This report describes the implementation and application of a multicompartment analysis of (31)P spectroscopic imaging data to determine the tissue-specific heterogeneities in metabolite content in the human brain and surrounding tissue. Using this information and a multicompartment regression analysis the phosphocreatine and ATP content of "pure" cerebral gray and white matter, the cerebellum, and skeletal muscle was determined in a group of 10 healthy volunteers. The data were converted to mM units using previously reported values for the T(1)s of phosphocreatine and ATP at 4 T, the water content of human brain, and an external reference for absolute quantification. The phosphocreatine concentration in cerebral gray and white matter, the cerebellum, and skeletal muscle was 3.53 +/- 0.33, 3.33 +/- 0.37, 3.75 +/- 0.66, and 25.8 +/- 2.3 mM, respectively. The ATP concentration in cerebral gray and white matter, the cerebellum, and skeletal muscle was 2.19 +/- 0.33, 3.41 +/- 0.33, 1.75 +/- 0.58, and 8.5 +/- 1.9 mM, respectively. Magn Reson Med 45:46-52, 2001.

BACKGROUND

Mesenchymal stromal cells (MSC) isolated from adult human BM are characterized by their fibroblast-like morphology, adherent growth and capacity to differentiate into adipocytes, osteocytes, chondrocytes, cardiomyocytes and neuroprogenitors. After culturing these cells in vitro, they express the cell-surface molecules CD44, CD90, SH2 and SH3, and are negative for CD34 and the hematopoietic marker CD45. The aim of this study was to characterize the in vivo phenotype of MSC relative to the expression of CD34 and CD45.

METHODS

BM mononuclear cells were stained with Ab against both molecules and separated into the CD34(+), CD34(-), CD45(+) CD34(+), CD45(high+) CD34(-), CD45(med,low+) CD34(-) and CD45(-) CD34(-) subpopulations, which were then cultured under the same conditions and analyzed for growth of MSC.

RESULTS

A small population of MSC arose from the CD45(+) CD34(+) fraction, although the majority was obtained from the CD45(-) CD34(-) subpopulation. MSC from all fractions could be differentiated into adipocytes and osteocytes. In addition, MSC from the CD34(+) and CD34(-) fractions were shown to differentiate into chondrocytes. After in vitro culture, MSC from both fractions possessed the same phenotype, which was negative for CD34 and CD45.

CONCLUSIONS

MSC from the CD45(+) CD34(+) fraction change their phenotype under in vitro conditions.

Sixty-four children aged 1-4 years were evaluated for the extent to which they ingest soil. The study followed the soil tracer methodology of S. Binder, D. Sokal, and D. Maughan (1986, Arch. Environ. Health, 41, 341-345). However, the present study included a number of modifications from the Binder et al. study. The principal new features were (1) increasing the tracer elements from three to eight; (2) using a mass-balance approach so that the contribution of food and medicine ingestion would be considered; (3) extending the period of observation from 3 days to 8 days; and (4) validating the methodology by having adult volunteers ingest known amounts of soil in a mass-balance validation study. The principal findings reveal the following. (1) The adult study confirmed the validity of the tracer methodology to estimate soil ingestion. (2) Of the eight tracers employed in the adult study, only Al, Si, and Y provided sufficient recovery data that was directly acceptably stable and reliable. (3) If food ingestion determinations were taken into consideration, the median estimates of soil ingestion from the eight tracers ranged from a low of 9 mg/day (Y) to a high of 96 mg/day (V); the median values of Al, Si, and Y, the three most reliable tracers, ranged from 9 mg/day to 40 mg/day. (4) One child had soil ingestion values ranging from 5 to 8 g/day, depending on the tracer. (5) If food ingestion had not been considered, the estimates of soil ingestion would have increased about two- to sixfold, depending on the tracer with Ti and Y being most affected by food intake. (6) Since soil and dust samples did not significantly differ in their levels of tracer elements, no reliable differentiation between the contribution of ingestion of dust and soil could be made. (7) These findings are generally consistent with the previously reported findings of Binder et al. (1986) and P. Clausing, B. Brunekreff, and J.H. van Wijnen (1987, Int. Arch. Occup. Med., 59, 73) if these latter studies are corrected for ingestion of tracers in food and medicine. The findings also account for the apparent discrepancy between the estimates from Al and Si and estimates based on Ti in previous studies. Thus the elevated estimates of soil ingestion by Ti were substantially reduced when food ingestion is considered.

