A micro-computed tomography analysis of internal and marginal fits of fixed partial dentures: Effect of preparation finish line designs on monolithic zirconia and heat-pressed zirconia-reinforced lithium disilicate.

PURPOSE: To evaluate the effect of finish line design (chamfer and feather-edge) and ceramic type on the internal and marginal fits of fixed partial dentures on abutment teeth. MATERIALS AND METHODS: Two typodont mandibular casts, missing right first premolar tooth, received tooth preparation on canine and second premolar abutments (one cast with chamfer finish line and the other cast with feather-edge finish line). The preparation segment of each typodont model was scanned, 3D printed in resin, and then invested and casted in metal to obtain two metal models. Polyvinyl siloxane impressions were made for the metal models and poured in type IV stone. The stone models (n = 40) were randomly assigned into four groups (n = 10): chamfer finish line with heat-pressed zirconia reinforced lithium disilicate fixed partial denture (CL), chamfer finish line with monolithic zirconia fixed partial denture (CZ), feather-edge finish line with heat-pressed zirconia-reinforced lithium disilicate fixed partial denture (FL), and feather-edge finish line with monolithic zirconia fixed partial denture (FZ). After the fabrication of ceramic restoration, micro-computed tomography was used to evaluate the internal and marginal fits of each fixed partial denture. Data were statistically analyzed with three-way ANOVA (α = 0.05). RESULTS: There were no significant interactions between preparation type, material type, and tooth type at any of the areas assessed. There was significant difference (p = 0.01) between CZ (59.15 ± 4.6 µm) and FZ (73.6 ± 17.1 µm) groups at the finish line area. Regarding the horizontal marginal discrepancy area, there were significant differences between CZ (62.65 ± 10.5 µm) and FZ (90.05 ± 5.6 µm) groups (p < 0.001), CL (77.45 ± 8.1 µm) and CZ (62.65 ± 10.5 µm) groups (p < 0.001), and FZ (90.05 ± 5.6 µm) and CL (77.45 ± 8.1 µm) groups (p < 0.001). At finish line area, there was a significant difference (p = 0.018) between feather-edge with canine (72.75 ± 13.3 µm) and chamfer with canine (59.05 ± 5.8 µm); however, there was no significant difference (p = 0.774) between feather-edge with premolar (69.45 ± 12 µm) and chamfer with premolar (65.1 ± 7.4 µm). Moreover, there was no significant difference (p = 0.886) between feather-edge with canine and feather-edge with premolar. CONCLUSIONS: The internal and marginal fits of the ceramic fixed partial dentures can be affected by the finish line design and ceramic type. The feather-edge finish line had a negative impact on the marginal and internal fits of ceramic fixed partial dentures at certain measurement points. Regarding the effect of finish line design on abutment teeth, the difference in fit was only detected at the finish line area of the anterior abutment (canine) with the feather-edge finish line.

Establishment of a novel mouse model of adenomyosis suitable for longitudinal and quantitative analysis and perinatal outcome studies.

The purpose of this study was to establish a novel mouse model of adenomyosis suitable for longitudinal and quantitative analyses and perinatal outcome studies. Using a 30 G needle, the entire uterine wall of one horn was mechanically punctured at a frequency of 100 times/1 cm (adenomyosis horn). The other horn was left unpunctured (control horn). Balb/c mice were sacrificed on day 14 (D14) or day 65 (D65) (n = 3 each). The uterus was fixed, paraffin-embedded, sliced, and stained. Lesions were detected and counted, and their volumes were measured. Cell proliferation and fibrosis were assessed by Ki67 and Masson's Trichrome staining, respectively. Blood vessels were detected using CD31 immunostaining. Some of the mice (n = 4), were mated and the date of delivery, litter size, number of implantations, and number and volume of postpartum lesions were measured. The number of lesions per horn did not differ between D14 and D65. The volume of the entire lesion was significantly greater on D65 than on D14 (p < 0.0001). The volume of the epithelial part of the lesion was significantly greater in D65 (p < 0.0001). The volume of the stromal part of the lesion was also greater on D65 (p < 0.0001). The percentage of Ki67 positive cells in the epithelial part of the lesion was significantly higher on D14 (p < 0.05). In contrast, the percentage of Ki67-positive cells in the stromal part was significantly higher on D65 (p < 0.01). Vascular density in the lesions was higher in on D65 (p < 0.05). The percentage of fibrotic area was significantly higher on D65 (p < 0.01). The date of delivery was slightly earlier than that reported for healthy mice of the same strain. The litter size was smaller than that reported in previous research. The number of implantation sites did not differ between the control and the adenomyosis horn. The number and volume of lesions did not differ between the non-pregnant and postpartum groups. This model can be applied to evaluate the pathogenesis of adenomyosis, validate the efficacy of therapeutic agents, and evaluate the effect of adenomyosis on pregnancy and vice versa.

