas locules in soft tissue in 100% and intra-articular in 18.2%, hyperechogenicity of the subcutaneous fat in 90.9%, cobblestoning of the subcutaneous fat in 24.2%, loss of normal differentiation between the epidermis/dermis and the subcutaneous fat in 57.6%, localized fluid collection in 9.9%, perifascial fluid in 12.1%, hypervascularization in 27.3%, and joint effusion in 18.2%.

CONCLUSION

US findings in pediatric patients treated with magnesium screws strongly resemble infection, but are normal findings in the setting of screw resorption.

CLINICAL RELEVANCE STATEMENT

Bioabsorbable magnesium-based alloy screws release gas during resorption. The resulting US findings in the adjacent soft tissues and joints in pediatric patients may mimic infection, but are normal findings.

KEY POINTS

• Bioabsorbable magnesium-based alloy screws release gas upon resorption. • The resulting ultrasound findings in children's soft tissues and joints closely resemble those of soft tissue infection or osteosynthesis-associated infection. • Be familiar with these ultrasound findings in order to avoid inadvertently misdiagnosing a soft tissue infection or osteosynthesis-associated infection.

The Alexis Laparoscopic System as Minimally Invasive Surgical Technique in Operative Management of Huge Cystic Ovarian Tumors in Children and Young Adolescents: A Case Report

BACKGROUND

The use of the Alexis wound protector-retractor (AWPR) could further improve the laparoscopic techniques for safely removing huge ovarian tumors in children.

CASE

A 15-year-old patient presented to our emergency department with a history of weeks of persistent abdominal pain. Clinical examination and magnetic resonance imaging demonstrated a 25 × 21 × 21 cm cystic mass arising from the left ovary. An en block unilateral oophorectomy and salpingectomy with the use of a medium-sized AWPR was performed without complications. The patient was discharged on the second postoperative day.

CONCLUSION

The AWPR is a safe and effective tool in treating such children and adolescents with huge ovarian tumors, preserving fertility, minimizing the postoperative pain and hospital stay, and providing an excellent cosmetic outcome.

Prospective Evaluation of Magnetic Resonance Imaging Features of Magnesium-Based Alloy Screw Resorption in Pediatric Fractures

BACKGROUND

The resorption of magnesium-based alloy bioabsorbable screws results in the release of hydrogen gas, which can mimic infection and enter the growth plate. The screw itself and the released gas may also affect image quality.

OBJECTIVE

The evaluation of magnetic resonance imaging (MRI) findings during the most active phase of screw resorption is the objective, with particular focus on the growth plate and to assess for the presence of metal-induced artifacts.

MATERIAL AND METHODS

In total, 30 prospectively acquired MRIs from 17 pediatric patients with fractures treated with magnesium screws were assessed for the presence and distribution of intraosseous, extraosseous, and intra-articular gas; gas within the growth plate; osteolysis along the screw; joint effusion; bone marrow edema; periosteal reaction; soft tissue edema; and metal-induced artifacts.

RESULTS

Gas locules were found in the bone and soft tissues in 100% of the examinations, intra-articular in 40%, and in 37% of unfused growth plates. Osteolysis and the periosteal reaction were present in 87%, bone marrow edema in 100%, soft tissue edema in 100%, and joint effusion in 50% of examinations. Pile-up artifacts were present in 100%, and geometric distortion in 0% of examinations. Fat suppression was not significantly impaired in any examination.

CONCLUSIONS

Gas and edema in the bone and soft tissues are normal findings during the resorption of magnesium screws and should not be misinterpreted as infection. Gas can also be detected within growth plates. MRI examinations can be performed without metal artifact reduction sequences. Standard fat suppression techniques are not significantly affected.

Radiographic features of magnesium-based bioabsorbable screw resorption in paediatric fractures

BACKGROUND

Resorption of magnesium-based alloy bioabsorbable screws produces hydrogen gas, which can be mistaken as a sign of infection and may affect the physis or fixed bone fragment.

OBJECTIVE

We evaluated the temporal and spatial occurrence of gas and the occurrence of a breakage of the fixed bone fragment or screw following magnesium screw fixation.

MATERIALS AND METHODS

Radiographs of paediatric patients treated with magnesium screws were retrospectively reviewed. Temporal occurrence and distribution of gas in the bone, the physis and soft tissues, breakage of the screw or fixed bone fragment and joint effusion were assessed.

RESULTS

One hundred and three radiographs in 35 paediatric patients were reviewed (mean age: 10.6 years). Follow-up ranged from 1 to 730 days. Gas in the bone increases up to week 5, remains constant up to week 16 and then decreases. Gas in soft tissues, intra-articular gas and joint effusions gradually reduce over time. In 1/23 (4.3%) patients with an open physis, gas intrusion into the physis occurred. Breakage of the bone fragment fixated by the screw was observed in 4/35 (11.4%) patients within the first 6 weeks. Screw breakage was observed in 16/35 (45.7%) patients, with a median time to first detection of 300 days.

