Deep-Sequencing Technologies and Potential Applications in Forensic DNA Testing.

Development of second- and third-generation DNA sequencing technologies have enabled an increasing number of applications in different areas such as molecular diagnostics, gene therapy, monitoring food and pharmaceutical products, biosecurity, and forensics. These technologies are based on different biochemical principles such as monitoring released pyrophosphate upon incorporation of a base (pyrosequencing), fluorescence detection subsequent to reversible incorporation of a fluorescently labeled terminator base, ligation based approach wherein fluorescence of cleaved nucleotide after ligation is measured, measuring the proton released after incorporation of a base (semiconductor-based sequencing), monitoring incorporation of a nucleotide by measuring the fluorescence of the fluorophore attached to the phosphate chain of the nucleotide, and by detecting the altered charge in a protein nanopore due to released nucleotide by exonuclease cleavage of a DNA strand. Analysis of multiple DNA fragments in parallel increases the depth of coverage while decreasing labor, cost, and time, highlighting some major advantages of deep-sequencing technologies. DNA sequencing has been routinely used in the forensic laboratories for mitochondrial DNA analysis. Fragment analysis, however, is the preferred method for Short Tandem Repeat genotyping due to the cumbersome and costly nature of fi rst-generation DNA sequencing methodologies. Deep-sequencing technologies have brought a new perspective to forensic DNA analysis. Studies include STR analysis to reveal hidden variation in the repeat regions, mtDNA sequencing, Single Nucleotide Polymorphism analysis, mixture resolution, and body fluid identification. Recent publications reveal that attempts are being made to expand the capability.

Legg-Calvé-Perthes disease affecting children less than eight years of age: a paired outcome study.

There is controversy as to whether operative treatment in Legg-Calvé-Perthes (LCP) disease improves the outcome obtained by conservative treatment. This article describes a paired study of mature patients, diagnosed with LCP disease before the age of 8 years, to compare the radiological results after conservative or surgical management. Patients were paired with strict matching of gender, body mass index, age at onset, disease stage at the first visit, necrotic area, and radiological at-risk signs. Each pair was assessed by comparing the values of five radiological measurements. Fourteen pairs (28 hips) fitted the criteria. The only radiological measure which showed a statistically better result in the surgical group was femoral head sphericity as measured by Mose's method. However, there was no difference between the two groups for Stulberg class. Our study supports the hypothesis that for hips affected with LCP disease under the age of 8 years, surgery does not improve the outcome.

Hemiarthroplasty: To cement or not to cement? A preliminary report.

Two hundred hemiarthroplasties were studied to compare uncemented Austin Moore and cemented Thompsons prostheses. The following variables were compared: preoperative mobility, ASA grade, Abbreviated Mental test scores, surgeon grade, peri-operative mortality, infection rate, operation time, intra-operative fractures, dislocation rate, thigh pain and revision rate to total hip replacement. Both groups were comparable in all respects. The incidence of intra-operative fractures, infection, postoperative dislocation and conversion to Girdlestone arthroplasty was higher in the uncemented group. The mortality remained the same in both groups. The incidence of significant thigh pain was higher in the uncemented group (13%), of whom half (6%) had to undergo a conversion to a total hip replacement within the 24 months follow-up period. Our current study of changed practice concluded that cemented Thompsons prosthesis performs better than uncemented Austin Moore when the incidence of hip pain and subsequent conversion to a total hip replacement were considered. (Hip International 2004; 14: 189-92).

Oral ketamine for radiotherapy in children with cancer.

Children coming for radiotherapy under sedation usually get repeated injections, which cause distress to both the child and the parents. A prospective study was conducted to evaluate the efficacy of oral ketamine for sedation for radiotherapy (RT) in children with cancer. Ten children who received 49 sittings of RT were given 8-15 mg/kg body weight of oral ketamine. The onset time, recovery time, efficacy of sedation and incidence of abnormal movements were compared with another group of 8 children, who received intramuscular ketamine in the dose of 6 mg/kg for a total of 28 sittings of RT. Onset time and recovery time were significantly longer in oral ketamine group as compared to the intramuscular group (p < 0.001). Limb movements in patients receiving oral ketamine necessitated further supplement of sedation and interruption of RT. These drawbacks discourage use of oral ketamine as a good sedative for radiotherapy treatment in paediatric oncology patients.