Impact of Chronic Exposure to Endometriosis on Perinatal Outcomes: Establishment of a Mouse Model.

The purpose of this study was to establish a new mouse model of endometriosis that mimics real-world women's health problems, in which women continue to be affected by endometriosis long before they wish to become pregnant, and to evaluate the impact of "chronic exposure to endometriosis" on perinatal outcome. Endometriosis was established by the intraperitoneal injection of homologous minced mouse uteri. Vehicle was injected for the control. Mating was initiated either 1 or 43 days after disease establishment (Young or Aged studies, respectively). Mice were sacrificed on 18 dpc. The number pups and resorptions were counted and pups' body weights (BW) were measured, and the endometriosis lesion was identified and weighted. In the Young study, the number of resorptions and BW were comparable between the groups. In the Aged study, the number of resorptions was significantly higher and BW was significantly lower in endometriosis than that in control. The total weight of endometriosis lesion per dam was significantly lower in the Aged compared to the Young endometriosis group; however, not a single mouse was found to have any lesions at all. These results suggest that in addition to the presence of endometriosis per se, "chronic exposure to endometriosis" prior to pregnancy affect perinatal outcomes.

Elevated phosphorylation of estrogen receptor α at serine-118 in ovarian endometrioma.

OBJECTIVE: To evaluate the phosphorylation of estrogen receptor α at serine-118 (phospho-ERα S118) in the endometrium, ovarian endometrioma, and deep infiltrating endometriosis (DIE). DESIGN: Experimental study. SETTING: University-affiliated hospital and academic research laboratory. PATIENT(S): Twenty-five patients underwent a hysterectomy, 18 patients underwent surgical removal of ovarian endometrioma, and 6 patients underwent DIE. INTERVENTION(S): Tissue samples were obtained from patients who underwent surgical procedures. MAIN OUTCOME MEASURE(S): Immunostaining for phospho-ERα S118, ERα, or phosphorylated p44/42 mitogen-activated protein kinase (phospho-p44/42 MAPK) was performed to evaluate the endometrium with or without endometriosis, ovarian endometrioma, and DIE. For in vitro analysis, endometrial epithelial cells (Ishikawa cells) were stimulated with estradiol (E2) or tumor necrosis factor alpha (TNFα), and the expression levels of phospho-ERα S118 and phospho-p44/42 MAPK were evaluated via Western blotting. RESULT(S): First, phospho-ERα S118 level was significantly higher in the glands and stroma of ovarian endometriosis samples than in those of endometrial and DIE samples. Second, colocalization of phospho-p44/42 MAPK and phospho-ERα S118 was observed in the glands of ovarian endometrioma. The proportions of cells strongly expressing phospho-p44/42 and phospho-ERα were 87% in phosphor-p44/42 MAPK-positive cells and 79% in phosphor-ERα-positive cells. Third, E2 stimulation significantly enhanced phospho-ERα S118 after 15 and 30 minutes in in vitro analysis using endometrial epithelial cells. Fourth, TNFα stimulation modestly but significantly enhanced phospho-ERα S118 after 15 and 30 minutes. Fifth, in Ishikawa cells, treatment with a p44/42 inhibitor (PD98059) significantly reduced phospho-ERα S118 by TNFα but not by E2. CONCLUSION(S): ERα-S118 phosphorylation was increased in ovarian endometriosis. Our findings may provide a new perspective for understanding the mechanism of increased ERα action in the pathophysiology of endometriosis.

Rehabilitation of severely-destructed endodontically treated premolar teeth with novel endocrown system: Biomechanical behavior assessment through 3D finite element and in vitro analyses.

