Diet changes due to urbanization in South Africa are linked to microbiome and metabolome signatures of Westernization and colorectal cancer

Transition from traditional high-fiber to Western diets in urbanizing communities of Sub-Saharan Africa is associated with increased risk of non-communicable diseases (NCD), exemplified by colorectal cancer (CRC) risk. To investigate how urbanization gives rise to microbial patterns that may be amenable by dietary intervention, we analyzed diet intake, fecal 16 S bacteriome, virome, and metabolome in a cross-sectional study in healthy rural and urban Xhosa people (South Africa). Urban Xhosa individuals had higher intakes of energy (urban: 3,578 ± 455; rural: 2,185 ± 179 kcal/d), fat and animal protein. This was associated with lower fecal bacteriome diversity and a shift from genera favoring degradation of complex carbohydrates (e.g., Prevotella) to taxa previously shown to be associated with bile acid metabolism and CRC. Urban Xhosa individuals had higher fecal levels of deoxycholic acid, shown to be associated with higher CRC risk, but similar short-chain fatty acid concentrations compared with rural individuals. Fecal virome composition was associated with distinct gut bacterial communities across urbanization, characterized by different dominant host bacteria (urban: Bacteriodota; rural: unassigned taxa) and variable correlation with fecal metabolites and dietary nutrients. Food and skin microbiota samples showed compositional differences along the urbanization gradient. Rural-urban dietary transition in South Africa is linked to major changes in the gut microbiome and metabolome. Further studies are needed to prove cause and identify whether restoration of specific components of the traditional diet will arrest the accelerating rise in NCDs in Sub-Saharan Africa.

Temporal trends in anticoagulation management for US active duty personnel with atrial fibrillation

ObjectivesThis study aims to investigate US active duty (AD) military members diagnosed with atrial fibrillation (AF) and the temporal trends of systemic anticoagulation (AC). Our secondary objective is to study the AC prescriptions in AD military members diagnosed with AF and associated military dispositions and deployment rates.

DESIGN AND SETTING

A retrospective investigation of Tricare pharmacy AC prescriptions within the San Antonio Military Health System from January 2004 to July 2019 for AD individuals diagnosed with AF was performed.

PARTICIPANTS

386 AD personnel with non-valvular AF were analysed (mean age 35.0±9.4 years; mean body mass index, 28.3±4.3 kg/m²; 93% male; 57% Caucasian, 94% paroxysmal AF).

OUTCOMES

The temporal trends of systemic AC prescriptions were the primary outcome measures. The association between AC prescriptions and military dispositions and deployments were secondary outcomes of interest.

STATISTICAL ANALYSIS

The association between AC management, future deployments and military disposition was analysed using χ² and Fisher's exact test for categorical variables. The t-test was used for comparison of continuous variables.

RESULTS

CHA₂DS₂-VASc and HAS-BLED scores were low (0.39±0.65 and 0.86±0.63, respectively). 127 (33%) members received warfarin and 58 (15%) received direct oral anticoagulants (DOACs). Rates of military retention were not different between AC histories (no AC (64%) vs warfarin (75%) vs DOAC (65%); p=0.425). There was a significant trend of more recent utilisation of DOACs compared with warfarin (p<0.0001). When adjusted for temporal changes in deployment rates, there was no significant difference in deployment between AC groups (no AC (39%) vs warfarin (49%) vs DOAC (27%); p=0.9472).

CONCLUSIONS

This is the first report describing AC utilisation in US AD military members with AF. Young AD personnel with low stroke and bleeding risks do not commonly receive AC prescriptions. DOAC prescription rates are increasing and predominate over warfarin for AC indications.

Method of micro-sampling human dentine collagen for stable isotope analysis

RATIONALE

Sampling of dentine for stable carbon (δ¹³ C) and nitrogen (δ¹⁵ N) isotope ratios in the direction of tooth growth allows the study of temporal changes to the diet and physiological stress of an individual during tooth formation. Current methods of sampling permanent teeth using 1 mm increments provide temporal resolution of 6-9 months at best depending on the tooth chosen. Although this gives sufficient sample sizes for reliable analysis by mass spectrometry, sectioning the dentine across the incremental structures results in a rolling average of the isotope ratios. A novel method of incremental dentine collagen sampling has been developed to decrease the collagen increment size to 0.35 mm along the incremental structures, thus reducing averaging and improving the temporal resolution of short-term changes within the δ¹³ C and δ¹⁵ N values.

METHODS

This study presents data for a MicroMill-assisted sampling method that allows for sampling at 0.35 mm width × 1 mm depth increments following the incremental growth pattern of dentine. A NewWave MicroMill was used to sample the demineralised dentine section of modern donated human third molars from Sudan and compared to data from the same teeth using the 1 mm incremental sectioning method 2 established by Beaumont et al. RESULTS: The δ¹³ C and δ¹⁵ N isotopic data showed an increased temporal resolution, with each increment providing data for 2-4 months of dentine formation.

CONCLUSIONS

The data show the potential of this method for studying dietary reconstruction, nutritional stress, and physiological change with greater temporal resolution potentially to seasonal level and with less attenuation of the δ¹³ C and δ¹⁵ N values than was previously possible from human dentine.

Characteristics of United States military pilots with atrial fibrillation and deployment and retention rates

Introduction

Atrial fibrillation (AF) is an arrhythmia that impacts deployment and retention rates for United States military pilots. This study aims to characterize United States active duty (AD) pilots with AF and review deployment and retention rates associated with medical and ablative therapies.

Methods

An observational analysis was performed to assess AD pilots diagnosed with AF in the largest military regional healthcare system from 2004 to 2019. Baseline characteristics and AF management were reviewed.

Results

27 AD pilots (mean age, 37.3 ± 7.9 years; mean BMI, 27.3 ± 3.1 kg/m²; 100% male sex) were diagnosed with AF during the study dates. 17 (63%) were Air Force branch pilots with hypertension as the most common risk factor (26%). There were overall low CHA₂DS₂-VASc scores (mean 0.29 ± 0.47). 22 (82%) pilots were equally treated with medical rate and rhythm strategies (41% and 41%, respectively). 16 (59%) underwent pulmonary vein isolation (PVI) with zero complications. 11 (41%) pilots received warfarin and 5 (19%) received a direct oral anticoagulant for stroke prevention. After diagnosis, 12 (44%) pilots deployed and 25 (93%) were retained in military. PVI was not associated with a change in subsequent deployments rates (PVI, 38% vs no PVI, 55%; p = 0.3809) or retention rates (PVI, 94% vs no PVI, 91%; p = 0.7835).

