Hg

Distribution by Scientific Domains
Distribution within Medical Sciences

Terms modified by Hg

  • hg atom
  • hg concentration
  • hg level
  • hg v

  • Selected Abstracts


    Borderline nuclear change; can a subgroup be identified which is suspicious of high-grade cervical intraepithelial neoplasia, i.e. CIN 2 or worse?

    CYTOPATHOLOGY, Issue 5 2002
    J. M. Edwards
    Borderline nuclear change; can a subgroup be identified which is suspicious of high-grade cervical intraepithelial neoplasia, i.e. CIN 2 or worse? Only 10% of first borderline smears are associated with a histological high-grade (HG) abnormality, i.e. CIN 2,3, invasive malignancy or glandular neoplasia on subsequent investigation. The advantages of highlighting this subgroup are obvious but is this possible? From 1996 and 1997, 242 borderline smears with histological follow-up were examined by two independent experienced observers (observer 1 and 2) without prior knowledge of further investigation results. For each smear a profile of nuclear details was produced, also noting the type of cell mainly affected by the process; then the observers were asked to assess the degree of worry of HG disease for each smear i.e. whether the smear fell into group 1 borderline changes indicative of low-grade (normal, inflammatory, CIN1/HPV) disease (BL/LG) or group 2 difficult borderline smear, HG disease (CIN 2,3, invasive neoplasia or glandular neoplasia) cannot be excluded (BL/HG). Observer 1 selected a group of BL/HG with a PPV for HG disease of 38%, with observer 2 having a PPV of 50%; this compared with the overall laboratory HG disease PPV for borderline smears of 14%. Both observers found the most useful criterion to be the increase in nuclear:cytoplasmic ratio. Our results show that it is possible to separate a small group of borderline smears which should be classified as ,borderline/high grade lesion difficult to exclude' (BL/HG). Both observers had some success in arriving at this classification although their method of selecting out this group was quite different. [source]


    Hyaline globules in ectopic decidua in a pregnant woman with cervical squamous cell carcinoma

    DIAGNOSTIC CYTOPATHOLOGY, Issue 9 2009
    M.I.A.C., Muralee Dharan M.D.
    Abstract Decidual reaction in pelvic lymph nodes has been increasingly documented during pregnancy. This may pose diagnostic difficulty during intraoperative frozen section (FS) and cytological consultation in women undergoing surgical procedures for cervical Squamous cell carcinoma (SCC). A 34-year-woman diagnosed to have invasive SCC (stage IB1) of the cervix at 14th week of her first pregnancy underwent abdominal radical trachelectomy and pelvic lymphadenectomy at 22 weeks of gestation. Cytological smears of two of the lymph nodes from intraoperative FS revealed isolated eosinophilic hyaline globules (HG) measuring 45,50 microns, in addition to large polygonal cells with amphophilic cytoplasm and hypochromatic nuclei and occasional squamous-looking cells with atypical hyperchomatic nuclei. These findings posed a diagnostic dilemma at intraoperative consultation and no definitive diagnosis was rendered. The formlin-fixed, paraffin-embedded histological sections of the same lymph nodes showed ectopic decidua with no evidence of metastatic SCC. Decidual cells are a cause of concern for both cytologists and histopathologists. In pregnant women complicated by cervical cancer intraoperative evaluation of pelvic lymph nodes is of utmost importance in order to adopt the optimal conservative treatment modality. In the absence of clear cut evidence of malignancy, a diagnosis of metastatic SCC should not be rendered. Diagn. Cytopathol. 2009. © 2009 Wiley-Liss, Inc. [source]


    Simultaneous optimization of response variables in protein mixture formulation: constrained simplex method approach

    INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2003
    I. A. Castro
    Summary The objective of this study was to test a complex constrained simplex, direct search, sequential method for the optimization of a ternary mixture of protein ingredients used in a formulation for the preparation of a milk drink regularly consumed in institutional nutritional programmes. Three proteins [hydrolysed gelatine (HG), wheat gluten (WG) and soybean protein isolate (SPI)] were mixed according to a simplex-centroid design, in order to explore the possible synergies between the sensory, nutritional and economic attributes. Mixtures containing different proportions of the three ingredients were submitted to sensory, nutritional and economic evaluations. All responses were modelled using Scheffé's canonical equations. A microinformatics application was developed in order to permit optimization to be computed. The optimum solution obtained by this non-linear programming was HG = 20%, WG = 27% and SPI = 53%, suggesting that the program is efficient and flexible enough for multiresponse optimization. The optimal point behaviour of the entry variables (HG, WG and SPI) can be monitored with graphs of the trace plot type, in which the proportion of two variables is fixed and the third is allowed to vary in relation to the desired response. [source]


    Astaxanthin protects mesangial cells from hyperglycemia-induced oxidative signaling,

    JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2008
    Emiko Manabe
    Abstract Astaxanthin (ASX) is a carotenoid that has potent protective effects on diabetic nephropathy in mice model of type 2 diabetes. In this study, we investigated the protective mechanism of ASX on the progression of diabetic nephropathy using an in vitro model of hyperglycemia, focusing on mesangial cells. Normal human mesangial cells (NHMCs) were cultured in the medium containing normal (5 mM) or high (25 mM) concentrations of D -glucose. Reactive oxygen species (ROS) production, the activation of nuclear transcription factors such as nuclear factor kappa B (NF,B) and activator protein-1 (AP-1), and the expression/production of transforming growth factor-beta 1 (TGF,1) and monocyte chemoattractant protein-1 (MCP-1) were evaluated in the presence or absence of ASX. High glucose (HG) exposure induced significant ROS production in mitochondria of NHMCs, which resulted in the activation of transcription factors, and subsequent expression/production of cytokines that plays an important role in the mesangial expansion, an important event in the pathogenesis of diabetic nephropathy. ASX significantly suppressed HG-induced ROS production, the activation of transcription factors, and cytokine expression/production by NHMCs. In addition, ASX accumulated in the mitochondria of NHMCs and reduced the production of ROS-modified proteins in mitochondria. ASX may prevent the progression of diabetic nephropathy mainly through ROS scavenging effect in mitochondria of mesangial cells and thus is expected to be very useful for the prevention of diabetic nephropathy. J. Cell. Biochem. 103: 1925,1937, 2007. © 2007 Wiley-Liss, Inc. [source]


