Profiling ephedrine/pseudoephedrine and methamphetamine synthesised from benzaldehyde, nitroethane and dimethyl carbonate

In previous work, a novel pathway for the synthesis of ephedrine/pseudoephedrine and methamphetamine using the precursors benzaldehyde, nitroethane and dimethyl carbonate was investigated, and an impurity profile presented. This paper presents chiral and stable isotope ratios of ephedrine/pseudoephedrine and methamphetamine synthesised by this pathway. Based on the chiral profile and the more negative δ13C (avg. -33.2‰) and more positive δ2H values, it is possible to distinguish ephedrine/pseudoephedrine and methamphetamine prepared from this pathway from those of "fully synthetic", "semi-synthetic" or "natural" origin. The more positive δ2H values of methamphetamine from this pathway allowed for differentiation from methamphetamine produced from phenyl-2-propanone. It was noted, however, that the use of stable isotope profiling would likely be limited when a benzaldehyde source having a negative δ2H value was used as a precursor. Furthermore, the stable isotope values alone could not be used to differentiate from methamphetamine prepared by the Akabori-Momotani reaction, highlighting the need for combination with impurity profiling.

Once upon a twine: The Donna Steele murder investigation and an improved methodology for the comparison of synthetic twine

In 2017 Cooktown resident Donna Steele was murdered and the case remained unsolved for more than a year. The forensic evidence from the investigation included two lengths of synthetic twine and a new protocol for the comparison of twine was developed to enhance the potential value of any evidence. The method was developed using 23 samples of similar twine collected across Australia. Traditional methods of physical and microscopic comparisons and polymer analysis by infrared spectroscopy were retained. Micro-spectrophotometry was used as an objective assessment of colour and was able to identify five groupings within the background samples. Measurements of hydrogen and carbon stable isotopic composition provided further delineation of the background samples. Combining traditional methods with micro-spectrophotometry and stable isotope measurements, the two case samples were found to be distinct from the background population and were indistinguishable when compared to each other.

Fingerprinting eukaryotic metabolism across the animal kingdom using position-specific isotope analysis (PSIA) 13C/12C measurements

Despite differences in their overall metabolism, eukaryotes share a common mitochondrial biochemistry. We investigated how this fundamental biochemistry supports overall metabolism using a high-resolution carbon isotope approach, position-specific isotope analysis. We measured carbon isotope ¹³C/¹²C cycling in animals, focusing on amino acids that are formed in mitochondrial reactions and are most metabolically active. Carboxyl isotope determinations for amino acids showed strong signals related to common biochemical pathways. Contrasting isotope patterns were measured for metabolism associated with major life history patterns, including growth and reproduction. Turnover of proteins and lipids as well as gluoconeogensis dynamics could be estimated for these metabolic life histories. The high-resolution isotomics measurements fingerprinted metabolism and metabolic strategies across the eukaryotic animal kingdom, yielding results for humans, ungulates, whales, and diverse fish and invertebrates in a nearshore marine food web.

Stable isotope characterisation of 3,4-methylenedioxyphenyl-2-propanone and 3,4-methylenedioxyamphetamine prepared from piperonal

RATIONALE

Stable isotopic ratios can provide information for illicit drug profiling. The research presented here investigated the variations in stable isotopic ratios of hydrogen (δ² H), carbon (δ¹³ C), nitrogen (δ¹⁵ N) and oxygen (δ¹⁸ O) during the synthesis of MDP2P (3,4-methylenedioxyphenyl-2-propanone) and MDA (3,4-methylenedioxyamphetamine) prepared via the 'nitrostyrene' route.

METHODS

Samples of MDA and MDP2P were synthesised from two isotopically characterised starting materials, piperonal and nitroethane. The isotopic compositions of the nitrostyrene intermediate (3,4-methylenedioxyphenyl-2-nitropropene, MDP2NP) and products MDP2P and MDA were also measured by isotope ratio mass spectrometry.

