453 research outputs found
Perception of Parental Acceptance-Rejection and Satisfaction with Life in Women with Binge Eating Disorder
The authors contribute to the validating literature for binge eating disorder (BED) by examining perceptions of parents and satisfaction with life among obese women with and without BED. Participants were female patients, recruited through a private medical clinic, who were assigned to groups on the basis of body mass index (BMI) and scores on the Questionnaire on Eating and Weight Patterns (QEWP; R. L. Spitzer et al., 1992). Groups consisted of (a) obese women with BED (n = 32). (b) obese women who had no eating disorders (n = 51). and (c) nonobese women with no eating disorders (n = 30). All participants completed the Parental Acceptance/Rejection Questionnaire (PARQ; R. P. Rohner, 1986). the Satisfaction with Life Scale (SWLS; J. Fischer & K. Corcoran, 1994). and the Beck Depression Inventory (BDI; A. T. Beck & R. A. Steer, 1987). Obese women with BED perceived their fathers as more rejecting than did women in the other groups. Moreover, obese women with BED perceived their fathers as significantly more rejecting than their mothers. The BED group indicated lower satisfaction with life and higher levels of depression than the groups without eating disorders. These findings further validate the diagnostic category of BED. Obese women with BED appear to be a distinct subgroup of the obese population. The results indicate a need for further assessment of the father-daughter relationship in connection to BED and other eating disorders
Pathway interactions between MAPKs, mTOR, PKA, and the glucocorticoid receptor in lymphoid cells
BACKGROUND: Glucocorticoids are frequently used as a primary chemotherapeutic agent in many types of human lymphoid malignancies because they induce apoptosis through activation of the glucocorticoid receptor, with subsequent alteration of a complex network of cellular mechanisms. Despite clinical usage for over fifty years, the complete mechanism responsible for glucocorticoid-related apoptosis or resistance remains elusive. The mitogen-activated protein kinase pathway is a signal transduction network that influences a variety of cellular responses through phosphorylation of specific target substrates, including the glucocorticoid receptor. In this study we have evaluated the pharmaceutical scenarios which converge on the mitogen-activated protein kinase pathway to alter glucocorticoid sensitivity in clones of human acute lymphoblastic CEM cells sensitive and refractory to apoptosis in response to the synthetic glucocorticoid dexamethasone. RESULTS: The glucocorticoid-resistant clone CEM-C1-15 displays a combination of high constitutive JNK activity and dexamethasone-induced ERK activity with a weak induction of p38 upon glucocorticoid treatment. The cells become sensitive to glucocorticoid-evoked apoptosis after: (1) inhibition of JNK and ERK activity, (2) stimulation of the cAMP/PKA pathway with forskolin, or (3) inhibition of mTOR with rapamycin. Treatments 1–3 in combination with dexamethasone alter the intracellular balance of phospho-MAPKs by lowering JNK phosphorylation and increasing the level of glucocorticoid receptor phosphorylated at serine 211, a modification known to enhance receptor activity. CONCLUSION: Our data support the hypothesis that mitogen-activated protein kinases influence the ability of certain malignant lymphoid cells to undergo apoptosis when treated with glucocorticoid. Activated/phosphorylated JNK and ERK appear to counteract corticoid-dependent apoptosis. Inhibiting these MAPKs restores corticoid sensitivity to a resistant clone of CEM cells. Forskolin, which activates the cAMP pathway, and rapamycin, which inhibits mTOR, also inhibit JNK. Further, the sensitizing treatments result in a largely dexamethasone-dependent increase in the total pool of glucocorticoid receptor phosphorylated at serine 211. The phospho-serine 211 receptor is known to be more potent in activating gene transcription and apoptosis. The interactive effects demonstrated here in reverting resistant cells to corticoid sensitivity could provide therapeutic clinical potential in the treatment of lymphoid malignancies
Simulations of Luminescent Solar Concentrators: Effects of Polarization and Fluorophore Alignment