    Thioredoxin interacting protein (TXNIP) induces inflammation through chromatin modification in retinal capillary endothelial cells under diabetic conditions

    JOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2009
    Lorena Perrone
    Chronic hyperglycemia and activation of receptor for advanced glycation end products (RAGE) are known risk factors for microvascular disease development in diabetic retinopathy. Thioredoxin-interacting protein (TXNIP), an endogenous inhibitor of antioxidant thioredoxin (TRX), plays a causative role in diabetes and its vascular complications. Herein we investigate whether HG and RAGE induce inflammation in rat retinal endothelial cells (EC) under diabetic conditions in culture through TXNIP activation and whether epigenetic mechanisms play a role in inflammatory gene expression. We show that RAGE activation by its ligand S100B or HG treatment of retinal EC induces the expression of TXNIP and inflammatory genes such as Cox2, VEGF-A, and ICAM1. TXNIP silencing by siRNA impedes RAGE and HG effects while stable over-expression of a cDNA for human TXNIP in EC elevates inflammation. p38 MAPK-NF-,B signaling pathway and histone H3 lysine (K) nine modifications are involved in TXNIP-induced inflammation. Chromatin immunoprecipitation (ChIP) assays reveal that TXNIP over-expression in EC abolishes H3K9 tri-methylation, a marker for gene inactivation, and increases H3K9 acetylation, an indicator of gene induction, at proximal Cox2 promoter bearing the NF-,B-binding site. These findings have important implications toward understanding the molecular mechanisms of ocular inflammation and endothelial dysfunction in diabetic retinopathy. J. Cell. Physiol. 221: 262,272, 2009. © 2009 Wiley-Liss, Inc [source]


    Ultrastructure of the gingiva in cardiac patients treated with or without calcium channel blockers

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 8 2003
    P. Bullon
    Abstract Objectives: In the last few years, several studies have suggested that periodontal diseases are related to the development of atherosclerosis and its complications. Our objective was to study the ultrastructural morphology of the gingiva from cardiac patients, some of whom were treated and some not with calcium channel blockers compared to a control group. Material and Methods: Fifty-five patients were studied and grouped in the following way: (a) healthy group (HG) (n=12) healthy patients with at least two pockets between 3 and 5 mm; (b) cardiac group (CG) (n=12) patients with cardiac disease untreated with calcium channel blockers; (c) diltiazem group (DG) (n=13) cardiac patients treated with diltiazem; (d) nifedipine group (NG) (n=18) cardiac patients treated with nifedipine. Results: Ultrastructural studies in the CG showed inflammatory cells, collagen fibers disruption and a more extended morphologically compromised fibroblast mitochondria. Morphometric studies in CG showed mitochondria that were impaired in number but increased in volume, suggesting metabolic cell suffering. In DG and NG, morphometric data were similar to HG. The presence of myofibroblasts and collagen neosynthesis was detected in DG and NG. Conclusions: Our data showed differences in the ultrastructure of the gingival fibroblasts between the studied groups; the DG and NG showed features that could be interpreted as an attempt to restore the cellular metabolic function. Zusammenfassung Ziele: In den letzten Jahren haben einige Studien darauf hingewiesen, dass parodontale Erkrankungen zur Entwicklung von Arteriosklerose und deren Komplikationen in Beziehung stehen. Unser Ziel war das Studium der gingivalen ultrastrukturellen Morphologie von herzkranken Patienten, von denen einige mit Kalzium-Kanal-Blockern und andere ohne diese Medikamente behandelt wurden, und mit Kontrollen zu vergleichen. Material und Methoden: 55 Patienten wurden untersucht und in eine der folgenden Gruppen eingeteilt: a, gesunde Gruppe (HG) (n=12): gesunde Patienten mit mindestens 2 Taschen zwischen 3 und 5 mm, b, herzkranke Gruppe (CG) (n=12): Patienten mit Herzerkrankung und nicht mit Kalzium-Kanal-Blockern behandelt, c, Diltiazem Gruppe (DG) (n=13): Herzkranke Patienten, die mit Diltiazem behandelt wurden, d, Nifedipin Gruppe (NG) (n=18): Herzkranke Patienten, die mit Nifedipin behandelt wurden. Ergebnisse: Die Ultrastruktur bei CG zeigte Entzündungszellen, zerrissene Kollagenfasern und stärker ausgedehnte morphologisch gefährdete Fibroblastenmitochondrien. Morphometrische Studien bei CG zeigten Mitochondrien, die in der Anzahl beeinträchtigt waren, aber im Volumen zugenommen hatten, was auf einen gestörten Zellstoffwechsel deutet. Bei DG und NG waren die morphometrischen Daten ähnlich zu HG. Die Präsenz von Myofibroblasten und Kollagensynthese wurde in DG und NG entdeckt. Schlussfolgerung: Unsere Daten zeigten Differenzen in der Ultrastruktur der gingivalen Fibroblasten zwischen den untersuchten Gruppen. DG und NG zeigten Eigenschaften, die als Versuch zur Restauration der zellulären Stoffwechselfunktion gedeutet werden könnten. Résumé Objectifs: Lors des dernières années, plusieurs études ont suggéré que les maladies parodontales sont liées au développement de l'athérosclérose et de ses conséquences. Notre objectif est d'étudier la morphologie ultrastructurale de la gencive de patients cardiaques traités et non traités par des bloqueurs des flux de calcium comparée à un groupe contrôle. Matériel et méthodes: 55 patients furent étudiés et groupés de la façon suivante: (a) groupe sain (HG) (n=12), patients sains avec au moins 2 poches entre 3 et 5 mm (b) groupe cardiaque(CG) (n=12) patients ayant une maladie cardiaque non traitée par des bloqueurs des flux de calcium (c) groupe diltiazem (DG) (n=13) patients cardiaques traits par diltiazem; (d) groupe nifedipine (NG) (n=18 patients cardiaques traits par nifedipine). Résultats: Des études ultrastructurale du groupe CG montraient des cellules inflammatoires, des interruptions des fibres de collagènes, et un nombre plus important de mitochondries des fibroblastes morphologiquement compromises. Les études morphométriques du groupe CG montraient des mitochondries altérées en nombre mais au volume augmenté ce qui suggérait une souffrance métabolique cellulaire. Dans les groupes DG et NG, les données morphométriques étaient similaires à celles du groupe HG. La présence de myofibroblastes et d'une néo-synthèse de collagène étaient détectées dans les groupes DG et NG. Conclusions: Nos données montrent des différences de l'ultrastructure des fibroblastes gingivaux entre les groupes étudiés, les groupes DG et NG présentant des caractéristiques qui peuvent être interprétées comme une tentative de restauration de la fonction métabolique cellulaire. [source]


