An analysis of data curated from 5 years of identifying human remains

An archive of 5 years of cases involving the identification of human remains was curated, collecting information on: The sample type submitted, the number of STR loci yielding interpretable results, the kinship challenge posed, and the outcome for the case. A total of 129 cases of remains ID were investigated using manual DNA extraction and recovery methods with amplification of STR markers using the Power Plex 21 multiplex STR kit from Promega Corp. In 52 cases, blood spots collected by the ME were provided as sample and in 100% of those cases, probabilities of relatedness to the reference samples was ≥99%. In 77 cases, tissue other than blood was provided as a source of DNA. These other samples were grouped categorically into long bones (femur and tibia; 40 cases), skull bones/teeth (11 cases), other bones (16 cases), and tissue (normally adherent to bone) (10 cases). Reference samples provided for cases included alleged parents or child(ren) of the victim (86 cases), alleged full siblings of the victim (38 cases), or alleged second-order relatives (five cases). The overall success rate in confirming the identity of the source of the remains in these cases was 89.2%. Our results demonstrate that a laboratory can be often successful identifying human remains using methods easily implemented in any DNA typing laboratory.

Deep sleep and beeps II: Sleep quality improvement project in general surgery patients

BACKGROUND

Poor sleep leads to poor health outcomes. Phase I of our sleep quality improvement project showed severe sleep disturbance in the ward setting. We implemented a novel PostOp Pack to improve sleep quality.

METHODS

Patients underwent elective, general surgery procedures. Fitbit trackers measured total sleep time. Patients completed the inpatient Richards-Campbell Sleep Questionnaire, which combines 5 domains into a cumulative score (0-100). Patients completed the outpatient Pittsburgh Sleep Quality Index preoperatively and postoperatively. Patients received the PostOp Pack, which included physical items and a sleep-protective order set to reduce nighttime awakenings. Patients from phase I served as the historical control. The primary outcome was the percentage of patients with Richards-Campbell Sleep Questionnaire total sleep score ≥50. The secondary outcomes included the mean Richards-Campbell Sleep Questionnaire domain scores and Fitbit total sleep time.

RESULTS

A total of 49 patients were compared with 64 historical controls. The percentage of patients with a total sleep score ≥50 was significantly higher in patients receiving a PostOp Pack versus historical control (69% vs. 44%, difference 26%, 95% confidence interval 6.1-45%, P = .01). The mean Richards-Campbell Sleep Questionnaire Total Sleep Score was significantly higher in patients with a PostOp Pack (62 vs 49, mean difference 13, 95% confidence interval 6-21, P ≤ .01). The PostOp Pack Richards-Campbell Sleep Questionnaire domain scores were significantly higher in various areas: Sleep Latency (68 vs 49, P ≤ .01), Awakenings (56 vs 40, P = .01), Sleep Quality (61 vs 49, P = .02), and Noise Disturbance (70 vs 59, P = .04). Of all patients, 92% would use PostOp Pack again in a future hospitalization. No patients had a failure to rescue event with PostOp Pack. The mean total sleep time was significantly improved with PostOp Pack on night 1 (6.4 vs 4.7 hours, P = .03).

CONCLUSION

The PostOp Pack improves inpatient sleep quality and is safe.

Deep Sleep and Beeps: Sleep Quality Improvement Project in General Surgery Patients

BACKGROUND

Poor sleep leads to poor health outcomes. Inpatient sleep disturbance has been studied primarily in the ICU. Minimal research exists on sleep in surgical populations.

METHODS

We recruited patients undergoing elective, inpatient general surgery procedures. Participants wore Fitbit trackers while inpatient to measure total sleep time (CDC recommendation is 7 or more hours per night). At discharge, patients completed the Richards-Campbell Sleep Questionnaire (RCSQ) to measure inpatient sleep quality. The RCSQ combines 5 domains into a cumulative score (0 to 100); a higher score means better sleep quality. Patients also completed the outpatient Pittsburgh Sleep Quality Index preoperatively and postoperatively. The primary end point was percentage of patients with total sleep score ≥ 50. Secondary outcomes included mean RCSQ domain scores, Fitbit total sleep time, and percentage with Pittsburgh Sleep Quality Index Score indicating poor sleep.

RESULTS

We included 64 patients (mean ± SD age 55.0 ± 14.1 years). Mean ± SD RCSQ total sleep score was 49 ± 20.5 and 53.1% with total sleep score < 50. Mean ± SD RCSQ domain scores were Awakenings: 40.4 ± 22.8, Sleep Quality: 49.1 ± 27.9, Sleep Latency: 49.2 ± 25.3, Sleep Depth: 50.2 ± 26.5, Returning to Sleep: 55.9 ± 28.1, and Noise Disturbance: 59.1 ± 27.9. On night one, 25 devices (40%) had recorded sleep data due to enough sleep. Mean ± SD total sleep time on night 1 was 4.7 ± 2.8 hours. Mean total sleep time for nights 2, 3, and 4 remained fewer than 7 hours. Percentages for each night that achieved the CDC goal of 7 or more hours were as follows: night one 10.9%, night two 32.8%, night three 35.3%, and night four 27.6%. Per the Pittsburgh Sleep Quality Index, 88.1% of patients were poor sleepers preoperatively and 84.5% were poor sleepers at follow-up (p = 0.6).