Conclusions

United States military pilots diagnosed with AF are younger patients with few traditional AF risk factors and  they receive medical rate and rhythm strategies equally. Many pilots maintain deployment eligibility and most remain on AD status after diagnosis. PVI is not associated with differences in retention or deployment rates. Further prospective study is needed to further evaluate these findings. 

A Review of the Collagen Orientation in the Articular Cartilage

OBJECTIVE

There has been a debate as to the alignment of the collagen fibers. Using a hand lens, Sir William Hunter demonstrated that the collagen fibers ran perpendicular and later aspects were supported by Benninghoff. Despite these 2 historical studies, modern technology has conflicting data on the collagen alignment.

DESIGN

Ten mature New Zealand rabbits were used to obtain 40 condyle specimens. The specimens were passed through ascending grades of alcohol, subjected to critical point drying (CPD), and viewed in the scanning electron microscope. Specimens revealed splits from the dehydration process. When observing the fibers exposed within the opening of the splits, parallel fibers were observed to run in a radial direction, normal to the surface of the articular cartilage, radiating from the deep zone and arcading as they approach the surface layer. After these observations, the same samples were mechanically fractured and damaged by scalpel.

RESULTS

The splits in the articular surface created deep fissures, exposing parallel bundles of collagen fibers, radiating from the deep zone and arcading as they approach the surface layer. On higher magnification, individual fibers were observed to run parallel to one another, traversing radially toward the surface of the articular cartilage and arcading. Mechanical fracturing and scalpel damage induced on the same specimens with the splits showed randomly oriented fibers.

CONCLUSION

Collagen fiber orientation corroborates aspects of Hunter's findings and compliments Benninghoff. Investigators must be aware of the limits of their processing and imaging techniques in order to interpret collagen fiber orientation in cartilage.

Characteristics of US military personnel with atrial fibrillation and associated deployment and retention rates

INTRODUCTION

Atrial fibrillation (AF) is an arrhythmia impacting military occupational performances. Despite being a recognised disqualifying condition, there is no literature describing US military service members with AF. This study aims to describe members with AF diagnoses, the distribution of treatment strategies and associated deployment and retention rates.

METHODS

Active duty service members identified with AF from 2004 to 2019 were investigated. Cardiovascular profiles, AF management strategies and military dispositions were assessed by electronic medical record review.

RESULTS

386 service members (mean age 35.0±9.4 years; 94% paroxysmal AF) with AF diagnoses were identified. 91 (24%) had hypertension followed by 75 (19%) with sleep apnoea. Mean CHA₂DS₂-VASc scores were low (0.39±0.65). Rhythm treatments were used in 173 (45%) followed by rate control strategies in 155 (40%). 161 (42%) underwent pulmonary vein isolation (PVI). In subgroup analysis of 365 personnel, 147 (40%) deployed and 248 (68%) remained active duty after AF diagnosis. Deployment and retention rates did not differ between those who received no medical therapy, rate control or rhythm strategies (p=0.9039 and p=0.6192, respectively). PVI did not significantly impact deployment or retention rates (p=0.3903 and p=0.0929, respectively).

CONCLUSION

Service members with AF are young with few AF risk factors. Rate and rhythm medical therapies were used evenly. Over two-thirds met retention standards and 40% deployed after diagnosis. There were no differences in deployment or retention between groups who receive rate therapy, rhythm medical therapy or PVI. Prospective evaluation of the efficacy of specific AF therapies on AF burden and symptomatology in service members is needed.

Active Duty Personnel With ST Elevation Myocardial Infarctions Are Deployment Ineligible Despite Receiving Standard Management

INTRODUCTION

ST elevation myocardial infarction (STEMI) is a high acuity diagnosis that requires prompt recognition and developed system responses to reduce morbidity and mortality. There is a paucity of literature describing active duty (AD) military personnel with STEMI syndromes at military treatment facilities (MTFs). This study aims to describe AD military members with STEMI diagnoses, military treatment facility management, and subsequent military dispositions observed.

MATERIALS AND METHODS

We performed a single-center, retrospective review of all STEMI diagnoses at San Antonio Military Medical Center (SAMMC) from January 2008 to June 2018. Patients met inclusion in the analysis if they were (1) AD personnel in the United States Air Force (USAF) or United States Army (USA) and (2) presented with electrocardiogram findings and cardiac biomarkers diagnostic of a STEMI diagnosis. ASCVD and STEMI diagnoses were confirmed by board certified interventional cardiologists with coronary angiography. The 2017 American College of Cardiology (ACC) STEMI clinical performance and quality measures were used as the standard of care metrics for our case reviews.

RESULTS

A total of 236 patients were treated for STEMI at SAMMC during the study period. Eight (3.4%) of these cases met inclusion criteria of being AD status at the time of diagnosis. Five (63%) of the AD STEMI diagnoses were USA members, three (37%) were USAF members, 50% were Caucasian, and 100% were male sex. The average age and body mass index were 46.3 ± 5.5 years old and 28.5 ± 3.1 kg/m 2, respectively. Preexisting cardiovascular risk factors were present in six (75%) of the individuals with hypertension being most common (63%). The eight patients had a baseline average low-density lipoprotein cholesterol of 110 ± 39 mg/dL, total cholesterol of 180 ± 49 mg/dL and calculated 10-year risk of atherosclerotic cardiovascular disease (ASCVD) 3.9 ± 1.6%. 100% of patients underwent primary percutaneous coronary intervention (PCI) within 90 minutes of presentation (average door-to-balloon time 59.3 ± 24 min). Single-vessel disease was found in all eight patients and seven of them underwent drug-eluting stent placement (average number of stents 2 ± 1.5). Performance and quality measures were met in all applicable categories including door-to-balloon times, discharge medical therapies, and cardiac rehabilitation enrollments for 100% AD personnel. Reported adverse events included two stent thromboses and two vascular complications. Three of eight individuals (37.5%) were diagnosed with behavioral health disorders secondary to their acute coronary syndrome. Medical retirement secondary to STEMI diagnosis occurred in 87.5% of subjects and all study personnel medically retired within 24 months (average 12.8 ± 7.9 months).