We model the effects of dye molecule alignment on the collection efficiency of luminescent solar concentrators (LSCs). A Monte Carlo model for photontransport in LSC’s is derived and utilized, which incorporates the effects of fluorescent-dye-molecular alignment and the subsequent control over absorption, emission, and propagation properties. We focus on the effects of molecular alignment statistics on photon absorption and subsequent emission, including polarization and propagation direction imparted by dipole direction, to model device light-capture efficiency, defined as the ratio of the amount of light reaching particular slab edges to that incident on a face. We find that modest control of alignment, coupled with reasonable and attainable emission-absorption dipole angles, can produce very large collection efficiencies for a range of device parameters. We note that efficiencies for small values of dye molecule Stoke’s shift may be made as large as those for homogeneous (unaligned) systems with large Stoke’s shift
\u3ci\u3eN\u3c/i\u3e\u3csup\u3e5\u3c/sup\u3e-Phosphonoacetyl-L-ornithine (PALO): A convenient synthesis and investigation of influence on regulation of amino acid biosynthetic genes in \u3ci\u3eSaccharomyces cerevisiae\u3c/i\u3e
A scalable four-step synthesis of the ornithine transcarbamylase inhibitor N5-phosphonoacetyl-L-ornithine (PALO) is achieved through boroxazolidinone protection of ornithine. Investigations in the model organism Saccharomyces cerevisiae found that, in contrast to a previous report, PALO did not influence growth rate or expression of genes involved in arginine metabolism
Senescent mouse cells fail to overtly regulate the HIRA histone chaperone and do not form robust Senescence Associated Heterochromatin Foci
<p>Abstract</p> <p>Background</p> <p>Cellular senescence is a permanent growth arrest that occurs in response to cellular stressors, such as telomere shortening or activation of oncogenes. Although the process of senescence growth arrest is somewhat conserved between mouse and human cells, there are some critical differences in the molecular pathways of senescence between these two species. Recent studies in human fibroblasts have defined a cell signaling pathway that is initiated by repression of a specific Wnt ligand, Wnt2. This, in turn, activates a histone chaperone HIRA, and culminates in formation of specialized punctate domains of facultative heterochromatin, called Senescence-Associated Heterochromatin Foci (SAHF), that are enriched in the histone variant, macroH2A. SAHF are thought to repress expression of proliferation-promoting genes, thereby contributing to senescence-associated proliferation arrest. We asked whether this Wnt2-HIRA-SAHF pathway is conserved in mouse fibroblasts.</p> <p>Results</p> <p>We show that mouse embryo fibroblasts (MEFs) and mouse skin fibroblasts, do not form robust punctate SAHF in response to an activated Ras oncogene or shortened telomeres. However, senescent MEFs do exhibit elevated levels of macroH2A staining throughout the nucleus as a whole. Consistent with their failure to fully activate the SAHF assembly pathway, the Wnt2-HIRA signaling axis is not overtly regulated between proliferating and senescent mouse cells.</p> <p>Conclusions</p> <p>In addition to the previously defined differences between mouse and human cells in the mechanisms and phenotypes associated with senescence, we conclude that senescent mouse and human fibroblasts also differ at the level of chromatin and the signaling pathways used to regulate chromatin. These differences between human and mouse senescence may contribute to the increased propensity of mouse fibroblasts (and perhaps other mouse cell types) to become immortalized and transformed, compared to human cells.</p
The relative importance of graft surveillance and warfarin therapy in infrainguinal prosthetic bypass failure
BackgroundWe sought to describe modes of failure and associated limb loss after infrainguinal polytetrafluoroethylene bypass grafting in patients lacking a saphenous venous conduit and to define specific clinical or hemodynamic factors prognostic for bypass failure.MethodsWe identified 121 patients (mean age, 67 years; 90 men and 31 women) with determinable outcomes (minimum follow-up, 2 months; mean, 17 months) after 130 prosthetic infrainguinal bypasses between 1997 and 2005. Ischemic presentation was rest pain in 52%, tissue loss in 34%, and disabling claudication and/or popliteal aneurysm in 14%, with 24% of patients requiring a redo bypass. Distal targets were the above-knee (n = 44), distal popliteal (n = 27), or tibial/pedal (n = 