Anti-skin aging effect of sea buckthorn proanthocyanidins in D-galactose-induced aging mice

Oxidative stress in skin cells caused by changes in the external environment is one of the principal causes of skin aging. Sea buckthorn proanthocyanidins (SBPs) have good free radical scavenging ability. We established a senescence model by injecting 500 mg/kg D-galactose into the dorsal necks of mice, and then different doses of SBP (25, 50, and 100 mg/kg) were gavaged to explore the effects of SBP on the skin tissues of senescent mice and elucidate the related mechanism of action. The results reveal that SBP can alleviate the skin aging phenomenon caused by D-galactose-induced aging. It can also enhance the total antioxidant capacity in the body, thereby strengthening the body's antioxidant defense capability. In addition, SBP can effectively improve skin aging by regulating the TGF-β1/Smads pathway and MMPs/TIMP system, increasing the relative content of Col I and tropoelastin, further maintaining the stability of collagen fiber and elastic fiber structure. These results will provide the development and production of the antioxidant function of cosmetics and health products, providing a new train of thought.

Extraction and characterization of a pectin from sea buckthorn peel

Sea buckthorn peel is the by-product of the sea buckthorn processing, which contains many bioactive compounds. In this paper, sea buckthorn high methoxyl pectin (SBHMP) was obtained, with a yield of 8% and a light-colored. The SBHMP was a high methoxyl with a degree of esterification of 57.75% and uronic acid content of 65.35%. The structural and morphological characterization of SBHMP were analyzed by high-performance liquid chromatography, Fourier-transform infrared spectroscopy, and scanning electron microscopy. Results showed that SBHMP presented a sheet and layered stacked morphological, and was mainly composed of galacturonic acid, arabinose, galactose, rhamnose, and mannose, which indicated that SBHMP mainly consisted of homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) type pectin polysaccharides. In addition, SBHMP also presented significant gel, thickening, and emulsifying properties. The results exhibited that SBHMP could form jelly-like gels under acid and high sucrose conditions, presenting a shear-thinning behavior and increasing apparent viscosity with the enhancement of pectin and sucrose contents. Besides, SBHMP could form oil-in-water emulsions with pectin concentrations of 1.0–3.0%. When the SBHMP concentrations were 2.0 and 3.0%, the emulsions were stable during 7 days of storage. Findings in this paper demonstrated the potential of SBHMP to be a food thickener and emulsifier and support the in-depth utilization of sea buckthorn by-products.

Sea Buckthorn Proanthocyanidins are the Protective Agent of Mitochondrial Function in Macrophages Under Oxidative Stress

Sea buckthorn proanthocyanidins (SBP) are the most important antioxidant components of sea buckthorn, which are widely used in functional foods and cosmetics. Studies have shown that SBP have significant protective effects on macrophages against oxidative stress induced by hydrogen peroxide (H₂O₂). However, the mechanism remains uncertain. In the present study, we explored the effects of SBP on mitochondrial function and the mechanism of their protective effects against oxidative stress in cells. Our results showed that SBP could increase mitochondrial membrane potential, inhibit mPTP opening, reduce mitochondrial swelling, and enhance mitochondrial synthesis and metabolism. Thus, they alleviated oxidative damage and protected the cells against mitochondrial function. Western blot analysis showed that SBP had a protective effect on RAW264.7 cells by activating the AMPK-PGC1α-Nrf2 pathway. These results showed that SBP alleviated mitochondrial damage and dysfunction caused by oxidative stress. This study revealed the mechanism of SBP in reducing oxidative damage and provided a theoretical basis for further research on natural bioactive compounds to exert antioxidant activity and prevent arteriosclerosis and other diseases.

Regulatory Effect of Sea-Buckthorn Procyanidins on Oxidative Injury HUVECs

As society develops and aging populations increase, the incidence of arteriosclerosis, a seriously harmful cardiovascular disease (CVD) which mostly results from endothelial cellular oxidative damage, has continuously risen. Procyanidins from sea-buckthorn is a powerful antioxidant, although its protective effect on the cardiovascular system is not yet clearly understand. In this study, oxidative damaged HUVECs induced by palmitate acid (PA) were used as a model and the regulatory effect of procyanidins from sea-buckthorn (SBP) on HUVECs were investigated. The results showed SBP can be used for 12 h by HUVECs and had no detective cytotoxicity to them under 400 μg/L. Also, different concentrations of SBP can increase mitochondrial membrane potential and NO level and decrease LDH leakage in a dose-effect relationship, indicating SBP can improve oxidative damage. In addition, western blots and qPCR results showed SBP regulation on oxidative injured HUVECs is probably through p38MAPK/NF-κB signal pathway. This study revealed the molecular mechanism of procyanidins in decreasing endothelial oxidative damage, providing a theoretical foundation for further research on natural bioactive compounds to exert antioxidant activity in the body and prevent and improve cardiovascular diseases.