CONCLUSIONS

AD personnel represent a small minority of MTF STEMI diagnoses and present with lower risk cardiovascular profiles. AD personnel received standard STEMI management compared to national performance measures, and were deployment ineligible after STEMI diagnoses. Further studies are needed to definitively explore the appropriate military dispositions for members with STEMI diagnoses and acute coronary syndromes.

Histology and Raman spectroscopy of limed human remains from the Rwandan Genocide

The Murambi Genocide Memorial Centre is one of the major centres in Rwanda that commemorate the 1994 Rwandan genocide. Seventeen months after the genocide, about 1000 excavated human remains were put on display in Murambi Technical School. Repeated efforts were made to desiccate the human remains with lime for educational reasons. The aim of this study was to assess their state of preservation and understand the extent of degradation of the tissue. Limed soft tissue samples from four individuals were examined with light and electron microscopy, and subjected to histological analysis. Raman spectroscopy at 785 nm and 1064 nm provided information about the impact of environmental conditions on the extent of deterioration to these samples, the presence of organics and the conversion of the associated lime from calcium hydroxide to calcium carbonate. While visual degradation of the bodies in Murambi has been reported, this study confirms deterioration at a microscopic and molecular level. Both histology and Raman spectroscopic analysis revealed that the limed bodies in Murambi were deteriorating at the time the samples were collected. The results of this study will inform future decisions regarding the long-term conservation of those human remains.

Multidisciplinary investigations of the diets of two post-medieval populations from London using stable isotopes and microdebris analysis

This paper presents the first multi-tissue study of diet in post-medieval London using both the stable light isotope analysis of carbon and nitrogen and analysis of microdebris in dental calculus. Dietary intake was explored over short and long timescales. Bulk bone collagen was analysed from humans from the Queen's Chapel of the Savoy (QCS) (n = 66) and the St Barnabas/St Mary Abbots (SB) (n = 25). Incremental dentine analysis was performed on the second molar of individual QCS1123 to explore childhood dietary intake. Bulk hair samples (n = 4) were sampled from adults from QCS, and dental calculus was analysed from four other individuals using microscopy. In addition, bone collagen from a total of 46 animals from QCS (n = 11) and the additional site of Prescot Street (n = 35) was analysed, providing the first animal dietary baseline for post-medieval London. Overall, isotopic results suggest a largely C₃-based terrestrial diet for both populations, with the exception of QCS1123 who exhibited values consistent with the consumption of C₄ food sources throughout childhood and adulthood. The differences exhibited in δ¹⁵N_coll across both populations likely reflect variations in diet due to social class and occupation, with individuals from SB likely representing wealthier individuals consuming larger quantities of animal and marine fish protein. Microdebris analysis results were limited but indicate the consumption of domestic cereals. This paper demonstrates the utility of a multidisciplinary approach to investigate diet across long and short timescales to further our understanding of variations in social status and mobility.

Using evidence from hair and other soft tissues to infer the need for and receipt of health-related care provision

The Bioarchaeology of Care approach developed by Tilley is usually applied to skeletalized human remains, given the usual constraints of preservation bias that are seen with archaeological assemblages. However, other tissues, such as hair are sometimes preserved and can provide a wealth of information that can supplement the skeletal data. Archaeological hair has been analysed for drug compounds for almost thirty years. This article integrates data from hair analyses for coca metabolites, stable light isotope analysis and aDNA to expand the potential of the Bioarchaeology of Care approach using the example of a spontaneously mummified adult female from northern Chile.

A matter of months: High precision migration chronology of a Bronze Age female

Establishing the age at which prehistoric individuals move away from their childhood residential location holds crucial information about the socio dynamics and mobility patterns in ancient societies. We present a novel combination of strontium isotope analyses performed on the over 3000 year old “Skrydstrup Woman” from Denmark, for whom we compiled a highly detailed month-scale model of her migration timeline. When combined with physical anthropological analyses this timeline can be related to the chronological age at which the residential location changed. We conducted a series of high-resolution strontium isotope analyses of hard and soft human tissues and combined these with anthropological investigations including CT-scanning and 3D visualizations. The Skrydstrup Woman lived during a pan-European period characterized by technical innovation and great social transformations stimulated by long-distance connections; consequently she represents an important part of both Danish and European prehistory. Our multidisciplinary study involves complementary biochemical, biomolecular and microscopy analyses of her scalp hair. Our results reveal that the Skrydstrup Woman was between 17–18 years old when she died, and that she moved from her place of origin -outside present day Denmark- to the Skrydstrup area in Denmark 47 to 42 months before she died. Hence, she was between 13 to 14 years old when she migrated to and resided in the area around Skrydstrup for the rest of her life. From an archaeological standpoint, this one-time and one-way movement of an elite female during the possible “age of marriageability” might suggest that she migrated with the aim of establishing an alliance between chiefdoms. Consequently, this detailed multidisciplinary investigation provides a novel tool to reconstruct high resolution chronology of individual mobility with the perspective of studying complex patterns of social and economic interaction in prehistory.

Fibroblast growth factor-mediated crosstalk in cancer etiology and treatment

It is becoming increasingly evident that multiple cell types within the tumor work together to drive tumour progression and impact on both the response to therapy and the dissemination of tumour cells throughout the body. Fibroblast growth factor signalling (FGF) is perturbed in a number of tumors, serving to drive tumor cell proliferation and migration, but also has a central role in orchestrating the plethora of cells that comprise the tumor microenvironment. This review focuses on how this family of signalling molecules can influence the interactions between tumor cells and their surrounding environment. Unraveling the complexities of FGF signalling between the distinct cell types of a tumor may identify additional opportunities for FGF-targeted compounds in therapy and could help combat drug resistance. Developmental Dynamics 246:493-501, 2017. © 2017 Wiley Periodicals, Inc.

Analyzing and Interpreting Lime Burials from the Spanish Civil War (1936-1939): A Case Study from La Carcavilla Cemetery

Over 500 victims of the Spanish Civil War (1936-1939) were buried in the cemetery of La Carcavilla (Palencia, Spain). White material, observed in several burials, was analyzed with Raman spectroscopy and powder XRD, and confirmed to be lime. Archaeological findings at La Carcavilla's cemetery show that the application of lime was used in an organized way, mostly associated with coffinless interments of victims of Francoist repression. In burials with a lime cast, observations made it possible to draw conclusions regarding the presence of soft tissue at the moment of deposition, the sequence of events, and the presence of clothing and other evidence. This study illustrates the importance of analyzing a burial within the depositional environment and taphonomic context.

