A comparison of four different techniques of assisted hatching

BACKGROUND: Assisted hatching (AH) has been proposed as a means to increase the implantation rate in patients with poor prognosis for pregnancy. The procedure appears to be effective when used selectively. Several different methods for AH have been introduced over the years but comparative studies are lacking. The aim of the current study was to compare retrospectively the efficacy of AH performed with four different methods in patients undergoing IVF or ICSI. METHODS: AH was performed prior to day 3 embryo transfer in 794 IVF/ICSI cycles. Indications for AH were females aged >35 years and/or elevated follicular phase FSH levels, previous failed IVF/ICSI cycles, poor embryo quality, and thick zona pellucida (>15 microm). Assignment to one of the four methods of AH was according to the availability of the particular method during the study period. The study was not randomized. RESULTS: Partial zona dissection was used in 239, acid Tyrode in 191, diode laser in 219 and pronase thinning of the zona pellucida in 145. Mean female age, mean number of previous failed IVF/ICSI cycles, number of oocytes retrieved, fertilization and cleavage rates, good quality embryos and zona thickness on day 3 did not differ between groups. Mean number of embryos transferred, implantation rate, clinical pregnancy rate, and abortion rates were likewise similar. CONCLUSIONS: Selective AH using four different methods yields similar implantation and pregnancy rates.     

Morphogenesis of the secondary palate in mouse embryos with special reference to the development of rugae

Morphological studies of secondary palate formation, with special reference to the development of rugae, were carried out on Jcl:ICR mouse embryos. Three rugae were observed on the anterior part of the future oral surface of the vertically developing palatal shelves in 13-day embryos. Rugae increased in number as the development of the palatal shelves proceeded, and five to six prominent rugae were observed in 14-day embryos just prior to shelf elevation. The folding of these five to six rugae progressed in conjunction with the formation of a sharp, valley-like groove at the base of the anterior two-fifths of the vertical palatal shelves. As palatal shelves elevated, the groove disappeared gradually, and, accordingly, the folding of rugae loosened. In the groove region, the superficial epithelial cells were roundish, while the basal ones were elongated. Such characteristic features were no longer observed when the disappearance of the groove was completed. Eight rugae were observed on the future hard palate of 14-day embryos with already completed palatal fusion. An additional ruga was frequently found in 15-day embryos, and the pattern then was almost the same as that of an adult. Epithelial thickening and condensation at the rugae region, as well as mesenchymal condensation under the epithelium of the rugae, were confirmed in embryos both before and after elevation of the palatal shelves. There is a possibility that these structural characteristics observed in the epithelial and mesenchymal cells of the rugae and groove regions may be related to palatal shelf elevation.     

A comparison among three different apheretic techniques for treatment of hyperbilirubinemia

Liver failure is associated to high mortality due to the accumulation of protein-bound metabolites, such as bilirubin, not removed by conventional hemodialysis. Different methods can efficiently remove them, such as the molecular adsorbent recirculating system (MARS), plasma exchange (PEX), and bilirubin or plasma adsorption perfusion (PAP). No direct comparison exists between MARS, PEX and PAP, and current guidelines do not specify which method (and when) to use. We have retrospectively evaluated MARS, PEX and PAP in their effectiveness in lowering plasma bilirubin concentration, and their effects on liver and kidney function. A total of 98 patients have been recruited, which comprised 68 patients treated with PAP (177 sessions), 16 patients with PEX (41 sessions) and 11 patients with MARS (21 sessions). Bilirubin, creatinine, liver enzymes were analyzed before and after the first treatment with each technique. The three methods did not differ for bilirubin lowering efficiency, with MARS showing only slightly less effective reductions. Finally, the three techniques did not differ in the amount of change of cholinesterase, but a lower reduction in AST was found using PAP. Our retrospective observation is one of the largest case series of hepatic failure treated with bilirubin absorption. The choice of the technique cannot be based on the desired reduction in bilirubin concentration. Based on costs and duration of treatment, we suggest that PAP could be considered as a first-line approach. In case of kidney involvement, MARS remains a valuable option.     

