Semiconstrained posterior-stabilized total knee arthroplasty: indications, risks and benefits in primary and revision surgery.

BACKGROUND: The constrained posterior-stabilized (CPS) implant for use in total knee arthroplasty (TKA) has a constraint level midway between that of a posterior-stabilized implant and a valgus-varus-constrained implant; there is currently no consensus on the surgical indications for use of this degree of constraint. We present our experience using this implant at our centre. METHODS: We reviewed the charts of patients who received a CPS polyethylene insert during TKA in our centre between January 2016 and April 2020. We collected patient demographic characteristics, surgical indications, pre- and postoperative radiographs, and complications. RESULTS: A total of 85 patients (74 females and 11 males with a mean age of 73 yr [standard deviation 9.4 yr, range 36-88 yr]) (85 knees) received a CPS insert over the study period. Of the 85 cases, 80 (94%) were primary TKA and 5 (6%) were revision TKA. The most common indications for primary CPS use were severe valgus deformity with medial soft-tissue laxity (29 patients [34%]), medial soft-tissue laxity without substantial deformity (27 [32%]) and severe varus deformity with lateral soft-tissue laxity (13 [15%]). The indications for the 5 patients who underwent revision TKA were medial laxity (4 patients) and an iatrogenic lateral condyle fracture (1 patient). Four patients had postoperative complications. The 30-day return to hospital rate was 2.3% (owing to infection and hematoma). A single patient required revision surgery for periprosthetic joint infection. CONCLUSION: We found excellent short-term survivorship of the CPS polyethylene insert when used for a spectrum of coronal plane ligamentous imbalances with or without pre-operative coronal plane deformities. Long-term follow-up of these cases will be important to identify adverse outcomes such as loosening or polyethylene-related problems.

Erratum: Orofacial overgrowth with peripheral nerve enlargement and perineuriomatous pseudo-onion bulb proliferations is part of the PIK3CA-related overgrowth spectrum.

[This corrects the article DOI: 10.1016/j.xhgg.2020.100009.].

Orofacial overgrowth with peripheral nerve enlargement and perineuriomatous pseudo-onion bulb proliferations is part of the PIK3CA-related overgrowth spectrum.

Individuals with orofacial asymmetry due to mucosal overgrowths, ipsilateral bone and dental aberrations with perineurial hyperplasia and/or perineuriomatous pseudo-onion bulb proliferations, comprise a recognizable clinical entity. In this article, we describe three individuals with this clinical entity and mosaic PIK3CA variants c.3140A>G (p. His1047Arg), c.328_330delGAA (p. Glu110del), and c.1353_1364del (p.Glu453_Leu456del). We conclude that the identification of these mosaic variants in individuals with orofacial asymmetry presenting histopathologically perineurial hyperplasia and/or intraneural pseudo-onion bulb perineurial cell proliferations supports the inclusion of this clinical entity in the PIK3CA-related overgrowth spectrum.

Corrosion Protection through Naturally Occurring Films: New Insights from Iron Carbonate.

Despite intensive study over many years, the chemistry and physics of the atomic level mechanisms that govern corrosion are not fully understood. In particular, the occurrence and severity of highly localized metal degradation cannot currently be predicted and often cannot be rationalized in failure analysis. We report a first-principles model of the nature of protective iron carbonate films coupled with a detailed chemical and physical characterization of such a film in a carefully controlled environment. The fundamental building blocks of the protective film, siderite (FeCO3) crystallites, are found to be very sensitive to the growth environment. In iron-rich conditions, cylindrical crystallites form that are highly likely to be more susceptible to chemical attack and dissolution than the rhombohedral crystallites formed in iron-poor conditions. This suggests that local degradation of metal surfaces is influenced by structures that form during early growth and provides new avenues for the prevention, detection, and mitigation of carbon steel corrosion.

LHFPL5 mutation: A rare cause of non-syndromic autosomal recessive hearing loss.