CONCLUSION

Gas bubbles in bone and soft tissue are normal findings in the context of screw resorption and should not be confused with soft-tissue infection or osteomyelitis. Gas is rarely visible in the physis. Breakage of the fixed bone fragment and/or screw can occur.

Zygote Diameter and Total Cytoplasmic Volume as Useful Predictive Tools of Blastocyst Quality

Introduction According to the Embryo Protection Act, the selection of embryos with the greatest potential for successful implantation in Germany must be performed in the pronucleus stage. The main aim of this study was to identify morphokinetic parameters that could serve as noninvasive biomarkers of blastocyst quality in countries with restrictive reproductive medicine laws. Materials and Methods The sample comprised 191 embryos from 40 patients undergoing antagonist cycles for intracytoplasmic sperm injection. Blastocysts were cultured in an EmbryoScope chamber and video records were validated to determine the post-injection timing of various developmental stages, cleavage stages, and blastocyst formation. The Gardner and Schoolcraft scoring system was used to characterize blastocyst quality. Results Morphokinetic data showed that the zygote diameter and total cytoplasmic volume were significantly different between good and poor blastocysts quality groups, where zygotes, which formed better blastocyst quality, had smaller diameter and smaller total cytoplasmic volume. Zygotes with more rapid pronuclear disappearance developed in better-quality blastocysts. Differences between good- and poor-quality blastocysts were also observed for late-stage parameters and for the spatial arrangement of blastomere where tetrahedral embryos more frequently forming good-quality blastocyst compare to the non-tetrahedral. Conclusions The study findings could be used to enhance embryo selection, especially in countries with strict Embryo Law Regulations. Further studies, including those in which the implantation potential and pregnancy rate are considered, are warranted to confirm these preliminary results.

Cholinergic Signaling Attenuates Pro-Inflammatory Interleukin-8 Response in Colonic Epithelial Cells

Infants affected by Hirschsprung disease (HSCR), a neurodevelopmental congenital disorder, lack ganglia of the intrinsic enteric nervous system (aganglionosis) in a variable length of the colon, and are prone to developing severe Hirschsprung-associated enterocolitis (HAEC). HSCR patients typically show abnormal dense innervation of extrinsic cholinergic nerve fibers throughout the aganglionic rectosigmoid. Cholinergic signaling has been reported to reduce inflammatory response. Consequently, a sparse extrinsic cholinergic innervation in the mucosa of the rectosigmoid correlates with increased inflammatory immune cell frequencies and higher incidence of HAEC in HSCR patients. However, whether cholinergic signals influence the pro-inflammatory immune response of intestinal epithelial cells (IEC) is unknown. Here, we analyzed colonic IEC isolated from 43 HSCR patients with either a low or high mucosal cholinergic innervation density (fiber-low versus fiber-high) as well as from control tissue. Compared to fiber-high samples, IEC purified from fiber-low rectosigmoid expressed significantly higher levels of IL-8 but not TNF-α, IL-10, TGF-β1, Muc-2 or tight junction proteins. IEC from fiber-low rectosigmoid showed higher IL-8 protein concentrations in cell lysates as well as prominent IL-8 immunoreactivity compared to IEC from fiber-high tissue. Using the human colonic IEC cell line SW480 we demonstrated that cholinergic signals suppress lipopolysaccharide-induced IL-8 secretion via the alpha 7 nicotinic acetylcholine receptor (a7nAChR). In conclusion, we showed for the first time that the presence of a dense mucosal cholinergic innervation is associated with decreased secretion of IEC-derived pro-inflammatory IL-8 in the rectosigmoid of HSCR patients likely dependent on a7nAChR activation. Owing to the association between IL-8 and enterocolitis-prone, fiber-low HSCR patients, targeted therapies against IL-8 might be a promising immunotherapy candidate for HAEC treatment.

P–233 The spatial arrangement of blastomeres and time of cavitation forming as predictors of blastocyst quality

Study question

Does the spatial arrangement of blastomeres and the start of blastulation affect blastocyst quality?

Summary answer

Better blastocyst quality is associated with the spatial arrangement of the embryo and the shorter time frame of blastulation (cavitation).

What is known already

The ability to select the human embryo with the highest implantation potential remains one of the greatest challenges in the management of In Vitro Fertilization patients. Several publications have proposed that additional morphological evaluations of blastomere arrangement and the dynamics of late-stage embryonic divisions might be a useful non-invasive way for embryo selection. In the last decade, the introduction of time-lapse technology enables continuous monitoring of embryo development, which leads to better outcomes than a selection based on the traditional morphology assessment.

Study design, size, duration

The spatial arrangement was defined as tetrahedrally if the cleavage planes were perpendicularly orientated, while embryos with rather parallelly orientated cleavage axes were considered as non-tetrahedral embryos. The injection time of ICSI was designated as “time zero” (t0), and EmbryoViewer software was used to calculate the time duration between injection and start of blastulation (cavitation). Obtained results were later correlated with the embryo’s capability to form a blastocyst as well as with blastocyst quality.

