tbuckley/cabot-search huggingface dataset:
Superoxide dismutase 1 encoding mutations linked to ALS adopts a spectrum of misfolded states
Authors: Mercedes Prudencio, David R Borchelt
Journal: Molecular Neurodegeneration (2011)

Mutations in superoxide dismutase 1 (SOD1), which are one cause of familial amyotrophic lateral sclerosis (fALS), induce misfolding and aggregation of the protein. Misfolding can be detected by the binding of antibodies raised against peptide epitopes that are normally buried in the native conformation, shifts in solubility in non-ionic detergents, and the formation of macromolecular inclusions. In the present study, we investigate the relationship between detergent-insoluble and sedimentable forms of mutant SOD1, forms of mutant SOD1 with aberrantly accessible epitopes, and mutant protein in inclusions with the goal of defining the spectrum of misfolded states that mutant SOD1 can adopt. Using combined approaches in cultured cell models, we demonstrate that a substantial fraction of mutant SOD1 adopts a non-native conformation that remains soluble and freely mobile. We also show that mutant SOD1 can produce multimeric assemblies of which some are insoluble in detergent and large enough to sediment by ultracentrifugation and some are large enough to detect visually. Three conformationally restricted antibodies were found to be useful in discriminating mal-folded forms of mutant SOD1. An antibody termed C4F6 displays properties consistent with recognition of soluble, freely mobile, mal-folded mutant SOD1. An antibody termed SEDI, which recognizes C-terminal residues, detects larger inclusion structures as well as soluble misfolded entities. An antibody termed hSOD1, which recognizes aa 24-36, detects an epitope shared by soluble non-natively folded WT and mutant SOD1. This epitope becomes inaccessible in aggregates of mutant SOD1. Our studies demonstrate how different methods of detecting misfolding and aggregation of mutant SOD1 reveal different forms of aberrantly folded protein. Immunological and biochemical methods can be used in combination to detect soluble and insoluble misfolded forms of mutant SOD1. Our findings support the view that mutant SOD1 can adopt multiple misfolded conformations with the potential that different structural variants mediate different aspects of fALS.
Enzymic properties of different types of human erythrocyte glucose-6-phosphate dehydrogenase, with characterization of two new genetic variants
Authors: L. Luzzatto, A. Afolayan
Journal: Journal of Clinical Investigation (1968)

Enzymic properties have been compared in the following five genetic variants of glucose-6-phosphate dehydrogenase from human erythrocytes: the two common variants with normal activity, A and B; the common variant associated with enzyme deficiency, A-; and two new rare variants, "Ijebu-Ode" and "Ita-Bale."The maximal velocity of the enzyme reaction (V(max)) increases steadily with pH over the entire range explored (from pH 5.5 to 9.5) for all enzyme variants when buffers are used that show no specific ion effects on enzyme activity. Small differences are found among the variants in the pH range 7.5-8.2, where A and B show a "peak and trough," while A-, "Ijebu-Ode," and "Ita-Bale" exhibit a plateau. When the effects of reagents that bind to sulphydryl groups are compared, iodoacetate, bromoacetate, and iodoacetamide are weak inhibitors, while N-ethylmaleimide (NEM) and hydroxymercuribenzoate (HMB) are potent inhibitors. The last two reagents have differential inhibitory action on different variants; one of these, "Ijebu-Ode," is strikingly resistant to HMB and totally resistant to NEM (up to 3 mmoles/liter). The enzyme inactivation as a function of temperature exhibits distinctive profiles for all variants examined. BOTH OF THE NEW VARIANTS DESCRIBED DIFFER SIGNIFICANTLY FROM THE NORMAL B TYPE IN SEVERAL RESPECTS: "Ijebu-Ode" in electrophoretic mobility, thermostability, dependence of V(max) on pH, and resistance to sulphydryl group reagents; "Ita-Bale" in electrophoretic mobility, Michaelis constant (K(m)) for glucose-6-phosphate, and dependence of V(max) on pH. When these data are compared with those available in the literature, both variants are different from all those previously described. The estimated frequencies of the corresponding genes in western Nigeria are between 0.0005 and 0.0025 for "Ijebu-Ode" and less than 0.0005 for "Ita-Bale". The A- variant, compared to A, has a distinctly higher K(m) for 2-deoxyglucose-6-phosphate and is more inhibited by very low concentrations of HMB. These are the first observed differences in kinetic properties between A and A-.
Mechanism of Action of (−)-Epigallocatechin-3-Gallate: Auto-oxidation–Dependent Inactivation of Epidermal Growth Factor Receptor and Direct Effects on Growth Inhibition in Human Esophageal Cancer KYSE 150 Cells
Authors: Zhe Hou, Shengmin Sang, Hui You, Mao-Jung Lee, Jungil Hong, Khew-Voon Chin, Chung S. Yang
Journal: Cancer Research (2005)