Hearing loss is a debilitating disorder that impairs language acquisition, resulting in disability in children and potential isolation in adulthood. Its onset can have a genetic basis, though environmental factors, which are often preventable, can also cause the condition. The genetic forms are highly heterogeneous, and early detection is necessary to arrange appropriate patient support. Here we report the molecular basis of hereditary hearing loss in a consanguineous family with multiple affected members from Oman. Combining homozygosity mapping with whole exome sequencing identified a novel homozygous nucleotide substitution c.575T > C in the lipoma HMGIC fusion partner-like 5 gene (LHFPL5), that converted the 192nd amino acid residue in the protein from a leucine to a proline, p.(Leu192Pro). Sanger sequencing confirmed segregation with the disease phenotype as expected for a recessive condition and the variant was absent in 123,490 subjects from various disease-specific and population genetic studies as well as 150 unrelated individuals and 35 deaf patients of Omani ethnicity. This study, which describes a novel LHFPL5 mutation in a family of Omani origin with hereditary hearing loss, supports previous clinical descriptions of the condition and contributes to the genetic spectrum of mutations in this form of deafness.

Chronic Water-Pipe Smoke Exposure Induces Injurious Effects to Reproductive System in Male Mice.

There is a global increase in the popularity of water-pipe tobacco smoking including in Europe and North America. Nevertheless, little is known about the male reproductive effects of water-pipe smoke (WPS), especially after long-term exposure. Here, we assessed effects of WPS exposure (30 min/day) in male mice for 6 months. Control mice were exposed to air-only for the same period of time. Twenty-four hours after the last exposure, testicular histopathology, and markers of inflammation and oxidative stress, and the tyrosine-protein kinase vascular endothelial growth factor receptor 1 (VEGFR1) were assessed in testicular homogenates. Moreover, plasma testosterone, estradiol, and luteinizing hormone (LH) concentrations were also measured. Chronic WPS exposure induced a significant decrease of testosterone and estradiol, and a slight but significant increase of LH. Glutathione reductase, catalase, and ascorbic acid were significantly decreased following WPS exposure. Plasma concentration of leptin was significantly decreased by WPS exposure, whereas that of tumor necrosis factor α and interleukin 6 was significantly increased. Histopathological analysis of the testes revealed the presence of a marked reduction in the diameter of the seminiferous tubules with reduced spermatogenesis. Transmission electron microscopy examination showed irregular thickening and wrinkling of the basement membranes with abnormal shapes and structures of the spermatozoa. VEGFR1 was overexpressed in the testis of the mice exposed to WPS and was not detected in the control. The urine concentration of cotinine, the predominant metabolite of nicotine, was significantly increased in the WPS-exposed group compared with the control group. We conclude that chronic exposure to WPS induces damaging effects to the reproductive system in male mice. If this can be confirmed in humans, it would be an additional concern to an already serious public health problem, especially with the increased use of WPS use all over the world, especially in young adults.

A comparison study on the design of mirror and anatomy reconstruction technique in maxillofacial region.

BACKGROUND: The customized mandible reconstruction has been a challenging task in maxillofacial surgery. Designing an implant taking into considering the surrounding bone contours is really critical. Various computer aided design techniques have been used in the designing the customized reconstruction implants, but nevertheless study on the comparison between these techniques is rarely used. OBJECTIVE: The objective of this study is to compare the mirroring and anatomical reconstruction design techniques used in the maxillofacial surgery and select the best design technique. METHODS: The three mandible bone defects-small (< 20 mm), medium (20 to 40 mm) and large (41 to 53 mm) tumors are reconstructed using the two reconstruction design techniques and compared to their accuracy, using a 3 dimensional (3D) implant design evaluation and part to Computer aided design (CAD) comparison using a Co-ordinate measuring machine (CMM). RESULTS: The analysis results indicate that the mirroring technique provides higher accuracy for the implant design as compared to the anatomical technique for the medium and large tumors at maxillofacial regions. In case of implant design in small tumors, the anatomical design provides perfect implant fitting. CONCLUSIONS: Based on the results, it is recommended to select the anatomy design technique only for small tumor regions and mirroring technique for medium and large tumors.