Participants/materials, setting, methods

A total of 195 oocytes from 40 patients undergoing the antagonist cycle for ICSI treatment were evaluated. All blastocysts were cultured in Embryoscope™ according to the manufacturer’s specifications (Vitrolife, Sweden). The Gardner and Schoolcraft scoring system was used to describe blastocyst quality. Statistical analyses were performed using IBM SPSS version 24. Data were reported as median and range. Differences between groups were tested using the Mann-Whitney U test. Statistical significance was defined as p < 0.05.

Main results and the role of chance

Obtained data showed that 83.6% (61/73) of embryos with tetrahedral arrangement formed blastocysts compared to 42.4% (50/116) of embryos with the non-tetrahedral arrangement (p < 0,001). Moreover, tetrahedral embryos more frequently formed good quality blastocyst compare to the non-tetrahedral [59% (36/61) vs 18 (9/50)% respectively; p < 0,001]. In addition, we found that good quality blastocyst had a significantly shorter time frame between injection and blastulation start, compared with blastocysts which did not reach good quality [95.00h (84–118) vs 102h (77–121) respectively; p = 0,006].

Limitations, reasons for caution

The limitation of the present study was that due to the double-embryo transfer correlation between those morphokinetic parameters and pregnancy rate can not be calculated. Further research should link these morphokinetic parameters with pregnancy rate and live birth rate as well.

Wider implications of the findings: The potential of our findings is considerable, especially for countries with strict Embryo Law Regulation. Obtained results might be highly useful for selecting embryos with high implantation potential. In addition, the present work illustrates the possibility of additional information that can potentially be incorporated into an embryo classification model.

Trial registration number

Not applicable

P–140 Zygote morphokinetics as a predictor of blastocyst quality

Study question

Does the total cytoplasmic volume (TCV) of the zygote and time of pronuclei disappearance (tPNf) affect blastocyst development potential and blastocyst quality?

Summary answer

The total cytoplasmic volume of zygote and the time of pronuclei disappearance strongly affect blastocyst development as well as blastocyst quality.

What is known already

Extended embryo culture with blastocyst transfer is considered a useful method for selecting embryos with a high implantation potential. One of the main concerns in the German Embryo Protection Act is that the choice of embryos that have a high potential for successful implantation must be made at the pronucleus stage. The introduction of time-lapse technology enabled comprehensive information regarding the morphology and kinetics of the embryo. Although for the past years, strong correlations between embryo morphokinetics and positive outcomes have been demonstrated, some disagreement concerning the wide application of these parameters into an early-stage embryo selection is still present.

Study design, size, duration

The injection time of ICSI was designated as “time zero”, and computer software was used to calculate the time frame between the injection and the moment of pronuclei disappearance (tPNf). The total cytoplasmic volume was calculated 16–18 h after injection based on manually drawn diameters of the zygotes, by the computer. Obtained measurements were later associated with the blastocyst formation potential as well as with blastocyst quality.

Participants/materials, setting, methods

A total of 187 oocytes from 34 patients undergoing the antagonist cycle for ICSI treatment were evaluated. All blastocysts were cultured in Embryoscope™ according to the manufacturer’s specifications (Vitrolife, Sweden). The Gardner and Schoolcraft scoring system was used to describe blastocyst quality. Statistical analyses were performed using IBM SPSS version 24. Data were reported as median and range. Differences between groups were tested using the Mann-Whitney U test. Statistical significance was defined as p < 0.05.

Main results and the role of chance

Obtained data showed that the total cytoplasmic volume values were significantly higher in zygotes that reached the blastocyst stage compared with those that did not [708376,268µm³ (560564,412µm³ - 838602,605µm³) vs 674349,917 (415749,353- 823640,638) respectively; p < 0.0001]. Furthermore, this parameter as well significantly affect blastocyst quality where zygotes which formed better blastocyst quality had smaller cytoplasmic volume [685568,079 µm³ (560564,412- 790112,397µm³) vs 745514,662 µm³ (616581,339- 838602,605) respectively; p < 0.0001]. Time of pronuclei disappearance (tPNf) was significantly different (p < 0.0001) in successfully formed blastocysts [22.00h (17–29 h)] versus arrested or non-blastulating embryos [23.00h (17–56 h)]. Zygotes who had a shorter time frame between injection and pronuclei disappearance showed better blastocyst quality values compared with those who had longer time frame [21.00h (17–28h) vs 23.00h (18–29h) respectively; p < 0.01].

Limitations, reasons for caution

The limitation of the presented study was that due to the double-embryo transfer correlation between morphokinetic parameters and pregnancy rate was not possible to be calculated. Further research should link these morphokinetic parameters with pregnancy rate and live birth rate as well.

Wider implications of the findings: The potential of the present findings is considerable, especially for countries with strict Embryo Law Regulation. Obtained results might be highly useful for selecting embryos with high implantation potential. In addition, the present work illustrates the possibility of additional information that can potentially be incorporated into an embryo classification model.

