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Michel C, Lerch S, Büetiger JR, Flückiger R, Cavelti M, Koenig J, Kaess M, Kindler J. An ecological momentary assessment study of age effects on perceptive and non-perceptive clinical high-risk symptoms of psychosis. Eur Child Adolesc Psychiatry 2023; 32:1841-1852. [PMID: 35585271 PMCID: PMC9116495 DOI: 10.1007/s00787-022-02003-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/30/2022] [Indexed: 11/15/2022]
Abstract
Among individuals with clinical high risk for psychosis (CHR), perceptive symptoms are more frequent but have less clinical significance in children/adolescents compared to adults. However, findings are based on clinical interviews relying on patient's recall capacity. Ecological momentary assessment (EMA) can be used to explore experiences in real-time in the subject's daily life. The aim of this study was to assess frequency and stability of (perceptive and non-perceptive) CHR symptoms and to explore potential age effects. EMA was used in a sample of an early detection for psychosis service in Bern, Switzerland (N = 66; 11-36 years). CHR symptoms were recorded in random time intervals for seven days: eight assessments per day per subject, minimum time between prompts set at 25 min. CHR symptoms were additionally assessed with semi-structured interviews including the 'Structured Interview for Psychosis-Risk Syndromes' and the 'Schizophrenia Proneness Instruments'. Mixed-effects linear regression analysis on the frequency of CHR symptoms revealed a significant effect of age group, and the interaction CHR symptoms x age group for both perceptive and non-perceptive symptoms. Further, regarding stability of CHR symptoms, there was a significant effect of the interaction CHR symptoms x age group for perceptive symptoms only. Based on EMA, perceptive CHR symptoms were more frequently reported but less stable in children/adolescents compared with adults. Together with previous findings, our finding of higher instability/variability of perceptive symptoms in younger persons might suggest that with advancing age and more stability of CHR symptoms, clinical relevance (reduced psychosocial functioning) may increase.
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Flückiger R, Cocuzzi E, Nagaraj RH, Shoham M, Kern TS, Medof ME. DAF in diabetic patients is subject to glycation/inactivation at its active site residues. Mol Immunol 2018; 93:246-252. [PMID: 28886871 PMCID: PMC5884443 DOI: 10.1016/j.molimm.2017.06.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 06/14/2017] [Accepted: 06/19/2017] [Indexed: 11/30/2022]
Abstract
Decay accelerating factor (DAF or CD55) is a cell associated C3 and C5 convertase regulator originally described in terms of protection of self-cells from systemic complement but now known to modulate adaptive T cell responses. It is expressed on all cell types. We investigated whether nonenzymatic glycation could impair its function and potentially be relevant to complications of diabetes mellitus and other conditions that result in nonenzymatic glycation including cancer, Alzheimer's disease, and aging. Immunoblots of affinity-purified DAF from erythrocytes of patients with diabetes showed pentosidine, glyoxal-AGEs, carboxymethyllysine, and argpyrimidine. HPLC/MS analyses of glucose modified DAF localized the sites of AGE modifications to K125 adjacent to K126, K127 at the junction of CCPs2-3 and spatially near R96, and R100, all identified as being critical for DAF's function. Functional analyses of glucose or ribose treated DAF protein showed profound loss of its regulatory activity. The data argue that de-regulated activation of systemic complement and de-regulated activation of T cells and leukocytes could result from non-enzymatic glycation of DAF.
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Obrenovich M, Flückiger R, Sykes L, Donskey C. The Co-Metabolism within the Gut-Brain Metabolic Interaction: Potential Targets for Drug Treatment and Design. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2016; 15:127-34. [PMID: 26831263 DOI: 10.2174/1871527315666160202123107] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 01/27/2016] [Indexed: 11/22/2022]
Abstract
We know that within the complex mammalian gut is any number of metabolic biomes. The gut has been sometimes called the "second brain" within the "gut-brain axis". A more informative term would be the gut-brain metabolic interactome, which is coined here to underscore the relationship between the digestive system and cognitive function or dysfunction as the case may be. Co-metabolism between the host and the intestinal microbiota is essential for life's processes. How diet, lifestyle, antibiotics and other factors shape the gut microbiome constitutes a rapidly growing area of research. Conversely, the gut microbiome also affects mammalian systems. Metabolites of the gut-brain axis are potential targets for treatment and drug design since the interaction or biochemical interplay results in net metabolite production or end-products with either positive or negative effects on human health. This review explores the gut-brain metabolic interactome, with particular emphasis on drug design and treatment strategies and how commensal bacteria or their disruption lead to dysbiosis and the effect this has on neurochemistry. Increasing data indicate that the intestinal microbiome can affect neurobiology, from mental and even behavioral health to memory, depression, mood, anxiety, obesity, cravings and even the creation and maintenance of the blood brain barrier.