Abstract (−)-Epigallocatechin-3-gallate (EGCG), the principal polyphenol in green tea, has been shown to inhibit the growth of many cancer cell lines and to suppress the phosphorylation of epidermal growth factor receptor (EGFR). We observed similar effects of EGCG in esophageal squamous cell carcinoma KYSE 150 cells and epidermoid squamous cell carcinoma A431 cells. Pretreatment of KYSE 150 cells with EGCG (20 μmol/L) for 0.5 to 24 hours in HAM's F12 and RPMI 1640 mixed medium at 37°C, before the addition of EGF, resulted in a decreased level of phosphorylated EGFR (by 32-85%). Prolonged treatment with EGCG (8 or 24 hours) also decreased EGFR protein level (both by 80%). EGCG treatment for 24 hours also caused decreased signals of HER-2/neu in esophageal adenocarcinoma OE19 cells. These effects of EGCG were prevented or diminished by the addition of superoxide dismutase (SOD, 5 units/mL), or SOD plus catalase (30 units/mL), to the cell culture medium. A similar phenomenon on inactivation of EGFR was observed in A431 cells as well. Under culture conditions for KYSE 150 cells, EGCG was unstable, with a half-life of ∼30 minutes; EGCG dimers and other oxidative products were formed. The presence of SOD in the culture medium stabilized EGCG and increased its half-life to longer than 24 hours and some EGCG epimerized to (+)-gallocatechin-3-gallate. A mechanism of superoxide radical-mediated dimerization of EGCG and H2O2 formation is proposed. The stabilization of EGCG by SOD in the culture medium potentiated the activity of EGCG in inhibiting KYSE 150 cell growth. The results suggest that in cell culture conditions, the auto-oxidation of EGCG leads to EGFR inactivation, but the inhibition of cell growth is due to other mechanisms. It remains to be determined whether the presently observed auto-oxidation of EGCG occurs in vivo. In future studies of EGCG and other polyphenolic compounds in cell culture, SOD may be added to stabilize EGCG and to avoid possible artifacts.
Local Recurrences Following Mastectomy: Support for the Concept of Tumor Dormancy
Authors: R. Democheli, M. Tereziani, P. Valagussa, A. Moliterni, M. Zambetti, G. Bonadonna
Journal: JNCI Journal of the National Cancer Institute (1994)

Local or regional recurrence of breast cancer occurs in 5%-30% of patients treated by Halsted radical or modified radical mastectomy. Lag time between treatment and recurrence varies widely, and it is not known whether the recurring tumor grows at a constant growth rate or at a more rapid rate after a period of tumor dormancy.This study was undertaken to discriminate between the above-mentioned hypotheses, i.e., determine whether a tumor that recurs after mastectomy grows at a constant rate or whether it grows rapidly following a period of tumor dormancy.A series of 122 patients with local recurrence as a first event after mastectomy for resectable breast cancer was evaluated. We measured the diameter of the recurring tumor (Dr) in each patient and calculated the diameter that the recurring tumor could have reached at the immediately preceding physical examination (Dpe), when no local relapse had yet been detected, by assuming an exponential growth during the treatment-free interval. For patients who had a calculated diameter Dpe that was large enough to have been detected at the previous examination, we assumed that a tumor 5 mm in diameter had been mistakenly missed, and the expected corresponding tumor diameter at the time of detection (Drc) was calculated. Finally, the minimum growth rate (mGR) consistent with the sequence "no detection-->recurrence of diameter Dr" was obtained by assuming an exponential growth from the tumor volume corresponding to a diameter 1 mm less than the diameter detection threshold.A wide overlap between Dr and Dpe values was observed. Seventy-two (59%) of 122 Dpe values were larger than the minimum Dr; 18 (15%) were even larger than the median Dr value. The difference between expected and observed detection rates was highly significant (P < .0001). Furthermore, when treatment-free intervals were longer than 4 years, the difference between median Dr and median Dpe values failed to reach statistical significance. The Drc values were significantly lower than the related Dr values, while the mGR values were significantly higher than the corresponding growth rates (paired sample t test: P < .001).This study provides evidence that the hypothesis of uninterrupted constant growth of locally recurring breast tumors should be rejected, as it implies a statistically significant departure from observed data. Our results suggest that a period of tumor dormancy followed by more rapid growth could provide an alternative and more reasonable description of tumor recurrence.
<i>Int7G24A</i> Variant of Transforming Growth Factor-β Receptor Type I Is Associated with Invasive Breast Cancer
Authors: Taiping Chen, Chad R. Jackson, Andrew Link, Michael P. Markey, Bruce M. Colligan, Larry E. Douglass, Jackson O. Pemberton, James A. Deddens, Jeremy R. Graff, Julia H. Carter
Journal: Clinical Cancer Research (2006)