Demonstration of Protein-Based Human Identification Using the Hair Shaft Proteome

Human identification from biological material is largely dependent on the ability to characterize genetic polymorphisms in DNA. Unfortunately, DNA can degrade in the environment, sometimes below the level at which it can be amplified by PCR. Protein however is chemically more robust than DNA and can persist for longer periods. Protein also contains genetic variation in the form of single amino acid polymorphisms. These can be used to infer the status of non-synonymous single nucleotide polymorphism alleles. To demonstrate this, we used mass spectrometry-based shotgun proteomics to characterize hair shaft proteins in 66 European-American subjects. A total of 596 single nucleotide polymorphism alleles were correctly imputed in 32 loci from 22 genes of subjects' DNA and directly validated using Sanger sequencing. Estimates of the probability of resulting individual non-synonymous single nucleotide polymorphism allelic profiles in the European population, using the product rule, resulted in a maximum power of discrimination of 1 in 12,500. Imputed non-synonymous single nucleotide polymorphism profiles from European-American subjects were considerably less frequent in the African population (maximum likelihood ratio = 11,000). The converse was true for hair shafts collected from an additional 10 subjects with African ancestry, where some profiles were more frequent in the African population. Genetically variant peptides were also identified in hair shaft datasets from six archaeological skeletal remains (up to 260 years old). This study demonstrates that quantifiable measures of identity discrimination and biogeographic background can be obtained from detecting genetically variant peptides in hair shaft protein, including hair from bioarchaeological contexts.

Tracing the dynamic life story of a Bronze Age Female

Ancient human mobility at the individual level is conventionally studied by the diverse application of suitable techniques (e.g. aDNA, radiogenic strontium isotopes, as well as oxygen and lead isotopes) to either hard and/or soft tissues. However, the limited preservation of coexisting hard and soft human tissues hampers the possibilities of investigating high-resolution diachronic mobility periods in the life of a single individual. Here, we present the results of a multidisciplinary study of an exceptionally well preserved circa 3.400-year old Danish Bronze Age female find, known as the Egtved Girl. We applied biomolecular, biochemical and geochemical analyses to reconstruct her mobility and diet. We demonstrate that she originated from a place outside present day Denmark (the island of Bornholm excluded), and that she travelled back and forth over large distances during the final months of her life, while consuming a terrestrial diet with intervals of reduced protein intake. We also provide evidence that all her garments were made of non-locally produced wool. Our study advocates the huge potential of combining biomolecular and biogeochemical provenance tracer analyses to hard and soft tissues of a single ancient individual for the reconstruction of high-resolution human mobility.

Short-term effects of hydrated lime and quicklime on the decay of human remains using pig cadavers as human body analogues: Laboratory experiments

Contradictions and misconceptions regarding the effect of lime on the decay of human remains have demonstrated the need for more research into the effect of different types of lime on cadaver decomposition. This study follows previous research by the authors who have investigated the effect of lime on the decomposition of human remains in burial environments. A further three pig carcasses (Sus scrofa), used as human body analogues, were observed and monitored for 78 days without lime, with hydrated lime (Ca(OH)2) and with quicklime (CaO) in the taphonomy laboratory at the University of Bradford. The results showed that in the early stages of decay, the unlimed and hydrated lime cadavers follow a similar pattern of changes. In contrast, the application of quicklime instigated an initial acceleration of decay. Microbial investigation demonstrated that the presence of lime does not eliminate all aerobic bacteria. The experiment also suggested that lime functions as a sink, buffering the carbon dioxide evolution. This study complements the field observations. It has implications for the investigation of time since death of limed remains. Knowledge of the effects of lime on decomposition processes is of interest to forensic pathologists, archaeologists, humanitarian organisations and those concerned with disposal of animal carcasses or human remains in mass disasters.

DNA from keratinous tissue. Part I: hair and nail

Keratinous tissues such as nail, hair, horn, scales and feather have been used as a source of DNA for over 20 years. Particular benefits of such tissues include the ease with which they can be sampled, the relative stability of DNA in such tissues once sampled, and, in the context of ancient genetic analyses, the fact that sampling generally causes minimal visual damage to valuable specimens. Even when freshly sampled, however, the DNA quantity and quality in the fully keratinized parts of such tissues is extremely poor in comparison to other tissues such as blood and muscle - although little systematic research has been undertaken to characterize how such degradation may relate to sample source. In this review paper we present the current understanding of the quality and limitations of DNA in two key keratinous tissues, nail and hair. The findings indicate that although some fragments of nuclear and mitochondrial DNA appear to be present in almost all hair and nail samples, the quality of DNA, both in quantity and length of amplifiable DNA fragments, vary considerably not just by species, but by individual, and even within individual between hair types.

Ancient human genome sequence of an extinct Palaeo-Eskimo

We report here the genome sequence of an ancient human. Obtained from approximately 4,000-year-old permafrost-preserved hair, the genome represents a male individual from the first known culture to settle in Greenland. Sequenced to an average depth of 20x, we recover 79% of the diploid genome, an amount close to the practical limit of current sequencing technologies. We identify 353,151 high-confidence single-nucleotide polymorphisms (SNPs), of which 6.8% have not been reported previously. We estimate raw read contamination to be no higher than 0.8%. We use functional SNP assessment to assign possible phenotypic characteristics of the individual that belonged to a culture whose location has yielded only trace human remains. We compare the high-confidence SNPs to those of contemporary populations to find the populations most closely related to the individual. This provides evidence for a migration from Siberia into the New World some 5,500 years ago, independent of that giving rise to the modern Native Americans and Inuit.

Fourier-transform Raman spectroscopic study of a Neolithic waterlogged wood assemblage

The use of Fourier-transform Raman spectroscopy for characterising lignocellulosics has increased significantly over the last twenty years. Here, an FT-Raman spectroscopic study of changes in the chemistry of waterlogged archaeological wood of Pinus sp. and Quercus sp. from a prehistoric assemblage recovered from northern Greece is presented. FT-Raman spectral features of biodeteriorated wood were associated with the depletion of lignin and/or carbohydrate polymers at various stages of deterioration. Spectra from the archaeological wood are presented alongside spectra of sound wood of the same taxa. A comparison of the relative changes in intensities of spectral bands associated with lignin and carbohydrates resulting from decay clearly indicated extensive deterioration of both the softwood and hardwood samples and the carbohydrates appear to be more deteriorated than the lignin. The biodeterioration of the archaeological timbers followed a pattern of initial preferential loss of carbohydrates causing significant loss of cellulose and hemicellulose, followed by the degradation of lignin.