RESULTS

A significantly negative change occurred to δ² H values during the production of MDP2NP, MDP2P and MDA, indicating a mechanism that favours inclusion or retention of ¹ H over ² H. This suggests that the δ² H compositions of MDA/MDP2P prepared from piperonal will not provide information on the synthetic history. Minimal changes were observed in δ¹³ C composition during the synthesis of MDP2NP, MDP2P and MDA, and minimal δ¹⁵ N compositional changes occurred in MDP2NP and MDA. Progressing from piperonal to MDP2NP, a minimal change occurred to δ¹⁸ O composition. A variable change to δ¹⁸ O was observed from MDP2NP with one sample becoming more positive in δ¹⁸ O composition and two samples becoming more negative. Progressing from MDP2NP to MDA, a significant negative change occurred to δ¹⁸ O composition.

CONCLUSIONS

The changes to stable isotopic ratios observed during the preparation of MDA and MDP2P from piperonal may prove useful when attempting to compare batch-to-batch variations between seizures and provide information with tactical intelligence applications.

Minimum requirements for publishing hydrogen, carbon, nitrogen, oxygen and sulfur stable-isotope delta results (IUPAC Technical Report)

Stable hydrogen, carbon, nitrogen, oxygen and sulfur (HCNOS) isotope compositions expressed as isotope-delta values are typically reported relative to international standards such as Vienna Standard Mean Ocean Water (VSMOW), Vienna Peedee belemnite (VPDB) or Vienna Cañon Diablo Troilite (VCDT). These international standards are chosen by convention and the calibration methods used to realise them in practice undergo occasional changes. To ensure longevity and reusability of published data, a comprehensive description of (1) analytical procedure, (2) traceability, (3) data processing, and (4) uncertainty evaluation is required. Following earlier International Union of Pure and Applied Chemistry documents on terminology and notations, this paper proposes minimum requirements for publishing HCNOS stable-isotope delta results. Each of the requirements are presented with illustrative examples.

Feeding Sugars to Stingless Bees: Identifying the Origin of Trehalulose-Rich Honey Composition

The beneficial disaccharide, trehalulose, is a feature of stingless bee honey, while not dominant in any other foods. By experimentally feeding sugar solutions to confined colonies of the Australian stingless bee Tetragonula carbonaria, the origin of trehalulose has now been established. Complete conversion of fed sucrose was observed, by analysis of the honey, forming trehalulose (64-72%) with lesser erlose (18-23%), fructose (9-12%), and minor glucose detected. Remarkably, feeding solutions of glucose/fructose (1:1) mixtures did not result in trehalulose/erlose formation. Hence, stingless bees with natural access to floral nectar high in sucrose will produce honey high in trehalulose, with its associated beneficial properties. Any temptation to artificially increase trehalulose content by feeding sucrose to stingless bees would produce "fake" honey lacking key natural phytochemicals available to the foraging bee. The sucrose-fed fake and natural honey were however readily distinguished via isotope ratio mass spectrometry δ¹³C values, to combat such potential indirect adulteration.

Food Matrix Reference Materials for Hydrogen, Carbon, Nitrogen, Oxygen, and Sulfur Stable Isotope-Ratio Measurements: Collagens, Flours, Honeys, and Vegetable Oils

An international project developed, quality-tested, and measured isotope-delta values of 10 new food matrix reference materials (RMs) for hydrogen, carbon, nitrogen, oxygen, and sulfur stable isotope-ratio measurements to support food authenticity testing and food provenance verification. These new RMs, USGS82 to USGS91, will enable users to normalize measurements of samples to isotope-delta scales. The RMs include (i) two honeys from Canada and tropical Vietnam, (ii) two flours from C3 (rice) and C4 (millet) plants, (iii) four vegetable oils from C3 (olive, peanut) and C4 (corn) plants, and (iv) two collagen powders from marine fish and terrestrial mammal origins. An errors-in-variables regression model included the uncertainty associated with the measured and assigned values of the RMs, and it was applied centrally to normalize results and obtain consensus values and measurement uncertainties. Utilization of these new RMs should facilitate mutual compatibility of stable isotope data if accepted normalization procedures are applied and documented.