Abstract Purpose: The transforming growth factor-β (TGF-β) signaling pathway has been frequently implicated in breast cancer. An intronic variant (Int7G24A) of TGF-β receptor type I (TGFBR1) is associated with kidney and bladder cancers in our recent study. We hypothesize that this germline variant may be involved in development and progression of breast cancer. Experimental Design: Case-control studies were designed from archived paraffin-embedded tissue specimens from the same geographic area with a homogenous ethnic population. We analyzed 223 patients (25 with preinvasive tumors and 198 with invasive and metastatic breast cancers) and 153 noncancer controls. The Int7G24A was identified by PCR-RFLP. Another germline deletion (TGFBR1*6A) and somatic mutations in the TGFBR1 were also analyzed by PCR and single-strand conformational polymorphism. Results: The Int7G24A allele was evident in 32% of patients with preinvasive neoplasms and 48% of patients with invasive breast cancers compared with 26% controls (P = 0.00008). In addition, 11 (5.6%) homozygous Int7G24A carriers were found in patients with invasive breast cancers, whereas only 3 (2%) homozygous carriers were found in the control group. The TGFBR1*6A allele was not significantly associated with breast cancer patients and only one somatic mutation was found in 71 breast cancers. Conclusion: These data suggest that the germline Int7G24A variant may represent a risk factor for invasive breast cancer and a marker for breast cancer progression. A separate study with a larger sample size is warranted to validate the association of the Int7G24A with human breast cancer.
A Common Dominant TLR5 Stop Codon Polymorphism Abolishes Flagellin Signaling and Is Associated with Susceptibility to Legionnaires' Disease
Authors: Thomas R. Hawn, Annelies Verbon, Kamilla D. Lettinga, Lue Ping Zhao, Shuying Sue Li, Richard J. Laws, Shawn J. Skerrett, Bruce Beutler, Lea Schroeder, Alex Nachman, Adrian Ozinsky, Kelly D. Smith, Alan Aderem
Journal: The Journal of Experimental Medicine (2003)

Although Toll-like receptors (TLRs) are critical mediators of the immune response to pathogens, the influence of polymorphisms in this gene family on human susceptibility to infection is poorly understood. We demonstrated recently that TLR5 recognizes flagellin, a potent inflammatory stimulus present in the flagellar structure of many bacteria. Here, we show that a common stop codon polymorphism in the ligand-binding domain of TLR5 (TLR5392STOP) is unable to mediate flagellin signaling, acts in a dominant fashion, and is associated with susceptibility to pneumonia caused by Legionella pneumophila, a flagellated bacterium. We also show that flagellin is a principal stimulant of proinflammatory cytokine production in lung epithelial cells. Together, these observations suggest that TLR5392STOP increases human susceptibility to infection through an unusual dominant mechanism that compromises TLR5's essential role as a regulator of the lung epithelial innate immune response.
Choriocarcinoma after Hydatidiform Mole. Studies Related to Effectiveness of Follow-up Practice after Hydatidiform Mole
Authors: K. D. Bagshawe, P. R. Golding, A. H. Orr
Journal: BMJ (1969)