OBJECTIVE: Rehabilitation of endodontically treated premolars with extensive coronal destruction through endocrown approach remains a controversial topic in reconstructive dentistry. There is no clear consensus in the literature which endocrown design with which material is the most effective restoration option for severely-destructed endodontically treated premolars. The aim of this study was to assess the biomechanical behavior of endodontically treated maxillary first premolars restored with a novel endocrown system compared to the conventional one varying the applied load type through finite element and in vitro analyses. MATERIALS AND METHODS: For finite element analysis, two models representing two endocrown systems used for restoration of severely-destructed endodontically treated maxillary first premolar tooth were generated: Model C for the conventional monolithic IPS e.max CAD endocrown and Model P for the novel bi-layered endocrown (PEKKTON ivory coping veneered with cemented IPS e.max CAD). Modified von Mises stress values on the remaining tooth structure, cement lines and restorative materials were evaluated separately under axial and oblique loading of 450 N. For in vitro analysis, forty sound human bifurcated maxillary first premolars were collected, endodontically-treated, and divided into 2 main groups (n = 20) according to the system used for endocrown fabrication; Group C: the conventional monolithic endocrowns and Group P: the novel bi-layered endocrowns. All specimens were subjected to an artificial thermomechanical aging protocol. Each main group was subdivided into two subgroups (n = 10) according to the loading type (axial and oblique) applied during the fracture resistance test. Qualitative analysis using Stereomicroscopy and Scanning Electron Microscopy was performed. Data were statistically analyzed at p-value ≤ 0.05. RESULTS: Regarding stress distribution pattern of remaining tooth structure (enamel and dentin), both endocrown systems and cement lines under both axial and oblique load application, Model P resulted in lower stresses than Model C. The oblique stress values of all analyzed structures were higher than corresponding values resulted axially. Considering failure load, a significantly higher load was recorded for Group P when axial or oblique loading was applied (p = 0.00). A significantly higher failure load was recorded with axial loading for both main groups. With regard to failure mode, a statistically significant difference was observed between main groups (p = 0.033), with more favorable failures detected for Group P axially. CONCLUSIONS: Compared to the conventional endocrown system, the studied novel system improved the biomechanical behavior within tooth/restoration complex of the restored severely-destructed endodontically treated maxillary first premolar teeth, whatever the applied load type. CLINICAL SIGNIFICANCE: The novel endocrown system using a PEKK coping veneered with cemented IPS e.max CAD can be considered a favorable promising option for restoration of severely-destructed endodontically treated premolar teeth, with more protection for residual tooth structure. It can be considered as a conservative alternative option to the conventional treatment modalities not only for normal clinical conditions, but also for parafunctional cases.

The roles of polymorphonuclear myeloid-derived suppressor cells in endometriosis.

OBJECTIVES: This study aimed to determine the systemic and local proportions, focal localization, and characteristics of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) in endometriosis. STUDY DESIGN: Peripheral blood and peritoneal fluid were obtained from patients with a benign gynecologic condition (controls) or endometriosis. PMN-MDSCs were defined as CD33+HLA-DRlow/-CD14-CD15+ and monocytic (M)-MDSCs were defined as CD33+HLA-DRlow/-CD14+CD15-, and were identified using flowcytometry. Ovarian endometriotic tissues were obtained, and the expression of lectin-type oxidized low density lipoprotein receptor-1 (LOX1) as a marker of PMN-MDSCs, arginine 1 (Arg1), and matrix metalloproteinase 9 (MMP9) were detected using immunohistochemistry. Anti-Ly6G antibody was administered to endometriosis model mice, and the number and weight of the lesions were measured, and cell proliferations and apoptosis in the lesions were analyzed using Ki67 immunohistochemistry and TUNEL assay. RESULTS: In the peripheral blood, the proportion of PMN-MDSCs was significantly higher in endometriosis (3.20 vs 1.63 %, p < 0.05), but the proportion of M-MDSCs did not differ between the groups. In the peritoneal fluid, the proportion of PMN-MDSCs was significantly higher in endometriosis (7.82 × 10-1% vs 6.48 × 10-2%, p < 0.05), whereas the proportion of M-MDSCs did not differ between the groups. PMN-MDSCs were detected in the stromal cell layer of the endometriotic cyst wall. Double staining for LOX1 and Arg1, and LOX1 and MMP9 was confirmed. Administration of Ly6G antibody did not change the number or weight of endometriosis lesions, but significantly decreased Ki67-positive cells and increased TUNEL-positive cells in the lesions. CONCLUSIONS: PMN-MDSCs may contribute to the pathogenesis of endometriosis via Arg1 and MMP9 expression.

Antimicrobial resistance and molecular genotyping of Escherichia coli and Staphylococcus aureus isolated from some Egyptian cheeses.