Stable carbon isotope diagnostics of mammalian metabolism, a high-resolution isotomics approach using amino acid carboxyl groups

The carbon isotopic compositions of amino acids are increasingly measured to characterize diets and metabolic response to diets. We report a new high-resolution system to measure the stable carbon isotopic composition of carboxyl atoms within amino acids. The automated system used HPLC to separate amino acids followed by addition of ninhydrin for decarboxylation and transfer of the evolved CO2 to a stable isotope ratio mass spectrometer for δ13CCARBOXYL measurement. The ninhydrin reaction was conducted at acidic pH (1.5) and elevated temperature (160 oC) giving yields close to 100% for most common amino acids. Eight mammalian keratin samples from herbivores (kudu and caribou), omnivores (humans) and carnivores (bowhead and humpback zooplanktivorous whales) were analysed with this new system. The data provide an initial calibration of reference materials to be used in studies of this type and is the first report of carboxyl carbon isotope distributions in mammals. Results showed widespread 13C enrichments in both essential and non-essential amino acid carboxyl groups, likely linked to decarboxylation of amino acids during normal metabolism. Analyses of non-essential amino acid isotope profiles showed (1) consistent and general taxon-level metabolic differences between the herbivore, human and whale samples, (2) marked differences among individual humans, ruminants and whales (3) evidence for gluconeogenesis in the wildlife samples, and (4) extensive 13C enrichment likely associated with fasting in the humpback whale sample. Future mammalian research related to the metabolism of growth, reproduction, aging and disease may benefit from using this technique. Values obtained for internationally available samples USGS42 and USGS43 (Tibetan and Indian human hair) provide a first characterization of reference materials for δ13CCARBOXYL profiles.

Position-specific 13 C/12 C analysis of amino acid carboxyl groups - automated flow-injection analysis based on reaction with ninhydrin

RATIONALE

The fundamental level of stable isotopic knowledge lies at specific atomic positions within molecules but existing methods of analysis require lengthy off-line preparation to reveal this information. An automated position-specific isotope analysis (PSIA) method is presented to determine the stable carbon isotopic compositions of the carboxyl groups of amino acids (δ¹³ C_CARBOXYL values). This automation makes PSIA measurements easier and routine.

METHODS

An existing high-performance liquid chromatography (HPLC) gas handling interface/stable isotope ratio mass spectrometry system was modified by the addition of a post-column derivatisation unit between the HPLC system and the interface. The post-column reaction was optimised to yield CO₂ from the carboxyl groups of amino acids by reaction with ninhydrin.

RESULTS

The methodology described produced δ¹³ C_CARBOXYL values with typical standard deviations below ±0.1 ‰ and consistent differences (Δ¹³ C_CARBOXYL values) between amino acids over a 1-year period. First estimates are presented for the δ¹³ C_CARBOXYL values of a number of internationally available amino acid reference materials.

CONCLUSIONS

The PSIA methodology described provides a further dimension to the stable isotopic characterisation of amino acids at a more detailed level than the bulk or averaged whole-molecule level. When combined with on-line chromatographic separation or off-line fraction collection of protein hydrolysates the technique will offer an automated and routine way to study position-specific carboxyl carbon isotope information for amino acids, enabling more refined isotopic studies of carbon uptake and metabolism.

A comparison of plastic cable ties based on physical, chemical and stable isotopic measurements