Guided bone regeneration in standardized calvarial defects using beta-tricalcium phosphate and collagen membrane: a real-time in vivo micro-computed tomographic experiment in rats.

Guided bone regeneration (GBR) procedures using graft materials have been used for reconstruction of osseous defects. The aim of the present in vivo micro-computed tomographic (µCT) and histologic study was to assess in real time the bone regeneration at GBR sites in standardized experimental calvarial defects (diameter 3.3 mm) using ß-tricalcium phosphate (ß-TCP) with and without collagen membrane (CM). A single full-thickness calvarial defect was created on the left parietal bone in young female Wistar albino rats (n = 30) weighing approximately 300 g and aged about 6 weeks. The animals were randomly divided into three groups for treatment, based on calvarial defect filling material: (1) control group (n = 10); (2) ß-TCP + CM group (n = 10); (3) ß-TCP group (n = 10). Real-time in vivo µCT analyses were performed immediately after surgery and at 2, 4, 6 and 10 weeks to determine the volume and mineral density of the newly formed bone (BVNFB, MDNFB) and remaining ß-TCP particles (VRBP, MDRBP). The animals were killed at 10 weeks and calvarial specimens were evaluated histologically. In the control group, MDNFB increased significantly at 6 weeks (0.32 ± 0.002 g/mm(3), P < 0.01) compared to that at baseline. In ß-TCP + CM group, BVNFB (1.10 ± 0.12 mm(3), P < 0.01) and MDNFB (0.13 ± 0.02 g/mm(3), P < 0.01) significantly increased at the 4th week than baseline. In the ß-TCP group, BVNFB (1.13 ± 0.12 mm(3), P < 0.01) and MDNFB (0.14 ± 0.01 g/mm(3), P < 0.01) significantly increased at 6 weeks compared to that at baseline. Significant reduction in VRBP was neither seen in the ß-TCP + CM group nor in the ß-TCP group. While in the ß-TCP + CM group MDRBP was reduced significantly at 6 weeks (0.44 ± 0.9 g/mm(3), P < 0.01) from baseline (0.98 ± 0.03 g/mm(3)), similar significant reduction in MDRBP from baseline (0.92 ± 0.07 g/mm(3)) was seen only at 10 weeks (0.45 ± 0.06 g/mm(3), P < 0.05) in the ß-TCP group. Histologic findings at 10 weeks revealed greater amount of NFB with osteocytes in the matrix, in the ß-TCP + CM group than in the ß-TCP group. Biomechanical assessment of NFB for hardness (H) and elastic modulus (E) revealed significantly higher values for the ß-TCP + CM group (H = 612.6 ± 4.28 Mpa; E = 13.57 ± 0.07 Gpa) when compared to those of the control (H = 192.1 ± 4.93 Mpa; E = 6.76 ± 0.04 Gpa) and the ß-TCP groups (H = 241.9 ± 6.29 Mpa; E = 4.34 ± 0.06 Gpa). In conclusion, based on real-time assessment, NFB is formed in calvarial defects as early as 4 weeks following GBR with ß-TCP + CM as compared to 6 weeks when ß-TCP alone was used.

Hoxb13, a potential prognostic biomarker for prostate cancer.

HOXB13, a member of the homeobox proteins family, is a key regulator of the epithelial differentiation in the prostate gland. HOXB13 is overexpressed during malignant progression of the prostatic tissue and suspected to contribute in the pathogenesis of the prostate gland. In androgen deprived conditions, HOXB13 is thought to act through inhibition of the tumour suppressor protein p21. Since HOXB13 has a multifaceted role in ventral prostate development, its critical partners in the cascade need to be elucidated for a further understanding of its role in prostate malignancy. In this report, we review the functions attributed to HOXB13, by highlighting the most recent findings supporting the hypothesis that HOXB13 might serve as a novel biomarker for the prognosis of prostate cancer.