Chemotherapy, in conjunction with other methods of treatment, was used in 100 patients with invasive hydatidiform mole or choriocarcinoma following mole. When treatment was instituted within two to six months of the antecedent mole serious drug resistance was not encountered, drug toxicity was slight, the duration of treatment was comparatively short, and sustained remissions were obtained in 57 out of 60 patients. When the start of chemotherapy was delayed beyond six months drug resistance occurred in many instances, toxicity was often severe, the duration of treatment was much longer, and sustained remissions were obtained in 22 out of 40 patients.The practice of giving prophylactic chemotherapy to all patients with mole is not established as effective or safe. Differences in the social background to hydatidiform mole in different geographical areas may be such that conclusions based on evidence from one area are not necessarily applicable to another.Careful follow-up after mole remains essential, though present methods often fail to ensure recognition of choriocarcinoma while it is still curable. Standard qualitative and quantitative methods for detecting the continued excretion of chorionic gonadotrophin, though useful, are sometimes too insensitive. It is suggested that to supplement local arrangements some form of centralized or regionalized follow-up service based on notification of patients with hydatidiform mole, and making use of radioimmunoassays for chorionic gonadotrophin, could reduce deaths attributable to late diagnosis.
Reciprocal regulation of airway rejection by the inducible gas-forming enzymes heme oxygenase and nitric oxide synthase
Authors: Kanji Minamoto, Hiroaki Harada, Vibha N. Lama, Maksim A. Fedarau, David J. Pinsky
Journal: The Journal of Experimental Medicine (2005)

Obliterative bronchiolitis (OB) develops insidiously in nearly half of all lung transplant recipients. Although typically preceded by a CD8+ T cell–rich lymphocytic bronchitis, it remains unresponsive to conventional immunosuppression. Using an airflow permissive model to study the role of gases flowing over the transplanted airway, it is shown that prolonged inhalation of sublethal doses of carbon monoxide (CO), but not nitric oxide (NO), obliterate the appearance of the obstructive airway lesion. Induction of the enzyme responsible for the synthesis of CO, heme oxygenase (Hmox) 1, increased carboxyhemoglobin levels and suppressed lymphocytic bronchitis and airway luminal occlusion after transplantation. In contrast, zinc protoporphyrin IX, a competitive inhibitor of Hmox, increased airway luminal occlusion. Compared with wild-type allografts, expression of inducible NO synthase (iNOS), which promotes the influx of cytoeffector leukocytes and airway graft rejection, was strikingly reduced by either enhanced expression of Hmox-1 or exogenous CO. Hmox-1/CO decreased nuclear factor (NF)-κB binding activity to the iNOS promoter region and iNOS expression. Inhibition of soluble guanylate cyclase did not interfere with the ability of CO to suppress OB, implicating a cyclic guanosine 3′,5′-monophosphate–independent mechanism through which CO suppresses NF-κB, iNOS transcription, and OB. Prolonged CO inhalation represents a new immunosuppresive strategy to prevent OB.
The Effect of Bilateral Nephrectomy and Midcollicular Decerebration with Pinealectomy and Hypophysectomy on the Corticosteroid Secretion of Sodium-deficient Sheep *
Authors: J. R. Blair-West, J. P. Coghlan, D. A. Denton, J. A. Munro, Marelyn Wintour, R. D. Wright
Journal: Journal of Clinical Investigation (1964)

The adrenal gland, whether in its normal situation or transplanted to another site, responds to sodium depletion (1, 2), constriction of the in- ferior vena cava (3), or hemorrhage (3, 4) by in- creased secretion of aldosterone.Crosscirculation studies of Denton, Goding, and Wright (1) and Yankopoulos, Davis, Kliman, and Peterson (5) indicate that the stimulus to the adrenal is humoral.Three local humoral circumstances, ACTH infusion (2, 6-8), angiotensin II infusion (2, 6, 9-12), and low sodium and high potassium concentration of plasma (1, 2, 6, 13), are known to cause an increase in aldosterone secretion, and the levels required for the reaction are not beyond those that are known or might be presumed to oc- cur naturally.However, conscious unstressed dogs with thoracic caval constriction showed a 20to 40-fold increase in aldosterone secretion rates associated with low corticosterone and Porter-Silber chromogen secretion (14).Experiments on conscious sheep with adrenal transplants have shown that with the development of sodium deficiency of 100 to 300 mEq, the aldosterone se- cretion may rise up to 10-fold without change of cortisol and corticosterone from basal level (2).These experiments clearly demonstrate that in the conscious animal ACTH is not the factor directly causal of increased aldosterone production in re- sponse to the physiological stimulus.In the ex-
Peak inspiratory flow and inspiratory vital capacity of patients with asthma measured with and without a new dry-powder inhaler device (Turbuhaler)
Authors: T Engel, JH Heinig, F Madsen, K Nikander
Journal: European Respiratory Journal (1990)