Trial registration number

Not applicable

Stereological Lung Parameters After Fetoscopic Abdominal Decompression of Congenital Diaphragmatic Hernia in an Ovine Model: A Pilot Study

Background: Fetoscopic endoluminal tracheal occlusion (FETO) improves lung maturation in severe cases of congenital diaphragmatic hernia (CDH) but it does not ameliorate lung compression by herniated abdominal organs. Surgically opening the fetal abdomen (abdominal decompression [AD]) reduces the intrathoracic pressure by diverting the abdominal organs into the amniotic cavity-a probable causal therapy for lung hypoplasia and pulmonary hypertension in CDH. Open surgical abdominal decompression has been reported: we describe a minimally invasive approach in an ovine model of CDH as a probable fetoscopic intervention. Materials and Methods: Eight fetuses were included, 2 were kept as HEALTHY controls. A CDH (left side, liver down) was created by open fetal surgery at midgestation in 6 fetuses, 2 were taken as CDH controls. Fetoscopic abdominal decompression (fAD) was performed 21 days later in 4 animals. The fetuses were retrieved at the end of gestation and evaluated by lung stereology. Results: fAD led to a near total evacuation of the thoracic cavity in 2 of the 4 animals. Fetuses with CDH had a lower total volume and fraction of alveolar air space, a lower volume fraction of the parenchyma, and an increase of the volume fraction of the alveolar septa and atelectasis, as well as an increased mean thickness of alveolar septa compared with HEALTHY fetuses. Fetuses treated with abdominal decompression showed an improvement of stereological parameters. Conclusions: In spite of relevant limitations (pilot study, small groups, spontaneous closure of the abdominal incision) we were able to demonstrate that abdominal decompression for CDH can be performed by fetoscopy. Our results support the hypothesis of causally improving lung development by abdominal decompression, thus implying increased survival in extreme cases of CDH. A refinement of the fetoscopic techniques and direct comparison to FETO appears warranted.

Lack of Mucosal Cholinergic Innervation Is Associated With Increased Risk of Enterocolitis in Hirschsprung's Disease

BACKGROUND & AIMS

Hirschsprung's disease (HSCR) is a congenital intestinal motility disorder defined by the absence of enteric neuronal cells (ganglia) in the distal gut. The development of HSCR-associated enterocolitis remains a life-threatening complication. Absence of enteric ganglia implicates innervation of acetylcholine-secreting (cholinergic) nerve fibers. Cholinergic signals have been reported to control excessive inflammation, but the impact on HSCR-associated enterocolitis is unknown.

METHODS

We enrolled 44 HSCR patients in a prospective multicenter study and grouped them according to their degree of colonic mucosal acetylcholinesterase-positive innervation into low-fiber and high-fiber patient groups. The fiber phenotype was correlated with the tissue cytokine profile as well as immune cell frequencies using Luminex analysis and fluorescence-activated cell sorting analysis of colonic tissue and immune cells. Using confocal immunofluorescence microscopy, macrophages were identified in close proximity to nerve fibers and characterized by RNA-seq analysis. Microbial dysbiosis was analyzed in colonic tissue using 16S-rDNA gene sequencing. Finally, the fiber phenotype was correlated with postoperative enterocolitis manifestation.

RESULTS

The presence of mucosal nerve fiber innervation correlated with reduced T-helper 17 cytokines and cell frequencies. In high-fiber tissue, macrophages co-localized with nerve fibers and expressed significantly less interleukin 23 than macrophages from low-fiber tissue. HSCR patients lacking mucosal nerve fibers showed microbial dysbiosis and had a higher incidence of postoperative enterocolitis.

CONCLUSIONS

The mucosal fiber phenotype might serve as a prognostic marker for enterocolitis development in HSCR patients and may offer an approach to personalized patient care and new therapeutic options.

The impact of anti-Müllerian hormone (AMH) on multiple pronuclei (PN) presence and oocyte maturity in ICSI treatments

This prospective study was designed to investigate whether anti-Müllerian hormone (AMH) levels are associated with the presence of multiple pronuclei in zygotes as well as with the ovarian response, fertilization rate and pregnancy outcome in ICSI cycles. A total of 413 patients undergoing ICSI cycles were included in the study. The assessment included 3084 MII oocytes. Serum AMH measurements were performed at the first initial presence of the patient. The outcome measures were the presence of multiple pronuclei (PN), a number of retrieved oocytes, number of mature/immature oocytes, fertilization rate and clinical pregnancy. Obtained results showed a statistically significant correlation between AMH levels and maternal age, the number of follicles, the number of cumulus-oocyte complexes, mature and immature oocyte, fertilization rate and pregnancy rate. Linear regression analysis showed that AMH significantly correlates with the presence of multiple pronuclei in the zygote. The further analysis confirmed that the number of zygotes with the presence of multiple pronuclei increased when AMH levels were higher. This is the first examination of the prognostic value of the serum AMH on the presence of multiple pronuclei in the zygote and our data in the preliminary study suggest that AMH levels could be used as a predictive marker.

Spaced Education Improves the Retention of Laparoscopic Suturing Skills: A Randomized Controlled Study

INTRODUCTION

 Spaced learning has been shown to be superior in complex motor skill acquisition like laparoscopic suturing and knot tying. By using a pre-post follow-up design, the aim of the study was to evaluate the long-term impact of implementation of the spaced learning concept in laparoscopic training.