Mammalian RNA polymerase II complexes and coactivators containing homologs of yeast Srb/Med proteins have been isolated recently from tissue culture cells. The yeast Srb/Med complex is involved in global gene expression and is essential, but it is not yet known if its mammalian counterparts are broadly expressed in tissues or if they are essential. We have isolated the murine gene encoding Srb7, an Srb/Med complex protein whose sequence and function is highly conserved between yeast and humans. The mouse Srb7 gene is single copy, and Northern analysis showed that it is expressed in all tissues examined. Disruption of the gene in embryonic stem cells revealed that it is essential for cell viability and murine embryonic development. These results, together with evidence that murine Srb7 is associated exclusively with high molecular weight forms of RNA polymerase II in extracts, suggest that Srb7-containing polymerase complexes occur in most tissues and have essential roles in expression of protein coding genes.

A theory is presented for describing the effect on the transverse NMR relaxation rate of microscopic spatial inhomogeneities in the static magnetic field. The theory applies when the inhomogeneities are weak in magnitude and the nuclear spins diffuse a significant distance in comparison with a length scale characterizing the inhomogeneities. It is shown that the relaxation rate is determined by a temporal correlation function and depends quadratically on the magnitude of the inhomogeneities. For the case of unrestricted diffusion, a simple algebraic approximation for the temporal correlation function is derived. The theory is illustrated by applying it to a model of randomly distributed magnetized spheres. The theory is also used to fit experimental data for the dependence of the relaxation rate on the interecho time for a Carr-Purcell-Meiboom-Gill pulse sequence. The experimental systems considered are in vitro red blood cell suspensions and samples of human gray matter and rat liver. Magn Reson Med 44:144-156, 2000.

This report outlines the B cell phenotype of transgenic mice that overexpresses the mouse CTLA-4-human gamma 1 (mCTLA4-H gamma 1) protein. Despite the fact that these mice prime CD4+ T cells (Ronchese, F., B. Housemann, S. Hubele, and P. Lane. 1994. J. Exp. Med. 179:809), antibody responses to T-dependent antigens are severely impaired. In contrast, T-independent responses are normal which suggests mCTLA4-H gamma 1 does not act directly on B cells, but acts indirectly by impairing T cell help. The impaired antibody defect is associated with impaired class switching, with low total immunoglobulin (Ig)G and antigen-specific IgG responses, and an absence of germinal center formation in spleen and lymph nodes but not gut-associated tissues. The defective germinal center formation is associated with a reduction in the degree of somatic mutation in hybridomas made from transgenic mice in comparison with those made from normal mice. It seems likely that mCTLA4-H gamma 1 exerts its effect by blocking an interaction between T and B cells that induce T cell help for B cells.

Excessive generation of reactive oxygen species (ROS) has been suggested as a causal factor in various neurodegenerative disorders, such as Parkinson's disease and Alzheimer's disease [Brain Res. 830 (1999) 10-15; Biochem. J. 310 (1995) 83-90; Free Radic. Biol. Med. 27 (1999) 612-616]. The present work examined the role of ROS in the neurotoxicity of methylmercury (MeHg). ROS formation in primary astrocytic cultures of neonatal rat cerebral cortex was monitored by 2',7'-dichlorodihydrofluorescein diacetate (H(2)DCF-DA) fluorescence. MeHg, at 10 and 20 microM caused a significant increase in ROS formation (10 microM, P<0.01; 20 microM, P<0.001). Additional studies established the effectiveness of antioxidants/free radical scavengers in attenuating the MeHg-stimulated ROS formation in the following rank-order: (1) Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), a non-thiol containing antioxidant, (2) n-propyl gallate (PG), a free radical scavenger, (3) superoxide dismutase (SOD), an antioxidant enzyme that dismutates superoxide anion radical, (4) alpha-phenyl-tert-butyl nitrone (PBN), a lipophilic hydroxyl radical spin trapping agent. A significant inhibition of MeHg-induced ROS generation was also noted in astrocytes preincubated (3 h) with arachidonyl trifluoromethyl ketone (AACOCF(3,) 20 microM, P<0.05), a specific inhibitor of cytosolic phospholipase A(2) (cPLA(2)). Conversely, pretreatment (24 h) with 100 microM buthionine-L-sulfoxamine [BSO, a glutathione (GSH) synthesis inhibitor], significantly increased (P<0.05) ROS formation in MeHg treated astrocytes compared to controls. Combined, these studies invoke ROS as potent mediators of MeHg cytotoxicity and support the hypothesis that excessive ROS generation, at least in part, plays an important role in MeHg-induced neurotoxicity.