CONCLUSIONS

Elective general surgery patients experience a severe inpatient sleep disturbance, worse than in similarly studied ICU cohorts. This disturbance is driven primarily by nighttime awakenings.

The effect of environmental conditions on the rate of RNA degradation in dried blood stains

The relationship between RNA degradation and the age of a bloodstain has been suggested by the work of several investigators. A prior study from this laboratory described a qPCR assay that was effective at estimating the age of bloodstains stored in an environmentally controlled laboratory for periods of up to one year. In this study, the effect of the environmental conditions on the rate of RNA degradation during storage was analyzed. Bloodstains were prepared on stain cards and stored in one of 9 different environments for periods of up to 24 weeks. At selected times during the storage term, RNA was extracted, reverse transcribed, and the integrity of select transcripts analyzed. Three temperatures (37 °C, 20 °C, and 4 °C) and three relative humidities (rH) (75 %, 35 %, and 10 %) were combined pairwise. The rate of RNA degradation was found to increase 5-10 fold in stains stored at 37 °C versus those stored at 20 °C. The rate of RNA degradation was faster for stains stored at 20 °C compared to 4 °C but differed only 2-4 fold. Multivariate regression analysis suggests elevations in temperature or rH will accelerate RNA degradation and will do so to a similar extent. It is clear from the data that the integrity of the transcriptome in dried bloodstains is better preserved in a cold and dry environment. Investigations are ongoing to develop an approach for the estimation of sample age that incorporates the environmental conditions of a crime scene into the age estimate.

Variable water input controls evolution of the Lesser Antilles volcanic arc

Oceanic lithosphere carries volatiles, notably water, into the mantle through subduction at convergent plate boundaries. This subducted water exercises control on the production of magma, earthquakes, formation of continental crust and mineral resources. Identifying different potential fluid sources (sediments, crust and mantle lithosphere) and tracing fluids from their release to the surface has proved challenging¹. Atlantic subduction zones are a valuable endmember when studying this deep water cycle because hydration in Atlantic lithosphere, produced by slow spreading, is expected to be highly non-uniform². Here, as part of a multi-disciplinary project in the Lesser Antilles volcanic arc³, we studied boron trace element and isotopic fingerprints of melt inclusions. These reveal that serpentine-that is, hydrated mantle rather than crust or sediments-is a dominant supplier of subducted water to the central arc. This serpentine is most likely to reside in a set of major fracture zones subducted beneath the central arc over approximately the past ten million years. The current dehydration of these fracture zones coincides with the current locations of the highest rates of earthquakes and prominent low shear velocities, whereas the preceding history of dehydration is consistent with the locations of higher volcanic productivity and thicker arc crust. These combined geochemical and geophysical data indicate that the structure and hydration of the subducted plate are directly connected to the evolution of the arc and its associated seismic and volcanic hazards.

Can changing the timing of outdoor air intake reduce indoor concentrations of traffic-related pollutants in schools?

Traffic emissions have been associated with a wide range of adverse health effects. Many schools are situated close to major roads, and as children spend much of their day in school, methods to reduce traffic-related air pollutant concentrations in the school environment are warranted. One promising method to reduce pollutant concentrations in schools is to alter the timing of the ventilation so that high ventilation time periods do not correspond to rush hour traffic. Health Canada, in collaboration with the Ottawa-Carleton District School Board, tested the effect of this action by collecting traffic-related air pollution data from four schools in Ottawa, Canada, during October and November 2013. A baseline and intervention period was assessed in each school. There were statistically significant (P < 0.05) reductions in concentrations of most of the pollutants measured at the two late-start (9 AM start) schools, after adjusting for outdoor concentrations and the absolute indoor-outdoor temperature difference. The intervention at the early-start (8 AM start) schools did not have significant reductions in pollutant concentrations. Based on these findings, changing the timing of the ventilation may be a cost-effective mechanism of reducing traffic-related pollutants in late-start schools located near major roads.

Evaluation of degradation in DNA from males with a quantitative gender typing, endpoint PCR multiplex

Evidentiary samples submitted to a forensic DNA laboratory occasionally yield DNA that is degraded. Samples of intact chromosomal DNA (both nuclear and mitochondrial) were subjected to a heating protocol to induce DNA degradation. The DNAs were then analyzed using a multiplex PCR assay that amplifies targets of low and high molecular weight on the X/Y and mitochondrial chromosomes. If degradation is random, the amplification of larger DNA targets should be more adversely affected by degradation than smaller targets. In nuclear and mitochondrial DNA from a male donor, exhibiting degradation, DNA quantity estimates based upon higher molecular weight amplicons (HMW) are significantly lower than estimates made using low molecular weight (LMW) Q-TAT amplicons. DNA degradation estimated using this approach correlated well with actual fluorescence associated with HMW and LMW STR alleles amplified from the same genomic DNA templates. Q-TAT is thus useful not only as a quantitation tool, but also as an indicator of template degradation.