MATERIALS AND METHODS

 To evaluate the effectiveness of spaced learning, subjects were asked to perform four surgeon's square knots on a bowel model within 30 minutes-prior and after 3 hours of hands-on training. To examine the long-term skills, the same students were asked to perform a comparable, but more complex, task (four slip knots in a model of esophageal atresia) 12 months later as follow-up measurement. Total time, knot stability (evaluated via tensiometer), suture accuracy, knot quality (Muresan scale), and laparoscopic performance (Munz checklist) were assessed. Moreover, motivation was accessed using Questionnaire on Current Motivation.

RESULTS

 Twenty students were included in the study; after simple randomization, 10 were trained using the "spaced learning" concept and 10 via traditional methods. Both groups had comparable baseline characteristics and improved after training significantly, regarding all aspects assessed in this study. Subjects that trained via spaced learning were superior in terms of speed (p = 0.021), knot quality (p = 0.008), and suture strength (p = 0.003). Additionally, spaced learning significantly decreased anxiety (p = 0.029) and probability of success (p = 0.005).

CONCLUSION

 The spaced learning concept is very suitable for long-term complex motor skill acquisition, like laparoscopic suturing and knot tying. It is superior to conventional training regarding speed and, most importantly, knot quality and stability, resulting in improved confidence and motivation. Thus, we strongly recommend to incorporate the spaced learning concept into training courses and surgical programs.

Effect of sexed semen on different production and functional traits in German Holsteins

•

Calf sex had an influence on calving ease and dystocia rates.

•

Sexed semen within same calf sex had only minor effects on most traits.

•

Stillbirth rate for the few male calves from semen sexed for females was 30.6%.

The aim of this study was to analyze possible effects of semen type (conventional vs. female sexed) and calf sex on fertility and production traits. For this purpose, field data of German Holstein heifers in Lower Saxony were evaluated.

Sexed semen was mainly used for first insemination. 87.0% female calves were born from sexed semen, while 52.7% female calves were born from conventional semen. Heifers inseminated with sexed semen were on average 43 to 48 days younger at their first calving than heifers inseminated with conventional semen.

Calf sex had an influence on the average calving ease and the dystocia rates. Male calves showed higher calving ease scores and caused a higher risk for dystocia than female calves. The semen type had no influence on these characteristics.

Within the same calf sex, sexed semen had only minor effects on most traits, except for stillbirth rates: the stillbirth rate for male calves from female sexed semen was 30.6%, which was 2.86 times the stillbirth rate of male calves from conventional semen, possibly due to trisomies.

Sexed semen played only a minor role for production traits in first lactations.

The extrapolated 305-day milk yield was 200 kg lower for first calf heifers, which were inseminated with sexed semen compared to heifers inseminated with conventional semen. Fat and protein yield were 6 kg to 8 kg lower after use of sexed semen. Animals with female offspring from sexed semen showed higher survival rates than the other groups.

Sternal elevation techniques during the minimally invasive repair of pectus excavatum

The aim of the review was to evaluate the routine use of sternal elevation techniques (SETs) during minimally invasive repair of pectus excavatum (MIRPE, the Nuss procedure). We performed a review of the literature between January 1998 and September 2018 with focus on different methods of SET during MIRPE. Reported effects and side effects were evaluated and compared with our own experience concerning the routine use of the vacuum bell for sternal elevation during MIRPE during the last 13 years. SET is more often used in adult patients than in adolescents. SET improves visualization and safety of MIRPE. Advancement of the pectus introducer, retrosternal dissection and placement of the pectus bar are easier. The risk of cardial and/or pericardial lesion is reduced significantly. Different types of retractors, a crane combined with a wire and/or customized hooks are reported to be used as SET. Furthermore, routine use of a subxiphoid incision is reported. However, more technical equipment, and in some SETs additional incisions are necessary. In contrast, no additional skin incision is necessary for the vacuum bell. The routine intraoperative use of the vacuum bell was safe and effective in 131 patients. It facilitates the retrosternal dissection and the insertion of the pectus bar like other SETs. Besides a temporary mild hematoma, no relevant side effect was observed. In conclusion, an increasing number of authors report on the routine use of SET during MIRPE to improve safety of the procedure. We recommend the routine intraoperative use of the vacuum bell during MIRPE.

Fetoscopic techniques for prenatal covering of gastroschisis in an ovine model are technically demanding and do not lead to permanent anchoring on the fetus until the end of gestation

INTRODUCTION

This is the cumulative technical report on the operative procedures and limitations of fetoscopic bag insertion, intestinal bag placement, and bag fixation to the fetus in a series of pilot studies in an ovine model for prenatal treatment of gastroschisis.

MATERIAL AND METHODS

In 24 German blackhead sheep, a surgically created gastroschisis was managed by fetoscopic placement of the extruded intestines into a bag. The bag was then fastened onto the fetal abdominal wall. Different materials (sterile gloves, latex condoms, laparosopic retrieval bags) and different fixation techniques (laparoscopic staplers, interrupted and continuous sutures) have been examined. The fetuses were retrieved and evaluated at the end of gestation.