Candida albicans HSP90 sequences were isolated by screening cDNA and genomic libraries with a probe derived from the Saccharomyces cerevisiae homolog, HSP82, which encodes a member of the heat shock protein 90 family of molecular chaperones. Identical sequences were obtained for the 2,197-bp overlap of the cDNA and gene sequences, which were derived from C. albicans 3153A and ATCC 10261, respectively. The C. albicans HSP90 gene contained no introns, and it showed strong homology (61 to 79% identity) to HSP90 sequences from other fungi, vertebrates, and plants. The C-terminal portion of the predicted Hsp90 amino acid sequence was identical to the 47-kDa protein which is thought to be immunoprotective during C. albicans infections (R. C. Matthews, J. Med. Microbiol. 36:367-370, 1992), confirming that this protein represents the C-terminal portion of the 81-kDa Hsp90 protein. Quantitative Northern (RNA) analyses revealed that C. albicans HSP90 mRNA was heat shock inducible and that its levels changed during batch growth, with its maximum levels being reached during the mid-exponential growth phase. HSP90 mRNA levels increased transiently during the yeast-to-hyphal transition but did not correlate directly with germ tube production per se. These data do not exclude a role for Hsp90 in the dimorphic transition. Southern blotting revealed only one HSP90 locus in the diploid C. albicans genome. Repeated attempts to disrupt both alleles and generate a homozygous C. albicans delta hsp90/delta hsp90 null mutant were unsuccessful. These observations suggest the existence of a single HSP90 locus which is essential for viability in C. albicans.

Biologically variable mechanical ventilation (Vbv)-using a computer-controller to mimic the normal variability in spontaneous breathing-improves gas exchange in a model of severe lung injury (Lefevre, G. R., S. E. Kowalski, L. G. Girling, D. B. Thiessen, W. A. C. Mutch. Am. J. Respir. Crit. Care Med. 1996;154:1567-1572). Improved oxygenation with Vbv, in the face of alveolar collapse, is thought to be due to net volume recruitment secondary to the variability or increased noise in the peak inspiratory airway pressures (Ppaw). Biologically variable noise can be modeled as an inverse power law frequency distribution (y approximately 1/f(a)) (West, B. J., M. Shlesinger. Am. Sci. 1990;78:40-45). In a porcine model of atelectasis-right lung collapse with one-lung ventilation-we studied if Vbv (n = 7) better reinflates the collapsed lung compared with conventional monotonously regular control mode ventilation (Vc; n = 7) over a 5-h period. We also investigated the influence of sigh breaths with Vc (Vs; n = 8) with this model. Reinflation of the collapsed lung was significantly enhanced with Vbv-greater Pa(O(2)) (502 +/- 40 mm Hg with Vbv versus 381 +/- 40 mm Hg with Vc at 5 h; and 309 +/- 79 mm Hg with Vs; mean +/- SD), lower Pa(CO(2)) (35 +/- 4 mm Hg versus 48 +/- 8 mm Hg and 50 +/- 8 mm Hg), lower shunt fraction (9.7 +/- 2.7% versus 14.6 +/- 2.0% and 22.9 +/- 6.0%), and higher respiratory system compliance (Crs) (1.15 +/- 0.15 ml/cm H(2)O/kg versus 0.79 +/- 0.19 ml/cm H(2)O/kg and 0.77 +/- 0.13 ml/cm H(2)O/kg)-at lower mean Ppaw (15.7 +/- 1.4 cm H(2)O versus 18.8 +/- 2.3 cm H(2)O and 18.9 +/- 2.8 cm H(2)O). Vbv resulted in an 11% increase in measured tidal volume (VT(m)) over that seen with Vc by 5 h (14.7 +/- 1.2 ml/kg versus 13. 2 ml/kg). The respiratory rate variability programmed for Vbv demonstrated an inverse power law frequency distribution ( y approximately 1/f(a)) with a = 1.6 +/- 0.3. These findings provide strong support for the theoretical model of noisy end-inspiratory pressure better recruiting atelectatic lung. Our results suggest that using natural biologically variable noise has enhanced the performance of a mechanical ventilator in control mode.