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Flückiger R, Schmidt S, Michel C, Klosterkötter J, Schimmelmann B, Ruhrmann S. TTe Predictive Power of the Wisconsin Scales of Schizophrenia Proneness in Patients of an Early Detection Service. Eur Psychiatry 2015. [DOI: 10.1016/s0924-9338(15)30720-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Heisterbach PE, Todorov A, Flückiger R, Evans CH, Majewski M. Effect of BMP-12, TGF-β1 and autologous conditioned serum on growth factor expression in Achilles tendon healing. Knee Surg Sports Traumatol Arthrosc 2012; 20:1907-14. [PMID: 22124845 DOI: 10.1007/s00167-011-1772-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 11/08/2011] [Indexed: 10/15/2022]
Abstract
PURPOSE Achilles tendon ruptures are devastating and recover slowly and incompletely. There is a great demand for biomolecular therapies to improve recovery, yet little is understood about growth factors in a healing tendon. Here, the role of growth factors during tendon healing in a rat model and their reaction to single and multiple growth factor treatment are explored. METHODS Rat tendons were transected surgically and resutured. The expression of bFGF, BMP-12, VEGF and TGF-β1 was assessed by immunohistochemical analysis one to 8 weeks after surgery. Paracrine effects of TGF-β1 or BMP-12 added by adenoviral transfer, as well as the effect of autologous conditioned serum (ACS) on growth factor expression, were evaluated. RESULTS bFGF, BMP-12 and VEGF expression was highest 1 week after transection. bFGF and BMP-12 declined during the remaining period whereas VEGF expression persisted. TGF-β1 expression dramatically increased after 8 weeks. ACS treatment increased bFGF (P = 0.007) and BMP-12 (P = 0.004) expression significantly after 8 weeks. Also overall expression of bFGF, BMP-12 and TGF-β1 regardless of time point was significantly greater than controls with ACS treatment (P < 0.05). Both BMP-12 and TGF-β1 treatments had no significant effect. No effect was observed in VEGF with any treatment. CONCLUSION bFGF, BMP-12, VEGF and TGF-β1 are differentially expressed during tendon healing. Additional BMP-12 or TGF-β1 has no significant influence, whereas ACS generally increases expression of all factors except VEGF. Staged application of multiple growth factors may be the most promising biomolecular treatment.
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Majewski M, Porter RM, Betz OB, Betz VM, Clahsen H, Flückiger R, Evans CH. Improvement of tendon repair using muscle grafts transduced with TGF-β1 cDNA. Eur Cell Mater 2012; 23:94-101; discussion 101-2. [PMID: 22354460 PMCID: PMC4339190 DOI: 10.22203/ecm.v023a07] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Tendon rupture is a common injury. Inadequate endogenous repair often leaves patients symptomatic, with tendons susceptible to re-rupture. Administration of certain growth factors improves tendon healing in animal models, but their delivery remains a challenge. Here we evaluated the delivery of TGF-β1 to tendon defects by the implantation of genetically modified muscle grafts. Rat muscle biopsies were transduced with recombinant adenovirus encoding TGF-β1 and grafted onto surgically transected Achilles tendons in recipient animals. Tissue regenerates were compared to those of controls by biomechanical testing as well as histochemical and immunohistochemical analyses. Healing was greatly accelerated when genetically modified grafts were implanted into tendon defects, with the resulting repair tissue gaining nearly normal histological appearance as early as 2 weeks postoperatively. This was associated with decreased deposition of type III collagen in favour of large fibre bundles indicative of type I collagen. These differences in tendon composition coincided with accelerated restoration of mechanical strength. Tendon thickness increased in gene-treated animals at weeks 1 and 2, but by week 8 became significantly lower than that of controls suggesting accelerated remodelling. Thus localised TGF-β1 delivery via adenovirus-modified muscle grafts improved tendon healing in this rat model and holds promise for clinical application.