A histochemical study of the development of premaxilla and maxilla during secondary palate formation in the mouse embryo

The development of premaxilla and maxilla in the mouse fetus during secondary palate formation from the 12th to the 16th days of gestation was histochemically assessed. To determine the developmental stages, a classification based on the morphogenesis of the limbs, or the "limb score" (LS) was employed. The stage of LS coincided with the gestational age from the 13th to the 15th days. Early on the 12th day, alkaline phosphatase (ALPase) activity was intense in the mesenchyme lateral to the incisor tooth bud and latero-inferior to the inferior orbital nerve. Subsequently, osteoblasts differentiated at these two sites. The ALPase positive area grew concomitantly with the nasal capsule, the molar tooth germ, and the closure of the secondary palate. The area of bone differentiation contoured the orbital nerve and extended to the rostral part of the secondary palate. At the LS stage -6 (13.52 days), ALPase activity was observed in the mesenchyme medial to, and also surrounding the molar tooth germ. The area of osteogenesis of the secondary palate spread along the medial side of the molar tooth germ, where the formation of the medial alveolar process of the maxilla was completed by the LS stage 3 (15.35 days). The ALPase positive area extended to the horizontal palatal shelves. By late on the 16th day, the palatal process was fully developed. In parallel, bone resorption began on the molar side of the alveolar process. Acid phosphatase and tartrate-resistant acid phosphatase activities (ACPase and TRACPase activity, respectively) revealed ACPase and TRACPase positive mononuclear cells around the molar tooth germ long before ossification occurred. Our results thus suggest an involvement of the incisor tooth bud and the infra-orbital nerve in the initial osteogenesis of the premaxilla and maxilla. Enzyme activities lead to the consideration that osteoclast precursors initiate differentiation around the molar tooth germ. Ostensibly, the mechanical force from the growth of the molar tooth would promote differentiation and activation of osteoclasts located on the alveolar process. Also, the LS classification would improve and simplify future studies of the development of the secondary palate.     

In vitro development of palatal tissues from embryonic mice. I. Differentiation of the secondary palate from 12-day mouse mebryos

Single palatal processes or homotypic paired palatal processes from 12-day mouse embryos (strain C57B1) were grown in organ culture on Millipore filters. The epithelium along the medial edge of each palatal process became disrupted, and, by 72 hours of culture, paired palatal processes achieved mesenchymal fusion at the site of disruption. The nasal epithelium of paired palatal processes became a recognizable pseudostratified ciliated columnar epithelium by 96 hours of culture, and the oral epithelium became a recognizable stratified squamous epithelium by 120 hours of culture. These events correspond temporally to the differentiation of palatal tissue in vivo. Differentiative changes of single palatal processes followed the same schedule as double processes. Observations also suggest that the epithelium at the tip of the vertically oriented young palatal process corresponds to the medial epithelium of the more advanced horizontal process — these observations have bearing on the mechanism of palatal movement. In addition, the results suggest that a re-evaluation of the terminology “potential for fusion” is necessary.     

A comparison of response exaggeration techniques

Compared the effectiveness of several response exaggeration techniques. Socially anxious college males (N = 34) were instructed to exaggerate some component of social anxiety onset. One group exaggerated their attending to manifestations of their anxiety, two groups exaggerated either a relevant or irrelevant anxiety response, a fourth group imagined an exaggerated consequence of their anxiety, and a fifth group served as a placebo control. All groups reported a greater willingness to initiate and maintain an interaction with a female and displayed less anxiety in a role-playing situation; no differential treatment effects were found. These findings fail to support results from other studies that attested to the efficacy of response exaggeration techniques.     

A comparison of two ulcerogenic techniques

Long Evans rats 45, 130, or 280 days old were exposed either to a supine restraint or a water restraint treatment for two hr. This was followed by a 2-hr rest period. Core body temperature was recorded every 30 min. Stress-induced hypothermia was greatest in the water restraint treatment and in younger rats irrespective in both restraint conditions. The water restraint procedure as compared to the supine restraint produced significantly more ulcers in 130- and 280-day-old rats.     

In vitro development of palatal tissues from embryonic mice. I. Differentiation of the secondary palate from 12-day mouse embryos.

Single palatal processes or homotypic paired palatal processes from 12-day mouse embryos (strain C57Bl) were grown in organ culture on Millipore filters. The epithelium along the medial edge of each palatal process became disrupted, and, by 72 hours of culture, paired palatal processes achieved mesenchymal fusion at the site of disruption. The nasal epithelium of paired palatal processes became a recognizable pseudostratified ciliated columnar epithelium by 96 hours of culture, and the oral epithelium became a recognizable stratified squamous epithelium by 120 hours of culture. These events correspond temporally to the differentiation of palatal tissue in vivo. Differentiative changes of single palatal processes followed the same schedule as double processes. Observations also suggest that the epithelium at the tip of the vertically oriented young palatal process corresponds to the medial epithelium of the more advanced horizontal process-these observations have bearing on the mechanism of palatal movement. In addition, the results suggest that a re-evaluation of the terminology "potential for fusion" is necessary.     