Effects of Ball Milling Combined With Cellulase Treatment on Physicochemical Properties and in vitro Hypoglycemic Ability of Sea Buckthorn Seed Meal Insoluble Dietary Fiber

To improve the rough texture and hypoglycemic ability of sea buckthorn insoluble dietary fiber (IDF), a novel combined modification method was developed in this study. The IDF was treated with ball milling and cellulase treatment to obtain co-modified insoluble dietary fiber (CIDF). The physicochemical and functional properties of IDF, milled insoluble dietary fiber (MIDF), and CIDF were studied. After treatments, MIDF had smaller particle sizes and a looser structure, and CIDF exhibited a wrinkled surface and sparse porous structure according to scanning electron microscopy (SEM) and X-ray diffraction. Compared to IDF, MIDF and CIDF showed improved water-holding, oil-binding, and swelling capacities, improved by 16.13, 14.29, and 15.38%, and 38.5, 22.2, and 25.0%, for MIDF and CIDF, respectively. The cation exchange ability of modified samples showed improvement as well. Treatments also changed the fluidity of MIDF and CIDF. Due to the smaller particles and increased stacking, the bulk density (BD) and angle of repose of MIDF improved by 33.3% and 4.1° compared to IDF, whereas CIDF had a looser structure and thus decreased by 7.1% and 13.3° with increased fluidity. Moreover, the modification also enhanced the effects of CIDF on glucose adsorption, glucose diffusion inhibition, starch digestion inhibition, starch pasting interference, and α-amylase activity inhibition. In summary, IDF modified by ball milling combined with cellulose treatment could be developed as a functional ingredient for regulating glucose content.

Composition analysis and antioxidant activity evaluation of a high purity oligomeric procyanidin prepared from sea buckthorn by a green method

Procyanidin is an important polyphenol for its health-promoting properties, however, the study of procyanidin in sea buckthorn was limited. In this paper, sea buckthorn procyanidin (SBP) was obtained through a green isolation and enrichment technique with an extraction rate and purity of 9.1% and 91.5%. The structure of SBP was analyzed using Ultraviolet–visible spectroscopy (UV–vis), Fourier-transform infrared spectroscopy (FT-IR), and liquid chromatography-mass spectrometry (LC-MS/MS). The results show that SBP is an oligomeric procyanidin, mainly composed of (−)-epicatechin gallate, procyanidin B, (+)-gallocatechin-(+)-catechin, and (+)-gallocatechin dimer. SBP showed superior scavenging capacity on free radicals. Furthermore, the cleaning rate of the ABTS radical was 4.8 times higher than vitamin C at the same concentration. Moreover, SBP combined with vitamin C presented potent synergistic antioxidants with combined index values below 0.3 with concentration rates from 5:5 to 2:8. SBP also provided significant protection against oxidative stress caused by hydrogen peroxide (H₂O₂) on RAW264.7 cells. These findings prove the potential of SBP as a natural antioxidant in food additives and support the in-depth development of sea buckthorn resources.

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A green method for the extraction of procyanidin was proposed.

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An oligomeric procyanidin in sea buckthorn was identified for the first time.

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SBP combined with VC exerted strong synergistic antioxidant.

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SBP provided protection of macrophages against oxidative damage.

Immunomodulatory effect of intracellular polysaccharide from mycelia of Agaricus bitorquis (QuéL.) Sacc. Chaidam by TLR4-mediated MyD88 dependent signaling pathway

Agaricus bitorquis (QuéL.) Sacc. Chaidam is a valuable edible fungus in Qinghai-Tibet plateau and ABSP is a novel intracellular polysaccharide from its mycelia. GC and NMR analysis determined ABSP is galactoglucomannan-like polysaccharide that may have immunomodulatory effect. This study used RAW264.7 as model cell to determine immunomodulatory effect of ABSP. After ABSP treatment, viability and phagocytic ability promoted, and NO, ROS, TNF-α levels also raised which proved ABSP had immune regulation to RAW264.7. WB and qRT-PCR determined the key proteins and genes expression of TLR4, MyD88, TRAF-6 and NF-κB significantly increased while protein and gene expression of TRAM had no significant increase. Also, TNF-α level extremely decreased by adding inhibitors of TLR4 and MyD88 which confirmed ABSP could immunologically regulate RAW264.7 byTLR4-MyD88 dependent pathway. This study would provide theoretical basis for further study on ABSP and be helpful for development of beneficial functionally foods and exploitation of this resource.

