Interpreting DNA Evidence in Paternity Cases

The ability of jurors and juries to comprehend and utilise scientific evidence in Australian criminal trials is discussed in the context of impediments which include legislation, proce-dural law, and the inherent scientific complexity of some evidence. Existing Australian and international literature on jury performance with expert evidence is examined, and recent doctoral research utilising mock juries, real jurors and forensic scientists, is highlighted.

“Good communication with the jury is afield in which anecdote, self-assurance and self-delusion abound, within the ranks of the legal profession and the judiciary.”     

Morphological assessment of pancreatic islet hormone content following aerobic exercise training in rats with poorly controlled Type 1 diabetes mellitus

Regular exercise has been shown to improve many complications of Type 1 diabetes mellitus (T1DM) including enhanced glucose tolerance and increased cardiac function. While exercise training has been shown to increase insulin content in pancreatic islets of rats with T1DM, experimental models were severely hyperglycemic and not undergoing insulin treatment. Further, research to date has yet to determine how exercise training alters glucagon content in pancreatic islets. The purpose of the present investigation was to determine the impact of a 10-week aerobic training program on pancreatic islet composition in insulin-treated rats with T1DM. Second, it was determined whether the acute, exercise-mediated reduction in blood glucose experienced in rats with T1DM would become larger in magnitude following aerobic exercise training. Diabetes was induced in male Sprague-Dawley rats by multiple low dose injections of streptozotocin (20mg/kg i.p.) and moderate intensity aerobic exercise training was performed on a motorized treadmill for one hour per day for a total of 10 weeks. Rats with T1DM demonstrated significantly less islet insulin, and significantly more islet glucagon hormone content compared with non-T1DM rats, which did not significantly change following aerobic training. The reduction in blood glucose in response to a single exercise bout was similar across 10 weeks of training. Results also support the view that different subpopulations of islets exist, as small islets (<50 μm diameter) had significantly more insulin and glucagon in rats with and without T1DM.     

Beta 2-integrin and L-selectin are obligatory receptors in neutrophil aggregation [see comments]

We have recently found that antibodies to L-selectin, the homing receptor on neutrophils, are as effective as those to beta 2-integrin at blocking formyl peptide-stimulated aggregation. Therefore, we investigated the requirements for expression of L-selectin and beta 2- integrin on adjacent cells during aggregation. Fluorescence flow cytometry allowed characterization of aggregates on the basis of size and color, as well as antibody binding to these two adhesive molecules. Formyl peptide-stimulated aggregate formation was measured for individual populations fluorescently labeled red (LDS-751) or green (CD44-FITC), and interpopulation red-green cell conjugates. Blocking either the beta 2-integrin or L-selectin adhesive epitope with monoclonal antibody on individual cell populations resulted in an approximately 50% reduction in two-color aggregation as compared with that in unblocked samples. Shedding the L-selectin on a cell population by preincubation with complexes of lipopolysaccharide and its plasma membrane binding protein also decreased aggregation to a control population by approximately 50%. We examined the aggregation of neutrophils from patients genetically deficient in beta 2-integrin and clinically leukocyte adhesion deficient (LAD). LAD adhesion to normal neutrophils was dependent on the expression of L-selectin on LAD cells and beta 2-integrin on normal cells. Thus, the minimum requirement for adhesion between two mixed populations of neutrophils was that one population expressed the beta 2-integrin and the other expressed the L- selectin adhesive epitope.     

Acute lymphoblastic leukemia of childhood: identification of two distinct regions of deletion on the short arm of chromosome 12 in the region of TEL and KIP1