Sulphonylureas and risk of cardiovascular disease: systematic review and meta-analysis

AIMS

Sulphonylurea use has been linked with increased cardiovascular disease risk; however, previous studies have been inconsistent. Type 2 diabetes independently increases risk for cardiovascular disease, so understanding the link between longer-term use of anti-diabetic medications and cardiovascular disease has important clinical implications.

METHODS

Literature search in MEDLINE and CENTRAL was conducted throughout December 2011 for clinical and observational studies that reported the association between sulphonylurea and cardiovascular disease events. Ratios (relative risk, odds ratios or hazard ratios) adjusted for potential confounders (concomitant medications, baseline cardiovascular risk, diabetes severity) were pooled using a random-effects model to yield relative risks and associated 95% confidence intervals.

RESULTS

This meta-analysis included 33 studies (n = 1,325,446 patients), followed for a range of 0.46-10.4 years. In all studies, compared with other oral diabetes drugs, sulphonylurea use was associated with a significantly increased risk of cardiovascular death (relative risk 1.27, 95% confidence interval 1.18-1.34, n = 27 comparisons) and composite cardiovascular event (including myocardial infarction, stroke, cardiovascular-related hospitalization or cardiovascular death) (relative risk 1.10, 95% confidence interval 1.04-1.16, n = 43 comparisons). In studies comparing sulphonylurea vs. metformin, these relative risks were 1.26 (95% confidence interval 1.17-1.35, n = 17 comparisons) and 1.18 (95%confidence interval 1.13-1.24, n = 16 comparisons), respectively.

CONCLUSIONS

Results suggest that sulphonylurea use may elevate the risk of cardiovascular disease among patients with diabetes. This meta-analysis expands the pool of studies evaluating cardiovascular mortality compared with prior observations while using adjusted estimates, and assessing an additional outcome of a composite cardiovascular event. This finding warrants consideration in clinical practice when other treatment options may be available.

Cinnamon use in type 2 diabetes: an updated systematic review and meta-analysis

PURPOSE

Cinnamon has been studied in randomized controlled trials (RCTs) for its glycemic-lowering effects, but studies have been small and show conflicting results. A prior meta-analysis did not show significant results, but several RCTs have been published since then. We conducted an updated systematic review and meta-analysis of RCTs evaluating cinnamon's effect on glycemia and lipid levels.

METHODS

MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched through February 2012. Included RCTs evaluated cinnamon compared with control in patients with type 2 diabetes and reported at least one of the following: glycated hemoglobin (A1c), fasting plasma glucose, total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), or triglycerides. Weighted mean differences (with 95% confidence intervals) for endpoints were calculated using random-effects models.

RESULTS

In a meta-analysis of 10 RCTs (n = 543 patients), cinnamon doses of 120 mg/d to 6 g/d for 4 to 18 weeks reduced levels of fasting plasma glucose (-24.59 mg/dL; 95% CI, -40.52 to -8.67 mg/dL), total cholesterol (-15.60 mg/dL; 95% CI, -29.76 to -1.44 mg/dL), LDL-C (-9.42 mg/dL; 95% CI, -17.21 to -1.63 mg/dL), and triglycerides (-29.59 mg/dL; 95% CI, -48.27 to -10.91 mg/dL). Cinnamon also increased levels of HDL-C (1.66 mg/dL; 95% CI, 1.09 to 2.24 mg/dL). No significant effect on hemoglobin A1c levels (-0.16%; 95%, CI -0.39% to 0.02%) was seen. High degrees of heterogeneity were present for all analyses except HDL-C (I(2) ranging from 66.5% to 94.72%).

CONCLUSIONS

The consumption of cinnamon is associated with a statistically significant decrease in levels of fasting plasma glucose, total cholesterol, LDL-C, and triglyceride levels, and an increase in HDL-C levels; however, no significant effect on hemoglobin A1c was found. The high degree of heterogeneity may limit the ability to apply these results to patient care, because the preferred dose and duration of therapy are unclear.

Diagnostic accuracy of rectal mucosa biopsy testing for chronic wasting disease within white-tailed deer (Odocoileus virginianus) herds in North America: effects of age, sex, polymorphism at PRNP codon 96, and disease progression

