Extrusion-based, Three-dimensional Printing of Calcium-phosphate Scaffolds

Small or large bone defects, can occur due to a variety of reasons: congenital disorders, infections, tumors, or traumas which can lead to significant disabilities. There is an assortment of bone grafting procedures, each having their own respective advantages and disadvantages and exhibiting certain essential characteristics. Among the available grafts, autogenous (autograft), allograft, xenograft, and alloplasts, all exhibit a minimum of two-thirds of the essential characteristics and have been proven useful in fully or partially repairing skeletal defects. However, different host-to-grafting material responses have been reported and should be taken into consideration when determining treatment options. A large range of physical and chemical properties can be achieved with calcium phosphate based materials, which possess two of the ideal characteristics for grafting procedures: osteoconduction and osseointegration. Calcium phosphate based scaffolds composed of hydroxyapatite (HA), ?-tri-calcium phosphate (?-TCP), or a combination of both (HA/?-TCP) were investigated as materials for three-dimensional printing process to create layer-by-layer structures for use as bone regeneration scaffolds. Different calcium-phosphate phases will result in different degrees of in vivo dissolution and/or cell-mediated resorption. There has been a growing interest in BCP because it has been shown that this material improves the formation of new bone inside the implanted scaffold. The literature indicates that the faster dissolution rate of ?-TCP would be greatly responsible of this enhancement. However, in vitro tests indicate that fast dissolution can decrease the mechanical strength of BCP scaffolds. Furthermore, studies reported that HA has higher mechanical strength and lower degradation rate than ?-TCP. Therefore, the HA/?-TCP ratio is a key parameter controlling the performance of the scaffold for bone repair applications, since it determines degradation rate, calcium (Ca2+) and phosphate (PO4) release and mechanical properties of the material.Chemical Engineerin

Presence of human papilloma virus in Caucasian women living in the central Europe diagnosed with vulvar intraepithelial neoplasia

Objectives: The role of human papilloma virus (HPV) in the development of cancerous states of female reproductive tracthas been widely debated. However, the information about presence of HPV in the Caucasian women living in the centralEurope diagnosed with vulvar intraepithelial neoplasia (VIN) is missing. So far, no recommendation was made to completeHPV detection in time of vulvar biopsy or after the results of positive VIN are obtained. We aimed to assess the presence ofHPV in women with vulvar intraepithelial neoplasia diagnosed at the Department of Gynecology, Obstetrics and OncologicalGynecology in Bytom, Poland.Material and methods: The retrospective examination of 120 consecutive vulvar biopsies obtained from women withpersistent vulvar itching was done. Only patients with diagnosis of VIN were included in the further analysis. HPV DNAwas detected using HPV Linear Array Genotyping Test including 14 HPV genotypes (16, 18, 31, 33, 35, 39, 45, 51, 52, 56,58, 59, 66, 68).Results: Out of 120 vulvar samples retrieved, 18 women were positive for VIN, including15 usual VIN (uVIN) and three differentiatedtype (dVIN ). 10 samples were eligible for DNA detection. HPV DNA was found in two women with uVIN (HPV16 and 51).Conclusions: It is advisable to recommend HPV genotyping in women with VIN, regardless of their age and histologic type.The incidence of HPV infection in Caucasian women from the central Europe with VIN should be further studied

Comparison of gene expression of mitogenic kinin path in adherent and non-adherent CD 34-stem cells using oligonucleotide microarrays.

One of the more interesting cells present in the umbilical cord blood - as far as their potential clinical use is concerned - are stem cells not presenting the CD34 antigen. These are the pluripotential cells with their biological properties similar to mesenchymal stem cells, with the ability to differentiate into such tissue types as bone, cartilage, nervous (to some extent), glia and muscle. The authors compared the activity of genes coding the proteins in mitogenic signal paths activated by kinin receptors using oligonucleotide microarrays in adherent and non-adherent CD 34- cells derived from umbilical cord blood. In the linear regression model with a 95% prognosis area for differentiating genes outside this area, the following genes were selected: c-jun (present in 3 isoforms) and c-fos. The fos and jun genes create the AP-1 transcriptive factor which regulates the expression of genes taking part in numerous cellular processes, including the cell cycle and mitosis. The obtained results shed some light on the molecular processes behind the MSC proliferation and are a starting point for further studies on the mesenchymal stem cell biology