    Pathogen inactivation technology: cleansing the blood supply

    JOURNAL OF INTERNAL MEDICINE, Issue 3 2005
    H. G. KLEIN
    Abstract., Klein HG (The Johns Hopkins School of Medicine and Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD, USA). Pathogen inactivation technology: cleansing the blood supply (Review). J Intern Med 2005; 257: 224,237. The calculated residual infectious risk of HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) from blood transfusion is extremely low. However, the risk of bacterial contamination remains and a variety of other agents including emerging viruses, protozoa and tick-borne agents threaten blood supplies and undermine public confidence in blood safety. Traditional methods of donor screening and testing have limited ability to further reduce disease transmission and cannot prevent an emerging infectious agent from entering the blood supply. Pathogen inactivation technologies have all but eliminated the infectious risks of plasma-derived protein fractions, but as yet no technique has proved sufficiently safe and effective for traditional blood components. Half-way technologies can reduce the risk of pathogen transmission from fresh frozen plasma and cryoprecipitate. Traditional methods of mechanical removal such as washing and filtration have limited success in reducing the risk of cell-associated agents, but methods aimed at sterilizing blood have either proved toxic to the cells or to the recipients of blood components. Several promising methods that target pathogen nucleic acid have recently entered clinical testing. [source]


    Antibacterial peptides: basic facts and emerging concepts

    JOURNAL OF INTERNAL MEDICINE, Issue 3 2003
    H. G. Boman
    Abstract., Boman HG (Microbiology and Tumor Biology Center, Karolinska Institutet, Stockholm, Sweden). Antibacterial peptides: basic facts and emerging concepts (Review). J Intern Med 2003; 254: 197,215. Antibacterial peptides are the effector molecules of innate immunity. Generally they contain 15,45 amino acid residues and the net charge is positive. The cecropin type of linear peptides without cysteine were found first in insects, whilst the defensin type with three disulphide bridges were found in rabbit granulocytes. Now a database stores more than 800 sequences of antibacterial peptides and proteins from the animal and plant kingdoms. Generally, each species has 15,40 peptides made from genes, which code for only one precursor. The dominating targets are bacterial membranes and the killing reaction must be faster than the growth rate of the bacteria. Some antibacterial peptides are clearly multifunctional and an attempt to predict this property from the hydrophobicity of all amino acid side chains are given. Gene structures and biosynthesis are known both in the fruit fly Drosophila and several mammals. Humans need two classes of defensins and the cathelicidin-derived linear peptide LL-37. Clinical cases show that deficiencies in these peptides give severe symptoms. Examples given are morbus Kostmann and atopic allergy. Several antibacterial peptides are being developed as drugs. [source]


    Granulocyte elastase activity in static and flow gingival crevicular fluid

    JOURNAL OF PERIODONTAL RESEARCH, Issue 3 2003
    Lijian Jin
    Objectives:, This study aimed to evaluate the volume of gingival crevicular fluid (GCF) and granulocyte elastase activity in static GCF (sGCF) and flow GCF (fGCF) from subjects with various periodontal conditions. Methods:, Eleven periodontally healthy, 10 gingivitis and 12 periodontitis subjects were recruited and the sites investigated consisted of healthy sites from healthy subjects (HH); healthy (HG) and gingivitis sites (GG) from gingivitis subjects; and healthy (HP), gingivitis (GP) and periodontitis sites (PP) from periodontitis subjects. fGCF samples were collected either 1 min or 5 min following sGCF collection by paper strip technique. GCF volume was determined by Periotron® 6000 and granulocyte elastase activity was assayed with a specific substrate [l -pyroglutamyl- l -prolyl- l -valine- p -nitroanilide(pGluProVal-pNA)]. Results:, At baseline, no significant differences existed in clinical and GCF parameters between the two matched sites for subsequent collection of fGCF samples either 1 min or 5 min after sGCF sampling in all subjects. The flow exudate in HG and HP sites quickly replenished to sGCF levels, while a delayed replenishment was found in HH sites, despite the similar sGCF volumes of these sites. The GCF volume and elastase levels in the fGCF at 1 min were higher in GP sites than in GG sites (P < 0.05). Overall, depletion of elastase levels in the fGCF at 1 min was observed in all subjects, whereas elastase levels in the fGCF at 5 min had replenished to sGCF levels in HP, GP, PP sites and GG sites, but had remained at a lower level in HH and HG sites. An overall positive correlation was found between sGCF and fGCF for GCF volume and elastase activity (P < 0.001); however, this correlation varied with GCF parameters and with site conditions of the subjects concerned. Conclusions:, This study shows that patterns of dynamic changes in GCF flow and elastase activity varied under different periodontal conditions. Assessment of both sGCF and fGCF may allow better insight into the dynamic change of the target components in GCF. [source]


    A solid-state approach to enable early development compounds: Selection and animal bioavailability studies of an itraconazole amorphous solid dispersion

    JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2010
    David Engers
    Abstract A solid-state approach to enable compounds in preclinical development is used by identifying an amorphous solid dispersion in a simple formulation to increase bioavailability. Itraconazole (ITZ) was chosen as a model crystalline compound displaying poor aqueous solubility and low bioavailability. Solid dispersions were prepared with different polymers (PVP K-12, K29/32, K90; PVP VA S-630; HPMC-P 55; and HPMC-AS HG) at varied concentrations (1:5, 1:2, 2:1, 5:1 by weight) using two preparation methods (evaporation and freeze drying). Physical characterization and stability data were collected to examine recommended storage, handling, and manufacturing conditions. Based on generated data, a 1:2 (w/w) ITZ/HPMC-P dispersion was selected for further characterization, testing, and scale-up. Thermal data and computational analysis suggest that it is a possible solid nanosuspension. The dispersion was successfully scaled using spray drying, with the materials exhibiting similar physical properties as the screening samples. A simple formulation of 1:2 (w/w) ITZ/HPMC-P dispersion in a capsule was compared to crystalline ITZ in a capsule in a dog bioavailability study, with the dispersion being significantly more bioavailable. This study demonstrated the utility of using an amorphous solid form with desirable physical properties to significantly improve bioavailability and provides a viable strategy for evaluating early drug candidates. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:3901,3922, 2010 [source]