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Flückiger R, Meier J, Crovini G, Demichelis F, Giorgis F, Pirri C, Tresso E, Pohl J, Rigato V, Zandolin S, Caccavale F. Structural and Electrical Properties of Undoped Microcrystalline Silicon Grown by 70 MHz and 13.56 MHz PECVD. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-358-751] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTMicrocrystalline silicon films deposited by plasma methods have an optical absorption for photon energies above 2.0 eV lower than a-Si:H films and can be efficiently doped with boron or phosphorus. The most widely used deposition technique is the 13.56 MHz PECVD. However quite recently µc-Si:H films were grown at high deposition rates by the 70 MHz PECVD. In this work the authors report on a comparison between µc-Si:H films deposited by both 70 MHz and 13.56 MHz techniques. Particular attention has been devoted to differences and similarities between structural, compositional and electrical properties of the films deposited with the two systems.
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Majewski M, Ochsner PE, Liu F, Flückiger R, Evans CH. Accelerated healing of the rat Achilles tendon in response to autologous conditioned serum. Am J Sports Med 2009; 37:2117-25. [PMID: 19875360 DOI: 10.1177/0363546509348047] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Despite advances in the treatment of ruptured Achilles tendon, imperfections of endogenous repair often leave patients symptomatic. Local administration of autologous conditioned serum (ACS) in patients with inflammatory, degenerative conditions has shown beneficial effects. PURPOSE Because ACS also contains growth factors that should accelerate tendon healing, we studied the effect of ACS on the healing of transected rat Achilles tendon. STUDY DESIGN Controlled laboratory study. METHODS In preliminary in vitro experiments, rat tendons were incubated with ACS and the effect on the expression of Col1A1 and Col3A1 was assessed by real-time quantitative polymerase chain reaction. To test its effect in vivo, the Achilles tendons of 80 Sprague Dawley rats were transected and sutured back together. Ten rats from each group (ACS group, n = 40; control group, n = 40) were euthanized at 1, 2, 4, and 8 weeks postoperatively for biomechanical (n = 7) and histologic (n = 3) testing. Lysyl oxidase activity was assayed by a flurometric assay. The organization of repair tissue was assessed histologically with hematoxylin and eosin- and with Sirius red-stained sections, and with immunohistochemistry. RESULTS Tendons exposed to ACS in vitro showed a greatly enhanced expression of the Col1A1 gene. The ACS-treated tendons were thicker, had more type I collagen, and an accelerated recovery of tendon stiffness and histologic maturity of the repair tissue. However, there were no differences in the maximum load to failure between groups up to week 8, perhaps because lysyl oxidase activities were unchanged. CONCLUSION AND CLINICAL RELEVANCE Overall, our study demonstrates that treatment with ACS has the potential to improve Achilles tendon healing and should be considered as a treatment modality in man. However, as strength was not shown to be increased within the parameters of this study, the clinical importance of the observed changes in humans still needs to be defined.
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Curtin P, McHugh KP, Zhou HY, Flückiger R, Goldhaber P, Oppenheim FG, Salih E. Modulation of bone resorption by phosphorylation state of bone sialoprotein. Biochemistry 2009; 48:6876-86. [PMID: 19518132 PMCID: PMC2748923 DOI: 10.1021/bi900066b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have determined transmembrane protein tyrosine phosphorylation (outside-in signaling) in cultured osteoclasts and macrophages in response to added native purified bone sialoprotein (nBSP) and its dephosphorylated form (dBSP). There were selective/differential and potent inhibitory effects by dBSP and minimal effect by nBSP on intracellular tyrosine phosphorylation in macrophages and osteoclasts. Further studies on the downstream gene expression effects led to identification of a large number of differentially expressed genes in response to nBSP relative to dBSP in both macrophages and osteoclasts. These studies were extended to a bone resorption model using live mouse neonatal calvarial bone organ cultures stimulated by parathyroid hormone (PTH) to undergo bone resorption. Inclusion of nBSP in such cultures showed no effect on type I collagen telopeptide fragment release, hence overall bone resorption, whereas addition of dBSP abolished the PTH-induced bone resorption. The inhibition of bone resorption by dBSP was shown to be unique since in complementary experiments use of integrin receptor binding ligand, GRGDS peptide, offered only partial reduction on overall bone resorption. Quantitative RANKL analysis indicated that mechanistically the PTH-induced bone resorption was inhibited by dBSP via down-regulation of the osteoblastic RANKL production. This conclusion was supported by the RANKL analysis in cultured MC3T3-E1 osteoblast cells. Overall, these studies provided direct evidence for the involvement of covalently bound phosphates on BSP in receptor mediated "outside-in" signaling via transmembrane tyrosine phosphorylation with concurrent effects on downstream gene expressions. The use of a live bone organ culture system augmented these results with further evidence that links the observed in vivo variable state of phosphorylation with bone remodeling.