A case of solitary kidney with duplex collecting systems and renal vascular variants in an adult male cadaver

We describe a unique solitary kidney with duplex collecting system and vascular variation observed in an 86-year-old white male formaldehyde- and phenol-fixed cadaver during routine academic dissection. The left renal fossa was empty with an intact adrenal gland, and the right renal fossa contained a fused renal mass with apparent polarity between the superior and inferior regions and two renal pelves converging into a single ureter. There were three right renal arteries supplying the renal mass; the superior and middle arteries were noted to be postcaval and the inferior artery was precaval. There were also two right renal veins draining into the inferior vena cava and following a regional distribution with the superior vein draining the inferior portion of the renal mass. Despite generally being asymptomatic, the detection of renal anatomical variants is clinically important for appropriate patient management and surgical interventions.

Abstract PD8-05: Single-cell analysis of breast cancer metastasis using patient-derived xenograft model reveals clonal relationship between primary tumor and its metastases

Introduction Breast cancer is the most common cancer in female and triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer which shows high rate of recurrence and metastasis. Malignant cells that comprise primary tumor are heterogeneous and during disease progression selection of tumor cells occur as a mean to adapt and survive. Tumor heterogeneity can be studied by grouping cells as clones which refer to a group of cells related to each other by descent from a unitary origin. Understanding the mechanism of clonal dynamics and selection during cancer evolution is important to develop new therapeutic strategies for cancer metastasis. Moreover, it is imperative to be able to detect rare subclones that are responsible for metastasis. Thus, single-cell analysis is critical to identify cellular heterogeneity of cancer and molecular basis of metastatic phenotype in depth. Measuring genome and transcriptome in single-cell level will enable us to discover clonal dynamics during cancer metastasis and infer molecular determinants of metastasis fitness. Here, we propose to investigate the clonal dynamics, genomic, and transcriptomic profiles of human breast tumor metastasis using TNBC patient-derived xenograft (PDX) model to understand the mechanism of breast cancer progression and metastasis. Methods Tumor cells from previously established PDXs were transplanted into mammary fat pad of mice. Tumors were removed when it reached maximum allowed endpoint size (1,000mm3) and mice were monitored and allowed to grow metastasis. PDXs that developed primary tumor and metastasis were selected for subsequent single cell analysis. Single-cell whole-genome sequencing (scWGS) was performed using direct library preparation (DLP+) method which is preamplification-free single-cell genome sequencing approach. scWGS data was used to call cell-specific copy number events, which allows us to cluster cells and identify clones. Hierarchical clustering was used to identify clonal structure of each sample. Phylogenetic tree was computed using copy number data of samples from each PDX. Results Nine different TNBC PDX lines were tested and 6 PDX lines developed metastasis. We focused on 2 PDX lines of which metastatic tissues were available for single cell sequencing. SA919 developed metastatic mass near cervical or lumbar spine area. SA535 developed metastasis to lung, axillary or inguinal area and tumor recurrence at mammary fat pad site. scWGS for SA919 and SA535 was carried out and we generated libraries from single cells of primary tumor and its metastases. Hierarchical clustering using copy number data revealed clonal structure of primary tumor and metastases. SA919 showed oligoclonal primary tumor and metastasis whereas SA535 showed polyclonal metastasis from polyclonal primary tumor. scWGS data of primary tumor and its metastases in each PDX were merged to compute phylogenetic trees. Phylogenetic analysis revealed that not all clones of primary tumor contributed to metastasis in both PDXs. Different metastatic lesions of SA535 harbored different clones from primary tumor. For example, clones consisting left axillary metastasis and right axillary metastasis in SA535 were different from each other, however they both originated from primary tumor clones. Metastatic lesions from SA919 and SA535 also had newly appearing clones that were not present in primary tumor inferring clonal evolution during metastasis. Conclusion We were able to capture different patterns of metastasis in several PDXs. Phylogenetic analysis using scWGS data revealed clonal relationship between primary tumor and metastases. Further analysis of single cell genomic and transcriptomic profiles will provide deeper understanding of metastasis in breast cancer.