An effective live animal diagnostic test is needed to assist in the control of chronic wasting disease (CWD), which has spread through captive and wild herds of white-tailed deer (Odocoileus virginianus) in Canada and the United States. In the present study, the diagnostic accuracy of rectal mucosa biopsy sample testing was determined in white-tailed deer from 4 CWD-infected captive herds. Specifically, the current study compared the immunohistochemical detection of disease-associated prion protein in postmortem rectal mucosa biopsy samples to the CWD status of each deer as determined by immunodiagnostic evaluations of the brainstem at the obex, the medial retropharyngeal lymph node, and the palatine tonsil. The effects of age, sex, genotype, and disease progression were also evaluated. Diagnostic sensitivity on rectal biopsy samples for CWD in white-tailed deer ranged from 63% to 100%; the pooled estimate of sensitivity was 68% with 95% confidence limits (95% CLs) of 49% and 82%. However, diagnostic sensitivity was dependent on genotype at prion protein gene (PRNP) codon 96 and on disease progression as assessed by obex grade. Diagnostic sensitivity was 76% (95% CLs: 49%, 91%) for 96GG deer but only 42% (95% CLs: 13%, 79%) for 96GS deer. Furthermore, diagnostic sensitivity was only 36% for deer in the earliest stage of disease (obex grade 0) but was 100% for deer in the last 2 stages of preclinical disease (obex grades 3 and 4). The overall diagnostic specificity was 99.8%. Selective use of antemortem rectal biopsy sample testing would provide valuable information during disease investigations of CWD-suspect deer herds.

Method: a single nucleotide polymorphism genotyping method for Wheat streak mosaic virus

BACKGROUND

The September 11, 2001 attacks on the World Trade Center and the Pentagon increased the concern about the potential for terrorist attacks on many vulnerable sectors of the US, including agriculture. The concentrated nature of crops, easily obtainable biological agents, and highly detrimental impacts make agroterrorism a potential threat. Although procedures for an effective criminal investigation and attribution following such an attack are available, important enhancements are still needed, one of which is the capability for fine discrimination among pathogen strains. The purpose of this study was to develop a molecular typing assay for use in a forensic investigation, using Wheat streak mosaic virus (WSMV) as a model plant virus.

METHOD

This genotyping technique utilizes single base primer extension to generate a genetic fingerprint. Fifteen single nucleotide polymorphisms (SNPs) within the coat protein and helper component-protease genes were selected as the genetic markers for this assay. Assay optimization and sensitivity testing was conducted using synthetic targets. WSMV strains and field isolates were collected from regions around the world and used to evaluate the assay for discrimination. The assay specificity was tested against a panel of near-neighbors consisting of genetic and environmental near-neighbors.

RESULT

Each WSMV strain or field isolate tested produced a unique SNP fingerprint, with the exception of three isolates collected within the same geographic location that produced indistinguishable fingerprints. The results were consistent among replicates, demonstrating the reproducibility of the assay. No SNP fingerprints were generated from organisms included in the near-neighbor panel, suggesting the assay is specific for WSMV. Using synthetic targets, a complete profile could be generated from as low as 7.15 fmoles of cDNA.

CONCLUSION

The molecular typing method presented is one tool that could be incorporated into the forensic science tool box after a thorough validation study. This method incorporates molecular biology techniques that are already well established in research and diagnostic laboratories, allowing for an easy introduction of this method into existing laboratories.

KEYWORDS

single nucleotide polymorphisms, genotyping, plant pathology, viruses, microbial forensics, Single base primer extension, SNaPshot Multiplex Kit.

Molecular assay for screening and quantifying DNA in biological evidence: the modified Q-TAT assay

A method is described for the quantitation of total human and male DNA. Q-TAT utilizes end-point, multiplex polymerase chain reaction (PCR) amplification of the amelogenin and SRY loci to quantify DNA and incorporates a cloned nonhuman template to detect PCR inhibition. Standard curves of fluorescence from amelogenin or SRY amplicons were generated from amplification of known amounts of NIST traceable SRM-female or SRM-male DNA. Curves showed good linearity up to 500 pg of SRM-template (R(2) > 0.99) and reliably estimated total and male DNA content in casework samples. The nonhuman pRL(null) template included in each PCR was a sensitive indicator of known PCR inhibitors including EDTA, hemin, blue denim dye, and humic acid. Finally, the SRY amplicon was a sensitive indicator of male DNA and, in mixtures, could reliably estimate male DNA present in an excess of female DNA. The Q-TAT multiplex is a reliable quantitation method for forensic DNA typing.

Small volume laboratory on a chip measurements incorporating the quartz crystal microbalance to measure the viscosity-density product of room temperature ionic liquids

A microfluidic glass chip system incorporating a quartz crystal microbalance (QCM) to measure the square root of the viscosity-density product of room temperature ionic liquids (RTILs) is presented. The QCM covers a central recess on a glass chip, with a seal formed by tightly clamping from above outside the sensing region. The change in resonant frequency of the QCM allows for the determination of the square root viscosity-density product of RTILs to a limit of approximately 10 kg m(-2) s(-0.5). This method has reduced the sample size needed for characterization from 1.5 ml to only 30 mul and allows the measurement to be made in an enclosed system.

Draft protocol for testing calibration and quality control material used with automatic blood-counting apparatus

A large number of commercial preparations are now available for calibrating or checking the stability of automatic blood counters. Most of these preparations are supplied with 'stated' values though the methods for assigning these values are not described in sufficient detail to allow for an adequate assessment of the validity. The Haemocytometry Panel of the British Committee for Standards in Haematology are therefore proposing a draft protocol for testing calibration and quality control materials. Comments on the draft protocol are invited, either as letters to the Editor of Clinical and Laboratory Haematology or in confidence to the Chairman of the Haemocytometry Panel.