Four different serotype strains of Bordetella pertussis, 3779BL(2)S(4), Tohama I, 353/Z, and 2753, were plated on Bordet-Gengou agar, where they grew as domed, hemolytic (D(+)H(+)) wild-type colonies. Cloned D(+)H(+) colony types of all four strains were passed onto modified Stainer-Scholte medium solidified with 1% Noble Agar. Colonies were selected from Stainer-Scholte agar, and these subsequently grew as flat, nonhemolytic (D(-)H(-)) colonies when transferred back onto Bordet-Gengou agar. The frequency of D(-)H(-) organisms within a population of cloned D(+)H(+) was determined to be between 5 x 10(-5) and 5 x 10(-6). The D(-)H(-) colony types maintained their flat, nonhemolytic characteristics for over 80 single-colony passages on Bordet-Gengou agar. The isogenic pairs of D(+)H(+) and D(-)H(-) colony types from the four strains were compared for hemagglutination titer, lymphocytosis-promoting activity, adenylate cyclase activity, and presence of agglutinogens by agglutination. In all cases the D(-)H(-) colony types showed reduced activities or amounts of antigen compared with their D(+)H(+) parents. Freely diffusible antigens were markedly different between the two phenotypes as noted by double diffusion of antisera added to plates on which colonies of the variants were growing. Antigens solubilized from the two colony types by Triton X-100 were also markedly different as judged by radial immunodiffusion with antifimbrial hemagglutinin, antilymphocytosis-promoting factor, and anti-353/Z adsorbed with autoclaved 353/Z. In addition, autoradiographs of (125)I-surface-labeled whole cells separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed unique banding patterns for each colony type. Since all organisms, regardless of colony type, were grown on Bordet-Gengou agar, the differences reported could not be due to medium composition. Differences between phenotypes were also independent of passage number on Bordet-Gengou agar. By analogy to previous studies, the D(-)H(-) organisms appear to fulfill the criteria for phase III or phase IV in the system of Leslie and Gardner (P. H. Leslie and A. D. Gardner, J. Hyg. 31:423-434, 1931) or phase III in the system of Kasuga et al. (T. Kasuga, Y. Nakase, K. Ukishima, and K. Takatsu, Kitasato Arch. Exp. Med. 26:121-134, 1954).

OBJECTIVE

To perform a systematic review of the emergency medicine literature to assess the appropriateness of offering routine HIV screening to patients in the emergency department (ED).

METHODS

The systematic review was conducted with the aid of a structured template, a companion explanatory guide, and a grading and methodological scoring system based on published criteria for critical appraisal. Two reviewers conducted independent searches using OvidR, PubMed, MD Consult, and Grateful Med. Relevant abstracts were reviewed; those most pertinent to the stated objective were selected for complete evaluation using the structured template.

RESULTS

Fifty-two relevant abstracts were reviewed; of these, nine were selected for detailed evaluation. Seven ED-based prospective cross-sectional seroprevalence studies found HIV rates of 2-17%. Highest rates of infection were seen among patients with behavioral risks such as male homosexual activity and intravenous drug use. Two studies demonstrated feasibility of both standard and rapid HIV testing in the ED, with more than half of the patients approached consenting to testing by either method, consistent with voluntary testing acceptance rates described in other settings. Several cost-benefit analyses lend indirect support for HIV screening in the ED.

CONCLUSIONS

Multiple ED-based studies meeting the Centers for Disease Control and Prevention Guideline threshold to recommend routine screening, in conjunction with limited feasibility trials and extrapolation from cost-benefit studies, provide evidence to recommend that EDs offer HIV screening to high-risk patients (i.e., those with identifiable risk factors) or high-risk populations (i.e., those where HIV seroprevelance is at least 1%).

Human immunodeficiency virus (HIV) type 1 encodes an essential protein, Rev, which functions to transport unspliced and singly spliced viral transcripts from the nucleus to the cytoplasm to allow expression of the viral structural proteins. It has previously been reported that Sam68 synergistically stimulates Rev activity (T. Reddy et al., Nat. Med. 5:635-642, 1999). Here we report that the Sam68-like mammalian proteins SLM1 and SLM2 also stimulate Rev activity. Their stimulation ability cannot be attributed to a shuttling property, since Sam68, SLM1, and SLM2 do not display significant shuttling activity alone or in the presence of Rev. In addition, Sam68, SLM1, and SLM2 do not affect the equilibrium between unspliced and completely spliced HIV RNA. The C-terminally truncated Sam68 mutant (Sam68DeltaC) previously observed to inhibit the Sam68-mediated stimulation of Rev activity (Reddy et al., 1999) also inhibits SLM1- and SLM2-mediated stimulation of Rev activity. This suggests that the mechanism by which Sam68, SLM1, and SLM2 stimulate Rev activity may be common. Sam68DeltaC does not inhibit Rev activity by inhibiting Rev from shuttling between the nucleus and cytoplasm. Inhibition by Sam68DeltaC is a consequence of its mislocalization to the cytoplasm, as evidenced by the fact that addition of an exogenous nuclear localization signal to Sam68DeltaC restores nuclear localization and stimulation of Rev activity. We demonstrate that Sam68DeltaC causes perinuclear accumulation of unspliced HIV env RNA and propose that Sam68DeltaC inhibits Rev activity by sequestering Rev-responsive RNA away from the translation apparatus.