Stable isotope and DNA evidence for ritual sequences in Inca child sacrifice

Four recently discovered frozen child mummies from two of the highest peaks in the south central Andes now yield tantalizing evidence of the preparatory stages leading to Inca ritual killing as represented by the unique capacocha rite. Our interdisciplinary study examined hair from the mummies to obtain detailed genetic and diachronic isotopic information. This approach has allowed us to reconstruct aspects of individual identity and diet, make inferences concerning social background, and gain insight on the hitherto unknown processes by which victims were selected, elevated in social status, prepared for a high-altitude pilgrimage, and killed. Such direct information amplifies, yet also partly contrasts with, Spanish historical accounts.

Whole-Genome Shotgun Sequencing of Mitochondria from Ancient Hair Shafts

Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has revolutionized the study of ancient DNA, it has been plagued by large fractions of contaminating environmental DNA. The genetic analyses of hair shafts could be a solution: We present 10 previously unexamined Siberian mammoth (Mammuthus primigenius) mitochondrial genomes, sequenced with up to 48-fold coverage. The observed levels of damage-derived sequencing errors were lower than those observed in previously published frozen bone samples, even though one of the specimens was >50,000 14C years old and another had been stored for 200 years at room temperature. The method therefore sets the stage for molecular-genetic analysis of museum collections.

Selective biodegradation in hair shafts derived from archaeological, forensic and experimental contexts

BACKGROUND

Hair is degraded by the action of both dermatophytic and nondermatophytic microorganisms. The importance of understanding hair sample condition in archaeological and forensic investigation highlights the need for a detailed knowledge of the sequence of degradation in samples that have been either buried or left exposed at the ground surface.

OBJECTIVES

To investigate the sequence of biodegradative change to human terminal scalp hair from archaeological and forensic contexts.

METHODS

Cut modern scalp hair from three individuals with caucasoid-type hair was inoculated with soil microorganisms through soil burial in the field and under laboratory conditions to produce experimentally degraded samples. The degraded hair fibres were subjected to detailed histological examination using a combination of high-resolution light microscopy, transmission electron microscopy and scanning electron microscopy to investigate the nature and sequence of degradative change to hair structural components.

RESULTS/DISCUSSION

Degradation was found to occur first within the least structurally robust components that afford the least resistance to microbial/chemical attack. The sequence of degradation (most to least-reflecting degree of vulnerability) in the hair cuticle was as follows: (1) intercellular delta-layer (cell membrane complex); (2) endocuticle; (3) cell membrane beta-layers; (4) exocuticle; (5) epicuticle; and (6) A-layer. In the hair cortex this was as follows: (I) intercellular delta-layer (cell membrane complex); (II) cell membrane beta-layers; (III) intermacrofibrillar matrix/nuclear remnants; (IV) microfibrils; (V) intermicrofibrillar matrix; and (VI) pigment granules (the hair fibre component that was the least vulnerable to degradation).

CONCLUSIONS

The selective progress of degradation in the hair shaft has been charted and this provides a basis for further histological work in better understanding the condition of hair fibres derived from archaeological or forensic contexts as well as being relevant to investigation of diseased hair, in particular hair infected by dermatophytes and hair weakened by genetic hair shaft abnormalities.

Modelling the buried human body environment in upland climes using three contrasting field sites

Despite an increasing literature on the decomposition of human remains, whether buried or exposed, it is important to recognise the role of specific microenvironments which can either trigger or delay the rate of decomposition. Recent casework in Northern England involving buried and partially buried human remains has demonstrated a need for a more detailed understanding of the effect of contrasting site conditions on cadaver decomposition and on the microenvironment created within the grave itself. Pigs (Sus scrofa) were used as body analogues in three inter-related taphonomy experiments to examine differential decomposition of buried human remains. They were buried at three contrasting field sites (pasture, moorland, and deciduous woodland) within a 15 km radius of the University of Bradford, West Yorkshire, UK. Changes to the buried body and the effect of these changes on hair and associated death-scene textile materials were monitored as was the microenvironment of the grave. At recovery, 6, 12 and 24 months post-burial, the extent of soft tissue decomposition was recorded and samples of fat and soil were collected for gas chromatography mass spectrometry (GCMS) analysis. The results of these studies demonstrated that (1) soil conditions at these three burial sites has a marked effect on the condition of the buried body but even within a single site variation can occur; (2) the process of soft tissue decomposition modifies the localised burial microenvironment in terms of microbiological load, pH, moisture and changes in redox status. These observations have widespread application for the investigation of clandestine burial and time since deposition, and in understanding changes within the burial microenvironment that may impact on biomaterials such as hair and other associated death scene materials.

mtDNA from hair and nail clarifies the genetic relationship of the 15th century Qilakitsoq Inuit mummies

The 15th century Inuit mummies excavated at Qilakitsoq in Greenland in 1978 were exceptionally well preserved and represent the largest find of naturally mummified specimens from the Arctic. The estimated ages of the individuals, their distribution between two adjacent graves, the results of tissue typing, and incomplete STR results led researchers to conclude that the eight mummies formed two distinct family groups: A grandmother (I/5), two daughters (I/3, I/4), and their two children (I/1, I/2) in one grave, and two sisters (II/6, II/8) and a daughter (II/7) of one of them in the other. Using mtDNA from hair and nail, we have reanalyzed the mummies. The results allowed the unambiguous assignment of each of the mummies to one of three mtDNA haplogroups: A2b (I/5); A2a (I/2, I/3, II/6, II/8); A2a-311 (I/1, I/4, II/7), excluded some of the previous relations, and pointed to new ones. I/5 is not the grandmother/mother of the individuals in Grave I, and she is not maternally related to any of the seven other mummies; I/3 and I/4 are not sisters and II/7 is neither the daughter of II/6 nor of II/8. However, I/1 may be the child of either I/4 or II/7 and these two may be sisters. I/2 may be the son of I/3, who may be the daughter of either II/6 or II/8, and these two may be sisters. The observation of haplogroups A2a and A2b amongst the 550-year-old Inuit puts a lower limit on the age of the two lineages in Greenland.