Citation Format: Hakwoo Lee, Farhia Kabeer, Ciara O'Flanagan, Jazmine Brimhall, Justina Biele, Biexi Wang, Teresa Ruiz Algara, So Ra Lee, Daniel Lai, Michael Yuen, Simong Song, Patricia Ye, Jenifer Pham, Richard Moore, Andy J Mungall, Sohrab P Shah, Samuel Aparicio. Single-cell analysis of breast cancer metastasis using patient-derived xenograft model reveals clonal relationship between primary tumor and its metastases [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD8-05.

Abstract P6-18-39: Abemaciclib after prior palbociclib exposure in patients with metastatic hormone-receptor positive (HR+)/HER2- breast cancer

Introduction: The advent of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) has transformed the clinical practice of HR+/HER2- metastatic breast cancer. Palbociclib, ribociclib, and abemaciclib have been approved in conjunction with anti-estrogens, while abemaciclib has also been approved as monotherapy based on single agent activity in the MONARCH-1 trial (objective response rate/ORR: 19.7% and median progression-free-survival/PFS = 6.0 months; Dickler M et al CCR 2017). However, there is limited insight into the mechanisms governing resistance to CDK 4/6i and the potential utility of continued CDK4/6i after progression on a prior CDK 4/6i-based therapy.

Methods: We evaluated the clinical outcomes of patients with metastatic HR+/HER2- breast cancer who had received abemaciclib following an initial course of palbociclib-based therapy at our institution. In addition, we conducted genomic analysis utilizing next-generation sequencing of tissue samples and blood (cell-free DNA/cfDNA analysis) where available.

Results: From June, 2014 through July, 2018, a total of 49 patients received abemaciclib, and 14 patients had prior palbociclib exposure. One patient was deceased shortly after initiating abemaciclib and one patient was lost to follow-up. Among the 12 remaining patients, eight had sequential courses of CDK4/6-based therapy, while four patients had at least one intervening non-CDK 4/6i based regimen. At data-cutoff of 8/15/2018, five patients (41.7%) had early progression on abemaciclib (PFS equal to or less than 120 days) while three (25%) patients had ongoing benefit (PFS greater than 120 days, two of three actively on therapy). Three additional patients had recently initiated abemaciclib therapy (less than 120 days prior to current analysis). Preliminary analysis of baseline cfDNA results in patients with early progression on abemaciclib therapy after prior CDK4/6i revealed the presence of RB1 mutation, FGFR1 amplification, and TP53 mutation, among others. Additional analyses with mature clinical data (including updated PFS and ORR), toxicity assessment during secondary CDK4/6i exposure, and further analysis of genomic sequencing results will be provided at the meeting.

Conclusions: The majority of patients had early disease progression on abemaciclib after prior exposure to CDK4/6i suggesting potential cross-resistance to CDK4/6i mediated by common drivers. However, a subset of patients derived clinical benefit with continued exposure to CDK4/6i, highlighting the need for additional research to evaluate potential predictive biomarkers and guide rational utilization of continued CDK4/6 blockade in metastatic HR+/HER2- breast cancer.

Citation Format: Wander SA, Spring LM, Stein CR, Yuen M, Zangardi M, O'Shaughnessy J, Bardia A. Abemaciclib after prior palbociclib exposure in patients with metastatic hormone-receptor positive (HR+)/HER2- breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-39.

Abstract P4-08-08: Genomic progression, detected by circulating tumor DNA (ctDNA) sequencing, as an early predictor of disease progression in metastatic breast cancer (MBC)

Background: The availability of multiple therapies has transformed the landscape of MBC, but also brought the challenge of selecting the right therapy for an individual patient. Furthermore, in patients with Hormone Receptor positive (HR+) breast cancer who have bone metastases only it may be difficult to assess effectiveness of therapy via imaging. Peripheral ctDNA detection and analysis by next-generation sequencing (NGS) has gained popularity in cancer diagnosis and therapeutics due to its relative noninvasiveness, ease of use, and high sensitivity. Here, we explore the utility of ctDNA change as a predictor for disease progression in MBC. We hypothesized that genomic progression is a harbinger of subsequent radiologic progression in patients with MBC.