Spinal cord injury and its devastating consequences are the subject of intensive research aimed at reversing or at least minimizing functional loss. Research efforts focus on either attenuating the post-injury spread of damage (secondary degeneration) or inducing some regeneration. In most of these studies, as well as in clinical situations, evaluation of the state of the injured spinal cord poses a serious difficulty. To address this problem, we carried out a diffusion-weighted MRI experiment and developed an objective routine for quantifying anisotropy in injured rat spinal cords. Rats were subjected to a contusive injury of the spinal cord caused by a controlled weight drop. Untreated control rats were compared with rats treated with T cells specific to the central nervous system self-antigen myelin basic protein, a form of therapy recently shown to be neuroprotective. After the rats were killed their excised spinal cords were fixed in formalin and imaged by multislice spin echo MRI, using two orthogonal diffusion gradients. Apparent diffusion coefficient (ADC) values and anisotropy ratio (AI) maps were extracted on a pixel-by-pixel basis. The calculated sum of AI values (SAI) for each slice was defined as a parameter representing the total amount of anisotropy. The mean-AI and SAI values increased gradually with the distance from the site of the lesion. At the site itself, the mean-AI and SAI values were significantly higher in the spinal cords of the treated animals than in the controls (P = 0.047, P = 0.028, respectively). These values were consistent with the score of functional locomotion. The difference was also manifested in the AI maps, which revealed well-organized neural structure in the treated rats but not in the controls. The SAI values, AI histograms, and AI maps proved to be useful parameters for quantifying injury and recovery in an injured spinal cord. These results encourage the development of diffusion anisotropy MRI as a helpful approach for quantifying the extent of secondary degeneration and measuring recovery after spinal cord injury. Magn Reson Med 45:1-9, 2001.

Despite the prominence of fear-avoidance models of chronic pain, there is a paucity of research regarding the origins of pain-related fear. Based on the premise that insecure attachment could be a developmentally based origin of elevated fear of pain, associations between adult attachment dimensions and constructs included in fear-avoidance models of chronic pain were investigated. Consistent with Bartholomew and Horowitz's [Bartholomew K, Horowitz LM. Attachment styles among young adults: a test of a four-category model. J Pers Soc Psychol 1991;61:226-44.] model, attachment was conceptualized as being comprised of a model of self dimension (i.e., degree of anxiety regarding rejection based on beliefs of personal unworthiness) and a model of others dimension (i.e., degree of interpersonal mistrust and discomfort with interpersonal closeness). A large university student sample free of chronic pain (N=278) completed a measure of adult romantic attachment (i.e., Experiences in Close Relationships Questionnaire; [Brennan KA, Clark CL, Shaver PR. Self-report measurement of adult attachment: an integrative overview. In: Simpson JA, Rholes WS, editors. Attachment theory and close relationships. New York: The Guilford Press, 1998. p. 46-76.]), the Fear of Pain Questionnaire-III [McNeil DW, Rainwater AJ. Development of the fear of pain questionnaire - III. J Behav Med 1998;21:389-410.], the Pain Vigilance and Awareness Questionnaire [McCracken LM. Attention to pain in persons with chronic pain: a behavioural approach. Behav Ther 1997;28:271-84.], and the Pain Catastrophizing Scale [Sullivan MJ, Bishop SR, Pivik J. The pain catastrophizing scale: development and validation. Psychol Assess 1995;7:24-532.]. It was hypothesized that insecure attachment would be positively associated with reports of pain-related fear, hypervigilance, and catastrophizing and that the model of self dimension would be the attachment variable most strongly associated with these variables. Correlation and multiple regression analyses supported these hypotheses. The model of self dimension had significant positive associations with each of the fear-avoidance constructs. The model of others dimension had a significant positive association with pain catastrophizing, but was not significantly associated with fear of pain and pain hypervigilance. Future research directions and potential clinical implications are discussed.

