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An extensive literature review and new post-irradiation experimental results are presented of genotyping blood stains and hair, and physical examinations of latent fingerprints, hairs, and fibers. Results indicate that successful development of nuclear short tandem repeat (STR) and mitochondrial DNA sequence profiles from human blood and hair evidence is possible-up to a point-following exposure to gamma, neutron, beta, and alpha radiation at several levels that would most likely be present at this type of crime scene (i.e., a "dirty bomb," etc.). Commencing at gamma radiation levels between 90 and 900kGy, DNA analysis using conventional DNA techniques was unsuccessful. In general, irradiation negatively affected the quality of latent fingerprints. All four radiation types degraded most fingerprint samples at all doses; nevertheless, many fingerprints remained of value for potential use in comparison. Although variable from one hair to another, microscopic changes observed for all types and levels of irradiation could potentially result in false exclusions. Negligible microscopic changes were observed in papers and fibers (used as substrates for fingerprints and bloodstains) up to 90kGy gamma, but fluorescence of fibers began to change above that dose. Paper and fibers, as well as plastic evidence enclosures, became extremely brittle leading to breakage after a gamma dose of 900kGy.

Mitochondria are critical for ocular function as they represent the major source of a cell’s supply of energy and play an important role in cell differentiation and survival. Mitochondrial dysfunction can occur as a result of inherited mitochondrial mutations (e.g. Leber’s hereditary optic neuropathy and chronic progressive external ophthalmoplegia) or stochastic oxidative damage which leads to cumulative mitochondrial damage and is an important factor in age-related disorders (e.g. age-related macular degeneration, cataract and diabetic retinopathy). Mitochondrial DNA (mtDNA) instability is an important factor in mitochondrial impairment culminating in age-related changes and pathology, and in all regions of the eye mtDNA damage is increased as a consequence of aging and age-related disease. It is now apparent that the mitochondrial genome is a weak link in the defenses of ocular cells since it is susceptible to oxidative damage and it lacks some of the systems that protect the nuclear genome, such as nucleotide excision repair. Accumulation of mitochondrial mutations leads to cellular dysfunction and increased susceptibility to adverse events which contribute to the pathogenesis of numerous sporadic and chronic disorders in the eye.

Objective: To investigate auditory neural involvement in patients with Leber's hereditary optic neuropathy (LHON).Methods: Auditory assessment was undertaken in two patients with LHON. One was a 45 year old woman with Harding disease (multiple-sclerosis-like illness and positive 11778mtDNA mutation) and mild auditory symptoms, whose auditory function was monitored over five years. The other was a 59 year old man with positive 11778mtDNA mutation, who presented with a long standing progressive bilateral hearing loss, moderate on one side and severe to profound on the other. Standard pure tone audiometry, tympanometry, stapedial reflex threshold measurements, stapedial reflex decay, otoacoustic emissions with olivo-cochlear suppression, auditory brain stem responses, and vestibular function tests were undertaken.Results: Both patients had good cochlear function, as judged by otoacoustic emissions ( intact outer hair cells) and normal stapedial reflexes ( intact inner hair cells). A brain stem lesion was excluded by negative findings on imaging, recordable stapedial reflex thresholds, and, in one of the patients, olivocochlear suppression of otoacoustic emissions. The deterioration of auditory function implied a progressive course in both cases. Vestibular function was unaffected.Conclusions: The findings are consistent with auditory neuropathy - a lesion of the cochlear nerve presenting with abnormal auditory brain stem responses and with normal inner hair cells and the cochlear nucleus (lower brain stem). The association of auditory neuropathy, or any other auditory dysfunction, with LHON has not been recognised previously. Further studies are necessary to establish whether this is a consistent finding.

A systematic study was conducted to investigate whether DNA can be successfully extracted from latent fingerprints deposited on ordinary paper and analysed using short tandem repeat profiling and mitochondrial DNA sequencing. In order to evaluate the performance of latent fingerprint analysis in a criminal case, experiments with varying conditions were carried out to improve our understanding of low copy number (LCN) DNA typing. After optimising the extraction methods to achieve increased sensitivity, the examination of touched paper can routinely yield the STR profile of the individual who has touched it. A fingerprint can therefore be considered as a potential source of DNA for genetic identification. Nevertheless, the findings of our "after enhancement experiment" (using chemically or physically pre-treated fingerprints), and our "mixture experiment" (using fingerprints from three to four people on the same sheet of paper) help to define the limitations of the low copy number PCR technique in forensic casework.

Proper DNA storage is critical for studies involving genetic analysis of insects and for molecular diagnostics of pathogens carried by them. Molecular surveillance of pathogens carried by insects can involve screening of thousands of insect DNA samples. Problems with storage and degradation of these samples can arise. In this study, a simple filter paper-based method for storage and preservation of insect DNA was evaluated using polymerase chain reaction (PCR). DNA was isolated from individual house fly, Musca domestica L., adults by using a cell lysis technique. From 50 house flies known to carry Campylobacter spp., a portion of the DNA sample was stored frozen and another portion was pipetted onto filter paper. At monthly intervals for 7 mo, PCR was conducted using 1 microl of the frozen DNA sample and a 2.0-mm disk from the filter paper samples as the PCR template. Two markers were used, a 450-bp region of the insect mitochondrial DNA (mtDNA) ND5 gene and a 857-bp region of the Campylobacter spp. mtDNA 16S rDNA gene. PCR amplification was successful for all of the samples regardless of the storage method. The filter paper method is a simple and economical way to store, preserve, and distribute DNA samples for PCR analysis.

Objectives: We report here the clinical and genetic features of two new families with autosomal dominant progressive external ophthalmoplegia (adPEO). Patients and methods: The examination of index patients included a detailed clinical characterisation, histological analysis of muscle biopsy specimens, and genetic testing of mitochondrial and nuclear DNA extracted from muscle and leucocytes. Results: Index patients in both families presented with PEO and developed other clinical disease manifestations, such as myopathy and cardiomyopathy (patient 1) and axonal neuropathy, diabetes mellitus, hearing loss, and myopathy (patient 2), later in the course of illness. Both patients had ragged red fibres on muscle histology. Southern blot of mtDNA from muscle of patient 2 showed multiple deletions. In this case, a novel heterozygous missense mutation F485L was identified in the nuclear encoded putative mitochondrial helicase Twinkle. The mutation co-segregated with the clinical phenotype in the family and was not detected in 150 control chromosomes. In the other index patient, sequencing of ANT1, C10orf2 (encoding for Twinkle), and POLG1 did not reveal pathogenic mutations. Conclusions: Our cases illustrate the clinical variability of adPEO, add a novel pathogenic mutation in Twinkle (F485L) to the growing list of genetic abnormalities in adPEO, and reinforce the relevance of other yet unidentified genes in mtDNA maintenance and pathogenesis of adPEO.

Kinetoplast DNA (kDNA) has been isolated from the human cutaneous Leishmania isolates, L. tropica major, L. aethiopica and an unknown Kenyan isolate, Leishmania SP48. DNA sequence relationships among these isolates have been studied by restriction enzyme digestion and two phase hybridisation to Southern blots of kDNA covalently coupled to diazobenzyloxymethyl (DBM) paper. The results of this analysis confirm that rapid kDNA sequence evolution is occurring in the Old World leishmanias although some sequence conservation in defined regions of the mini-circle sequence is present. These results emphasise the danger of constructing a rigid Leishmania classification on buoyant density data alone. The covalent binding of kDNA electrophoretic separations to DBM paper permits the construction of a DNA sequence "library' which can be used in the classification and diagnosis of unknown Leishmania isolates.