Plastic cable ties can be utilised in a range of serious criminal activities and a comparison of cable ties, or fragments, may form part of the physical evidence presented to a Court of law. This research assessed the potential value of evidence based on the analysis of plastic cable ties. Twenty packets of black coloured plastic cable ties (nominally 200mm×4.8mm) were purchased in pack sizes ranging from 25 to 100 individual cable ties (Brisbane, Australia, March 2015). Representative samples from each packet were visually examined, compared and tested to determine their physical dimensions, chemical compositions and stable isotopic compositions (δ²H, δ¹³C and δ¹⁵N). All of the individual cable ties from a given packet were found to be indistinguishable with respect to appearance, physical, chemical and isotopic measurements (within-batch variability). Individual cable ties were also found to be isotopically homogeneous with respect to hydrogen, carbon and nitrogen. All of the cable ties analysed were found to have very similar chemical compositions and to be manufactured predominantly from nylon 6,6. The elemental compositions of composite samples, prepared from each packet, were found to be highly variable and, as such, were of very limited value. Cable ties from ten of the twenty packets were uniquely characterised by physical appearance (between-batch variability). Physical measurements such as the width, thickness and tooth-count of the grip section did not provide additional discrimination. Cable ties from nineteen of the twenty packets were uniquely characterised by isotopic composition, based on δ²H and δ¹⁵N measurements. Samples from two packets of Crescent brand cable ties were found to be indistinguishable with respect to all of the tests applied in this study. These two packets were inadvertently purchased from the same retailer and had the same barcode and batch number. It was considered a reasonable assumption that these two packets originated from the same manufacturing batch. The authors reason that a likelihood ratio (that might be presented to a Court of law) can be derived from this type of discrete data based on a calculation of the possible combinations of distinguishable objects (unordered sampling with replacement) in a convenience sample collected from the background population. In this example, a database of 19 distinguishable objects can yield a likelihood ratio as high as 210, with a verbal equivalent of "moderately strong support" for a proposition that two cable ties have the same isotopic composition because they originate from the same batch rather than by random chance.

Prawn biomonitors of nutrient and trace metal pollution along Asia-Pacific coastlines

To assess coastal ecosystem status and pollution baselines, prawns were collected from the commercial catches of eight Asia-Pacific countries (Australia, Bangladesh, Indonesia, Myanmar, Philippines, Pakistan, Sri Lanka and Thailand). Samples collected from 21 sites along regional coastlines were analysed for trace metal and stable isotopic compositions of H, C, N, O and S. A combination of simple averaging and multivariate analyses was used to evaluate the data. Sites could be assigned to easily recognise polluted and unpolluted groups based on the prawn results. Some filter-feeding clams were also collected and analysed together with the benthic-feeding prawns, and the prawns generally had lower trace metal burdens. Climate change effects were not strongly evident at this time, but altered ocean circulation and watershed run-off patterns accompanying future climate change are expected to change chemical patterns recorded by prawns along these and other coastlines. Stable isotopes, especially (15)N, can help to distinguish between relatively polluted and unpolluted sites.

Isotopic and Elemental Composition of Roasted Coffee as a Guide to Authenticity and Origin

This study presents the stable isotopic and elemental compositions of single-origin, roasted coffees available to retail consumers. The δ(13)C, δ(15)N, and δ(18)O compositions were in agreement with those previously reported for green coffee beans. The δ(15)N composition was seen to be related to organic cultivation, reflected in both δ(2)H and δ(18)O compositions. The δ(13)C composition of extracted caffeine differed little from that of the bulk coffee. Stepwise discriminant analysis with jackknife tests, using isotopic and elemental data, provided up to 77% correct classification of regions of production. Samples from Africa and India were readily classified. The wide range in both isotopic and elemental compositions of samples from other regions, specifically Central/South America, resulted in poor discrimination between or within these regions. Simpler X-Y and geo-spatial plots of the isotopic data provided effective visual means to distinguish between coffees from different regions.

Stable isotope and chemical compositions of European and Australasian ciders as a guide to authenticity

This paper presents a data set derived from the analysis of bottled and canned ciders that may be used for comparison with suspected counterfeit or substitute products. Isotopic analysis of the solid residues from ciders (predominantly sugar) provided a means to determine the addition of C4 plant sugars. The added sugars were found to comprise cane sugar, high-fructose corn syrup, glucose, or combinations. The majority of ciders from Australia and New Zealand were found to contain significant amounts of added sugar, which provided a limited means to distinguish these ciders from European ciders. The hydrogen and oxygen isotopic compositions of the whole ciders (predominantly water) were shown to be controlled by two factors, the water available to the parent plant and evaporation. Analysis of data derived from both isotopic and chemical analysis of ciders provided a means to discriminate between regions and countries of manufacture.