RESULTS

Uterine bag insertion was successful in 15 of 24 (62.5%) and intestinal bag placement in 10 of 15 available fetuses (66.6%). The main factor limiting fetoscopic procedures was chorioamniotic separation (CAS). Sterilized condoms provided the most appropriate type of bags and the V-Loc™ running suture, the most expedient type of fixation, which was achieved in 9 of the 10 fetuses (complete = 2, partially = 7) by using a three port access (5 mm and 2 × 3 mm). All bags were encountered completely or partially dislocated from the fetus at the end of gestation.

CONCLUSIONS

Fetoscopic intestinal bag placement and fixation in gastroschisis technically demanding. None of the evaluated techniques led to permanent anchorage of the bag to the fetus. The development of specially designed instruments, bags and fixation methods is required to optimize this approach.

Delayed deep dermal necrosis after jellyfish sting in a 4-year-old female infant

We report the case of a 4-year-old female infant who developed ongoing deep dermal necrosis of the bilateral legs after jellyfish contact in Thailand. Stepwise radical debridement and vacuum assisted wound therapy seemed to be an effective strategy to prevent progressive soft tissue loss.

Positive effect of progesterone on motility and velocity of fresh, vitrified without permeable cryoprotectants and frozen with permeable cryoprotectants human spermatozoa

Steroid hormone progesterone has been found to play an important role in the migration of spermatozoa through the reproductive tract, as well as to induce hyperactive motility and increase sperm velocity. The aim of this study was to examine whether progesterone could induce beneficial effects in vitrified and slow-frozen spermatozoa. During the research process, 50 semen samples were divided into three treatment groups; noncryopreserved, slow-freezing and vitrification. After thawing and an incubation period of 2 hr to induce capacitation, semen samples from each treatment group were treated with 50 nM, 25 nM progesterone and a control solution for 30 min. Thereafter, the sperm suspensions were examined manually to assess the proportion of viable and motile spermatozoa, as well as using the CASA to evaluate the velocity parameters. The results indicated a higher proportion of progressively motile spermatozoa in vitrified teratozoospermic samples and improved velocity parameters in slow-frozen normozoospermic and teratozoospermic samples. The main conclusion of this research was that the used progesterone concentration of 50 nM was sufficient to significantly improve the motility of vitrified teratozoospermic samples and velocity parameters of cryopreserved sperm samples. The present findings might have important implications in determining ways of improving the current low rates of motility in cryopreserved spermatozoa.

The spaced learning concept significantly improves training for laparoscopic suturing: a pilot randomized controlled study

BACKGROUND

Spaced learning has been shown to be effective in various areas like traditional knowledge or motor skill acquisition. To evaluate the impact of implementation of the spaced learning concept in laparoscopic training was the aim of this study.

METHODS

To evaluate the effectiveness of spaced learning, subjects were asked to perform four surgeon's square knots on a bowel model prior and post 3 h of hands-on training. All subjects were medical students and novice in laparoscopic suturing. Total time, knot stability (evaluated via tensiometer), suture accuracy, knot quality (Muresan score), and laparoscopic performance (Munz checklist) were assessed. Moreover, motivation was accessed using Questionnaire on Current Motivation.

RESULTS

Twenty students were included in the study; after simple randomization, ten were trained using "spaced learning" concept and ten conservatively. Both groups had comparable baseline characteristics and improved after training significantly regarding all aspects assessed in this study. Subjects that trained via spaced learning were superior in terms of suture performance, knot quality, and suture strength. Ultimately, spaced learning significantly decreased anxiety and impression of challenge compared to controls.

CONCLUSION

The spaced learning concept is very suitable for complex motor skill acquisition like laparoscopic suturing and knot tying. It significantly improves laparoscopic performance and knot quality as shown by the knot score and suture strength. Thus, we recommend to incorporate spaced learning into training courses and surgical programs.

Cistopexia videoassistida em cadela com cistocele após prolapso uterino: relato de caso

O prolapso de vesícula urinária associado ao prolapso uterino é condição rara em cães e gatos. O tratamento preconizado para essa afecção é o reposicionamento anatômico das estruturas afetadas. No presente relato é descrito o manejo por meio de ovariossalpingo-histerectomia por celiotomia e, após dois dias, cistopexia videoassistida. Essa condição, conforme o conhecimento dos autores, não havia sido previamente descrita. A operação apresentou-se como possibilidade viável de tratamento, sem complicações pós-operatórias.

Midterm outcome of transumbilically laparoscopic-assisted versus laparoscopic and open appendectomy in children--a matched prospective study

BACKGROUND

Prospective data of transumbilically laparoscopic-assisted appendectomies (TULAA) is absent in the pediatric population. We therefore compared the midterm outcome of TULAA with open (OA) and laparoscopic (LA) appendectomies in children with appendicitis in a matched prospective study.