    TAXONOMIC REEXAMINATION OF 17 SPECIES OF NITELLA SUBGENUS TIEFFALLENIA (CHARALES, CHAROPHYCEAE) BASED ON INTERNAL MORPHOLOGY OF THE OOSPORE WALL AND MULTIPLE DNA MARKER SEQUENCES,

    JOURNAL OF PHYCOLOGY, Issue 1 2005
    Hidetoshi Sakayama
    In an attempt to reconstruct the natural taxonomic system for Nitella, 17 species of Nitella subgenus Tieffallenia were reexamined using SEM observations of the internal morphology of the oospore wall (IMOW) and phylogenetic analyses of 4553 base pairs from multiple DNA markers (atpB, rbcL, psaB, and ITS-5.8S rRNA genes). Our SEM observations identified three types of IMOW: homogeneous (HG), weakly spongy (W-SG), and strongly spongy (S-SG) types. Based on differences in the IMOW, species with reticulate or tuberculate oospore wall ornamentation in the external morphology of the oospore wall (EMOW) were subdivided into two distinct groups (characterized by the HG or S-SG types of IMOW, respectively), which were robustly separated from each other in our molecular phylogenetic analyses. In our molecular phylogeny, the subgenus Tieffallenia consisted of four robust monophyletic groups,three clades of the HG type and a spongy (S-SG and W-SG) type clade,that were characterized by differences in the IMOW and EMOW. In addition, our SEM observations and sequence data verified the distinct status of five species (N. japonica Allen, N. oligospira A. Braun, N. vieillardii stat. nov., N. imperialis stat. nov., and N. morongii Allen) that R. D. Wood had assigned as infraspecific taxa. Moreover, our SEM observations of the IMOW also suggested that N. megaspora (J. Groves) Sakayama originally identified by LM includes at least two distinct species, characterized by W-SG and S-SG types of IMOW, respectively. [source]


    In vitro degradation of forage chicory (Cichorium intybus L.) by endopoly- galacturonase

    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2007
    Xuezhao Sun
    Abstract BACKGROUND: Leaves of forage chicory break down rapidly in the rumen despite little or no rumination. Because chicory cell walls contain high concentrations of pectin, degradation of leaf midrib and leaf lamina tissues by pectinolytic enzymes was investigated. RESULTS: Treatment with endopolygalacturonase (endo-PG) degraded fresh intact chicory leaves to particles of less than 1 mm in length and solubilised more than 70% of the dry matter within 16 h. Uronic acids were released more extensively than neutral monosaccharides. In similar treatments, 77% of white clover leaflets and 12% of perennial ryegrass leaf blades were solubilised or broken down to particles with a size of less than 1 mm. The degradation of pectic polysaccharides in chicory midribs was monitored by immunofluorescence labelling with monoclonal antibodies JIM5 and JIM7 which target partially methyl-esterified epitopes of the homogalacturonan (HG) domain of pectin. Examination by fluorescence microscopy revealed that cell separation in the cortical parenchyma of chicory midrib following endo-PG treatment was associated with loss of HG from the middle lamella, the corners of intercellular spaces and from the tricellular junctions. CONCLUSION: The results of the current study suggest that one of the main contributions to chicory breakdown in the rumen may be cell separation caused by degradation of HG by pectinolytic enzymes from rumen bacteria. Copyright © 2007 Society of Chemical Industry [source]


    Perfusion in free breast reconstruction flap zones assessed with positron emission tomography

    MICROSURGERY, Issue 6 2010
    Aleksi Schrey M.D.
    The aim of this pilot study was to determine the postoperative blood perfusion (BFPET) and perfusion heterogeneity (BFPET HG) in free microvascular breast reconstruction flap zones with positron emission tomography (PET). Regional BFPET and BFPET HG of the adipose tissue in medial, central, and lateral parts of 13 free flaps were assessed on the first postoperative morning with PET using oxygen-15-labeled water ([15O]H2O) in 12 patients undergoing breast reconstruction with a deep inferior epigastric perforator (DIEP) or a transverse rectus abdominis muscle (TRAM) flap. The mean BFPET values did not differ between DIEP and TRAM flaps (P = 0.791). The mean BFPET values were higher in zone III compared with zone I (P = 0.024). During follow-up, fat necrosis was identified in three patients in the medial part (zone II) of the flap. However, the adipose tissue BFPET assessed on the first postoperative day from all zones of the flap using PET with radiowater was normal. The BFPET HG was higher in the control side (i.e., in the healthy breast tissue) compared with the flap (P = 0.042). The BFPET HG was lower in zone III than in zone I (P = 0.03) and in zone II (P < 0.001). In this pilot study, PET was used for the first time for studying the adipose tissue perfusion in different zones in free flaps in a clinical setup, finding that the mean BFPET values did not differ between DIEP and TRAM flaps, and that zone II was sometimes not as well perfused as zone III supporting revisited zone division. © 2010 Wiley-Liss, Inc. Microsurgery 30:430,436, 2010. [source]


    High fitness is associated with a healthier programming of body composition at adolescence

    AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 6 2008
    Francisco B. Ortega
    The programming effect of birth weight on later body composition has become of increasing interest in recent years. This programming effect is affected by factors such as gender. Physical fitness could be another factor of influence. This study aimed to examine whether handgrip strength (HG) or cardiovascular fitness (CVF) modify the associations between birth weight and body composition in adolescents. A sample of 1,740 (942 females) adolescents aged 13 to 18.5 years, born at more than 35 weeks of gestation, from the AVENA study was studied. Waist circumference was measured, percentage body fat was calculated from skinfold thicknesses and fat free mass was derived by subtracting fat mass from total body weight. HG and CVF were assessed using the HG test and the 20 m shuttle run test, respectively. Birth weight was positively associated with fat free mass in females with high (above the median) CVF (P < 0.001), but not in those with low (below the median) CVF. In contrast, birth weight was positively associated with total and central adiposity in males with low HG (both P = 0.002), but not in those with high HG. These results suggest that the programming effect of birth weight on later body composition is dependent on gender and fitness level. A high birth weight may have a healthy programming effect on body composition in those adolescents with a high fitness level, being associated with increased fat free mass levels in females and not showing the increased adiposity levels observed in unfit males. Am. J. Hum. Biol., 2008. © 2008 Wiley-Liss, Inc. [source]