Periodontal tissue regeneration using brain-derived neurotrophic factor delivered by collagen sponge

To evaluate the influence of brain-derived neurotrophic factor (BDNF) in combination with collagen sponges on periodontal tissue regeneration. Methods: Unilateral, "box-type" (4 x 5 mm), one-wall intrabony defects were surgically created at posterior mandibular teeth in 14 Beagle dogs. Animals received all experimental groups, and the defects were randomly treated as follows: Emdogain (R) (positive control) [EMD]; HeliPlug (R)+BDNF [H/B]; RCP (R)+BDNF [R/B]; negative control [Control]; TeruPlug (R)+BDNF [Tp/B]; and TeruPlug (R)+BDNF2 [Ts/B]. Periodontal wound healing was observed every 2 weeks by computed tomography. The animals were euthanized at 8 weeks postsurgery for microcomputed tomography and histomorphometric evaluation. Results: All groups presented similar to 1 mm apical epithelial attachment relative to cementoenamel junction. Although linear measurements did not demonstrate significant differences between groups for cementum and periodontal ligament regeneration, semiquantitative analysis depicted higher percentage of samples with mineralized cementum and functional PDL for Ts/B, R/B, and H/B groups relative to EMD and Control (p < 0.046). Irrespective of quantification method (2D or 3D), Ts/B, Control, Tp/B, and H/B groups presented the highest mean percentage of new bone (not significantly different) followed by R/B and EMD groups. Conclusion: While no significant differences were detected in quantitative analyses, Ts/B combination results in significantly more samples with full periodontal tissue regeneration relative to control groups. Impact Statement The various roles played by brain-derived neurotrophic factor (BDNF) in a multitude of tissues and at different scenarios have rendered BDNF a favorable candidate for improving tissue regeneration. Although the tested formulations of BDNF quantitatively regenerate tissue to a level similar to control groups, it resulted in significantly more instances of full regeneration2515-1610721083COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP88881.132654/2016-012016/17793-1; 2017/19362-

Lineage-specific mutation of Lmx1b provides new insights into distinct regulation of suture development in different areas of the calvaria

The calvaria (top part of the skull) is made of pieces of bone as well as multiple soft tissue joints called sutures. The latter is crucial to the growth and morphogenesis of the skull, and thus a loss of calvarial sutures can lead to severe congenital defects in humans. During embryogenesis, the calvaria develops from the cranial mesenchyme covering the brain, which contains cells originating from the neural crest and the mesoderm. While the mechanism that patterns the cranial mesenchyme into bone and sutures is not well understood, function of Lmx1b, a gene encoding a LIM-domain homeodomain transcription factor, plays a key role in this process. In the current study, we investigated a difference in the function of Lmx1b in different parts of the calvaria using neural crest-specific and mesoderm-specific Lmx1b mutants. We found that Lmx1b was obligatory for development of the interfrontal suture and the anterior fontanel along the dorsal midline of the skull, but not for the posterior fontanel over the midbrain. Also, Lmx1b mutation in the neural crest-derived mesenchyme, but not the mesoderm-derived mesenchyme, had a non-cell autonomous effect on coronal suture development. Furthermore, overexpression of Lmx1b in the neural crest lineage had different effects on the position of the coronal suture on the apical part and the basal part. Other unexpected phenotypes of Lmx1b mutants led to an additional finding that the coronal suture and the sagittal suture are of dual embryonic origin. Together, our data reveal a remarkable level of regional specificity in regulation of calvarial development

Effect of implant placement depth on the peri-implant bone defect configurations in ligature-induced peri-implantitis : an experimental study in dogs

The subcrestal placement of implant platform has been considered a key factor in the preservation of crestal bone, but the influence of implant placement depth on bone remodeling combined with peri-implantitis is not fully understood. The aim of this study was to assess the effect of the crestal or subcrestal placement of implants on peri-implant bone defects of ligature-induced peri-implantitis in dogs. Eight weeks after tooth extraction in six beagle dogs, two different types of implants (A: OsseoSpeed?, Astra, Mölndal, Sweden; B: Integra-CP?, Bicon, Boston, USA) were placed at either crestal or subcrestal (-1.5 mm) positions on one side of the mandible. Ligature-induced peri-implantitis was initiated four weeks after the installation of the healing abutment connections. After 12 weeks, tissue biopsies were processed for histological analyses. Supra-alveolar bone loss combined with a shallow infrabony defect was observed in crestal level implants while deep and wide infrabony defects were present in subcrestal level groups. Subcrestal groups showed significantly greater ridge loss, depths and widths of infrabony defects when compared to crestal groups (P<0.001). Within the limitations of the animal study, it can be stated that the implants at subcrestal position displayed greater infra-osseous defect than implants at crestal position under an experimental ligature-induced peri-implantitis