Cytogenetic analysis of acute lymphoblastic leukemia (ALL) of childhood identified nonrandom chromosomal abnormalities of the short arm of chromosome 12. The alterations include deletions that are thought to be indicative of the presence of a tumor suppressor gene that is mutated on the remaining allele. To refine further the chromosomal localization of this gene, we analyzed the loss of heterozygosity (LOH) of chromosome 12 in 100 primary ALL samples using 22 polymorphic markers and identified two distinct smallest common deleted regions on chromosome 12p13. One region is flanked by D12S77 and D12S98 and has a size of 4 cM. Twenty-six percent of informative patients showed LOH in this region. This region may contain the TEL gene. The other region is flanked by D12S269 and D12S308 including the KIP1 gene. Forty-four percent of informative patients showed LOH in this second region. Mutational analysis of KIP1 using polymerase chain reaction-single- strand conformation polymorphism analysis and Southern blot analysis showed no homozygous deletions and point mutations suggesting that the altered gene in this second region is not the KIP1. Clinical data showed that LOH of 12p was demonstrated more frequently in precursor-B ALLs (32 of 80; 40%) than in T-ALLs (1 of 20; 5%) (P = .0027). Furthermore, patients with 12p LOH were younger (P = .013), with a lower DNA index (P = .046), but they had the same survival rates at 3 years. In summary, these data suggest that two different tumor suppressor genes are on chromosome arm 12p, which act separately in the development of childhood precursor-B ALLs. One of the tumor suppressor genes is in the region the KIP1 gene, but our data suggest this gene is not abnormal. The other target is in the region of the TEL gene; and this candidate deserves further study.     

Molecular basis of the Kell (K1) phenotype

K1 (K, Kell) is a strong immunogen; its antibodies can cause severe reactions if incompatible blood is transfused and may cause hemolytic disease of the newborn in sensitized mothers. K1 is a member of the Kell blood group system, which is complex, containing over 20 different antigens. Some of the antigens are organized in allelic pairs of high and low prevalence whereas others are independently expressed. K1, which is present in 9% of the population, is antithetical to the high- prevalence K2 (k) antigen. We have determined the molecular basis of the K1/K2 polymorphism by sequencing the 19 exons of the Kell gene (KEL) of a K1/K1 person. Polymerase chain reaction was performed on genomic DNA isolated from peripheral blood and the amplified products were either directly sequenced or subcloned and sequenced. Comparisons of K1/K1 and K2/K2 DNA showed a C to T base substitution in exon 6 that predicts a threonine to methionine change at amino acid residue 193. This amino acid substitution occurs at a consensus N-glycosylation site (Asn. X. Thr) and probably prevents N-glycosylation, leading to a change in phenotype. The C to T substitution creates a Bsm I restriction enzyme site, which was tested in 42 different samples to confirm that this base change identifies the K1/K1 genotype. This test differentiates genotypes, K1/K1, K2/K2, and the K1/K2 heterozygote and should prove useful in the prenatal diagnosis of K1-related hemolytic disease of the newborn.     

Exploring the utility of whole‐exome sequencing as a diagnostic tool in a child with atypical episodic muscle weakness

The advent of whole‐exome next‐generation sequencing (WES) has been pivotal for the molecular characterization of Mendelian disease; however, the clinical applicability of WES has remained relatively unexplored. We describe our exploration of WES as a diagnostic tool in a 3½‐year old female patient with a 2‐year history of episodic muscle weakness and paroxysmal dystonia who presented following a previous extensive but unrevealing diagnostic work‐up. WES was performed on the proband and her two parents. Parental exome data was used to filter potential de novo genomic events in the proband and suspected variants were confirmed using di‐deoxy sequencing. WES revealed a de novo non‐synonymous mutation in exon 21 of the calcium channel gene CACNA1S that has been previously reported in a single patient as a rare cause of atypical hypokalemic periodic paralysis. This was unexpected, as the proband's original differential diagnosis had included hypokalemic periodic paralysis, but clinical and laboratory features were equivocal, and standard clinical molecular testing for hypokalemic periodic paralysis and related disorders was negative. This report highlights the potential diagnostic utility of WES in clinical practice, with implications for the approach to similar diagnostic dilemmas in the future.     