Methods: We analyzed change from pre-treatment (baseline) to on-treatment ctDNA mutant allele fraction (MAF) among patients with MBC. Patients receiving standard-of-care therapies or investigational agents on clinical trials at our institution were included. All patients were followed from the date of baseline test until death or data cutoff (6/20/2018). All peripheral blood specimens were collected and analyzed between 1/7/2016 and 3/1/2018 via NGS (Guardant360®). Peripheral blood specimens were sequenced prior to initiation of a new therapeutic regimen (baseline) and subsequently at least once while on-treatment, on average 4-12 weeks later. All patients had a follow-up CT scan of chest, abdomen and pelvis 2-4 weeks after the on-treatment NGS. A priori, we defined genomic progression as increase in ctDNA total MAF of at least 20% from baseline. We utilized Cox regression analysis to identify whether genomic progression was a predictor of radiologic progression, adjusting for common prognostic variables.

Results: All patients (N= 77) were female, predominantly White (83.1%), and median age was 57 (range 32 to 77). Fifty one out of 77 patients (66.2%) were ER+, 5 HER2+, and 9 had triple negative breast cancer. The median MAF at baseline was 2.2% (range 0% - 61.7%). Common genomic alterations in ctDNA included PIK3CA, TP53, ESR1, AKT1, NF1. 27 out of 77 (35%) patients showed disease progression on the first subsequent CT scan, while 59 out of 77 (76.6%) progressed during the follow up time. We found that an increase in ctDNA MAF of at least 20% was a strong predictor of disease progression (HR =2.46, CI [1.14-5.32], p=0.02), compared to those who had a MAF increase of less than 20% or a decrease in total MAF. In multi-variable analysis, adjusting for age, number of prior therapies, type of therapy, and visceral metastases, increase in ctDNA remained a significant predictor for subsequent disease progression (HR =3.84, CI [1.63-9.07], p=0.002). Subset results in patients with bone metastases only, and relative comparison of ctDNA with standard tumor markers will be presented at the meeting.

Conclusions: Genomic progression, identified by an increase in ctDNA MAF, is potentially an early predictor of subsequent disease progression in patients with MBC. Further research is needed to prospectively evaluate the clinical utility of ctDNA change as a surrogate marker in guiding treatment decision-making for patients with MBC.

Citation Format: Velimirovic M, Juric D, Niemierko A, Spring LM, Vidula N, Malvarosa G, Yuen M, Moy B, Isakoff SJ, Ellisen LW, Bardia A. Genomic progression, detected by circulating tumor DNA (ctDNA) sequencing, as an early predictor of disease progression in metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-08-08.

Abstract P4-01-06: Comparison of tumor genotyping and cell-free circulating tumor DNA sequencing in metastatic breast cancer patients and their utility in the selection of matched therapy

Background: Oncogenic mutations are potential targets for therapeutic intervention in metastatic breast cancer (MBC). While tumor genotyping (TG) has been viewed as the gold standard for identifying oncogenic mutations, cell-free circulating tumor DNA (cfDNA) is emerging as an alternate technique. We previously reported the selection of matched therapy targeted to an actionable mutation based on either TG or cfDNA testing (Vidula N, ASCO, 2018). Therefore, we are now comparing TG and cfDNA results in MBC patients undergoing both tests to examine their relative utility in the selection of matched therapy.

Methods: Patients with MBC at an academic institution who underwent both TG (Next Generation Sequencing/NGS, institutional platform, 104 gene assay) and cfDNA testing (NGS/Guardant360, 73 gene assay) between 1/2016-10/2017 were identified. A chart review was conducted to identify tumor subtype, demographics, treatment, TG and cfDNA results, and clinical outcomes. The relative utility of these tests in the selection of matched therapy was determined, and linked with clinical outcomes (progression-free survival and overall survival).