Considerations for the interpretation of STR results in cases of questioned half-sibship

Likelihood ratios (LRs) were calculated for a cohort of 60 pairs of true half-sibs and compared with LR values calculated for unrelated, paired children. STR results for the half-sib group were obtained from 60 archived cases involving a true mother, two children, and an alleged father subjected to typing with a multiplex STR kit (Identifiler multiplex, Applied Biosystems) and in which the alleged father was excluded as the father of only one of the two children (half-sib pairs). The distribution of LR values among true half-sibs was compared to those produced from paired, unrelated children selected in two ways: One method for producing unrelated pairs was to randomly select Identifiler profiles from children in 120 distinct paternity cases and group them into 60 ethnically matched pairs (random pairs). In a second approach, the children in the true half-sib group were shuffled and ultimately paired with someone from a different case. A total of 49 ethnically matched, unrelated pairs were created (shuffled pairs). In the shuffled pairs group, comparisons were thus based on a constant set of phenotypes. LRs comparing the probability of half-sibship versus being unrelated were produced for all groups with standard methods. Among pairs of known half-sibs, LRs ranged from a low of 0.1 to a maximum of 3763. Among random and shuffled pairs, LRs ranged from a low of 0.0001 to 12 for shuffled pairs or 42 for random pairs. LRs of greater than 2 were produced in 8 instances among random pairs and in 4 instances among the shuffled pairs. Overall, results suggest that half-sib indices of 30 or greater are fairly characteristic of individuals who are related as half-sibs. In contrast, half-sib indices of 0.1 or less are fairly characteristic of unrelated individuals who claim to be half-sibs. LRs falling between 0.1 and 10.0 are uninformative, as this region represents the overlap in the LR distributions produced from the true and false half-sib groups when the Identifiler multiplex kit is used for testing.

Quantitation of Human Genomic DNA Through Amplification of the Amelogenin Locus*

An alternate method for quantitation of human genomic DNA is presented. Quantitative template amplification technology (abbreviated "Q-TAT") estimates the quantity of human DNA present in an extract by comparing fluorescence in X and Y amplicons produced from unknowns with fluorescence in a standard curve amplified from known quantities of reference DNA. Q-TAT utilizes PCR and electrophoresis with fluorescent detection/quantitation, precluding the need for new instrumentation, methodology, or quality assurance associated with slot-blot or real-time PCR. In a comparison study incorporating shared samples, Q-TAT was found to be more sensitive than widely used slot-blot methods but somewhat less sensitive than real-time PCR. Among samples containing DNA concentrations ranging from 100 pg/microL to 2-4 ng/microL, Q-TAT produced DNA concentration estimates that agreed reasonably well with either Quantiblot or real-time PCR. Q-TAT was reproducible with a typical coincidence of variation of about 35%. Quantitation of human DNA in this study involved summing fluorescence in X and Y amplicons in unknowns and quantitation standards. However, analyzing fluorescence in X and Y amplicons individually could allow estimates of male and female DNA present in mixtures to be made. Moreover, since X and Y amplicons exhibit sizes of 210 and 216 bp, respectively, the integrity as well as the concentration of the genomic DNA template can be assessed. Q-TAT represents an alternate method useful for the quantitation of human genomic DNA prior to amplification of STR loci used for identity testing purposes. The method uses existing equipment and procedures in conjunction with a well-characterized DNA standard to produce concentration estimates for unknowns that reliably produce STR profiles suitable for analysis.

Resolution of a serum sample mix-up through the use of short tandem repeat DNA typing

BACKGROUND

A sample mix-up occurred in a tissue procurement laboratory in which aliquots of serum from two tissue donors were accidentally mislabeled. The clues to the apparent mixup involved discrepant Hepatitis C test results. In an attempt to resolve the apparent mix up, DNA typing was performed using serum samples as a possible source of genomic DNA.

STUDY DESIGN AND METHODS

Two hundred microliter aliquots of two reference sera and aliquots prepared from them were subjected to DNA extraction. PCR amplification of 9 STR loci was performed on the extracts and amplicons were analyzed by capillary electrophoresis.

RESULTS

About 1 microg/ml of DNA was recovered from all serum samples and was of sufficient quality to direct the amplification of most, if not all STR loci allowing the mislabeled specimens to be traced to the proper tissue donor.

CONCLUSIONS

Serum is a useful source of genomic DNA for STR analysis in situations in which such samples are the only source of DNA for testing. Interestingly, one of the tissue donors on life support and repeatedly receiving blood products, exhibited a mixed DNA profile indicative of the presence of DNA from multiple individuals in the bloodstream.

Characteristics of mutations at the D5S818 locus studied with a tightly linked marker

BACKGROUND

Mutations to STR alleles are not well understood in terms of the mechanism(s) underlying such mutations or their relative frequency among different alleles at the locus.