A global survey of the stable isotope and chemical compositions of bottled and canned beers as a guide to authenticity

This study presents a dataset, derived from the analysis of 162 bottled and canned beers from around the globe, which may be used for comparison with suspected counterfeit or substitute products. The data comprise δ2H and δ18O compositions of the whole beer and δ13C compositions of the dry residue (mostly sugar) together with the concentrations of five anions (F, Cl, NO3, SO4, PO4) and seven cations (Ca, K, Mg, SiO2, V, Mn, Sr). A strong correlation, consistent with natural waters but offset from the Global Meteoric Water Line, was observed between the δ2H/δ18O composition of the beers. The extent of the offset could be explained by the brewing process and the alcohol and sugars present in the beers. Correlations between inorganic analytes were consistent with the addition of salts in the brewing process. Beers were classified as follows: ale, lager, stout or wheat-beer and the chemical composition was found to be characteristic of the assigned type, with lagers being the most readily classified. A combination of chemical and isotopic data was found to be characteristic of the geographical origin (on a continental scale) and could most easily identify beers from Australasia or Europe. A global map of δ18O data revealed a geo-spatial distribution that mirrored existing maps of the isotopic composition of annual precipitation. This confirmed a commonsense view that local precipitation will be the primary source for the water used in brewing. Using this isoscape (or alcoscape) it may be possible to assess the geographical origins of samples for which genuine comparative samples cannot be obtained.

Stable isotope and trace metal compositions of Australian prawns as a guide to authenticity and wholesomeness

This research has explored the potential of stable isotope and trace metal profiles to distinguish Australian prawns from prawns imported from neighbouring Asian countries. Australian prawns were collected mostly from the Brisbane area. Strong differences in Australian vs. imported prawns were evident from both the isotope and trace element data, with the differences most likely occurring because imported prawns are typically reared in aquaculture facilities and frozen prior to sale in Australia. The aquaculture origins are characterised by comparatively; low δHVSMOW, δ(13)CVPDB values, low concentrations of arsenic, zinc and potassium, and high water contents (>80%). Relatively high arsenic and cadmium contents were found within Australian prawns, but the concentrations did not exceed local human health guidelines.

Laparoscopic removal of abdominal cerclage at 19 weeks' gestation

We discuss laparoscopic removal of an abdominal cerclage in a 39-year-old woman, gravida 4, para 0, abortus 3, who presented at 19 weeks' gestation with ruptured membranes. This patient had a failed previous vaginal cerclage. An abdominal cerclage was performed at the time of abdominal myomectomy. A subsequent pregnancy was diagnosed, with ruptured membranes at 19 weeks' gestation, and the patient opted for pregnancy termination. After laparoscopic removal of the cerclage, cervical laminaria were placed, and the patient underwent an uncomplicated dilation and curettage procedure the following day.

Abdominal cerclage for the treatment of recurrent cervical insufficiency: laparoscopy or laparotomy?

OBJECTIVE

The purpose of this study was to compare the efficacy of traditional abdominal cerclage (AC) with laparoscopic cerclage (LC).

STUDY DESIGN

Eligible women had at least 1 second trimester pregnancy loss due to cervical insufficiency, and had undergone at least 1 failed transvaginal cerclage. A prospective cohort of patients undergoing LC was compared with a historical control group of patients who had AC. A successful primary outcome was defined as delivery of a viable infant with neonatal survival.

RESULTS

We were able to evaluate 19 pregnancies following unique abdominal cerclage placement, 12 laparoscopic and 7 at the time of laparotomy. Nine of 12 (75%) undergoing LC and 5 of 7 (71%) pregnancies undergoing AC successfully delivered a viable infant (P = .63). LC during pregnancy was successful in 4 of 5 (80%) cases as compared to 3 of 5 (60%) cases with AC during pregnancy (P = 1.0).

CONCLUSION

Operative laparoscopy is a safe and effective alternative to laparotomy for the placement of abdominal cerclage.