Leukotoxin is clinically associated with acute respiratory distress syndrome (ARDS). Recently, we found that leukotoxin-diol, the hydrated product of leukotoxin, is more toxic than the parent leukotoxin in vitro (Moghaddam and colleagues, Nature Med. 1997;3:562-566). To test if this difference in the toxicity of leukotoxin and leukotoxin-diol exists in vivo, Swiss Webster mice were administered leukotoxin or leukotoxin-diol. All mice treated with leukotoxin-diol died of ARDS-like respiratory distress, whereas the animals exposed to leukotoxin at the same dose survived. Histopathologic evaluation of the lungs revealed massive alveolar edema and hemorrhage with interstitial edema around blood vessels in the lungs of mice treated with leukotoxin-diol, whereas the lungs of mice treated with identical doses of leukotoxin had perivascular edema only and little change in alveolar spaces. Immunohistochemistry showed that the soluble epoxide hydrolase responsible for the hydrolysis of leukotoxin to its diol is concentrated in the vascular smooth muscle of small and medium-sized pulmonary vessels. In addition, 4-phenylchalcone oxide, an inhibitor of soluble epoxide hydrolase, was found to decrease the mortality induced by leukotoxin but had no effect on mortality induced by leukotoxin-diol. These studies provide strong in vivo evidence that leukotoxin may act as a protoxicant and that the corresponding diol is a putative toxic mediator involved in the development of ARDS.

8-Hydroxy-2'-deoxyguanosine (8-OHdG) is a mutation-prone (G:C to T:A transversion) DNA base-modified product generated by reactive oxygen species or photodynamic action. G:C to T:A transversions are observed in the p53 and ras genes of UVB-induced skin cancers of mice and in squamous and basal cell carcinomas of human skin exposed to sunlight. In the current study, 8-OHdG formation was evaluated in the epidermis of hairless mice after repeated exposure to UVB, and possible mechanisms involved were studied. Exposure of hairless mice to either 3.4 [2 minimal erythema dose (MED)] or 16.8 (10 MED) kJ/m2 of UVB three times a week for 2 wk induced a 2.5- or 6.1-fold increase, respectively, in the levels of 8-OHdG in DNA, compared to the unexposed controls. An immunohistochemical method using a monoclonal antibody specific for 8-OHdG showed stronger and more extensive staining in the nuclei of UV-irradiated epidermal cells than in those of nonirradiated cells. Western blots probed with antibodies against 4-hydroxy-2-nonenal-modified proteins confirmed the involvement of reactive oxygen species in the epidermal damage induced by chronic UVB exposure. 3-Nitro-L-tyrosine was detected in western blots in a concentration-dependent manner, suggesting that peroxynitrite derived from the reaction of nitric oxide and superoxide, both of which were probably released from inflammatory cells, was involved in modifying the DNA bases. Therefore, the formation of 8-OHdG after UVB exposure appears to be regulated by at least three pathways: photodynamic action, lipid peroxidation, and inflammation and may play a role in sunlight-induced skin carcinogenesis.

BACKGROUND

The effects of medical and surgical treatments for obesity on peptide YY (PYY) levels, in patients with similar weight loss, remain unclear.

OBJECTIVE

The objective of the study was to assess PYY and appetite before and after Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and medical treatment (MED).

METHODS

This was a prospective, controlled, nonrandomized study.

METHODS

The study was conducted at the Departments of Nutrition and Digestive Surgery at a university hospital.

METHODS

PARTICIPANTS included three groups of eight patients with similar body mass indexes (RYGB 37.8 +/- 0.8, SG 35.3 +/- 0.7, and MED 39.1 +/- 1.7 kg/m(2), P = NS) and eight lean controls (body mass index 21.7 +/- 0.7 kg/m(2)).

METHODS

Total plasma PYY, hunger, and satiety visual analog scales in fasting and after ingestion of a standard test meal were measured.

RESULTS

At baseline there were no differences in the area under the curve (AUC) of PYY, hunger, or satiety in obese groups. Two months after the interventions, RYGB, SG, and MED groups achieved similar weight loss (17.7 +/- 3, 14.9 +/- 2.4, 16.6 +/- 4%, respectively, P = NS). PYY AUC increased in RYGB (P < 0.001) and SG (P < 0.05) and did not change in MED. PYY levels decreased at fasting, 30 min, and 180 min after a standard test meal in MED (P < 0.05). Hunger AUC decreased in RYGB (P < 0.05). Satiety AUC increased in RYGB (P < 0.05) and SG (P < 0.05). Appetite did not change in MED. PYY AUC correlated with satiety AUC (r = 0.35, P < 0.05).

CONCLUSIONS

RYGB and SG increased PYY and reduced appetite. MED failed to produce changes. Different effects occur despite similar weight loss. This suggests that the weight-loss effects of these procedures are enhanced by an increase in PYY and satiety.