Assessing osseointegration of metallic implants with boronized surface treatment

Modification of endosteal implants through surface treatments have been investigated to improve osseointegration. Boronization has demonstrated favorable mechanical properties, but limited studies have assessed translational, in vivo outcomes. This study investigated the effect of implant surface boronization on bone healing. Two implant surface roughness profiles (acid etched, machined) in CP titanium (type II) alloy implants were boronized by solid-state diffusion until 10-15µm boron coating was achieved. The surface-treated implants were placed bilaterally into 5 adult sheep ilia for three and six weeks. Four implant groups were tested: boronized machined (BM), boronized acid-etched (BAA), control machined (CM), and control acid-etched (CAA). Osseointegration was quantified by calculating bone to implant contact (BIC) and bone area fraction occupancy (BAFO). Both implant types treated with boronization had BIC values not statistically different from machined control implants at t=3 weeks, and significantly less than acid-etched control (p<0.02). BAFO values were not statistically different for all 3-week groups except machined control (significantly less at p<0.02). BAFO had a significant downward trend from 3 to 6 weeks in both boronized implant types (p<0.03) while both control implant types had significant increases in BIC and BAFO from 3 to 6 weeks. Non-decalcified histology depicted intramembranous-like healing/remodeling in bone for controls, but an absence of this dynamic process in bone for boronized implants. These findings are inconsistent with in vitro work describing bone regenerative properties of elemental Boron and suggests that effects of boron on in vivo bone healing warrant further investigation

Prolactin-secreting pituitary adenomas: male-specific differences in pathogenesis, clinical presentation and treatment

Prolactinomas (PRLomas) constitute approximately half of all pituitary adenomas and approximately one-fifth of them are diagnosed in males. The clinical presentation of PRLomas results from direct prolactin (PRL) action, duration and severity of hyperprolactinemia, and tumor mass effect. Male PRLomas, compared to females, tend to be larger and more invasive, are associated with higher PRL concentration at diagnosis, present higher proliferative potential, are more frequently resistant to standard pharmacotherapy, and thus may require multimodal approach, including surgical resection, radiotherapy, and alternative medical agents. Therefore, the management of PRLomas in men is challenging in many cases. Additionally, hyperprolactinemia is associated with a significant negative impact on men’s health, including sexual function and fertility potential, bone health, cardiovascular and metabolic complications, leading to decreased quality of life. In this review, we highlight the differences in pathogenesis, clinical presentation and treatment of PRLomas concerning the male sex

Heat shock protein 27 (hsp27) in patients with ovarian cancer

Objectives: Ovarian cancer remains a very common cause of death among women worldwide. The cause is to be found in too late of a diagnostic process and therapeutic difficulties The presence of heat shock proteins in the serum of ovarian cancer patients is still a new area of study. It is necessary to continue studies on the possibilities for using these markers to predict a patient’s response to a specific therapy and to monitor treatment progress. Material and methods: The study included 52 women with ovarian cancer, hospitalised at the Department of Obstetrics, Gynaecology and Oncological Gynaecology, Medical University of Silesia. The control group consisted of 25 healthy women. The levels of HSP27 in the studied sera were determined by an immunoenzymatic method (ELISA). Results: The mean concentration of HSP27 in the group of patients with ovarian cancer was significantly higher than in the control group of healthy women. We have shown that mean HSP27 levels in ovarian cancer patients increase with tumour progression and further depend on the clinical stage of the disease (FIGO). Positivity values analysis revealed in all clinical stages of ovarian cancer, excluding stage 1, it was significantly higher than in the control group, and at the 4th stage, it is significantly higher than at the 1st, 2nd, and 3rd stages. However, both for the untreated patients and those patients after chemotherapy, the mean HSP27 levels were significantly higher than in the control group. Conclusions: Our studies indicate a significant contribution of HSP27 to the pathogenesis of ovarian cancer. It seems that serum HSP27 can be a marker for this cancer’s development, and a marker for the clinical stage