OBJECTIVE: This work investigated the antimicrobial resistance (AMR) and virulence of Escherichia coli and Staphylococcus aureus in communally consumed cheeses in Egypt. MATERIALS AND METHODS: This study examined 100 samples of Domiati, Tallaga, Cheddar, and Ras cheese collected from several shops and supermarkets. Samples were spread on selective media to isolate bacterial strains. Molecular characterization of bacterial isolates was carried out using polymerase chain reaction to determine Shiga toxin 1 (stx1), Shiga toxin 2 (stx2), eaeA, and nuc genes. The isolates were tested for susceptibility to 14 antibiotics by disk diffusion assay. RESULTS: In this study, several E. coli serotypes were identified. E. coli O26:H11, O103:H2, and O111:H2 expressed stx1/2, E. coli O114:H4 expressed stx1, E. coli O17:H18, O21:H7 and O146:H21 expressed stx2, while only E. coli O26:H11 and O111:H2 expressed eaeA. The E. coli isolates were resistant to at least one antibiotic, while most isolates (82.4%) showed multidrug resistance (MDR). AMR to erythromycin was the highest (100%), followed by nalidixic acid (94.1%), cefotaxime (82.4%), vancomycin and cephalothin (64.7%), penicillin G (52.9%), sulfamethoxazole (47.1%), amikacin and kanamycin (35.3%), ampicillin (29.4%), tetracycline and ciprofloxacin (23.5%), and doxycycline (11.8%), while gentamicin showed the least resistance (5.9%). The multiple antibiotic resistance (MAR) index of the isolated E. coli ranged from 0.071 to 1 (mean = 0.478). All S. aureus isolates expressed the nuc gene and demonstrated resistance to at least one antibiotic, and 90% of isolates were MDR. AMR to kanamycin and cephalothin was the highest (100%), followed by penicillin (90%), doxycycline (70%), nalidixic acid and sulfamethoxazole (60%), erythromycin (50%), tetracycline, cefotaxime, and gentamicin (40%), ciprofloxacin and ampicillin (30%), and amikacin (20%). In comparison, vancomycin showed the least resistance (10%). MAR index of isolated S. aureus ranged from 0.143 to 1 (mean = 0.529). CONCLUSION: The antimicrobial-resistant E. coli and S. aureus are potential risks for public health and may have a role in disseminating AMR to other pathogenic and non-pathogenic microbes.

Combined d-Tryptophan Treatment and Temperature Stress Exert Antimicrobial Activity against Listeria monocytogenes in Milk.

ABSTRACT: d-Tryptophan (d-Trp) has a significant inhibitory effect on growth of gram-negative bacteria under osmotic stress. However, the inhibitory effect of d-Trp on the gram-positive Listeria monocytogenes under chilled and thermal stresses has not been evaluated previously. The effect of d-Trp on L. monocytogenes growth under cold and/or heat stress in milk and cream was dependent on the magnitude of the temperature stress. Low temperatures (4, 7, and 10°C) and treatment with 40 mM d-Trp resulted in significant inhibition of L. monocytogenes growth during the 4-week storage period. Lower temperatures more effectively inhibited growth. When added before thermal processing, 40 mM d-Trp completely inactivated L. monocytogenes (>6-log reduction) heated at 60°C for 25 min or 65°C for 20 min. These results suggest that d-Trp can be used as a preservative for controlling the growth of L. monocytogenes in milk and cream at refrigeration temperatures and could be used to enhance the thermal inactivation of L. monocytogenes.

Prevalence and antimicrobial resistance of Shiga toxin-producing Escherichia coli in milk and dairy products in Egypt.

Food contaminated with Shiga toxin-producing Escherichia coli (STEC) represents a hazardous public health problem worldwide. Therefore, the present study was performed to elucidate the virulent and antimicrobial resistance characteristics of STEC isolated from milk and dairy products marketed in Egypt. A total of 125 samples (raw market milk, bulk tank milk, Kareish cheese, white soft cheese, and small scale-produced ice cream, 25 each) were collected for determination the prevalence and antimicrobial resistance profiling of STEC. Thirty-six STEC isolates were recovered from milk and dairy products. Serological analysis illustrated that three isolates were E. coli O157:H7 and 33 isolates belonged to different serotypes. Molecular examination indicated that all isolates harboured stx1 and/or stx2 genes, 14 isolates expressed eaeA gene and 3 isolates possessed rfbE gene. Antimicrobial resistance profiling of the isolates was both phenotypically and genetically examined. Interestingly, 31 out of 36 (86.11%) isolates were multidrug-resistant and harboured the extended-spectrum ß-lactamase encoding genes, namely, blaCTX-M-15, blaSHV-12 and blaCTX-M-14. Moreover, 12 isolates (33.33%) harboured plasmid-mediated quinolone resistant gene, qnrS. The overall conclusion of the current investigation indicated insufficient hygienic measures adopted during milking, handling, and processing leading to development of pathogenic and multidrug-resistant STEC.