Ultrasound measurements of the human carotid artery walls are conventionally obtained by manually tracing interfaces between tissue layers. In this study we present a snakes segmentation technique for detecting the intima-media layer of the far wall of the common carotid artery (CCA) in longitudinal ultrasound images, by applying snakes, after normalization, speckle reduction, and normalization and speckle reduction. The proposed technique utilizes an improved snake initialization method, and an improved validation of the segmentation method. We have tested and clinically validated the segmentation technique on 100 longitudinal ultrasound images of the carotid artery based on manual measurements by two vascular experts, and a set of different evaluation criteria based on statistical measures and univariate statistical analysis. The results showed that there was no significant difference between all the snakes segmentation measurements and the manual measurements. For the normalized despeckled images, better snakes segmentation results with an intra-observer error of 0.08, a coefficient of variation of 12.5%, best Bland-Altman plot with smaller differences between experts (0.01, 0.09 for Expert1 and Expert 2, respectively), and a Hausdorff distance of 5.2, were obtained. Therefore, the pre-processing of ultrasound images of the carotid artery with normalization and speckle reduction, followed by the snakes segmentation algorithm can be used successfully in the measurement of IMT complementing the manual measurements. The present results are an expansion of data published earlier as an extended abstract in IFMBE Proceedings (Loizou et al. IEEE Int X Mediterr Conf Medicon Med Biol Eng POS-03 499:1-4, 2004).

BACKGROUND

Radiation Therapy Oncology Group (RTOG) 0515 is a Phase II prospective trial designed to quantify the impact of positron emission tomography (PET)/computed tomography (CT) compared with CT alone on radiation treatment plans (RTPs) and to determine the rate of elective nodal failure for PET/CT-derived volumes.

METHODS

Each enrolled patient underwent definitive radiation therapy for non-small-cell lung cancer (≥ 60 Gy) and had two RTP datasets generated: gross tumor volume (GTV) derived with CT alone and with PET/CT. Patients received treatment using the PET/CT-derived plan. The primary end point, the impact of PET/CT fusion on treatment plans was measured by differences of the following variables for each patient: GTV, number of involved nodes, nodal station, mean lung dose (MLD), volume of lung exceeding 20 Gy (V20), and mean esophageal dose (MED). Regional failure rate was a secondary end point. The nonparametric Wilcoxon matched-pairs signed-ranks test was used with Bonferroni adjustment for an overall significance level of 0.05.

RESULTS

RTOG 0515 accrued 52 patients, 47 of whom are evaluable. The follow-up time for all patients is 12.9 months (2.7-22.2). Tumor staging was as follows: II = 6%; IIIA = 40%; and IIIB = 54%. The GTV was statistically significantly smaller for PET/CT-derived volumes (98.7 vs. 86.2 mL; p < 0.0001). MLDs for PET/CT plans were slightly lower (19 vs. 17.8 Gy; p = 0.06). There was no significant difference in the number of involved nodes (2.1 vs. 2.4), V20 (32% vs. 30.8%), or MED (28.7 vs. 27.1 Gy). Nodal contours were altered by PET/CT for 51% of patients. One patient (2%) has developed an elective nodal failure.

CONCLUSIONS

PET/CT-derived tumor volumes were smaller than those derived by CT alone. PET/CT changed nodal GTV contours in 51% of patients. The elective nodal failure rate for GTVs derived by PET/CT is quite low, supporting the RTOG standard of limiting the target volume to the primary tumor and involved nodes.

African trypanosomes produce some prostanoids, especially PGD2, PGE2 and PGF2alpha (Kubata et al. 2000, J. Exp. Med. 192: 1327-1338), probably to interfere with the host's physiological response. However, addition of prostaglandin D2 (but not PGE2 or PGF2alpha) to cultured bloodstream form trypanosomes led also to a significant inhibition of cell growth. Based on morphological alterations and specific staining methods using vital dyes, necrosis and autophagy were excluded. Here, we report that in bloodstream form trypanosomes PGD2 induces an apoptosis-like programmed cell death, which includes maintenance of plasma membrane integrity, phosphatidylserine exposure, loss of mitochondrial membrane potential, nuclear chromatin condensation and DNA degradation. The use of caspase inhibitors cannot prevent the cell death, indicating that the process is caspase-independent. Based on these results, we suggest that PGD2-induced programmed cell death is part of the population density regulation as observed in infected animals.