Raman spectroscopic analysis of human remains from a seventh century cist burial on Anglesey, UK

Specimens from human remains exhibiting unusual preservation excavated from a seventh century stone cist burial at Towyn y Capel in Anglesey, UK, have been analysed using Raman spectroscopy with near-infrared laser excitation at 1,064 and 785 nm. Specimens of hair and bone provided evidence for severe degradation and microbial colonisation. The deposits within the stone cist showed that some microbially mediated compounds had been formed. Analysis of crystals found at the interface between the hair and the skeletal neck vertebrae revealed a mixture of newberyite and haematite, associated with decomposition products of the hair and bone. An interesting differential degradation was noted in the specimens analysed which could be related to the air-void and the presence of plant root inclusions into the stone cist. This is the first time that Raman spectroscopy has been used in the forensic archaeological evaluation of burial remains in complex and dynamic environments.

Development of an interactive learning tool for teaching rheumatology—a simulated clinical case studies program*

OBJECTIVES

To promote independent self-study involving problem solving and decision analysis in the undergraduate medical curriculum, we have developed a series of interactive web-based clinical case studies.

METHODS

An initial needs assessment was performed to determine students' attitudes to e-learning. From these results we designed a series of 30 interactive case studies for delivery from a web-server.

RESULTS

A survey of 59 undergraduate students believed that online teaching resources were a useful supplement to existing teaching and they could see a positive use for e-learning. The interactive case studies program was well received by a broad range of respondents (n = 84) of different abilities and backgrounds who felt that the program was realistic and clearly presented in an intuitive manner.

CONCLUSIONS

The recent increases in numbers of medical undergraduates, the trend towards student-centred learning and the emphasis on patient-related teaching means a great pressure on teachers and resources in medical schools. The case studies program we have developed was effective and well received by both biomedical and medical students. This approach may provide a way to increase the exposure of students to clinical cases involving interactive diagnostic and treatment procedures, that mimic real-world scenarios, but with fewer resource implications.

Histological correlates of post mortem mitochondrial DNA damage in degraded hair

We have assessed the histological preservation of naturally degraded human hair shafts, and then assayed each for levels of amplifiable mitochondrial DNA and damage-associated DNA miscoding lesions. The results indicate that as sample histology is altered (i.e. as hairs degrade) levels of amplifiable mitochondrial DNA decrease, but no correlation is seen between histology and absolute levels of mitochondrial DNA miscoding lesions. Nevertheless, amplifiable mitochondrial DNA could be recovered across the complete range of the histological preservation spectrum. However, when template copy number is taken into consideration, a correlation of miscoding lesions with histology is again apparent. These relationships indicate that a potential route for the generation of misleading mitochondrial sequence data exists in samples of poor histology. Therefore, we argue that in the absence of molecular cloning, the histological screening of hair may be necessary in order to confirm the reliability of mitochondrial DNA sequences amplified from hair, and thus represents a useful tool in forensic mitochondrial DNA analyses.

The influence of alcohol pre-treatment on the discriminative stimulus, subjective, and relative reinforcing effects of nicotine

Alcohol intake may acutely alter the discriminative stimulus and subjective effects of nicotine, perhaps explaining why alcohol increases tobacco smoking. In this study, cigarette smokers were initially trained to discriminate 20 microg/kg nicotine by nasal spray from placebo. Three sessions then followed, in which the generalization of nicotine discrimination was tested across a range of doses (0--20 microg/kg) following pre-treatment with 0, 0.4, and 0.8 g/kg alcohol p.o. Intermittent 'topping' doses of alcohol maintained a steady breath alcohol level (BAL) throughout testing. Generalization testing involved both two- and three-choice ('novel' option) procedures. A visual discrimination task was also conducted to determine the specificity of effects of alcohol. Subjective and cardiovascular measures were obtained concurrent with discrimination responding. The relative reinforcing effects of nicotine were assessed after the end of generalization testing using a choice procedure. Alcohol pre-treatment had no significant effects on nicotine discrimination or self-administration behavior. Alcohol and nicotine each influenced selected subjective responses and heart rate, but virtually no interactions between the drugs were observed. Within the limitations of this study, these results do not support the notion that alcohol acutely alters nicotine's discriminative stimulus, subjective, or relative reinforcing effects at these low nicotine doses. Acute effects of alcohol on smoking behavior may be due to alterations in other effects of nicotine intake or in non-nicotine effects of tobacco smoking.

Otago Diagnostic Laboratories' (ODL) Method for the detection of beta-lactamases in Enterobacteriaceae

AIM

The rapid evolvement of beta-lactamases in Enterobacteriaceae is an important concern and the clinical microbiology laboratory is required to detect them, where possible, using a rapid, reliable, simple and low cost methodology.

MATERIALS AND METHODS

A disc diffusion method using NCCLS breakpoints, Jarlier's principle and cefoxitin test for AmpC was carried out. It incorporated seven antimicrobial discs in one agar plate: cefotaxime, aztreonam, amoxicillin-clavulanate, ceftazidime, cefpodoxime, cefepime and cefoxitin. NCCLS disc confirmation test for extended-spectrum beta-lactamase (ESBL) was carried out simultaneously.

RESULTS

AmpC, ESBL, CTX-M, and K1 were detected using these tests. The prevalence of ESBL was <1% in the hospital.

CONCLUSION

The method is recommended for the phenotypic detection of beta-lactamases in Enterobacteriaceae or for confirmation after the results are obtained by conventional automated systems.

Resistance of degraded hair shafts to contaminant DNA

We have investigated the susceptibility of degraded human hair shaft samples to contamination by exogenous sources of DNA, including blood, saliva, skin cells, and purified DNA. The results indicate that on the whole hair shafts are either largely resistant to penetration by contaminant DNA, or extremely easy to successfully decontaminate. This pertains to samples that are both morphologically and biochemically degraded. We suggest that this resistance to the incorporation of contaminant DNA relates to the hydrophobic and impermeable nature of the keratin structures forming the hair shaft. Therefore, hair samples represent an important and underestimated source of DNA in both forensic and ancient DNA studies.

Raman spectroscopic analyses of preserved historical specimens of human hair attributed to Robert Stephenson and Sir Isaac Newton

The Raman spectra of two historical specimens of human hair attributed to the engineer Robert Stephenson and scientist Sir Isaac Newton, preserved in private collections are reported. Comparisons are made with the Raman spectra of modern hair specimens and with hair from archaeological excavations. The hair spectra collected with a laser excitation of 785 nm are of a better quality than those collected using 1064 nm. The historical hair specimens are remarkably well-defined spectroscopically in terms of the amide I vibrational mode and the [small nu](SS), ascribed to a predominantly gauche-gauche-gauche CSSC conformation. The contrast with degraded hair specimens recovered from archaeological excavations is striking. The presence of a weak feature near 2590 cm(-1) in the hair samples attributed to a [small nu](SH) vibration could be indicative of a reduction process operative on the CSSC cystine keratotic linkages and a possible origin of this is bacterial biodegradation identified histologically. This study demonstrates the molecular information available from non-destructive Raman spectroscopic analysis from single hair shafts or small bundles of fibres which complements information available from histological and destructive analytical techniques for rare biological specimens subjected to conservation or curation procedures in museums or private collections.