Results: Thirty patients who underwent both TG and cfDNA testing were identified. The median age was 60 years, the majority (97%) had hormone receptor (HR) positive/HER2 negative disease, and most patients had recurrent disease (83.3%) at MBC diagnosis. The median number of therapies prior to obtaining either test was 1 (cfDNA range 0-9, TG range 0-8). The majority had simultaneous cfDNA and tumor genotyping testing (83.3%) versus sequential testing (16.7%). Twenty-four (80%) patients had actionable mutations detected by cfDNA compared to 19 (63.3%) patients with actionable mutations detected by TG. The median number of actionable mutations detected by cfDNA was 2 (range 0-11) compared with a median of 1 (range 0-4) detected by TG. Failure of TG occurred in 2 of 30 patients (6.7%) but no test failures were seen with cfDNA. Eleven of 30 patients (36.7%) had ≥ 1 concordant mutation via cfDNA and TG. Altogether, 12 out of 30 (40%) patients received matched therapy, 5 of which were based on cfDNA actionable mutations alone (ESR1, ERBB2, CCND1, and PIK3CA), and 7 based on cfDNA and TG results (ESR1, PIK3CA, STK11, and BRCA). Twelve of 24 (50%) patients with actionable cfDNA mutations went on to receive matched therapy compared with 7 of 19 (36.8%) patients with actionable TG results. Matched therapies included SERDs, inhibitors of CDK 4/6, PI3K, mTOR, HER2 directed therapy, and DNA damaging chemotherapy. The impact of matched therapy on survival outcomes will be presented at the meeting.

Conclusions: In patients undergoing both TG and cfDNA testing, both tests identify a significant cohort of HR+ MBC patients with actionable mutations, with greater detection of actionable mutations by cfDNA. Greater application of matched therapy occurred via cfDNA, which independently informed the selection of matched therapies. Further research is needed to prospectively evaluate the clinical utility of blood based genotyping assays versus TG for patients with MBC.

Citation Format: Vidula N, Juric D, Niemierko A, Spring L, Moy B, Malvarosa G, Yuen M, Habin K, Shin J, Peppercorn J, Isakoff S, Ellisen L, Iafrate AJ, Bardia A. Comparison of tumor genotyping and cell-free circulating tumor DNA sequencing in metastatic breast cancer patients and their utility in the selection of matched therapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-06.

Exploring genetic suppression interactions on a global scale

Genetic suppression occurs when the phenotypic defects caused by a mutation in a particular gene are rescued by a mutation in a second gene. To explore the principles of genetic suppression, we examined both literature-curated and unbiased experimental data, involving systematic genetic mapping and whole-genome sequencing, to generate a large-scale suppression network among yeast genes. Most suppression pairs identified novel relationships among functionally related genes, providing new insights into the functional wiring diagram of the cell. In addition to suppressor mutations, we identified frequent secondary mutations,in a subset of genes, that likely cause a delay in the onset of stationary phase, which appears to promote their enrichment within a propagating population. These findings allow us to formulate and quantify general mechanisms of genetic suppression.

Postglacial history of a widespread conifer produces inverse clines in selective neutrality tests

Deviations of the site frequency spectrum of mutations (SFS) from neutral expectations may be caused by natural selection or by demographic processes such as population subdivision or temporal changes in population size. As most widespread temperate and boreal tree species have expanded from glacial refugia in the past 13,000 years, colonization bottlenecks associated with this migration may have left variable demographic signatures among geographic populations corresponding to distance from the refugia. To determine whether the signature of postglacial re-colonization has skewed the SFS in the widely distributed conifer Sitka spruce (Picea sitchensis (Bong.) Carr.), we re-sequenced 153 nuclear genes in six populations from across the species range. We found that while the SFS for the pooled sample produced negative values for Tajima's D and Fay and Wu's H, these statistics exhibited strong clinal variation when populations were analysed separately (R(2) = 0.84, P = 0.007 for Tajima's D and R(2)  = 0.65, P = 0.033 for Fay and Wu's H). When historical bottlenecks of varying age were simulated using approximate Bayesian computation, distance of populations from the southern range limit explained most of the variation in bottleneck timing among populations (R(2) = 0.89, P = 0.003). These data suggest that sequential population bottlenecks during postglacial re-colonization have resulted in diverse among-population signatures within the contemporary SFS in Sitka spruce, with rare variants more common in the south, and medium-frequency variants more common in the north. Our results also emphasize the need to consider sampling strategy and to explore population-specific null demographic models in surveys of nucleotide variation in widely distributed species.

Reconstruction of crashes involving injured child occupants: the risk of serious injuries associated with sub-optimal restraint use may be reduced by better controlling occupant kinematics

OBJECTIVE

To determine whether injuries to sub-optimally restrained child occupants in real-world crashes were likely to be preventable by alternative restraint usage practices and to assess the usefulness of crash reconstruction for exploring injury mechanisms in child occupants.