    Sex-specific responses of Populus cathayana to drought and elevated temperatures

    PLANT CELL & ENVIRONMENT, Issue 6 2008
    XIAO XU
    ABSTRACT Dioecious plant species represent an important component of terrestrial ecosystems. Yet, little is known about sex-specific responses to drought and elevated temperatures. Populus cathayana Rehd, which is a dioecious, deciduous tree species, widely distributed in the northern, central and southwestern regions of China, was employed as a model species in our study. In closed-top chamber experiments, sex-specific morphological, physiological and biochemical responses of P. cathayana to drought and different elevated temperatures were investigated. Compared with the controls, drought significantly decreased the growth and the net photosynthesis rate (A), and increased the intrinsic water use efficiency (WUEi), carbon isotope composition (,13C), and the malondialdehyde (MDA) and abscisic acid (ABA) contents in droughted plants. In contrast, elevated temperatures significantly promoted the growth and the A, but decreased the WUEi, ,13C, MDA and ABA contents in well-watered individuals. When compared with males, elevated temperatures induced well-watered females to express a greater increase in the height growth (HG), basal diameter (BD), leaf area (LA), total number of leaves (TNL), dry matter accumulation (DMA) and specific leaf area (SLA), and a lower decrease in the A value, transpiration (E), stomatal conductance (gs), MDA and ABA contents, while elevated temperatures induced drought-stressed females to exhibit lower values of HG, BD, LA, TNL, DMA, A, E, gs and the intercellular CO2 concentration (Ci), and higher levels of SLA, WUEi, ,13C, MDA and ABA contents. Our results indicated that the female individuals of P. cathayana are more responsive and suffer from greater negative effects than do males when grown under environments with increased drought stress and elevated temperature. [source]


    Comparison of collision- versus electron-induced dissociation of Pt(II) ternary complexes of histidine- and methionine-containing peptides,

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 19 2009
    Linda Feketeová
    Incubation of the histidine-containing peptides (GH, HG, GGH, GHG, HGG) and methionine-containing peptides (GM, MG, GGM, GMG, MGG) with the platinum complexes [Pt(terpy)Cl]+ (A) and [Pt(dien)Cl]+ (B) followed by electrospray ionisation (ESI) led to a number of singly and doubly charged ternary platinum peptide complexes, including [Pt(L)M]2+ and [Pt(L)M,H]+ (where L,=,the ligand terpy or dien; M is a peptide). Each of the [Pt(L)M]2+ complexes was subjected to electron capture dissociation (ECD), collision-induced dissociation (CID) and electron-induced dissociation (EID), while each of the [Pt(L)M,H]+ complexes was subjected to CID and EID. Results from ECD suggest that the free electron is captured by the metal ion thus weakening the bonds to its ligands. In the case of the ligand terpy, which binds more strongly than dien, this weakening leads to the loss of the peptide. The minor products in the ECD spectra of [Pt(terpy)M]2+ complexes do show fragmentation along the peptide backbone, but the ions observed are of the a-, b-, and y-type. For the complexes with methionine-containing peptides, a marker ion, [Pt(L)SCH3]+, was found which is indicative of binding of Pt to the methionine side chain. For the histidine-containing peptides, an ion containing platinum, the auxiliary ligand, and the histidine imine was observed in many instances, thus indicating the binding of the histidine side chain to the metal, but other modes of Pt coordination (N-terminus) were also found to be competitive. These findings are consistent with a recent finding (Sze et al. J. Biol. Inorg. Chem. 2009; 14: 163) that Pt occupies the methionine-rich copper(I)-binding site rather than histidine-rich copper(II)-binding site in the CopC protein. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    Management and Outcome of Patients With Mucoepidermoid Carcinoma of Major Salivary Gland Origin: A Single Institution's 30-Year Experience,

    THE LARYNGOSCOPE, Issue 2 2008
    Katri Aro MD
    Abstract Background: Mucoepidermoid carcinoma (MEC) is one of the most frequent epithelial malignancies of the salivary glands. Prediction of clinical outcome of MEC is challenging. Material and Methods: We retrospectively reviewed 52 cases of MEC of major salivary gland origin diagnosed at the Department of Otolaryngology,Head and Neck Surgery, Helsinki University Central Hospital, Helsinki, Finland, during a 30-year period of 1976 to 2005. Criteria used for diagnosis were those of World Health Organization classifications valid at each time point, and criteria for grading were those recommended by Armed Forces Institute of Pathology fascicle (1996). Since 1993, the degree of cell proliferation was used at our institution as an adjunct tool when grading MEC. The majority of cases occurred in the parotid gland (n = 47, 90%) followed by the submandibular gland (n = 5, 10%). Results: We had 39% high-grade (HG), 14% intermediate-grade (IMG), and 44% low-grade (LG) MECs. T categories were T1, n = 18; T2, n = 16; T3, n = 9; T4, n = 9. Forty-nine (94%) patients were treated with curative intent. These patients underwent surgery, and 24 (49%) patients received postoperative radiotherapy. Follow-up time varied from 6 months to 9 years. Forty-five percent of HG-MEC patients and 67% of IMG-MEC patients developed locoregional failures or distant metastases during a 3-year follow-up as opposed to none of the LG-MEC patients. Of MEC patients with N0 neck, two HG-MEC patients and one IMG-MEC (8%) patient developed regional recurrence during follow-up. Conclusions: Patient outcome in the different grades of MEC suggests a need for overview of the treatment protocol, especially with regard to LG-MEC and IMG-MEC. The apparently unusual occurrence of locoregional failures and metastases in LG-MEC suggests a restrictive approach in surgical management. However, the frequent occurrence of such failures in IMG-MEC warrants an aggressive approach with these tumors. [source]