STUDY DESIGN AND METHODS

A cytosine/thymosine (C/T) polymorphism was discovered 13 nucleotides upstream from the 5'-end of the tandem array of the D5S818 locus (-13SNP). The -13SNP coincidentally creates a restriction site polymorphism for the restriction endonuclease SnaBI that is tightly linked to the tandem array of D5S818. Forty D5S818 addition/deletion mutations in the tandem array were characterized with RFLP analysis with SnaBI.

RESULTS

Among 40 mutations studied, 34 (approximately 85%) were of paternal origin, 1 ( approximately 3%) was of maternal origin, and 5 (approximately 13%) had an unclear lineage of origin. In 26 cases where the magnitude of the repeat change could be determined, 23 (88%) involved changes of a single repeat unit, whereas 3 (12%) involved changes of 2 or more repeats. The number of additions to the tandem array was roughly equal to the number of deletions from the tandem array. In 19 instances it was possible to identify the parental allele that underwent the mutation. Alleles 13 and 14 were prone to mutation, whereas Allele 11 was resistant. Thus, there is an unequal sensitivity to mutation among D5S818 alleles.

CONCLUSIONS

The use of the linked -13SNP marker has revealed several features of mutations at the D5S818 locus: 1) Single repeat changes are the most commonly observed. 2) Mutations are more likely in the paternal lineage. 3) Not all alleles undergo mutation with equal frequency.

Paternity Testing Commission of the International Society of Forensic Genetics: recommendations on genetic investigations in paternity cases

The International Society for Forensic Genetics (ISFG) has established a Paternity Testing Commission (PTC) with the purpose of formulating international recommendations concerning genetic investigations in paternity testing. The PTC recommends that paternity testing be performed in accordance with the ISO 17025 standards. The ISO 17025 standards are general standards for testing laboratories and the PTC offers explanations and recommendations concerning selected areas of special importance to paternity testing.

Prenatal genotyping for the RhD blood group antigen: considerations in developing an accurate test

Experience performing prenatal genotyping for RHD has shown that consideration must be given to developing a molecular test capable of detecting recombination/gene conversion events involving the RHD and RHCE genes that can lead to erroneous results. Out of 50 prenatal RHD tests performed over the past 5 years, four samples were encountered that gave false-positive results. In only one of the tests, incorrect results were issued to the physician. In the other three instances, the erroneous nature of the test results was revealed through the analysis of multiple regions of the RHD gene and, more importantly, because the mother, and sometimes the father, were tested in parallel with the fetus. In an extension of the observations obtained from the prenatal testing program, a large panel of RhD-negative blood donors were subjected to molecular analysis of the RHD gene. Of 1,183 donors screened, 187 were found to phenotype as RhD negative. Of the 187 donors confirmed RhD negative serologically, 22 (11.8%) were found to retain remnants of the RHD gene that, depending upon the characteristics of the molecular assay performed, could lead to a false-positive result in a genotyping assay. On the basis of the experience presented here, it is recommended that any molecular RHD assay include an analysis of multiple areas of the RHD gene so as to allow for the detection of recombination/gene conversion events between the RHD and RHCE genes. Moreover, it is strongly recommended that the mother (at a minimum) and father be subjected to molecular analysis simultaneously with the fetus to confirm that the known phenotypes of the parent(s) are consistent with their respective genotypes.

DNA analysis in a paternity case involving a triploid fetus

BACKGROUND

A parentage testing laboratory was asked to perform testing in a case of sexual assault that resulted in the conception of a child. Samples submitted to the laboratory included blood from the mother, the alleged father, and the fetus.

CASE REPORT

DNA typing was used to determine if the suspect in this sexual assault was the father of the expected child. DNA extracted from these samples was subjected to both restriction fragment length polymorphism and polymerase chain reaction/short-tandem repeat analysis at a total of 13 genetic loci. Examination of DNA profiles for selected markers suggested that the fetus was triploid. Triploidy was confirmed through the use of fluorescent in situ hybridization of chromosomes, employing three chromosome-specific alpha satellite probes and fetal trophoblast nuclei. Statistical interpretation of the test results required identifying a method for calculation that would consider two transmitted paternal genes. Attempts to modify the standard method of calculating a paternity index were unsuccessful, because it was not possible to distinguish between dispermy and diandry as the mechanism of conception. Therefore, the likelihood ratio was calculated as the reciprocal of the random men not excluded value or the proportion of the population that possesses all of the paternal markers observed in the triploid fetus.

CONCLUSION

Calculation of a likelihood ratio employing the exclusionary power of a collection of DNA markers appears to be the only method suitable for assigning weight to the significance of DNA matches between an alleged father and a child who is triploid.