A comparison of different extracts of Candida albicans in agar gel double diffusion techniques

A preliminary comparative study, by 4 independent groups, of certain extracts of Candida albicans, showed variation in their antigenicity. Different agar gel double diffusion tests were used by each group; two groups used micro-methods and two used macro-methods. The number of positive precipitin reactions detected by these methods was shown to vary greatly.     

In vivo and in vitro assessment of mitogen activated protein kinase involvement during quail secondary palate formation

Spatiotemporally regulated cell proliferation and differentiation are crucial for the successful completion of morphogenesis of the vertebrate secondary palate. An understanding of the mechanisms by which these cellular phenomena are regulated during palate development involves the identification of the various signal transduction pathways. In the present study, the presence and activation of mitogen-activated protein (MAP) kinases were investigated during the development of quail secondary palate. The palatal shelves were dissected on days 5–9 of incubation, homogenized, and centrifuged, after which the samples were separated by anion exchange fast protein liquid chromatography. The fractions were analyzed for myelin basic protein (MBP) phosphorylation. In addition, primary cultures of quail palate mesenchymal cells (QPMCs) were treated with epidermal growth factor (EGF) and prepared for MBP phosphorylation assays. A temporally regulated pattern of phosphotransferase activity, characterized by a three-fold increase in phosphotransferase activity toward MBP between days 5 and 8 of incubation, was observed during quail palate development. Western blotting, using MAP kinase antibodies, demonstrated the presence of a 42-kDa isoform between days 5 and 9 of incubation, during which the level of protein remained constant. Antityrosine immunoblotting with 4G10 also detected a 42-kDa protein. Phosphotransferase assays, using either a MAP kinase-specific substrate peptide (S5) or a protein kinase C inhibitor (R3), further confirmed the presence of a MAP kinase in the developing palate of quail. Because diverse biological processes occur concurrently during in vivo palate morphogenesis, the involvement of MAP kinase was explored further in primary cell culture. The data showed that EGF stimulated proliferation and activated 42-kDa MAP kinase in QPMCs. It is suggested that MAP kinase cascade may be involved in growth factor-regulated cell proliferation during morphogenesis of quail secondary palate. Anat. Rec. 252:194–204, 1998. © 1998 Wiley-Liss, Inc.     

上腭发生的分子调控机制

哺乳动物上腭的发生包括原生腭和次生腭的发生.其中,次生腭的发生涉及到高度动态的形态发生过程,分为腭突生长及模式化,两侧腭突的上抬/重定位,两侧腭突的黏附和融合形成次生腭等过程.近来的研究表明,上腭发育所需的基因,包括了声波刺猬蛋白(Shh)、成纤维细胞生长因子(FGF)、转化生长因子β(TGF-β)和Wnt信号通路,这...     

A theoretical and experimental comparison of different techniques for B1 mapping at very high fields

With the increasing use of ultrahigh‐field MR with multiple transmit channels, mapping of the B₁⁺ field has become a critical factor in many studies, leading to the publication of a large number of sequences for the measurement of the flip angle in recent years. In this article, the accuracy, precision and practicability of some of the most prominent of these techniques are investigated both theoretically, using error propagation computations and Monte‐Carlo simulations, and experimentally for different settings. For an exemplary experiment, which is typical for high‐field applications, the flip angle uncertainty is calculated and measured for two‐ and three‐dimensional acquisitions for techniques based on both magnitude and phase data. Simulated and measured results show good agreement. An experimental assessment of T₁ and B₀ dependence yields weak variations with these parameters for only a few of the sequences. Measurements on human scanners show crucial influences of specific absorption rate limitations, especially at ultrahigh field. Copyright © 2012 John Wiley & Sons, Ltd.     