In 101 asthmatic adults with varying degrees of bronchial obstruction, lung function tests including peak inspiratory flow (PIF), inspiratory vital capacity (IVC), peak expiratory flow (PEF), forced vital capacity (FVC), and forced expiratory volume in one second (FEV1) measurements were made. Significant correlations between inspiratory and expiratory volumes were found. In most patients, PIF was less reduced than the expiratory parameters of pulmonary function. When inhalation was performed through the new multi-dose, dry-powder inhalation device, Turbuhaler (PIF-TBH), it was significantly lower than PIF measured without Turbuhaler. In previous studies, PIF-TBH of 30 l.min-1 or more has proven sufficient to produce a therapeutic dose of terbutaline, and to produce significant bronchodilatation. Of 101 asthmatics in the present study, only four had PIF-TBH of less than 30 l.min-1. Although no parameters of spirometry could accurately predict PIF-TBH, there was a tendency for patients with severely impaired ventilatory capacity to produce lower PIF-TBH than patients with normal or near-normal ventilatory capacity. If patients with severely impaired ventilatory capacity are to receive inhalation therapy through Turbuhaler, either PIF or PIF-TBH should be measured, or the effect should be carefully monitored.
Prospective Study of Posttraumatic Stress, Anxiety, and Depressive Reactions After Earthquake and Political Violence
Authors: Armen K. Goenjian, Alan M. Steinberg, Louis M. Najarian, Lynn A. Fairbanks, Madeline Tashjian, Robert S. Pynoos
Journal: American Journal of Psychiatry (2000)

OBJECTIVE: The authors sought to assess the severity and longitudinal course of posttraumatic stress, anxiety, and depressive reactions among two groups of adults differentially exposed to severe and mild earthquake trauma and a third group exposed to severe violence. They also examined interrelationships among these reactions and predictors of outcome and compared posttraumatic stress disorder (PTSD) symptom category profile and course between those exposed to earthquake and those exposed to violence.METHOD: Seventy-eight non-treatment-seeking subjects were assessed with self-report instruments approximately 1.5 and 4.5 years after the 1988 Spitak earthquake in Armenia and the 1988 pogroms against Armenians in Azerbaijan.RESULTS: The two groups that had been exposed to severe trauma (earthquake or violence) had high initial and follow-up PTSD scores that did not remit over the 3-year interval. Overall, depressive symptoms subsided. Posttraumatic stress, anxiety, and depressive reactions were highly intercorrelated within and across both time intervals. No significant differences in PTSD severity, profile, or course were seen between subjects exposed to severe earthquake trauma versus those exposed to severe violence.CONCLUSIONS: After exposure to severe trauma, either an earthquake or violence, adults are at high risk of developing severe and chronic posttraumatic stress reactions that are associated with chronic anxiety and depressive reactions. Clinical evaluation and therapeutic intervention should include specific attention to these reactions. Early mental health intervention is recommended to prevent their chronicity.
Sprouty1 Haploinsufficiency Prevents Renal Agenesis in a Model of Fraser Syndrome
Authors: Jolanta E. Pitera, Adrian S. Woolf, M. Albert Basson, Peter J. Scambler
Journal: Journal of the American Society of Nephrology (2012)

Deficiency of the extracellular matrix molecule FRAS1, normally expressed by the ureteric bud, leads to bilateral renal agenesis in humans with Fraser syndrome and blebbed (Fras1(bl/bl)) mice. The metanephric mesenchyme of these mutants fails to express sufficient Gdnf, which activates receptor tyrosine kinase (RTK) signalling, contributing to the phenotype. To determine whether modulating RTK signalling may overcome the abnormal nephrogenesis characteristic of Fraser syndrome, we introduced a single null Sprouty1 allele into Fras1(bl/bl) mice, thereby reducing the ureteric bud's expression of this anti-branching molecule and antagonist of RTK signalling. This prevented renal agenesis in Fras1(bl/bl) mice, permitting kidney development and postnatal survival. We found that fibroblast growth factor (FGF) signalling contributed to this genetic rescue, and exogenous FGF10 rescued defects in Fras1(bl/bl) rudiments in vitro. Whereas wild-type metanephroi expressed FRAS1 and the related proteins FREM1 and FREM2, FRAS1 was absent and the other proteins were downregulated in rescued kidneys, consistent with a reciprocally stabilized FRAS1/FREM1/FREM2 complex. In addition to contributing to knowledge regarding events during nephrogenesis, the demonstrated rescue of renal agenesis in a model of a human genetic disease raises the possibility that enhancing growth factor signaling might be a therapeutic approach to ameliorate this devastating malformation.