The difference between drug money and a “lifetime's savings”

In many countries, monies suspected of being associated with drug trafficking can be seized by the authorities. One of the ways of investigating this association is through the analysis of seized banknotes for traces of controlled drugs. We report three studies which may assist the expert in assessing whether banknotes contaminated with diamorphine are part of the general population of notes in circulation or whether they show unusual contamination patterns which require explanation. Study 1 is based on three plausible contamination scenarios as they may occur during the various stages of an illicit drug transaction and seizure. It shows that notes which have been in direct contact with visible traces of diamorphine show significantly higher contamination to those in more indirect contact with the drug. Study 2 investigates the transfer of diamorphine from one highly contaminated note to other notes in a bundle over a period of 10 weeks with and without agitation. It was found that the total amount of drug transferred was smaller than 6% and no more than 4 out of a bundle of 10 previously clean notes became lightly contaminated. Based on extensive background data, study 3 proposes a probabilistic model to assess whether an observed proportion of diamorphine bearing banknotes is likely to have been contaminated by chance. The model predicts that there is only a 0.3% chance that a bundle of 100 notes from the general banknote population contains more than six contaminated specimens. Jointly, the three studies give useful indications for the spread of contamination throughout a sample and the amounts of heroin which may be expected given plausible contamination scenarios.

Laparoscopic removal of abdominal cerclage

Abdominal cerclage is necessary when the more commonly used transvaginal cerclage fails or anatomical abnormalities of the cervix preclude transvaginal placement. The disadvantage of an abdominal approach is that the patient can expect 2 laparotomies during her pregnancy, one for cerclage placement and the other associated with cesarean delivery. We report on an abdominal cerclage removed laparoscopically in the case of an intrauterine fetal death at 17 weeks. This minimally invasive surgical technique eliminates the need for laparotomy in response to a poor pre-viable pregnancy outcome.

Factors influencing the contamination of UK banknotes with drugs of abuse

Bank of England banknotes sampled from different locations in the UK have been analysed for the presence of cocaine, diamorphine (DAM), Delta(9)-tetrahydrocannabinol (THC) and 3,4-methylenedioxymethamphetamine (MDMA). A database of the contamination detected is routinely used as a benchmark against which the contamination detected on seized banknotes can be compared. Evidence presented at court details how banknotes seized from a suspect may differ from banknotes in general circulation in terms of their contamination with controlled drugs. A question arising from such evidence is whether seized banknotes could have become contaminated through being in circulation in drug "hot spots". In order to address this issue, a Plackett-Burman experimental design was used to investigate the influence of source location and other factors on banknote contamination with drugs of abuse. Banknotes were drawn from banks in eight regions throughout the UK. Each location could be described by a unique combination of the factors under investigation, namely whether the location was rural or urban, in the North or South of the UK, and whether it was a port of entry. The socio-economic class and the proportion of drug offenders in the area and the denomination of the banknotes were also considered as potentially influential factors. Indices were calculated to describe the degree to which samples were contaminated with different drugs, and normal probability plots were used to identify the factors that could account for the contamination observed. Whilst some factors were more influential than others, it was shown that, at the 95% confidence level, none of the proposed factors were significant influences on the contamination. Cocaine contamination on banknotes has been shown to follow a log-normal distribution. It was, therefore, possible to calculate F- and t-statistics to compare the cocaine contamination on the entire sample set with that detected on a second sample set consisting of banknotes all drawn from a single bank branch. It was shown that both inter-bank samples and intra-bank samples had similar variance and similar contamination levels at the 95% confidence level. This suggests that there are no significant regional trends in the contamination of banknotes with drugs of abuse across the UK.

A comparative study of hysteroscopic sterilization performed in-office versus a hospital operating room

STUDY OBJECTIVE

To compare hysteroscopic female sterilization procedures performed in-office versus a hospital operating room (OR) among newly trained physicians.

DESIGN

Multisite hospital operating rooms and physician offices.

PATIENTS

Women desiring permanent hysteroscopic sterilization.

INTERVENTION

Hysteroscopic female sterilization with the Essure system.

MEASUREMENTS AND MAIN RESULTS

Procedure time (scope in/scope out time), device placement rates, and incidence of complications and adverse events were compared. There was no significant difference in scope time between the 2 settings. There was no significant difference in placement rates, although the placement rate was somewhat higher in-office (91% vs 88%). There were no complications among any of the procedures, and the incidence of minor adverse events was extremely low in both settings (OR=2%, in-office=1%).

CONCLUSION

There is no clear advantage to performing hysteroscopic sterilization in a hospital OR. Hysteroscopic sterilization can be performed safely and efficiently in an office setting.