METHODS

A total of 20 patients operated with TULAA were matched to 20 cases operated by LA and OA, respectively, according to sex, age, and histology of the resected appendix. All 60 children were evaluated during a 3-month follow-up visit.

RESULTS

The subjective pain level after discharge, the rate of complications, and persistent painful wound as well as the duration of days refraining from school or kindergarten were similar in all three groups. The wound satisfaction was significantly higher in TULAA and LA. Children operated with TULAA had a faster return to full physical activity compared with OA.

CONCLUSION

Our data suggest that TULAA, LA, and OA have a similar outcome 3 months after surgery apart from cosmetic appearance of the wound and return to full physical activity in pediatric patients. Whether parental bias or the increased wound satisfaction act as confounders for early return to full physical activity should be evaluated in larger prospective randomized trials.

Manipulating and quantifying temperature-triggered coalescence with microcentrifugation

In this paper we describe a new approach to quantify the stability and coalescence kinetics of thermally switchable emulsions using an imaging-based microcentrifugation method. We first show that combining synchronized high-speed imaging with microfluidic centrifugation allows the direct measurement of the thermodynamic stability of emulsions, as expressed by the critical disjoining pressure. We apply this to a thermoresponsive emulsion, allowing us to measure the critical disjoining pressure as a function of temperature. The same method, combined with quantitative image analysis, also gives access to droplet-scale details of the coalescence process. We illustrate this by measuring temperature-dependent coalescence rates and by analysing the temperature-induced switching between two distinct microscopic mechanisms by which dense emulsions can destabilise to form a homogeneous oil phase.

An inter-machine comparison of tobacco smoke particle deposition in vitro from six independent smoke exposure systems

There are several whole smoke exposure systems used to assess the biological and toxicological impact of tobacco smoke in vitro. One such system is the Vitrocell® VC 10 Smoking Robot and exposure module. Using quartz crystal microbalances (QCMs) installed into the module, we were able to assess tobacco smoke particle deposition in real-time. We compared regional deposition across the module positions and doses delivered by six VC 10s in four independent laboratories: two in the UK, one in Germany and one in China. Gauge R&r analysis was applied to the total data package from the six VC 10s. As a percentage of the total, reproducibility (between all six VC 10s) and repeatability (error within an individual VC 10) accounted for 0.3% and 7.4% respectively. Thus Gauge R&r was 7.7%, less than 10% overall and considered statistically fit for purpose. The dose-responses obtained from the six machines across the four different locations demonstrated excellent agreement. There were little to no positional differences across the module at all airflows as determined by ANOVA (except for one machine and at three airflows only). These results support the on-going characterisation of the VC 10 exposure system and suitability for tobacco smoke exposure in vitro.

A microfluidic method to study demulsification kinetics

We present the results of experiments studying droplet coalescence in a dense layer of emulsion droplets using microfluidic circuits. The microfluidic structure allows direct observation of collisions and coalescence events between oil droplets dispersed in water. The coalescence rate of a flowing hexadecane-in-water emulsion was measured as a function of the droplet velocity and droplet concentration from image sequences measured with a high-speed camera. A trajectory analysis of colliding droplet pairs allows evaluation of the film drainage profile and coalescence time t(c.) The coalescence times obtained for thousands of droplet pairs enable us to calculate coalescence time distributions for each set of experimental parameters, which are the mean droplet approach velocity (v(0)), the mean dispersed phase fraction (φ) and the mean hydraulic diameter of a droplet pair (d(p)). The expected value E(t(c)) of the coalescence time distributions scales as E(t(c)) is proportional to (v(0))(-0.105±0.043)(d(p))(0.562±0.287), but is independent of φ. We discuss the potential of the procedure for the prediction of emulsion stability in industrial applications.

Reactions of HCl and D2O with molten alkali carbonates

The acidic oxide SO₂ and protic acid HCl are among the gases released in the combustion of coal and the incineration of municipal waste. They are typically removed by wet or dry scrubbing involving calcium carbonate or calcium hydroxide. The molten alkali carbonate eutectic provides a liquid-state alternative that readily absorbs SO₂ and HCl and does not become covered with a passivating layer. Gas-liquid scattering experiments utilizing the eutectic mixture (44 mol % Li₂CO₃, 31 mol % Na₂CO₃, 25 mol % K₂CO₃) reveal that the reaction probability for HCl(g) + CO₃²⁻ → CO₂(g) + OH⁻ + Cl⁻ is 0.31 ± 0.02 at 683 K and rises to 0.39 at 783 K. Gaseous CO₂ is formed within 10⁻⁴ s or less, implying that the reaction takes place in a liquid depth of less than 1000 Å. When the melt is exposed to D₂O, the analogous reaction D₂O(g) + CO₃²⁻ → CO₂(g) + 2OD⁻ occurs too slowly to measure and no water uptake is observed. Together with previous studies of SO₂(g) + CO₃²⁻ → CO₂(g) + SO₃²⁻, these results demonstrate that molten carbonates efficiently remove both gaseous HCl and SO₂ while reacting at most weakly with water vapor. The experiments further highlight the remarkable ability of hot CO₃²⁻ ions to behave as a base in reactions with protic and Lewis acids.