Macrophages take up zymosan in the absence of exogenous complement via receptors for iC3b (type 3 complement receptors) acting with or without lectin-like receptors for mannosyl-fucosyl-terminated glycoconjugates. We previously provided evidence that macrophages themselves secrete complement-alternative pathway components able to opsonize zymosan locally (Ezekowitz et al., J. Exp. Med. 1984. 159:244-260). We show here that covalently bound C3 cleavage products C3b and iC3b can be eluted from zymosan particles cultivated with 36-h adherent human monocytes in the absence of serum. The ligand binding site of type 3 complement receptors is involved in macrophage-zymosan interactions as shown by inhibition studies of zymosan binding and uptake with Fab fragments of anti-C3 antibodies and monoclonal antireceptor antibodies M01 and OKM10. In contrast, antibody IB4, which binds to a receptor epitope distinct from the binding site, does not inhibit zymosan uptake. Selective modulation of macrophage receptors onto anticomplement receptor antibody and mannose-rich yeast mannan, respectively, confirms that the complement and lectin-like receptors are distinct. Human polymorphonuclear leukocytes, which express receptors for complement, but are not known to secrete complement proteins, bind and ingest only exogenously opsonized zymosan. Unopsonized zymosan is a poor trigger of respiratory burst activity in neutrophils or 7-d adherent human macrophages, but induces cell aggregation and secretion of large amounts of superoxide anion when these cells are co-cultivated in serum-free medium and challenged with zymosan. Our studies indicate that complement and/or other products synthesized by macrophages at extravascular sites could play an important role in opsonization and lysis of pathogens able to activate the alternative pathway and mediate macrophage-neutrophil collaboration in first-line host defence.

In this study, we identified two brush border glycoproteins (210 and 240 kDa) that bind both K88ac+ Escherichia coli and purified K88ac adhesin. The specificity of these binding glycoproteins for the K88ac adhesin was demonstrated in studies in which the binding of 35S-labeled K88ac+ E. coli and biotinylated K88ac adhesin to these glycoproteins was blocked in the presence of a 100-fold molar excess of unlabeled K88ac adhesin but not in the presence of the K99 adhesin. Pretreatment of adhesive brush borders with sodium metaperiodate destroyed both binding activities, indicating that the interaction between the K88ac adhesin and the binding glycoproteins requires the glycoprotein carbohydrate moiety. It was demonstrated previously that K88ac+ E. coli binds to adhesive brush borders but not to nonadhesive brush borders (R. Sellwood, R. A. Gibbons, G. W. Jones, and J. M. Rutter, J. Med. Microbiol. 8:405-411, 1975). In the present study, brush borders isolated from 10 different pigs were tested first for brush border adhesiveness and then for the presence of the binding glycoproteins. In all cases, the binding glycoproteins were detected only in the adhesive brush border preparations. These two binding glycoproteins may be the receptors used by K88ac+ ETEC to adhere to intestinal brush border cells. Their presence on adhesive brush borders and absence on nonadhesive brush borders may be the basis for resistance and susceptibility of pigs to K88ac+ ETEC infections.

A recent paper analyzed the sensitivity to various simulation parameters of the Monte Carlo simulations of nine beams from three major manufacturers of commercial medical linear accelerators, ranging in energy from 4-25 MV. In this work the nine models are used: to calculate photon energy spectra and average energy distributions and compare them to those published by Mohan et al. [Med. Phys. 12, 592-597 (1985)]; to separate the spectra into primary and scatter components from the primary collimator, the flattening filter and the adjustable collimators; and to calculate the contaminant-electron fluence spectra and the electron contribution to the depth-dose curves. Notwithstanding the better precision of the calculated spectra, they are similar to those calculated by Mohan et al. The three photon spectra at 6 MV from the machines of three different manufacturers show differences in their shapes as well as in the efficiency of bremsstrahlung production in the corresponding target and filter combinations. The contribution of direct photons to the photon energy fluence in a 10 x 10 field varies between 92% and 97%, where the primary collimator contributes between 0.6% and 3.4% and the flattening filter contributes between 0.6% and 4.5% to the head-scatter energy fluence. The fluence of the contaminant electrons at 100 cm varies between 5 x 10(-9) and 2.4 x 10(-7) cm(-2) per incident electron on target, and the corresponding spectrum for each beam is relatively invariant inside a 10 x 10 cm2 field. On the surface the dose from electron contamination varies between 5.7% and 11% of maximum dose and, at the depth of maximum dose, between 0.16% and 2.5% of maximum dose. The photon component of the percentage depth-dose at 10 cm depth is compared with the general formula provided by AAPM's task group 51 and confirms the claimed accuracy of 2%.