Development and assessment of a World Wide Web site for systemic lupus erythematosus patient information

Patient education is an important component of the management of chronic diseases such as SLE. We have investigated the value of the World Wide Web as a medium for delivery of SLE patient information. Volunteers recruited from the clinic and from the website completed interviews and questionnaires aimed at defining their information needs. A new website was then established and its impact on users tested using knowledge questionnaires. The new website was used extensively (20-30 users each day) over the 24 month period of study until April 2001. A total of 510 participants completed an online questionnaire that showed that for some users it was their first use of the internet to gather lupus information, but the majority (58.9%) accessed it at least monthly for this purpose. We also found that, while most users (56.9%) found current disease information was at an appropriate level, 37.5% thought it was too basic. Knowledge questionnaires from 42 participants before and after using the site showed a significant rise in users' knowledge of the areas covered by the site. As far as we are aware this study is the first to show that a patient-oriented website can have a positive effect on disease knowledge. The relative ease with which good quality information can be disseminated via the web suggests that this medium is likely to be less costly and perhaps more educationally effective than printed information, and so is likely to become a primary vehicle for patient education. The website tested can be found at: www.rheumatology.bham.ac.uk/lupus/intro.html.

Computerized information-gathering in specialist rheumatology clinics: an initial evaluation of an electronic version of the Short Form 36

OBJECTIVES

Longitudinal outcome data are important for research and are becoming part of routine clinical practice. We assessed an initial version of an electronic Short Form 36 (SF-36), a well-established health assessment questionnaire, in comparison with standard paper forms, in two specialist rheumatology clinics.

METHODS

Out-patients (20 with systemic lupus erythematosus and 31 with vasculitis) were randomly selected to complete either paper (n=29) or electronic and paper SF-36 versions (n=51) before and after consultation (paper vs paper comparison). Data were evaluated as the response correlation, internal consistency, missing data, patient satisfaction and preference.

RESULTS

There were very good correlations in SF-36 responses (P<0.001) between the paper and electronic forms and the paper and paper forms. Internal reliability coefficients (Cronbach's alpha) showed good internal consistency for all reported responses in either computer or paper forms. There were no missing data in the computerized version but 24% of patients failed to answer all of the paper form questions. Ease of use of the computer version was rated highly by 71% of all the respondents, and 69% would prefer to use the computer version in future.

DISCUSSION

Computerized data collection is acceptable to patients and feasible in clinical settings. It provides responses that are at least comparable to those to the paper form, improves data capture and is available immediately.

Yesterday's hair--human hair in archaeology

Hair removed from archaeological burials can tell us a lot about the diet and lifestyle of our ancestors--information that may survive because of the unique biology of hair formation. But hair is also biodegradable and the effects of time and burial conditions can result in conflicting evidence of past lives.

Provision of Internet-based rheumatology education (http://rheuma.bham.ac.uk)

OBJECTIVES

The Internet is becoming an important way of delivering medical information, and if used appropriately may assist in improving patients' self-management of their disease. We have established an arthritis education website ('Arthritis Help') and investigated its use over the last 2 yr.

METHODS

Computer-generated log-file analysis and on-line questionnaires were used to create user profiles of our website.

RESULTS

An average of 288 people visited our site each day, predominantly from America and the UK (49% of users). The typical questionnaire respondent (n = 770) was an American female with arthritis, aged 30+ yr, accessing the Internet from home. Typically, respondents had previously obtained information from medical staff or in written form, but were now more likely to use the Internet. One hundred and sixty-seven out of 585 respondents found our site to be useful, prompting them to seek more information (29%), change their behaviour or engage in more effective discussions with their physician (15%).

CONCLUSIONS

These data indicate that it is possible to use the Internet to deliver medical information to its target audience, and that this process can have some impact on the way disease is self-managed. This information may aid more focused website design to maximize the use and potential benefits of such a resource.

Hubble Space Telescope and Very Large Array Observations of the H2O Gigamaser Galaxy TXS 2226-184

We present Hubble Space Telescope/Wide-Field and Planetary Camera 2 images in Halpha + [N ii] lambdalambda6548, 6583 lines and continuum radiation and a VLA map at 8 GHz of the H2O gigamaser galaxy TXS 2226-184. This galaxy has the most luminous H2O maser emission known to date. Our red continuum images reveal a highly elongated galaxy with a dust lane crossing the nucleus. The surface brightness profile is best fitted by a bulge plus exponential disk model, favoring classification as a highly inclined spiral galaxy (i=70&j0;). The color map confirms that the dust lane is aligned with the galaxy major axis and is crossing the putative nucleus. The Halpha + [N ii] map exhibits a gaseous, jetlike structure perpendicular to the nuclear dust lane and the galaxy major axis. The radio map shows compact, steep spectrum emission that is elongated in the same direction as the Halpha + [N ii] emission. By analogy with Seyfert galaxies, we therefore suspect that this alignment reflects an interaction between the radio jet and the interstellar medium. The axes of the nuclear dust disk, the radio emission, and the optical line emission apparently define the axis of the active galactic nucleus. The observations suggest that in this galaxy the nuclear accretion disk, obscuring torus, and large-scale molecular gas layer are roughly coplanar. Our classification of the host galaxy strengthens the trend for megamasers to be found preferentially in highly inclined spiral galaxies.

The effects of cardiopulmonary bypass on remifentanil kinetics in children undergoing atrial septal defect repair

Cardiopulmonary bypass (CPB) can greatly influence the pharmacokinetics of opioids. This study investigated the pharmacokinetic profile of remifentanil in 12 pediatric patients undergoing CPB for repair of an atrial septal defect. All patients received remifentanil (5 microg/kg) over 1 min into a peripheral vein both before the onset of CPB and after the discontinuation of CPB. Arterial blood samples were obtained at defined time periods, and remifentanil concentration was determined using high-performance liquid chromatography ultraviolet detection. The pharmacokinetic profiles both before and after bypass were determined in all 12 patients. There was no change in the volume of distribution at steady state, the volume of the central compartment, or the alpha- and beta-elimination half-life. Although the clearance values increased 20% in the postbypass period (from 38.7 +/- 9.6 to 46.8 +/- 14 mL x kg(-1) x min(-1), there was no meaningful change in the coefficient of variation (from 25% to 30%).