Treatment of intractable pain with topical large-dose capsaicin: preliminary report

Complex regional pain syndromes (CRPS) and neuropathic pain are often poorly controlled by conventional pharmacologic interventions. We administered 8-methyl-N-vanillyl-noneamide (capsaicin) at doses of 5%-10% to individuals with such disorders in this trial. Previous limitations to trials with larger-dose, topical concentrations of capsaicin included intense burning sensations experienced after application. To enable patients to tolerate the high concentrations, we first performed regional anesthesia. All patients reported at least some relief. Of 10 patients, 9 obtained substantial analgesia that lasted 1-18 wk. At Week 1 after therapy, the mean verbal analog scale (VAS) scores decreased from 8.0 to 3.0. At Week 4 after therapy, mean VAS score was 4.5. Analgesia lasted from < 1 wk (1 patient) to more than 50 wk (1 patient). Patients received one to eight treatments. With one exception, patients receiving more than one treatment obtained additional relief with subsequent treatment. Pain responsive to opioids was the only side effect of treatment. Large-dose capsaicin administered with regional anesthesia may effectively minimize refractory CRPS and neuropathic pain. A double-blind, placebo-controlled study in patients with bilateral peripheral neuropathy using epidural anesthesia with and without large-dose topical capsaicin is in progress.

IMPLICATIONS

Sensory neuropathies are associated with many diseases. Pain from these disorders can produce greater disability than the primary disease processes themselves. Currently available therapies are limited. However, the intermittent application of large-dose topical capsaicin may provide significant pain relief, decrease chronic analgesic dependence, and decrease aggregate health care expenditures.

Space product development: bringing the benefits of space down to Earth

In fulfilling the National Aeronautics and Space Administration's (NASA) responsibility to encourage the fullest commercial use of space the Space Product Development (SPD) Program, within the Microgravity Research Program Office (MRPO) located at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama, is managing an organization of Commercial Space Centers (CSC's) that have successfully employed methods for encouraging private industries to exploit the benefits of space-based research. Unique research opportunities of the space environment are being made available to private industry in an effort to develop new, competitive products; create jobs; and enhance the country's quality of life. Over 200 commercial research activities have been conducted in space by the CSC's and their industrial partners during the last several years. The success of this research is evidenced by the increasing amount of industrial participation in commercial microgravity research and the potential products nearing marketability.

Prolonged muscle weakness following emergency tonsillectomy in a patient with familial periodic paralysis and infectious mononucleosis

A thirteen-year-old girl with normokalaemic familial periodic paralysis (FPP) suffered life threatening upper airway obstruction secondary to tonsillopharyngitis resulting from infectious mononucleosis (IM). Emergency tonsillectomy was performed, but her postoperative course was complicated by persistent muscle weakness requiring a very prolonged period of artificial ventilation.

Low-cost high-resolution fast spin-echo MR of acoustic schwannoma: an alternative to enhanced conventional spin-echo MR?

PURPOSE

To determine whether unenhanced high-resolution T2-weighted fast spin-echo MR imaging provides an acceptable and less expensive alternative to contrast-enhanced conventional T1-weighted spin-echo MR techniques in the diagnosis of acoustic schwannoma.

METHODS

We reviewed in a blinded fashion the records of 25 patients with pathologically documented acoustic schwannoma and of 25 control subjects, all of whom had undergone both enhanced conventional spin-echo MR imaging and unenhanced fast spin-echo MR imaging of the cerebellopontine angle/internal auditory canal region. The patients were imaged with the use of a quadrature head receiver coil for the conventional spin-echo sequences and dual 3-inch phased-array receiver coils for the fast spin-echo sequences.

RESULTS

The size of the acoustic schwannomas ranged from 2 to 40 mm in maximum dimension. The mean maximum diameter was 12 mm, and 12 neoplasms were less than 10 mm in diameter. Acoustic schwannoma was correctly diagnosed on 98% of the fast spin-echo images and on 100% of the enhanced conventional spin-echo images. Statistical analysis of the data using the kappa coefficient demonstrated agreement beyond chance between these two imaging techniques for the diagnosis of acoustic schwannoma.

CONCLUSIONS

There is no statistically significant difference in the sensitivity and specificity of unenhanced high-resolution fast spin-echo imaging and enhance T1-weighted conventional spin-echo imaging in the detection of acoustic schwannoma. We believe that the unenhanced high-resolution fast spin-echo technique provides a cost-effective method for the diagnosis of acoustic schwannoma.

Relief of tension subcutaneous emphysema using a large bore subcutaneous drain

We report a case of subcutaneous emphysema following multiple attempts to cannulate both subclavian veins for pacemaker insertion. Initial bilateral pneumothoraces were complicated by subcutaneous emphysema which became so severe that respiration and cardiac output became seriously impaired. The insertion of a single large bore subcutaneous drain produced a dramatic improvement. The aetiology, complications and management of tension subcutaneous emphysema are discussed.

Religion and children with disabilities

Religion as a personal coping resource used by parents of infants and toddlers with disabilities has received some attention in recent literature. This exploratory study involved indepth interviews of 12 parents who had children with disabilities ranging in age from 15 months to 30 years. The ways in which religion can be used as a coping resource across the life-cycle are exemplified through excerpts from these interviews. Prayer, church attendance, and specific religious beliefs were identified as sources of support which helped some parents feel a growing sense of hope and strength. Suggestions for future research are discussed.