METHODS

Real-world crashes in which child occupants sustained significant injuries were reconstructed on a laboratory crash sled using the Hybrid III family of child dummies. Alternative restraint scenarios and cases in which children were not seriously injured were also simulated to compare dummy kinematics and dynamic responses in optimal restraint configurations.

RESULTS

Restraint misuse was associated with greater motion of the dummy torso and head during crashes, often allowing contact between the child and the vehicle interior, resulting in injury. Poor pre-crash posture for a child inappropriately restrained in an adult belt appeared to worsen the geometry of the sash (shoulder) belt, resulting in a cervical injury due to direct interaction with the belt. Dynamic dummy data did not appear to discriminate between injury and non-injury cases.

CONCLUSIONS

Dummy kinematics suggest that injuries in which inappropriate use and misuse were a factor were less likely if the most appropriate restraint was used correctly. Adequately controlling the head and upper body of the child occupant was seen to prevent undesirable interactions with the vehicle interior and restraint system, which were associated with injury in the real world. Neck forces and moments and injury criteria calculated from these did not predict injury reliably.

Atmospheric mercury speciation in Yellowstone National Park

Atmospheric concentrations of elemental mercury (Hg(0)), reactive gaseous Hg (RGM), and particulate Hg (pHg) concentrations were measured in Yellowstone National Park (YNP), U.S.A. using high resolution, real time atmospheric mercury analyzers (Tekran 2537A, 1130, and 1135). A survey of Hg(0) concentrations at various locations within YNP showed that concentrations generally reflect global background concentrations of 1.5-2.0 ng m(-3), but a few specific locations associated with concentrated geothermal activity showed distinctly elevated Hg(0) concentrations (about 9.0 ng m(-3)). At the site of intensive study located centrally in YNP (Canyon Village), Hg(0) concentrations did not exceed 2.5 ng m(-3); concentrations of RGM were generally below detection limits of 0.88 pg m(-3) and never exceeded 5 pg m(-3). Concentrations of pHg ranged from below detection limits to close to 30 pg m(-3). RGM and pHg concentrations were not correlated with any criteria gases (SO(2), NO(x), O(3)); however pHg was weakly correlated with the concentration of atmospheric particles. We investigated three likely sources of Hg at the intensive monitoring site: numerous geothermal features scattered throughout YNP, re-suspended soils, and wildfires near or in YNP. We examined relationships between the chemical properties of aerosols (as measured using real time, single particle mass spectrometry; aerosol time-of-flight mass spectrometer; ATOFMS) and concentrations of atmospheric pHg. Based on the presence of particles with distinct chemical signatures of the wildfires, and the absence of signatures associated with the other sources, we concluded that wildfires in the park were the main source of aerosols and associated pHg to our sampling site.

Helicobacter westmeadii sp. nov., a new species isolated from blood cultures of two AIDS patients

A slowly growing anaerobic Helicobacter species was isolated from the blood cultures of two human immunodeficiency virus-positive patients admitted to Westmead Hospital, Westmead, Australia, with fevers. The morphology of the isolates was consistent with Helicobacter cinaedi or Helicobacter fennelliae. The results of culture growth conditions, biochemical tests, gas chromatography data, ribotyping, and 16S rDNA sequencing showed that these isolates represent a new Helicobacter species, for which the name Helicobacter westmeadii has been proposed.

Absence of retroviral antibodies in the sera of patients with systemic lupus erythematosus

Retroviruses have been postulated as environmental triggers in the aetiopathogenesis of systemic lupus erythematosus. Sera from 100 lupus patients were screened for the presence of antibodies against recombinant HIV-1 core and envelope, and HIV-2 envelope antigens by an enzyme immunoassay. This will detect antibodies resulting from direct HIV-1 or HIV-2 infections or those generated as a result of antigenic similarities by other human retroviruses. The sera were obtained from 11 male and 89 female lupus patients. Retroviral antibodies were not detected in the sera of these lupus patients, thus contradicting published findings that up to 30% of lupus patients have antibodies against the p24 gag protein of HIV-1.

Serological cross-reaction between Legionella spp. and Capnocytophaga ochracea by using latex agglutination test

Cross-reactivity between Legionella spp. and Capnocytophaga ochracea was noted by latex agglutination tests (Serobact Legionella; Disposable Products, Adelaide, Australia). Four of 11 (36%) C. ochracea isolates agglutinated with latex reagents designed to identify Legionella pneumophila serogroups. C. ochracea isolated on buffered charcoal yeast extract media may give false-positive results in this Legionella latex agglutination assay.