Reactive collisions of sulfur dioxide with molten carbonates

Molecular beam scattering experiments are used to investigate reactions of SO(2) at the surface of a molten alkali carbonate eutectic at 683 K. We find that two-thirds of the SO(2) molecules that thermalize at the surface of the melt are converted to gaseous CO(2) via the reaction SO(2)(g) + CO(3)(2-) --> CO(2)(g) + SO(3)(-2). The CO(2) product is formed from SO(2) in less than 10(-6) s, implying that the reaction takes place in a shallow liquid region less than 100 A deep. The reaction probability does not vary between 683 and 883 K, further implying a compensation between decreasing SO(2) residence time in the near-interfacial region and increasing reactivity at higher temperatures. These results demonstrate the remarkable efficiency of SO(2) --> CO(2) conversion by molten carbonates, which appear to be much more reactive than dry calcium carbonate or wet slurries commonly used for flue gas desulfurization in coal-burning power plants.

Orientation of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine at the surface of formamide and hydroxypropionitrile

Phospholipids are a main component of cell membranes. Therefore, the experimental investigation of the self-organization of phospholipids is of great interest. Here we present results concerning the orientation of the phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) at the surface of the polar solvents formamide and 3-hydroxypropionitrile (HPN), which we investigated by means of neutral impact collision ion scattering spectroscopy. It is shown that, in HPN, at low POPC surface excesses, the phospholipids are oriented with the polar headgroups pointing out of the solution. It is concluded that the behavior of lipids at the surface of liquids is more complex than expected and to a great extent dependent on the solvent. Comprehension of the behavior of POPC in the applied solvents might contribute to the understanding of the self-organization of phospholipids in water.

[Anti-metastatic effects of serine protease inhibitors: animal models for analysis]

To date, no effective adjuvant drug preventing the aggressive spread of tumour cells in late stages of cancer disease or at the time-point of primary tumour removal is available. Although proteases, including members of the large serine protease family, were shown to be promising targets for an anti-metastatic cancer therapy, synthetic protease inhibitors (SPIs) have so far failed to be introduced into the clinic. In addition to considerations in the design of classical in vivo -tests of SPIs as cancer therapy agents, we here review our findings with a straightforward, highly sensitive and very fast in vivo metastasis model and its implications in the development of efficient anti-metastatic SPIs. The lacZ-tagging of tumour cells of this very aggressive T-cell lymphoma model allowed highly sensitive and reproducible detection of metastases within seven days after tumour cell inoculation by X-gal staining of whole organs, allowing cost-effective and material-saving side-by-side screening of a series of SPIs with different specificities for different serine proteases. By establishment of specificity/antimetastatic efficacy correlations we identified coagulation factor Xa as one important target of anti-metastatic SPIs and could use this information for the subsequent design and optimization of factor Xa-specific lead structures.

CONCLUSION

We exemplify the usefulness of high-throughput in vivo analysis to direct optimization of lead structures and how this may allow unexpected insight into the molecular biology of metastasis.

Antimetastatische Effizienz synthetischer Serinproteaseinhibitoren

Es gibt kein wirksames adjuvantes Therapeutikum, das die aggressive Ausbreitung von Tumorzellen in fortgeschrittenen Tumorstadien oder bei chirurgischer Entfernung des Primärtumors verhindert. Obwohl Proteasen einschließlich der Serinproteasen als vielversprechende Zielstrukturen für eine antimetastatische Krebstherapie ausgewiesen wurden, schlug die klinische Einführung synthetischer Proteaseinhibitoren (SPIs) fehl. Zusätzlich zu Überlegungen zu klassischen Herangehensweisen bei der Prüfung von SPIs als Krebstherapeutika in vivo, beleuchten wir hier unsere Ergebnisse mit einem einfach handhabbaren, hochsensitiven und schnellen In-vivo-Metastasierungsmodell und seine Bedeutung für die Entwicklung effizienter, antimetastatisch wirksamer SPIs. Die lacZ-Markierung sehr aggressiver T-Zell-Lymphomzellen ermöglicht die hochsensitive und reproduzierbare Detektion von Metastasen innerhalb von sieben Tagen nach Tumorzellinokulation, durch X-Gal-Färbung ganzer Organe. Dieses Modell erlaubt ein kostengünstiges und materialsparendes paralleles Screening einer Serie von SPIs mit unterschiedlichen Spezifitäten für verschiedene Serinproteasen. Durch Korrelationen zwischen Spezifität und antimetastatischer Effizienz identifizierten wir den Gerinnungsfaktor Xa als wichtige Zielstruktur antimetastatischer SPIs und konnten diese Information für das weitere Design und die Optimierung von Faktor-Xaspezifischen Leitstrukturen verwenden. Schlussfolgerung: Wir können exemplarisch zeigen, dass In-vivo-Analysen mit hohem Durchsatz die Optimierung von Leitstrukturen dirigieren können und darüber hinaus zu unerwarteten, neuen Einblicken in die Molekularbiologie der Metastasierung führen.