59) arteries. Sixty-six (77%) of the below-knee (BK) target (distal popliteal or tibial) bypasses had distal anastomotic adjuncts (vein cuff or patch). Duplex graft surveillance was performed at 1, 4, and 7 months after surgery and twice yearly thereafter, with recording of midgraft velocities and imaging encompassing inflow and outflow vessels. Arteriography and open/endovascular intervention was performed for stenoses identified by duplex scanning (peak systolic velocity >300 cm/s; velocity ratio >3.5). An attempt was made to salvage occluded grafts by using catheter-directed thrombolysis or open techniques. Eighty-six patients (74% of BK bypasses) were placed on chronic warfarin therapy with a target international normalized ratio range between 2 and 3. Prognostic factors were identified by using univariate statistics and multivariate logistic regression analysis.ResultsThree-year primary, assisted, and secondary patency rates were 39%, 43%, and 59%, respectively, for all bypasses, with no difference noted between above-knee and BK grafts (P = .5). At 3 years, freedom from limb loss was 75%, and patient survival was only 70%, with no adverse effect on survival imparted by amputation. Sixty-nine total adverse events occurred as a result of thrombotic occlusion (n = 51), duplex scan–detected stenosis (n = 13), or graft infection (n = 5). Forty-nine percent of all initial graft occlusions eventually led to amputation. Twenty-three grafts (27% of 86 patients) in patients maintained on chronic warfarin were subtherapeutic at the time of occlusion. Use of a distal anastomotic adjunct with BK bypasses reduced graft thrombosis (35% with vs 60% without) but did not impart a significant patency advantage (P = .07). Multivariate analysis revealed low graft flow (midgraft velocity ≤45 cm/s; odds ratio [OR], 6.1; 95% confidence interval [CI], 1.9-19.2), use of warfarin (OR, 8.4; 95% CI, 2.1-34.5), and therapeutic warfarin (OR, 24.6; 95% CI, 5.7-106) to be independently predictive for bypass patency. Graft patency was maintained in 89% of grafts remaining therapeutic on warfarin compared with only 55% of subtherapeutic or nonanticoagulated grafts (P < .001). Low-flow grafts (n = 61) occluded more frequently than higher-flow grafts (46% vs 13%; P < .001). Therapeutic warfarin augmented the patency of low-flow (P < .001) but not high-flow (P = .15) grafts.ConclusionsLow graft flow was a more common mode of prosthetic bypass failure than development of duplex scan–detected stenotic lesions during follow-up. Early duplex scanning may be more important for characterizing midgraft velocity and related thrombotic potential and selecting patients for chronic anticoagulation. Maintenance of therapeutic warfarin is paramount in optimizing prosthetic bypass patency and limb preservation
Outcome of carotid stent-assisted angioplasty versus open surgical repair of recurrent carotid stenosis
AbstractPurposeWe compared outcome and durability of carotid stent-assisted angioplasty (CAS) with open surgical repair (ie, repeat carotid endarterectomy [CEA]) to treat recurrent carotid stenosis (RCS).MethodsA retrospective review of anatomic and neurologic outcomes was carried out after 27 repeat CEA procedures (1993-2002) and 52 CAS procedures (1997-2002) performed to treat high-grade internal carotid artery (ICA) RCS after CEA. The incidence of intervention because of symptomatic RCS was similar (repeat CEA, 63%; CAS, 60%), but the interval from primary CEA to repeat intervention was greater (P < .05) in the repeat CEA group (83 ± 15 months) compared with the CAS group (50 ± 8 months). In the CAS group, 17 of 52 arteries (33%) were judged not to be surgical candidates because of surgically inaccessible high lesions (n = 8), medical comorbid conditions (n = 4), neck irradiation (n = 3), or previous surgery with cranial nerve deficit or stroke (n = 2). Three patients who underwent repeat CEA had lesions not appropriate for treatment with CAS.ResultsOverall 30-day morbidity was similar after CAS (12%; death due to ipsilateral intracranial hemorrhage, 1; nondisabling stroke, 1; reversible neurologic deficits or transient ischemic attack, 2; access site complication, 2) and repeat CEA (11%; no death; nondisabling stroke, 1; reversible cranial nerve injury, 1; cervical hematoma, 1). Combined stroke and death rate was 3.7% for repeat CEA and 5.7% for CAS (P > .1). All duplex ultrasound scans obtained within 3 months after CEA and CAS demonstrated patent ICA and velocity