Cytotype regulation by telomeric P elements in Drosophila melanogaster: evidence for involvement of an RNA interference gene.

P elements inserted at the left telomere of the X chromosome evoke the P cytotype, a maternally inherited condition that regulates the P-element family in the Drosophila germline. This regulation is completely disrupted in stocks heterozygous for mutations in aubergine, a gene whose protein product is involved in RNA interference. However, cytotype is not disrupted in stocks heterozygous for mutations in two other RNAi genes, piwi and homeless (spindle-E), or in a stock heterozygous for a mutation in the chromatin protein gene Enhancer of zeste. aubergine mutations exert their effects in the female germline, where the P cytotype is normally established and through which it is maintained. These effects are transmitted maternally to offspring of both sexes independently of the mutations themselves. Lines derived from mutant aubergine stocks reestablish the P cytotype quickly, unlike lines derived from stocks heterozygous for a mutation in Suppressor of variegation 205, the gene that encodes the telomere-capping protein HP1. Cytotype regulation by telomeric P elements may be tied to a system that uses RNAi to regulate the activities of telomeric retrotransposons in Drosophila.

Cytotype regulation by telomeric P elements in Drosophila melanogaster: interactions with P elements from M' strains.

P strains of Drosophila are distinguished from M strains by having P elements in their genomes and also by having the P cytotype, a maternally inherited condition that strongly represses P-element-induced hybrid dysgenesis. The P cytotype is associated with P elements inserted near the left telomere of the X chromosome. Repression by the telomeric P elements TP5 and TP6 is significantly enhanced when these elements are crossed into M' strains, which, like P strains, carry P elements, but have little or no ability to repress dysgenesis. The telomeric and M' P elements must coexist in females for this enhanced repression ability to develop. However, once established, it is transmitted maternally to the immediate offspring independently of the telomeric P elements themselves. Females that carry a telomeric P element but that do not carry M' P elements may also transmit an ability to repress dysgenesis to their offspring independently of the telomeric P element. Cytotype regulation therefore involves a maternally transmissible product of telomeric P elements that can interact synergistically with products from paternally inherited M' P elements. This synergism between TP and M' P elements also appears to persist for at least one generation after the TP has been removed from the genotype.

Patellofemoral Dysfunction in Sports Trochleoplasty: Indications and Techniques.

Patellofemoral instability (PFI) is a pathological knee syndrome that frequently affects young patients. The patellofemoral joint's structural morphology is the determining factor in the extent of PFI. Structural factors that play leading roles in patellofemoral stability can be classified into static (bone morphology), passive (ligamentous), and active (muscular). The predominant static factor leading to patella dislocation and thus patellofemoral dysfunction is trochlear dysplasia, which we focus on in this review. After orienting clinical examinations, MRI can provide the best information about trochlear dysplasia. This includes trochlear shape, orientation, and tibial tuberosity to trochlear groove distance. In convex trochleas or trochlea dysplasia with PFI at flexion over 30 degrees, we recommend performing a deepening trochleoplasty to correct for static pathomorphology. In this review, we will focus on the pathology of trochlea dysplasia, its role in PFI, the correct indication for trochleoplasty as a primary intervention, and the role of a simultaneous medial patellofemoral ligament reconstruction.

Early stage oropharyngeal carcinomas: comparing quality of life for different treatment modalities.

OBJECTIVE: To compare long-term quality of life outcomes after treating early stage oropharyngeal carcinoma either with surgery, surgery combined with radiotherapy, or surgery combined with chemoradiotherapy. METHODS: Questionnaire based method: 111 eligible patients agreed to fill out a quality of life questionnaire. RESULTS: Of the 32 scales contained in the EORTC's combined QLQ-C30 and HN35, 11 scales show significantly better results for the surgery-only treatment group when compared to either surgery combined with radiotherapy or surgery combined with any type of adjuvant therapy. These eleven scales are role function (P = 0.019/0.008), social function (P = 0.01/0.034), nausea (P = 0.017/0.025), pain (P = 0.014/0.023), financial problems (P = 0.030/0.012), speech (P = 0.02/0.015), social eating (P = 0.003/<0.001), mouth opening (P = 0.033/0.016), sticky saliva (P = 0.001/<0.001), swallowing (P < 0.001/<0.001), and dry mouth (P < 0.001/0.001). CONCLUSION: Treatment of early stage oropharyngeal carcinoma with surgery alone has definite advantages over treatments including any form of adjuvant therapy when considering quality of life. Advantages manifest themselves especially in functional aspects of the head and neck realm; however general health aspects as well as psychosocial aspects show improvements as well. This study does not show any indication of QOL-related drawbacks of surgery-only treatment approaches.