Institution and validation of an observed structured assessment of technical skills (OSATS) for obstetrics and gynecology residents and faculty

OBJECTIVE

This study was undertaken to further evaluate the construct validity of the observed structured assessment of technical skills (OSATS) by comparing resident scores to faculty scores.

STUDY DESIGN

This study is a prospective blinded observational study. Four residents from each year (1-4) and 5 faculty members were examined. The OSATS examination was in the form of a dry laboratory with 10 stations: 4 laparoscopic and 6 open surgical skills. The sessions were videotaped and graded by the senior authors who used a task-specific checklist. The scoring of the videos was performed by the 2 senior authors blinded to the other examiners results. The examinations were videotaped, and the identity of the participants was blinded. The scores for each station were determined by adding all the numbers from the skills rating with a time score. Higher scores denote superior performance. Statistical analysis was performed with a nonparametric test (Kruskal-Wallis) for a total score with resident years divided into junior residents (first and second year), senior residents (third and fourth year), and faculty status as the independent variable. To determine the interrelater reliability between the 2 scores, the Kendall tau beta statistic was used.

RESULTS

The results show definite trends for 7 stations, with junior residents performing the worst and faculty performing the best. This trend was statistically significant for 6 of the 10 stations.

CONCLUSION

The OSATS examination has good construct validity that extends beyond residency to faculty.

Isotope ratio mass spectrometry as a tool for forensic investigation (examples from recent studies)

The versatility of isotope ratio mass spectrometry is demonstrated by reference to diverse case studies. Variations in the natural isotopic composition of non-biological, organic materials are compared as a means by which samples may be associated or discriminated. These techniques may be used to augment or compliment conventional forensic methodologies. delta13C analysis was used to demonstrate that different masking tape had been recovered in two, apparently similar cases, involving the smuggling of money. Visually similar ecstasy tablets were compared by consideration of the delta13C and delta15N composition of MDMA extracted from the tablets. Although only a limited number of tablets were analysed, the isotopic similarity between two different seizures was sufficient to induce a guilty plea from a person suspected of possessing both. A combination of delta2H, delta13C, delta15N and delta18O together with GC-MS analyses were applied to small samples of seized heroin. Although GC-MS analysis indicated differences between the chemical composition of two of the heroin samples, isotopic analysis suggested similarities, which were confirmed by further delta2H, delta13C and delta18O isotopic analysis of the clingfilm in which the samples were wrapped.

Bulk and compound-specific isotopic characterisation of illicit heroin and cling film

Comparative analysis involves various but complementary methods and can be used for forensic intelligence purposes to group seizures of heroin into batches. Much forensic analysis now combines expertise in the traditional area of drugs investigation with a detailed understanding of supply, packaging, distribution, and drugs intelligence. It was the intention of this research to determine whether illicit heroin seizures and packaging material can be grouped according to isotopic compositions, and to explore factors that affect the isotopic compositions. In order to achieve these aims, 14 samples of seized heroin, thirteen provided by Avon and Somerset Constabulary (UK), were analysed by elemental analysis/isotope ratio mass spectrometry (EA/IRMS) and gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) for carbon and hydrogen isotopes. These tests elucidated that a combination of the delta13C, delta15N, delta18O and delta2H results from EA/IRMS is able to distinguish between most samples of bulk heroin. We speculate that the delta13C values of the alkaloids, obtained by GC/C/IRMS, give indications of different geographical or temporal origins of some of the heroin samples. GC/C/IRMS of the cutting agent, caffeine, provides a means to link dilution events. Fifteen retail cling film samples and seven cling film samples from heroin seizures were analysed by EA/IRMS. A multivariate comparison of the carbon, hydrogen and oxygen isotope ratios was able to distinguish between most of the samples. This technique enabled the cling films from the heroin to be grouped according to seizure. Three solvents were tested on two samples of cling film of known composition. Methanol and chloroform were both found to extract material from PVC and from non-PVC cling films. Water-treated PVC was indistinguishable from the untreated PVC and thus water was found to be the most suitable solvent when washing cling film prior to IRMS analysis.