    Mapping QTL for growth and shank traits in chickens divergently selected for high or low body weight

    ANIMAL GENETICS, Issue 4 2010
    G. A. Ankra-Badu
    Summary An F2 population (695 individuals) was established from broiler chickens divergently selected for either high (HG) or low (LG) growth, and used to localize QTL for developmental changes in body weight (BW), shank length (SL9) and shank diameter (SD9) at 9 weeks. QTL mapping revealed three genome-wide QTL on chromosomes (GGA) 2, 4 and 26 and three suggestive QTL on GGA 1, 3 and 5. Most of the BW QTL individually explained 2,5% of the phenotypic variance. The BW QTL on GGA2 explained about 7% of BW from 3 to 7 weeks of age, while that on GGA4 explained 15% of BW from 5 to 9 weeks. The BW QTL on GGA2 and GGA4 could be associated with early and late growth respectively. The GGA4 QTL also had the largest effect on SL9 and SD9 and explained 7% and 10% of their phenotypic variances respectively. However, when SL9 and SD9 were corrected with BW9, a shank length percent QTL was identified on GGA2. We identified novel QTL and also confirmed previously identified loci in other chicken populations. As the foundation population was established from commercial broiler strains, it is possible that QTL identified in this study could still be segregating in commercial strains. [source]


    A multistep process for the dispersal of a Y chromosomal lineage in the Mediterranean area

    ANNALS OF HUMAN GENETICS, Issue 4 2001
    P. MALASPINA
    In this work we focus on a microsatellite-defined Y-chromosomal lineage (network 1.2) identified by us and reported in previous studies, whose geographic distribution and antiquity appear to be compatible with the Neolithic spread of farmers. Here, we set network 1.2 in the Y-chromosomal phylogenetic tree, date it with respect to other lineages associated with the same movements by other authors, examine its diversity by means of tri- and tetranucleotide loci and discuss the implications in reconstructing the spread of this group of chromosomes in the Mediterranean area. Our results define a tripartite phylogeny within HG 9 (Rosser et al. 2000), with the deepest branching defined by alleles T (Haplogroup Eu10) or G (Haplogroup Eu9) at M172 (Semino et al. 2000), and a subsequent branching within Eu9 defined by network 1.2. Population distributions of HG 9 and network 1.2 show that their occurrence in the surveyed area is not due to the spread of people from a single parental population but, rather, to a process punctuated by at least two phases. Our data identify the wide area of the Balkans, Aegean and Anatolia as the possible homeland harbouring the largest variation within network 1.2. The use of recently proposed tests based on the stepwise mutation model suggests that its spread was associated to a population expansion, with a high rate of male gene flow in the Turkish,Greek area. [source]


    Effect of dietary protein and energy levels on growth, oxygen consumption, haemolymph and digestive gland carbohydrates, nitrogen excretion and osmotic pressure of Litopenaeus vannamei (Boone) and L. setiferus (Linne) juveniles (Crustacea, Decapoda; Penaeidae)

    AQUACULTURE RESEARCH, Issue 7 2001
    C Rosas
    Abstract The influence of protein and energy levels on growth rate, survival, pre- and post-prandial oxygen consumption, ammonia excretion, haemolymph glucose (HG), glycogen in digestive gland and osmotic pressure (OP) in white shrimp Litopenaeus vannamei (Boone) and L. setiferus (Linne) juveniles was studied. Diets containing a high-quality protein at a protein/energy (P/E) ratio of 16, 26, 31 and 36 mg kJ,1 were fed at 20% of shrimp body weight of two sizes: < 1 g and >,1 g. Both species showed a optimum P/E ratio of 36 mg kJ,1 (33,44% protein and 6,23% carbohydrate) in juveniles <,1 g. For shrimp >,1 g, L. setiferus showed a higher growth rate in the diet with 16 mg kJ,1 (27% protein; 32% carbohydrate) and L. vannamei between 26 and 36 mg kJ,1 (33,44% protein and 6,23% carbohydrate). In both experiments, the growth rate of L. vannamei was 2,3 times that observed in L. setiferus. Routine oxygen consumption and apparent heat increment (AHI) of L. setiferus juveniles was two times higher than that observed in L. vannamei juveniles, which could indicate that L. setiferus has a higher metabolic rate. The O/N ratio varied according to protein level, with higher values (O/N = 180) with a 16-mg kJ,1 diet and lower values (O/N = 73) with a 36-mg kJ,1 diet in L. setiferus juveniles. A similar variation in O/N ratio was obtained in L. vannamei fed with all diets with an interval between 22 and 50. An inverse relation between ammonia excretion and HG, and digestive gland glycogen (DGG) in relation to an increase in the P/E ratio indicate that both shrimp species are well adapted to use carbohydrates and/or proteins from their diet. The higher values of hyper-osmotic capacity (hyper-OC) were observed in L. setiferus <,1 g fed with 36 mg kJ,1 and the lowest in L. vannamei <,1 g fed with 31 mg kJ,1. Intermediate values of hyper-OC were observed in both species fed all diets indicating that osmotic factors of juveniles <,1 g of both species are more affected by the P/E ratio than juveniles >,1 g. All results showed that juveniles >,1 g of both species are less dependent of P/E ratio than juveniles <,1 g. Litopenaeus vannamei is a most tolerant shrimp species with a high capacity to use a wide range of dietary P/E ratios for growth, which may be due to its lower energy requirements. Litopenaeus setiferus showed a lower capacity to accept different P/E ratios but the optimum P/E ratio obtained with this species shows that L. setiferus accept diets with a high carbohydrate level as well. These results demonstrate that there are nutritional and physiological differences that explain the differences that have been observed when both species were cultured in commercial ponds. [source]


    Pyruvate Preserves Neutrophilic Superoxide Production in Acidic, High Glucose-Enriched Peritoneal Dialysis Solutions