The p53 Mutation/Deletion Profile in a Small Cohort of the Omani Population with Diffuse Large B-Cell Lymphoma.

OBJECTIVES: Mutations/deletions affecting the TP53 gene are considered an independent marker predicting a poor prognosis for patients with diffuse large B-cell lymphoma (DLBCL). A cohort within a genetically isolated population was investigated for p53 mutation/deletion status. METHODS: Deoxyribonucleic acid (DNA) samples were extracted from 23 paraffin-embedded blocks obtained from DLBCL patients, and subjected to polymerase chain reaction (PCR) amplification and sequencing of exons 4-9 of the p53 gene. RESULTS: While 35% of patients analysed displayed allelic deletions (P <0.01), immunohistochemical analysis revealed a mutation rate of 69.5%. It is noteworthy that the rate of p53 mutations/deletions in this small cohort was found to be higher than that previously reported in the literature. Interestingly, patients with p53 mutations displayed a better overall survival when compared to those without. The survival of patients treated with rituximab-containing combination chemotherapy was significantly better than those who did not receive rituximab (P <0.05). Furthermore, a modelling analysis of the deleted form of p53 revealed a huge structural change affecting the DNA-binding domain. CONCLUSION: The TP53 mutation/deletion status plays a role in mechanism(s) ruling the pathogenesis of DLBCL and may be useful for stratifying patients into distinct prognostic subsets.

Association of E-cadherin (CDH1) gene polymorphisms and gastric cancer risk.

AIM: To investigate the associations between CDH1 gene polymorphisms and gastric cancer (GC) risk predisposition. METHODS: We analyzed four CDH1 polymorphisms (+54 T>C, -160 C>A, -616 G>C, -3159 T>C) in an Omani population, by extraction of genomic DNA from the peripheral blood of 192 patients with GC and 170 control participants and performed CDH1 genotyping using DNA sequencing. RESULTS: CDH1 -160 -AA genotype was associated with an increased risk of GC (OR = 3.6, 95% CI: 1.1-11.8) (P = 0.03). There was no significant association between the other polymorphisms and GC risk. The haplotype analysis of +54 T>C, -160 C>A, -616 G>C, -3159 T>C genotypes revealed that the OR of CCGC and CAGC haplotypes was 1.5 (95% CI: 0.7-3.5) and 1.5 (95% CI: 0.2-3.0), but did not reach statistical significance. CONCLUSION: The current study suggests that the -160 AA genotype was associated with an increased risk of GC in Oman.

Clinical and molecular analysis of Grebe acromesomelic dysplasia in an Omani family.

Grebe syndrome is a rare autosomal recessive acromesomelic dysplasia. The syndrome was studied clinically, radiographically, and genetically in an Omani family with four affected children. The affected persons had normal axial skeletons, severely shortened, and deformed limbs with severity increasing in a proximo-distal gradient, and subluxated joints. The humeri and femora were hypoplastic with distal malformations. The radii/ulnae were shortened and deformed whereas carpal bones were invariably rudimentary or absent. The tibiae appeared rudimentary; fibulae were absent in two children, and some tarsal and metatarsal bones were absent. The proximal and middle phalanges were absent while the distal phalanges were present. The father and mother had short first metacarpal and middle phalynx of the fifth finger and hallux valgus respectively. Transition A1137G and deletion delG1144 mutations in the gene encoding the cartilage-derived morphogenetic protein-1 (CDMP-1) were identified in this family. The A1137G is a silent mutation coding for lysine, whereas the delG1144 predicts a frameshift mutation resulting in a presumable loss of the CDMP-1 biologically active carboxy-terminal domain. The affected siblings were homozygous for the delG1144 mutation while parents were heterozygous.