Focal fibrocartilaginous dysplasia and tibia vara: a case report

A 2-year-old black boy with focal fibrocartilaginous dysplasia is described with illustrations of the typical radiographic appearances supplemented by computed tomographic and magnetic resonance images. Since this rare condition is self-correcting, diagnosis is important so that surgical intervention and biopsy can be avoided and conservative management instituted.

Influence of lactoferrin on iron absorption from human milk in infants

Lactoferrin (Lf) is a major iron (Fe)-binding protein in human milk and has been proposed to facilitate Fe absorption. The potential effect of Lf on Fe absorption was investigated by measuring Fe absorption in infants fed breast milk (with its native content of Lf) and the same milk from which Lf had been removed (> 97%) by treatment with heparin-Sepharose. Eight breast-fed infants (2-10 mo; mean age 5 mo) were fed 700 to 1000 g of each milk in a randomized, cross-over design with each child acting as his/her own control. The milk was labeled with 8.6 mumol (0.5 mg) of 58Fe and Fe absorption was measured by quantifying the incorporation of the isotope into red blood cells 14 d after intake using thermal ionization mass spectrometry. Fractional Fe absorption was significantly lower (p < 0.05) from breast milk than from Lf-free breast milk. The geometric mean (range) was 11.8% (3.4-37.4%) for breast milk and 19.8% (8.4-72.8%) for Lf-free breast milk. These results do not support a direct role for Lf in the enhancement of Fe absorption from human milk at this age. In addition, Fe absorption (11.8%) from human milk fed over several feeds was lower than that previously reported for single feed studies.

Magnesium bioavailability from human milk, cow milk, and infant formula in suckling rat pups

Little is known about the absorption of magnesium from infant diets. Magnesium bioavailability was evaluated from infant diets that varied by protein and carbohydrate source; magnesium, calcium, and phosphorus contents; and the form of magnesium fortification. Diets were separated into soluble, insoluble, and fat fractions to determine magnesium distribution. Most of the magnesium (> 62%) was found in the soluble fraction. Gel filtration of the soluble fraction from all diets studied showed that > 95% of magnesium is free or associated with low-molecular-weight compounds. Distribution of 28Mg and native magnesium in fractions of the diets was similar, thus validating the use of an extrinsic label. In vitro digestion decreased the percent insoluble magnesium from as high as 35% to 2-8%. Whole-body retention of 28Mg-labeled diets in suckling rat pups 4 h after oral intubation ranged from 51% to 92%. No significant differences were found between human milk, cow milk, and infant formula. In conclusion, magnesium from the infant diets studied has high bioavailability, and moderate differences in their composition do not affect bioavailability significantly.

Proliferative periosteal processes of phalanges: a unitary hypothesis

A unitary hypothesis is offered to explain the various proliferative processes occurring around the phalanges. In the past, these have been separately designated as proliferative periostitis, bizarre parosteal osteochondromatous proliferation, and turret exostosis. Because the appearances of these entities depend on temporal factors, breaching of the periosteum, and local anatomic features, we suggest a single term, proliferative periosteal processes of phalanges.

Diagnosis of classical Morquio's disease: N-acetylgalactosamine 6-sulphate sulphatase activity in cultured fibroblasts, leukocytes, amniotic cells and chorionic villi

The tritiated disulphated trisaccharide 6-sulpho-N-acetylgalactosamine-glucuronic acid-6-sulpho-N-acetyl-[1-3H]galactosaminitol was prepared from chondroitin 6-sulphate for use as a substrate for N-acetylgalactosamine 6-sulphate sulphatase. The reaction product was separated on ECTEOLA cellulose rather than Dowex 1 X 2. The mean activities of normal fibroblasts, leukocytes and amniotic cells were 8.43, 2.59 and 3.14 nmol h-1 mg protein-1, respectively. Fibroblasts from five patients with classical Morquio's disease (mucopolysaccharidosis IVA; MPSIVA) and one patient with neonatal multiple sulphatase deficiency displayed activities of less than 5% of control mean. Activity in amniotic cells from a pregnancy where the fetus was affected with MPS IVA was 6% of control mean. Activity was also found to be present in normal specimens of chorionic villi (mean value 1.21 nmol h-1 mg protein-1), demonstrating the feasibility of first trimester prenatal diagnosis of MPS IVA by assay of activity in this tissue.