    ARTIFICIAL ORGANS, Issue 3 2003
    Yi Tai Wu
    Abstract: Aim: To investigate effects of pyruvate (Py)-based peritoneal dialysis solutions (P-PDS) on neutrophilic superoxide (O2,) production against high glucose (HG) concentrations at acidic or physiologic pH value, and explore potential mechanisms. Methods: Human neutrophils were incubated with both dl -lactate (La, 40 mM)-based PDS (L-PDS) and equimolar P-PDS at various pH and HG levels, respectively. Hanks' balanced salt solution (HBSS) served as controls. O2, generation was determined by the reduction of ferricytochrome c. Results: Acidic pH and high La induced acute and substantial inhibitions of O2, production. HG in both PDS and HBSS resulted in a suppression of O2, in a dose-dependent manner. P-PDS generated near twofold O2, formation of L-PDS counterparts at various pH and HG levels. P-PDS with HG produced significantly more O2, than Py-free HBSS counterparts. Conclusions: Py in PDS effectively protected neutrophils from HG-induced inhibition of O2, production, even at a physiological pH. The Py cytoprotection may be associated with the preservation of carbohydrate metabolic pathways in addition to its alkalization. [source]


    Characterising the local immune responses in cervical intraepithelial neoplasia: a cross-sectional and longitudinal analysis

    BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 13 2008
    YL Woo
    Introduction, Immunological competence influences the progression of cervical intraepithelial neoplasia (CIN) to invasive cancer. Information on the local immunological changes during the natural course of CIN is central for the development of new therapies. Objective, This study defines the populations of tissue-infiltrating immune cells in a cross-sectional cohort of different grades of CIN and also in a longitudinal cohort of regressing, persistent and progressing low-grade (LG)-CIN. Design, A cohort of 125 women with LG cytological atypia was recruited, of which 64/125 (51%) women with LG-CIN were followed prospectively for 1 year. Paraffin-embedded entry and exit cervical biopsies were used for immunohistochemistry analysis (CD4, CD8, CD56, FOXP3, CD1a and granzyme B). Results, At recruitment, 74/125 (59%), 39/125 (31%) and 12/125 (10%) women referred with LG smears had histologically proven LG-CIN, high-grade (HG) and normal biopsies, respectively. Seventeen of 64 (24.6%) women with LG-CIN progressed to HG-CIN within 1 year. In both LG-CIN and HG-CIN, the predominant intraepithelial cell population were cytotoxic T cells, while CD4+ and FOXP3+ T cells predominated the stromal compartment. Women with LG-CIN who later on regressed displayed a significantly higher number of cytotoxic (granzyme B+) cells in their entry samples. In addition, the ratio between CD8+ cells and granzyme B+ cells was close to 1, suggesting that all infiltrating CD8+ T cells were highly active. In contrast, this ratio was three-fold lower in women, in whom the lesions persisted or progressed. Conclusions, This study suggests that the early infiltration of lesions by highly cytotoxic effector cells protects against progression. [source]


    Handgrip strength in English schoolchildren

    ACTA PAEDIATRICA, Issue 7 2010
    DD Cohen
    Abstract Aims:, The aims of this study were to evaluate patterns of handgrip (HG) strength in relation to gender and age in English schoolchildren and to compare this with existing data and produce reference data for this population. Methods:, The HG of 7147 English schoolchildren (3773 boys and 3374 girls) aged 10,15.9 years was measured using a portable Takei handgrip dynamometer (Takei Scientific Instruments Co. Ltd, Tokyo, Japan). Centile data were produced using the Generalized Additive Models for Location, Scale and Shape. Z -scores were generated using existing data for European children. Age and gender interactions were analysed using analysis of covariance. Results:, In boys and girls, significant increases in HG were found between every age-group (p < 0.001). Boys were significantly stronger than girls at every age (p < 0.001) and the boys' age-related increase was significantly greater than the girls' (p < 0.001). Conclusion:, This study provides reference data for handgrip strength in English schoolchildren. Handgrip strength in English children is broadly similar to existing European data, after adjusting for mass and stature. These data could be used for clinical or athletic screening of low and high strength in this population. [source]


    HIGH GLUCOSE-INDUCED HUMAN UMBILICAL VEIN ENDOTHELIAL CELL HYPERPERMEABILITY IS DEPENDENT ON PROTEIN KINASE C ACTIVATION AND INDEPENDENT OF THE Ca2+,NITRIC OXIDE SIGNALLING PATHWAY

    CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2005
    Lei Dang
    SUMMARY 1.,Endothelial barrier dysfunction plays a pivotal role in the pathogenesis of diabetic vascular complications. The precise molecular mechanisms by which hyperglycaemia causes the increased permeability in endothelial cells are not yet well understood. In the present study, we investigated whether high concentrations of glucose induce endothelial permeability through the activation of protein kinase C (PKC) and/or the calcium,nitric oxide (NO) signalling pathway in human umbilical vein endothelial cells (HUVEC). 2.,Endothelial permeability was measured by albumin diffusion across endothelial monolayers under the stimuli of high glucose (HG; 20 mmol/L), 100 nmol/L phorbol-myristate-acetate (PMA) or 100 nmol/L histamine. The intracellular calcium concentration ([Ca2+]i) was detected in HUVEC using the fluorescent probe fura-2 AM. The effects of PKC inhibitors (LY379196 and hypocrellin A) and the NO synthase (NOS) inhibitor NG -monomethyl- l -arginine (l -NMMA) on endothelial permeability and [Ca2+]i were determined. 3.,High glucose and PMA increased endothelial permeability associated with decreased [Ca2+]i, whereas histamine triggered significant increases in endothelial permeability, accompanied by increases in [Ca2+]i in HUVEC. Hypocrellin A (HA) and LY379196 reversed both HG- and histamine-induced endothelial permeability. The NOS inhibitor l -NMMA only abolished histamine- and not HG-induced endothelial permeability. Neither LY379196, HA nor l -NMMA had any significant effects on alterations in [Ca2+]i caused by HG and histamine. 4.,These results indicate that increased endothelial permeability in HUVEC induced by HG is dependent on PKC activity and is independent of the [Ca2+]i,NO pathway. Increased endothelial permeability due to other inflammatory factors, such as histamine, may also be mediated by the PKC pathway. Thus, PKC inhibitors would be a potential therapeutic approach to endothelial dysfunction induced by hyperglycaemia, as well as other inflammatory factors, in diabetes. [source]


    Abnormal myocardial perfusion and contractile recruitment during exercise in type 1 diabetic patients