Differential changes in cartilage cell proliferation and cell density in the rat craniofacial complex during secondary palate development

During mammalian secondary palate formation sagittal growth of the lower face has been shown to be more rapid than that of the upper face, and the tongue and mandible extend beneath the primary palate. In order to identify factors contributing to this differential growth pattern, cellular and morphologic growth of the major cartilages of the upper and lower facial regions were studied in radioautographic sections labeled with tritiated thymidine. Evaluation of cell-density recordings, labeling indices, and structural dimensions revealed significant differences between Meckel's cartilage in the lower face, and the nasal cartilage and anterior cranial base cartilage in the upper face. After formation of the precartilaginous blastema, labeling indices were high in Meckel's cartilage (20–30%), but very low in the nasal cartilage and the anterior cranial base (0–2%). During secondary palate formation of the volume of Meckel's cartilage increased more rapidly than the other cartilages and its growth was primarily in the sagittal direction. Between days 15 and 17, the increase in the length of Meckel's cartilage (165%) was approximately twice as great as the increase in the combined length of the nasal cartilage and the anterior cranial base (77%). During this period induction of cleft palate with some teratogens has been shown to severely retard growth of Meckel's cartilage and produce mandibular retrognathia that contributes to delayed elevation of the palatal shelves. Therefore, extensive cell proliferation in Meckel's cartilage, during a period of limited proliferation in other craniofacial cartilages, appears to contribute to its rapid growth and its differential sensitivity to growth inhibition.     

A comparison of micro CT with other techniques used in the characterization of scaffolds

The structure and architecture of scaffolds are crucial factors in scaffold-based tissue engineering as they affect the functionality of the tissue engineered constructs and the eventual application in health care. Therefore, effective scaffold assessment techniques are required right at the initial stages of research and development so as to select or design scaffolds with suitable properties. Various techniques have been developed in evaluating these important features and the outcome of the assessment is the eventual improvement on the subsequent design of the scaffold. An effective evaluation approach should be fast, accurate and non-destructive, while providing a comprehensive overview of the various morphological and architectural characteristics. Current assessment techniques would include theoretical calculation, scanning electron microscopy (SEM), mercury and flow porosimetry, gas pycnometry, gas adsorption and micro computed tomography (CT). Micro CT is a more recent method of examining the characteristics of scaffolds and this review aims to highlight this current approach while comparing it with other techniques.     

In vivo and in vitro comparison of three different allografts vitalized with human mesenchymal stromal cells

Bone allografts are commonly used by orthopedists to provide a mechanical support and template for cellular colonization and tissue repair. There is an increasing demand for bone graft substitutes that are safe and easy to store but which are equally effective in supporting new bone growth. In this study, we compared three different human bone allografts: (1) the cryopreserved allograft (frozen), (2) the gamma-irradiated and cryopreserved allograft (γ-irradiated), and (3) the solvent dehydrated and γ-irradiated-processed bone allograft (Tutoplast(?) Process Bone [TPB]). Human mesenchymal stromal cells (hMSCs) have the potential to differentiate into osteogenic, chondrogenic, and adipogenic lineages. Our results showed that hMSC seeding efficiency was equivalent among the three bone allografts. However, differences were observed in terms of cell metabolism (viability), osteoblastic gene expression, and in vivo bone formation. Frozen allografts had the higher frequency of new bone formation in vivo (89%). Compared with frozen allografts, we demonstrated that TPB allografts allowed optimal hMSC viability, osteoblastic differentiation, and bone formation to occur in vivo (72%). Further, the frequency of successful bone formation was higher than that obtained with the γ-irradiated allograft (55%). Moreover, after hMSC osteoinduction, 100% of the TPB and frozen allografts formed bone in vivo whereas only 61% of the γ-irradiated allografts did. As healthcare teams around the world require bone-grafting scaffolds that are safe and easy to store, the TPB allograft appears to be a good compromise between efficient bone formation in vivo and convenient storage at room temperature.     

Assessment of murine lung tumour development: a comparison of two techniques

Two techniques (surface photographic analysis [SPA] and microscopic tumour analysis [MTA]) are described for assessing the stage of tumour development induced by intraperitoneal 4-(methyl nitrosamino)- 1-(3 pyridyl)-1-butanone in syngeneic A/J mice. Parameters used to assess the number and size of tumours were surface tumour count (STC), surface tumour area (STA). and relative tumour surface area (RTSA)--all using SPA; and mean tumour count (MTC), mean tumour area, and relative tumour area (RTA)--all using MTA. In a study examining the possible effects of Millipore chamber implantation on lung tumours, the stage of tumour development was assessed in 239 mice using both SPA and MTA. Statistically significant correlations (Spearman-Rank) were apparent between the derived parameters: STC vs. MTC (r = 0.6, P <0.0001); STA vs. mean tumour area (r = 0.5, P <0.0001); RTSA vs. RTA (r = 0.4, P <0.0001). Therefore, it is concluded that SPA--the simpler technique--is an appropriate method for assessing the stage of tumour development in this model.