Activated natural killer cells and interleukin-2 promote granulocytic and megakaryocytic reconstitution after syngeneic bone marrow transplantation in mice

Purified populations of natural killer (NK) cells were obtained from mice with severe combined immune deficiency (SCID). SCID spleen cells were cultured and activated with recombinant human interleukin-2 (rhIL- 2) in vitro. The activated NK cells were then transferred with syngeneic BALB/c bone marrow cells (BMC) and rhIL-2 into lethally irradiated syngeneic recipients to determine their effect on long-term hematopoietic reconstitution. On analysis, the transfer of rhIL-2- activated NK cells along with BMC resulted in significant increases in splenic and BM hematopoietic progenitor cells when compared with those for mice not receiving NK cells. Histologic and flow cytometric analysis showed a marked increase in granulocytic and megakaryocytic lineage cells present in the spleens of the mice receiving activated NK cells. Analysis of the peripheral blood indicated that the transfer of activated NK cells with BMC also significantly improved platelet and total white blood cell counts, with increases in segmented neutrophils. Erythroid recovery was not affected. Finally, lethally irradiated mice receiving activated NK cells and rhIL-2 along with limiting numbers of syngeneic BMC showed a marked increase in survival rate. These results show that the use of populations enriched for activated NK cells after syngeneic BM transplantation (BMT) has a profound enhancing effect on engraftment primarily affecting megakaryocytic and granulocytic cell reconstitution. Therefore, the transfer of activated NK cells and rhIL- 2 may be of clinical use to promote hematopoietic reconstitution after BMT.     

Evidence summaries and recommendations from the international evidence‐based guideline for the assessment and management of polycystic ovary syndrome: Lifestyle management

Lifestyle is fundamental in chronic disease prevention and management, and it has been recommended as a first‐line treatment in the Australian polycystic ovary syndrome (PCOS) guideline 2011. The first international evidence‐based guideline on PCOS was developed in 2018, which expanded the scope and evidence in the Australian guideline. This paper summarizes the lifestyle recommendations and evidence summaries from the guideline. International multidisciplinary guideline development groups delivered the International Evidence‐based Guideline for the Assessment and Management of Polycystic Ovary Syndrome 2018. The process followed the Appraisal of Guidelines for Research and Evaluation II and The Grading of Recommendations, Assessment, Development and Evaluation framework. Extensive communication and meetings addressed six prioritized clinical questions through five reviews. Evidence‐based recommendations were formulated before consensus voting within the panel. Evidence shows the benefits of multicomponent lifestyle intervention, efficacy of exercise and weight gain prevention with no specific diet recommended. Lifestyle management is the first‐line management in the intervention hierarchy in PCOS. Multicomponent lifestyle intervention including diet, exercise and behavioural strategies is central to PCOS management with a focus on weight and healthy lifestyle behaviours. The translation programme optimizes reach and dissemination for health professionals and consumers.     

Long‐term benzodiazepine use: Problems for the criminal justice system

Benzodiazepines (BZs) were introduced into clinical practice in the 1960's. The major indications for their use are to treat anxiety, as sedative‐hypnotics, anti‐convulsants, muscle relaxants and pre‐anaesthetics. They replaced barbiturate tranquillisers and hypnotics which have significant and well‐documented dependence and overdose risks (Dupont & Saylor, 1991). Initially the BZs were thought not to induce dependence, to be of low overdose risk and to be relatively free of adverse side‐effects. However, during the 1970's it became apparent that these drugs do have quite serious adverse effects, especially in the elderly fluergens, 1993), and that dependence and withdrawal symptoms are not uncommon. Regular use of BZs, at normally prescribed doses, can lead to dependence in patients who do not abuse either BZs or other drugs (Owen & Tyrer, 1983). Dependence can develop in as little as 6–8 weeks' continuous administration (Lader & Petursson, 1983), and may persist for many months (Ashton, 1984). Symptoms include anxiety, insomnia, depression, aches and pains, muscle spasm, gastrointestinal disorders, and increased sensitivity to light sound & touch (Petursson & Lader, 1981; Ashton, 1984). At the same time the problems of drug interactions, whereby polydrug users add BZs to their drug cocktails, have brought them to the attention of the criminal justice system. This paper will review the mechanisms of action and patterns of use of BZs in Australia. The major adverse effects of BZs, on psychomotor skills and memory, in addition to the less common paradoxical effects on aggressive behaviour, will be discussed. The wide‐spread, long‐term use of these drugs, at least by certain groups, has consequences for the criminal justice system.