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Abstract
Current HIV entry inhibitors target the binding of the viral envelope glycoprotein gp120 to cellular CD4 and co-receptors, or block a late stage of the fusogenic activation of adjacent gp41. New targets are suggested by the role of cell surface protein disulfide isomerase (PDI), which attaches to the primary receptor CD4 close to the gp120-binding site. This could enable PDI to reduce gp120 disulfide bonds, which triggers the major conformational changes in gp120 and gp41 required for virus entry. Inhibiting cell surface PDI prevents HIV-1 entry. The new potential targets outlined are PDI activity as well as the sites of PDI-CD4 and PDI-gp120 interaction.
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Saad FA, Salih E, Wunderlich L, Flückiger R, Glimcher MJ. Prokaryotic expression of bone sialoprotein and identification of casein kinase II phosphorylation sites. Biochem Biophys Res Commun 2005; 333:443-7. [PMID: 15950178 DOI: 10.1016/j.bbrc.2005.05.124] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Accepted: 05/18/2005] [Indexed: 11/28/2022]
Abstract
Bone sialoprotein is an extracellular noncollagenous acidic protein that plays a role in bone mineralization and remodeling. Its expression is restricted to mineralized tissues and is subjected to variety of posttranslational modifications including phosphorylation and glycosylation. We have expressed the full-length and half domains of bovine bone sialoprotein in a prokaryotic system and identified the phosphorylation sites of casein kinase II. The N-terminal automated solid-phase sequencing defined four phosphorylated peptides: residues 28-38 (LEDS(P)EENGVFK), 51-86 (FYPELKRFAVQSSS(P)DS(P)S(P)EENGNGDS(P)S(P)EEEEEEEETS(P)), 151-165 (EDES(P)DEEEEEEEEEE), and 295-305 (GRGYDS(P)YDGQD). Nine phosphoserines were identified within the four peptides. Seven of them were in the N-terminus (S31, S64, S66, S67, S75, S76, and S86) and two were in the C-terminus (S154 and S300) of the protein.
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Salih E, Flückiger R. Complete topographical distribution of both the in vivo and in vitro phosphorylation sites of bone sialoprotein and their biological implications. J Biol Chem 2004; 279:19808-15. [PMID: 15004024 DOI: 10.1074/jbc.m310299200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bone sialoprotein (BSP) is a multifunctional, highly phosphorylated, and glycosylated protein with key roles in biomineralization and tissue remodeling. This work identifies the complete topographical distribution and precise location of both the in vitro and in vivo phosphorylation sites of bovine BSP by a combination of state-of-the-art techniques and approaches. In vitro phosphorylation of native and deglycosylated BSPs by casein kinase II identified seven phosphorylation sites by solid-phase N-terminal peptide sequencing that were within peptides 12-22 (LEDS(P)EENGVFK), 42-62 (FAVQSSSDSS(P)EENGNGDS(P)S(P)EE), 80-91 (EDS(P)DENEDEES(P)E), and 135-145 (EDES(P)DEEEEEE). The in vivo phosphorylation regions and sites were identified by use of a novel thiol reagent, 1-S-mono[(14)C]carboxymethyldithiothreitol. This approach identified all of the phosphopeptides defined by in vitro phosphorylation, but two additional phosphopeptides were defined at residues, 250-264 (DNGYEIYES(P)ENGDPR), and 282-289 (GYDS(P)YDGQ). Furthermore, use of native BSP and matrix-assisted laser desorption ionization time-of-flight mass spectrometry identified several of the above peptides, including an additional phosphopeptide at residues 125-130 (AGAT(P)GK) that was not defined in either of the in vitro and in vivo studies described above. Overall, 7 in vitro and 11 in vivo phosphorylation sites were identified unequivocally, with natural variation in the quantitative extent of phosphorylation at each in vivo phosphorylation site.