Single-base substitutions give rise to a five-banded DNA profile at the D10S28 locus

BACKGROUND

DNA profiles from variable number of tandem repeat (VNTR) loci typically are composed of two bands, one derived from each member of the homologous pair of chromosomes. DNA profiles composed of more than two bands result from mutations, and the question arises as to the mechanism underlying these unusual multi-banded DNA profiles.

STUDY DESIGN AND METHODS

An alleged father in a paternity test was found to have a five-banded DNA profile at the D10S28 locus when his DNA was subjected to single-locus restriction fragment length polymorphism mapping with the restriction enzyme Pvu II.

RESULTS

Several results suggest that this complex DNA profile is the result of several single-base changes within the VNTR locus. First, there was no evidence of partial digestion of the DNA with Pvu II. Furthermore, the multi-banded allele happened, in this case, to be transmitted to the child, who also showed a five-banded pattern composed of four bands inherited from the alleged father and one band inherited from the mother. Second, digestion of this DNA with Hae III resulted in the visualization of just two bands at the D10S28 locus.

CONCLUSION

The results confirm the notion that mutations at VNTR loci are not always the result of additions or deletions of tandem repeats, but that they can also involve single-base substitutions either within or flanking VNTR loci that give rise to atypical DNA profiles and new alleles at the locus.

Isolation of tumor cell-specific single-chain Fv from immunized mice using phage-antibody libraries and the re-construction of whole antibodies from these antibody fragments

Enhanced expression of epidermal growth factor receptor (EGFR) occurs on a variety of malignant tissues thus making anti-EGFR antibodies possible agents for the diagnosis and therapy of human tumors. Standard hybridoma technology has been used successfully to isolate anti-EGFR antibodies from immunized mice and rats. This report demonstrates that phage-antibody libraries are an alternative, and more versatile, method for isolating antibodies from immunized mice. Anti-EGFR antibodies were isolated from phage-antibody libraries constructed not only from the spleen of an immunized mouse but also from the draining lymph node of an immunized mouse and from in vitro immunized mouse cells. Two of the single-chain Fv isolated from the phage-antibody libraries were engineered to create partially humanized whole antibody molecules.

Metastatic choriocarcinoma: correlation of MRI, CT, and angiography

We have described a 46-year-old woman with metastatic choriocarcinoma, anemia, and a liver mass. She subsequently had widespread metastatic disease and died despite chemotherapy. Without an antecedent history of pregnancy, her clinical presentation posed a diagnostic dilemma. This case emphasizes the importance of including choriocarcinoma in the differential diagnosis of liver masses in women of childbearing age and of correlating CT, MRI, and angiographic findings.

A preliminary assessment of epidural chloroprocaine for day procedures

Twenty-five patients underwent epidural anaesthesia with a new formulation of chloroprocaine 3% (1.0-1.5 ml x 10 cm body height-1) for a variety of day procedures. The mean (range) duration of surgery was 17 (5-35) min. The mean (range) time taken to establish maximal block was 16 (15-21) min and the mean (range) time to ambulation was 78 (55-95) min after administration of chloroprocaine. Twenty-three patients experienced a decrease in systolic arterial blood pressure of up to 15% of baseline values with another two decreasing by up to 25%. Two patients complained of severe backache immediately after operation and a further 16 and four patients reported mild or moderate backache respectively. Operating conditions were excellent in all but one patient and 23 patients said they would be happy to have the same anaesthetic again.

Genetic differences at four DNA typing loci in Finnish, Italian, and mixed Caucasian populations

Highly polymorphic segments of the human genome containing variable numbers of tandem repeats (VNTRs) have been widely used to establish DNA profiles of individuals for use in forensics. Methods of estimating the probability of occurrence of matching DNA profiles between two randomly selected individuals have been subject to extensive debate regarding the possibility of significant substructure occurring within the major races. We have sampled two Caucasian subpopulations, Finns and Italians, at four commonly used VNTR loci to determine the extent to which the subgroups differ from each other and from a mixed Caucasian database. The data were also analyzed for the occurrence of linkage disequilibrium among the loci. The allele frequency distributions of some loci were found to differ significantly among the subpopulations in a manner consistent with population substructure. Major differences were also found in the probability of occurrence of matching DNA profiles between two individuals chosen at random from the same subpopulation. With respect to the Finnish and Italian subpopulations, the conventional product rule for estimating the probability of a multilocus VNTR match using a mixed Caucasian database consistently yields estimates that are artificially small. Systematic errors of this type were not found using the interim ceiling principle recently advocated in the National Research Council's report [National Research Council (1992) DNA Technology in Forensic Science (Natl. Acad. Sci., Washington)]. The interim ceiling principle is based on currently available racial or ethnic databases and sets an arbitrary lower limit on each VNTR allele frequency. In the future the ceiling frequencies are expected to be established from more adequate data acquired for relevant VNTR loci from multiple subpopulations.