Low incidence of androgen receptor mutation among Egyptian children with androgen resistance

In Egypt, disorders of sex development [DSD] constitute a significant entity among the birth defect list. Previous studies have reported that end organ androgen unresponsiveness, i.e. Androgen resistance, was the most prevalent underlying mechanism among Egyptian 46, XY DSD cases. Based on cytogenetic and hormonal diagnostic criteria as well as few sporadic case reports, it was proposed that androgen receptor [AR] defects [i.e. Androgen insensitivity syndrome [AIS], OMIM#300068] might constitute a major etiology within this category. However, this has never been systematically ascertained through an AR molecular diagnostic approach. The current study aimed to assess the role of AR mutations as an underlying etiology among a sample of Egyptian 46,XY DSD pediatric patients presenting with androgen end organ unresponsiveness. In the current study, 21 children [age <18years] with male undermasculinization due to androgen end organ unresponsiveness were selected from 46, XY DSD cases. The selection criteria included ambiguous genital phenotype or genitalia discordant to the genotypic sex; 46,XY Karyotype and normal testicular response to HCG stimulation in prepubertal -patients or normal basal testosterone [T] levels in postpubertal subjects. Molecular studies of the AR entailed PCR amplification for screening of major deletions/ insertions, single stranded conformational polymorphism [SSCP] screening for point mutations in the AR 2-8 exons followed by sequencing of these exons for all cases. The results showed that none had major deletions/insertions. Five exons out of 147 [3.4%] showed abnormal SSCP migrational patterns. Out of those 5, two mutations in two Egyptian patients were detected by sequencing. The first was R840G [Arginine 840 glycine], in exon 7 [The ligand binding domain]. The other was A596T [Alanine 596 Threonine] in exon 3 [The DNA binding domain]. This study shows that AR mutation is an uncommon underlying etiology among Egyptian paediatric 46,XY cases

Wettability of chair-side and visible light cure Denture relining materials

The objective of this study was to characterize the wettability of different hard denture relining materials by water contact angle measurements. The relining materials tested were, two chair-side hard denture lining materials, heat cure resin, chemical cure resin and a visible light cure resin [VLCR]. The results showed higher contact angles in case of the two chair-side relining resins tested as compared to the heat and cold cured acrylic resins while there was lower contact angles with the visible light, cure resin. It was concluded that the chemically cured chair side relining materials have lower wettability than those of the heat and cold cured acrylic resins while the visible light cure resin has higher wettability

Abutment tooth mobility using three clasping design systems

The aim of this study was to estimate the effect of three clasping design systems on the abutment tooth mobility in mandibular distal extension ridges. Each patient received three removable partial denture designs. Tooth mobility was measured following a previous report. Mobility was measured before appliance replacement [base line]. Following placement of the first removable partial denture, mobility was measured at two intervals and the replacement was taken from the patient until tooth mobility had returned to its base line and the same procedure was repeated for both the second and the third replacements. The results showed that, greater tooth mobility toward the buc-cal direction rather than toward the lingual direction was recorded and the comparison between measurements of base line and at intervals for the three systems was statistically non significant at p

Surface detail reproduction of hydrophillic polyvinyl siloxane impression materials, dental stone and liquid media

The aim of the study was to evaluate surface detail reproduction of hydrophilic poly vinlysiloxane impression materials and dental stone mixed with different liquid media. Four systems were arranged in order that each system contained impression material and dental stone mixed with three different liquid media. Experiments were carried out in accordance with ADA specification No. 19 for elastomeric impression materials and surface detail reproduction was evaluated by means of a traveling microscope. Analysis of data revealed that, large main effect variations caused by differences between impression materials and by differences between dental stones while no significant main effect variation was found to be caused by differences between liquid media