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Abstract
The long life spans and slow aging rates of birds relative to mammals are paradoxical in view of birds' high metabolic rates, body temperatures and blood glucose levels, all of which are predicted to be liabilities by current biochemical theories of aging. Available avian life-table data show that most birds undergo rapid to slow "gradual" senescence. Some seabird species exhibit extremely slow age-related declines in both survival and reproductive output, and even increase reproductive success as they get older. Slow avian senescence is thought to be coupled evolutionarily with delayed maturity and low annual fecundity. Recent research in our lab and others supports the hypothesis that birds have special adaptations for preventing age-related tissue damage caused by reactive oxygen species (ROS) and advanced glycosylation endproducts, or AGEs, as well as an unusual capacity for neurogeneration in brain. Much of this work is in its early stages, however, and reliable biomarkers for comparing avian and mammalian aging need more thorough development.
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Palakurthi SS, Flückiger R, Aktas H, Changolkar AK, Shahsafaei A, Harneit S, Kilic E, Halperin JA. Inhibition of translation initiation mediates the anticancer effect of the n-3 polyunsaturated fatty acid eicosapentaenoic acid. Cancer Res 2000; 60:2919-25. [PMID: 10850438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Eicosapentaenoic acid (EPA), an n-3 polyunsaturated fatty acid that is abundant in the fish-based diets of populations that exhibit a remarkably low incidence of cancer, exerts anticancer activity in vitro and in animal models of experimental cancer. Here we define the molecular basis for the anticancer effects of EPA. EPA inhibits cell division by inhibiting translation initiation. This is a consequence of the ability of EPA to release Ca2+ from intracellular stores while inhibiting their refilling via capacitative Ca2+ influx that results in partial emptying of intracellular Ca2+ stores and thereby activation of protein kinase R. Protein kinase R phosphorylates and inhibits eukaryotic initiation factor 2alpha, resulting in inhibition of protein synthesis at the level of translation initiation, preferentially reducing the synthesis and expression of growth-regulatory proteins, including G1 cyclins, and causes cell cycle arrest in G1. In a KLN-205 squamous cell carcinoma mouse model, daily oral administration of EPA resulted in a significant reduction of tumor size and expression of cyclin D1 in the tumor tissues. Furthermore, EPA-treated tumors showed a significant increase in the proportion of diploid cells, indicative of cell cycle arrest in G0-G1, and a significant reduction of malignant hypertetraploid cells. These results characterize EPA as a member of an emerging new class of anticancer compounds that inhibit translation initiaton.
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Acosta J, Hettinga J, Flückiger R, Krumrei N, Goldfine A, Angarita L, Halperin J. Molecular basis for a link between complement and the vascular complications of diabetes. Proc Natl Acad Sci U S A 2000; 97:5450-5. [PMID: 10805801 PMCID: PMC25849 DOI: 10.1073/pnas.97.10.5450] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Activated terminal complement proteins C5b to C9 form the membrane attack complex (MAC) pore. Insertion of the MAC into endothelial cell membranes causes the release of growth factors that stimulate tissue growth and proliferation. The complement regulatory membrane protein CD59 restricts MAC formation. Because increased cell proliferation characterizes the major chronic vascular complications of human diabetes and because increased glucose levels in diabetes cause protein glycation and impairment of protein function, we investigated whether glycation could inhibit CD59. Glycation-inactivation of CD59 would cause increased MAC deposition and MAC-stimulated cell proliferation. Here, we report that (i) human CD59 is glycated in vivo, (ii) glycated human CD59 loses its MAC-inhibitory function, and (iii) inactivation of CD59 increases MAC-induced growth factor release from endothelial cells. We demonstrate by site-directed mutagenesis that residues K41 and H44 form a preferential glycation motif in human CD59. The presence of this glycation motif in human CD59, but not in CD59 of other species, may help explain the distinct propensity of humans to develop vascular proliferative complications of diabetes.
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Aktas H, Flückiger R, Acosta JA, Savage JM, Palakurthi SS, Halperin JA. Depletion of intracellular Ca2+ stores, phosphorylation of eIF2alpha, and sustained inhibition of translation initiation mediate the anticancer effects of clotrimazole. Proc Natl Acad Sci U S A 1998; 95:8280-5. [PMID: 9653178 PMCID: PMC20967 DOI: 10.1073/pnas.95.14.8280] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Regulation of translation initiation plays a critical role in the control of cell growth and division in eukaryotic cells. Translation of many growth regulatory proteins including cyclins depends critically on translation initiation factors because their mRNAs are translated inefficiently. We report that clotrimazole, a potent antiproliferative agent both in vitro and in vivo, inhibits cell growth by interfering with translation initiation. In particular, clotrimazole causes a sustained depletion of intracellular Ca2+ stores, which results in activation of PKR, phosphorylation of eIF2alpha, and thereby in inhibition of protein synthesis at the level of translation initiation. Consequently, clotrimazole preferentially decreases the expression of the growth promoting proteins cyclin A, E and D1, resulting in inhibition of cyclin-dependent kinase activity and blockage of cell cycle in G1.