spectra of less than 50% stenosis. During follow-up, no repeat CEA (mean, 39 months) or CAS (mean, 26 months) repair demonstrated ICA occlusion, but two patients (8%) who underwent repeat CEA and 4 patients (8%) who underwent CAS required balloon or stent angioplasty because of 80% RCS. At last follow-up, no patient had ipsilateral stroke and all ICA remain patent. At duplex scanning, stenosis-free (<50% diameter reduction) ICA patency at 36 months was 75% after repeat CEA and 57% after CAS (P = .26, log-rank test).ConclusionsCarotid angioplasty for treatment of high-grade stenotic ICA after CEA resulted in similar anatomic and neurologic outcomes compared with open surgical repair. Most lesions are amenable to endovascular therapy, and CAS enabled treatment in patients judged not to be suitable surgical candidates. Duplex scanning surveillance after repeat CEA or CAS is recommended, because stenosis can recur after either secondary procedure
Plaque excision with the Silverhawk catheter: Early results in patients with claudication or critical limb ischemia
ObjectiveThis study was conducted to detail the early experience after infrainguinal atherectomy using the Silverhawk plaque excision catheter for the treatment of symptomatic peripheral vascular disease.MethodsA prospective database was established in August 2004 in which data for operations, outcomes, and follow-up were recorded for patients undergoing percutaneous plaque excision for peripheral arterial occlusive disease. Society for Vascular Surgery (SVS) ischemia scores and femoropopliteal TransAtlantic Inter-Society Consensus (TASC) criteria were assigned. A follow-up protocol included duplex ultrasound surveillance at 1, 3, and 6 months and then yearly thereafter. Standard statistical analyses were performed.ResultsDuring a 17-month period, 66 limbs of 60 patients (37 men [61.7%]) underwent 70 plaque excisions (four repeat procedures). Indications included tissue loss based on SVS ischemia at grades 5 and 6 (25/70), rest pain at grade 4 (22/70), and claudication at grades 2 to 3 (23/70). The mean lesion length was 8.8 ± 0.7 cm. The technical success rate was 87.1% (61/70). Adjunctive treatment was required in 17 procedures (24.3%), consisting of 14 balloon angioplasties and three stents. Femoropopliteal TASC criteria included 5 TASC A lesions, 14 TASC B lesions, 32 TASC C lesions, and 19 TASC D lesions. Although 17 plaque excisions included a tibial vessel, no patient underwent isolated tibial atherectomy. The mean increase in ankle-brachial index was 0.27 ± 0.04 and in toe pressure, 20.3 ± 6.9 mm Hg. Mean duplex ultrasound follow-up was 5.2 months (range, 1 to 17 months). One-year primary, primary assisted, and secondary patency was 61.7%, 64.1%, and 76.4%, respectively. Restenosis or occlusion developed in 12 patients (16.7%) and was detected at a mean of 2.8 ± 0.7 months. Restenosis or occlusion was significantly more common (P < .05) in patients with TASC C and D lesions compared with patients with TASC A and B lesions. Six (8.3%) of 12 patients underwent reintervention on the basis of duplex ultrasound surveillance results. Four (33.3%) of 12 patients experienced reocclusion during the same hospitalization, and amputation and open revascularization were required in two patients each.ConclusionsPercutaneous plaque excision is a viable treatment option for lower extremity revascularization. Outcomes are related to ischemia and lesion severity. Patency and limb salvage rates are equivalent to other endovascular modalities
Composite Fermion Theory, Edge Currents and the Fractional Quantum Hall Effect
We present a mean field theory of composite fermion edge channel transport in
the fractional and integer quantum Hall regimes. An expression relating the
electro-chemical potentials of composite fermions at the edges of a sample to
those of the corresponding electrons is obtained and a plausible form is
assumed for the composite fermion Landau level energies near the edges. The
theory yields the observed fractionally quantized Hall conductances and also
explains other experimental results. We also discuss some experiments that are
relevant to the question whether fractional edge states in real devices should
be described as Fermi or Luttinger liquids.Comment: 4 pages + 1 figure. Talk presented at EP2DSXI in Nottingham in
August, 1995. Self-unpacking uuencoded postscript. Unpacking instructions at
beginning of fil
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