Rapid comparison of diacetylmorphine on banknotes by tandem mass spectrometry

A procedure is described for the determination of the distribution of the contamination of banknotes with controlled drugs using tandem mass spectrometry. The method is illustrated using diacetylmorphine, which is the major active component of heroin. A series of banknotes is introduced into the mass spectrometer and the intensities of two product ions (m/z 328 and 268) derived from the precursor protonated molecule (m/z 370) are recorded. A banknote is considered contaminated if it shows a significant peak for both product ions, and if the ratio of intensities of these two peaks falls within accepted limits. The distribution of diacetylmorphine on sterling banknotes taken from general circulation within the UK can be modelled by an arcsin (square root) transformation of the data or by a log transformation of the data with a higher proportion of contamination. The two models were found to be in close agreement, predicting an upper limit (at 99.9% confidence) of contamination on banknotes from general circulation between 9 and 10%. The percentage contamination in a case study was calculated and compared to the background distribution using the two models proposed. This comparison revealed that the contamination present in the case study was inconsistent with that present on banknotes in general circulation.

Laparoscopic abdominal cerclage

Abdominal cerclages are necessary when the standard transvaginal cerclages fail or anatomical abnormalities preclude the vaginal placement. The disadvantage of the transabdominal approach is that it requires at least 2 laparotomies with significant morbidity and hospital stays. We discuss a case of abdominal cerclage performed laparoscopically. We feel it offers less morbidity and in the proper hands eliminates or significantly shortens hospital stays.

Forensic isotope ratio mass spectrometry of packaging tapes

Pressure sensitive adhesive tape (brown parcel tape) is employed in a great many criminal activities such as the restraint of individuals during robbery and offences against the person, the enclosure of explosive devices and the packaging and concealment of controlled drugs. Packaging materials are ubiquitous in modern society and are produced in such vast quantities that it is increasingly difficult to distinguish between different products or to link materials to a common source. This study demonstrates the potential of stable isotope ratio mass spectrometry to characterise parcel tapes based on a number of properties. The carbon isotopic signature, derived from the substrate polymer, associated additives and adhesive is highly characteristic of a particular tape and allows samples from different sources to be readily distinguished. Further discrimination may be achieved by the incorporation of deuterium and oxygen isotopic data and by analysis of the isolated backing polymer. Recovery of intact tape from simulated forensic samples proved straightforward and the isotopic signature of the tape did not appear to be affected by adverse storage conditions.

Operative laparoscopy in pregnancy

OBJECTIVE

We compared the surgical outcomes of pregnant women undergoing laparotomy in the first 2 trimesters of pregnancy with those undergoing laparoscopy for the management of acute pelvic pain.

METHODS

We performed a systematic retrospective chart review of patients whose discharge diagnosis included intrauterine pregnancy with exploratory laparotomy or laparoscopy from August 1, 1993 to October 31, 1999. The following factors were assessed: preoperative diagnosis, postoperative diagnosis, gestational age at the time of surgery, operative time, hospital stay, pathology, gestational age at delivery, complications, and outcome of the pregnancy in both groups.

RESULTS

Sixteen pregnant patients underwent surgery during the study period. All but one had abdominopelvic pain, and all patients had an associated adnexal mass. The mean gestation age at the time of surgery was 15+/-6 weeks versus 13+/-4 weeks in the laparoscopic and laparotomy groups, respectively (P=NS). All patients undergoing laparoscopy remained in the hospital for one day compared with a mean of 4.4+/-1.1 days in the laparotomy group (P<0.0001). Pregnancy outcomes were similar and uniformly good.

CONCLUSION

Laparotomy can be avoided and pregnant patients managed safely by operative laparoscopy, with shorter hospital stays.

The distribution of controlled drugs on banknotes via counting machines

Bundles of paper, similar to sterling banknotes, were counted in banks in England and Wales. Subsequent analysis showed that the counting process, both by machine and by hand, transferred nanogram amounts of cocaine to the paper. Crystalline material, similar to cocaine hydrochloride, could be observed on the surface of the paper following counting. The geographical distribution of contamination broadly followed Government statistics for cocaine usage within the UK. Diacetylmorphine, Delta(9)-tetrahydrocannabinol (THC) and 3,4-methylenedioxymethylamphetamine (MDMA) were not detected during this study.