    CLINICAL CARDIOLOGY, Issue 2 2005
    Roldano Scognamiglio M.D.
    Abstract Background: No data are available on the relationship between myocardial perfusion and left ventricular (LV) function in type 1 diabetes mellitus (T1DM), which may constitute a factor explaining the progressive contractile dysfunction to the overt phase of diabetic cardiomyopathy. Hypothesis: This study was undertaken to test whether myocardial perfusion abnormalities are present at rest and during exercise and whether they are related to contractile dysfunction in T1DM. Methods: Twenty-two patients with T1DM, aged 32 ± 8.3 years, without macro-or microvascular complications, and 10 controls, aged 31 ± 3 years, were studied. Left ventricular function and myocardial perfusion were assessed by two-dimensional and myocardial contrast echocardiography at rest and during handgrip (HG). Results: Fourteen patients with T1DM showed a decline in LV ejectionfraction (LVEF) during HG (Group 1) while 8 had a normal response (Group 2). Both basal myocardial blood volume (MBV) and velocity ((3) were normal inT1DM. During exercise, MBV and (3 increased and were associated with an increase in myocardial blood flow (MBF) in controls. In T1DM, (3 did not change and MBV increased only in Group 2, while this increase was not observed in Group 1 (controls: 14.9 ±2.3 vs. Group 1:7.6± 1.6, p< 0.001; and vs. Group2:10.2± 2.8, p<0.001), (3(0.86±0.12vs.0.68±0.14, p<0.001;and vs. 0.67±0.15, p<0.001). A correlation between the ratio exercise MBF/resting MBF and LVEF at peak exercise in T1DM was observed (r=0.805, p< 0.001). Conclusions: A large proportion of patients with T1DM exhibit abnormalities in myocardial adaptable capacity to match an acute overload, which are related to a defective increase in myocardial perfusion. [source]


    Weighted Constraints in Generative Linguistics

    COGNITIVE SCIENCE - A MULTIDISCIPLINARY JOURNAL, Issue 6 2009
    Joe Pater
    Abstract Harmonic Grammar (HG) and Optimality Theory (OT) are closely related formal frameworks for the study of language. In both, the structure of a given language is determined by the relative strengths of a set of constraints. They differ in how these strengths are represented: as numerical weights (HG) or as ranks (OT). Weighted constraints have advantages for the construction of accounts of language learning and other cognitive processes, partly because they allow for the adaptation of connectionist and statistical models. HG has been little studied in generative linguistics, however, largely due to influential claims that weighted constraints make incorrect predictions about the typology of natural languages, predictions that are not shared by the more popular OT. This paper makes the case that HG is in fact a promising framework for typological research, and reviews and extends the existing arguments for weighted over ranked constraints. [source]


    Optimal measurement placement for security constrained state estimation using hybrid genetic algorithm and simulated annealing

    EUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 2 2009
    T. Kerdchuen
    Abstract This paper proposes a hybrid genetic algorithm and simulated annealing (HGS) for solving optimal measurement placement for power system state estimation. Even though the minimum number of measurement pairs is N considering the single measurement loss, their positions are required to make the system observable. HGS algorithm is a genetic algorithm (GA) using the acceptance criterion of simulated annealing (SA) for chromosome selection. The P, observable concept is used to check the network observability with and without single measurement pair loss contingency and single branch outage. Test results of 10-bus, IEEE 14, 30, 57, and 118-bus systems indicate that HGS is superior to tabu search (TS), GA, and SA in terms of higher frequency of the best hit and faster computational time. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Curing behavior and mechanical properties of hollow glass microsphere/bisphenol a dicyanate ester composites

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2010
    Jinhe Wang
    Abstract Hollow glass microsphere (HGS)/bisphenol A dicyanate ester (BADCy) composites have been prepared by mechanical mixing, followed by a stepped curing process. The effect of HGS on the curing behavior of BADCy was studied using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The mechanical properties of the composites were examined by mechanical tests, and the improvements of the mechanical properties were investigated by scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA). The results show that HGS is catalytic for the polycyclomerization of the BADCy, which is advantageous to reduce the maximal processing temperature. The impact strength, flexural strength, flexural modulus and storage modulus of BADCy are improved. The improvements of the mechanical properties without sacrificing thermal properties, the ability of lowing processing temperature and the low cost make HGS good filler for cyanate ester resin. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]


    Hydrogels for tissue engineering and delivery of tissue-inducing substances

    JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2007
    Biancamaria Baroli
    Abstract This manuscript presents hydrogels (HGs) from a tissue engineering perspective being especially written for those who are approaching this field by offering a concise but inclusive review of hydrogel synthesis, properties, characterization methods, and applications. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 2197,2223, 2007 [source]


    Genetic perspectives on forager-farmer interaction in the Luangwa Valley of Zambia

    AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010
    Cesare de Filippo
    Abstract The transformation from a foraging way of life to a reliance on domesticated plants and animals often led to the expansion of agropastoralist populations at the expense of hunter-gatherers (HGs). In Africa, one of these expansions involved the Niger-Congo Bantu-speaking populations that started to spread southwards from Cameroon/Nigeria ,4,000 years ago, bringing agricultural technologies. Genetic studies have shown different degrees of gene flow (sometimes involving sex-biased migrations) between Bantu agriculturalists and HGs. Although these studies have covered many parts of sub-Saharan Africa, the central part (e.g. Zambia) was not yet studied, and the interactions between immigrating food-producers and local HGs are still unclear. Archeological evidence from the Luangwa Valley of Zambia suggests a long period of coexistence (,1,700 years) of early food-producers and HGs. To investigate if this apparent coexistence was accompanied by genetic admixture, we analyzed the mtDNA control region, Y chromosomal unique event polymorphisms, and 12 associated Y- short tandem repeats in two food-producing groups (Bisa and Kunda) that live today in the Luangwa Valley, and compared these data with available published data on African HGs. Our results suggest that both the Bisa and Kunda experienced at most low levels of admixture with HGs, and these levels do not differ between the maternal and paternal lineages. Coalescent simulations indicate that the genetic data best fit a demographic scenario with a long divergence (62,500 years) and little or no gene flow between the ancestors of the Bisa/Kunda and existing HGs. This scenario contrasts with the archaeological evidence for a long period of coexistence between the two different communities in the Luangwa Valley, and suggests a process of sociocultural boundary maintenance may have characterized their interaction. Am J Phys Anthropol 2010. © 2009 Wiley-Liss, Inc. [source]