IMPLICATIONS

After cardiopulmonary bypass the clearance of remifentanil increases in children. However, the relative lack of change in the coefficient of variation suggests that remifentanil should be a predictable drug in the postcardiopulmonary bypass period.

Are ball pits the playground for potentially harmful bacteria?

Ball pits, enclosed play areas with padded floors and pits of small plastic balls, have become popular features for children at fast food restaurants. This pilot study sought to identify and confirm bacterial organisms that place children at a potential health risk in three play pits within fast food restaurants. Data for this descriptive study were randomly collected from restaurants offering play pits with multicolored, round, hollow, plastic balls within urban communities of the Tidewater region of Virginia. Specimens were collected from entrances into the ball pits as well as various areas of the bottom lining to incur a representative sample. Results indicated an increased level of normal flora as well as nonhuman flora, demonstrating that bacteria are present within the ball pits. The results question the safety of these play pits for both health care providers and parents. Nurses play a vital role in public awareness through health education. Disinfection protocol and proper handwashing are the keys to making ball pit play areas safe for children.

Effects of central and peripheral nicotinic blockade on human nicotine discrimination

Nicotine produces interoceptive stimulus effects in humans, which may be critical in understanding tobacco use. It has not yet clearly been demonstrated that discrimination of nicotine, or any drug, in humans is due to its central effects. We compared effects of mecamylamine (10 mg p.o.), a central and peripheral nicotine antagonist, on nicotine discrimination with those of trimethaphan (10-40 microg/kg per min i.v.), a peripheral nicotine antagonist only, and placebo. Smokers (n = 6) were first trained to reliably discriminate 0 versus 20 microg/kg nicotine by nasal spray and then tested on generalization of this discrimination across a range of nicotine doses (0, 3, 6, 12, 20 microg/kg) following antagonist/placebo pretreatment. Nicotine self-administration was also assessed after generalization testing by having participants intermittently choose between nicotine versus placebo spray. Compared with responding following placebo pre-treatment, discrimination of the highest dose of nicotine was significantly attenuated following mecamylamine but not trimethaphan. Similar results were observed for some subjective responses to nicotine. Mecamylamine also tended to increase nicotine self-administration. Consistent with previous animal studies, these results suggest that discriminative stimulus effects of nicotine in humans are mediated at least in part by its central effects.

Bioactivation and inactivation of aflatoxin B1 by human, mouse and rat liver preparations: effect on SCE in human mononuclear leucocytes

The purpose of this study was to investigate the use of human and animal subcellular liver fractions in an in vitro evaluation of carcinogenic risk. The bioactivation and bioinactivation of the known genotoxic carcinogen aflatoxin B1 by human, mouse and rat liver preparations was investigated using the SCE assay in human lymphocytes as a genotoxic endpoint. There was a 10-fold variation in SCE response (1.1-11.6 SCE/Cell) in human mononuclear leucocytes (MNLs) after aflatoxin B1 was activated by human liver microsomes (n = 6). Activation correlated with the CYP1A2 phenotype of livers (r = 0.8; p < 0.05), but there was no correlation with either GST M1 genotype or epoxide hydrolase phenotype. Mouse liver microsomes activated aflatoxin B1 to a greater extent [(1 micro M) 12.8 +/- 2.51 SCE/Cell] than either rat [(10 micro M) 12.0 +/- 3.84 SCE/Cell or human (L25) [(10 micro M) 8.8 +/- 2.00 SCE/Cell liver microsomes. The addition of mouse liver cytosol and reduced glutathione (GSH) significantly (p < 0.001) reduced aflatoxin B1-dependent genotoxicity, whereas the addition of either human or rat cytosol (+GSH) was without effect. These data indicate that species variation in both bioactivation and bioinactivation can exist. Therefore there is a necessity for careful selection of activation systems from species whose biochemical profile reflects that of man.

Acute reinforcing effects of low-dose nicotine nasal spray in humans

Tobacco smoking behavior is reinforced by nicotine intake, but there has been little human research examining self-administration of nicotine per se, isolated from tobacco. In this study, 10 smokers (5 men, 5 women) who wanted to quit smoking sampled 0 (placebo), 0.75, and 1.5 ug/kg/spray nicotine via nasal spray during separate lab sessions before engaging in a free choice session, involving ad lib access to all three spray doses. Subjects also ad lib smoked during another session. For the group as a whole, neither nicotine spray dose was self-administered significantly more than placebo during the free choice session, suggesting low abuse potential. However, 4 of 10 subjects self-administered 1.5 ug/kg/spray on more than 50% of all sprays (vs. 33% chance) and were designated nicotine "choosers," while the others were "nonchoosers." Choosers responded to initial nicotine spray exposure during sampling sessions with greater positive subjective effects (similar to their responses to tobacco smoking), smoked more during the ad lib smoking session (i.e., self-administered more nicotine via tobacco smoking), and tended to be more heavily dependent smokers. They did not report greater withdrawal relief or less aversive effects from nicotine, suggesting their greater nicotine choice reflected greater positive reinforcement rather than negative reinforcement. These results are consistent with the few existing studies demonstrating that acute nicotine intake per se, in the absence of tobacco, may be reinforcing in some smokers.

Fentanyl and alfentanil plasma protein binding in preterm and term neonates

The effects of gestational age (GA) and plasma protein concentrations on the plasma protein binding of fentanyl and alfentanil were studied in preterm and term neonates. Binding experiments were performed using split-cell equilibrium dialysis. Fentanyl and alfentanil concentrations were measured using specific radioimmunoassay, and the proteins albumin and alpha-1-acid glycoprotein (AAG) were measured using radial immunodiffusion assays. In the preterm neonates, 77% of fentanyl and 65% of alfentanil was bound. In the term neonates, 70% of fentanyl and 79% of alfentanil was bound. The binding ratio of alfentanil showed a positive correlation with gestational age and AAG concentration. The binding ratio of fentanyl showed a weak, negative correlation with gestational age. These data indicate that fentanyl and alfentanil are not interchangeable at the GA studied because of age-related changes in protein binding.