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Pacher K, Flückiger R, Schaub N, Wegmann W, Huber A. [Duplication cyst of the stomach antrum as the cause of an acute gastric emptying disorder in an adult]. Dtsch Med Wochenschr 1998; 123:621-5. [PMID: 9627570 DOI: 10.1055/s-2007-1024029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
HISTORY AND CLINICAL FINDINGS A 35-year old woman without previous history of gastrointestinal complaints developed increasing upper abdominal pain with nausea and postprandial vomiting over 2 days during which she had been unable to take any food. She had no fever; her general physical condition was slightly reduced. While her abdomen felt soft on palpation, she had epigastric pain on pressure but no resistance to palpation. INVESTIGATIONS Blood picture and routine laboratory tests were unremarkable. Plain film of the abdomen demonstrated marked gastric retention. Abdominal ultrasound showed an invagination in the gastric antrum suggesting a layering phenomenon. Gastroscopy revealed a submucosal tumour-like lesion with central ulceration which obstructed gastric exit. TREATMENT AND COURSE After conclusion of the diagnostic tests on the first hospital day partial gastric resection (Billroth I) was performed as, in the absence of any surrounding reaction, a leiomyoma had been suspected. The further course was without complication and she was discharged on the 13th hospital day. The surgical specimen revealed a duplication cyst of the gastric antrum. CONCLUSION (Endo)sonography, computed tomography and endoscopy make it possible to diagnose duplication cyst, as long as it is included in the differential diagnosis of acute abdomen in an adult. Emergency resection of the cyst is indicated because of the acute nature of the symptoms. But even in less urgent cases or as an incidental finding it is the treatment of choice.
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Abstract
Right colon diverticulitis, representing 1-3.6% of cases of diverticular disease is an uncommon cause of right lower quadrant pain. Its presentation is difficult to distinguish from acute appendicitis. Patients are between 35 and 50 years old, have a history of 2-3 days of abdominal pain and few gastrointestinal symptoms. The diagnosis is best confirmed by computed tomography and colonoscopy. Conservative treatment is justified in uncomplicated disease, whereas perforations, abcesses and inflammatory tumors require resection. We describe the cases of six patients treated at our institution from 1991 to 1996. Presentation, geographic variations, diagnostic procedures and management are discussed.
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Paz MA, Martin P, Flückiger R, Mah J, Gallop PM. The catalysis of redox cycling by pyrroloquinoline quinone (PQQ), PQQ derivatives, and isomers and the specificity of inhibitors. Anal Biochem 1996; 238:145-9. [PMID: 8660603 DOI: 10.1006/abio.1996.0267] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Pyrroloquinoline quinone (PQQ) is a widely distributed redox-active cofactor and essential nutrient. For its detection in protein-free ultrafiltrates or dialysates, a highly sensitive amplification assay was developed on the basis of PQQ's ability to catalyze redox cycling at pH 10 in the presence of excess glycine, oxygen, and nitro blue tetrazolium. Herein, we examine the propensities of PQQ, PQQ triester, and its various isomers, and certain PQQ triester derivatives, to catalyze glycine-fueled redox cycling and show that PQQ is the most capable of catalyzing redox cycling. Furthermore, PQQ has a unique pattern of inhibition induced by a series of PQQ antagonists of different potencies. The data indicate that putative PQQ from a biological sample, separated by HPLC and detected by the glycine-fueled redox-cycling assay, can be further identified as PQQ based on the profile of inhibition it displays with the antagonists such as those employed in this study. The methodology presented here should facilitate the specific detection of PQQ in biological samples.
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Flückiger R, Wegmann W, Huber A. [Tumor of the gastrointestinal autonomic nervous system (GAN-tumor or plexus sarcoma)]. Chirurg 1996; 67:371-9. [PMID: 8646924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
GAN-tumors or plexosarcomas, first described by Herrera et al. in 1984, are uncommon neurogenic stromal spindle cell tumors of the intestinal tract mainly located in the stomach and the small intestine. The distinctive immunohistochemical pattern is the positive staining for vimentin and neuron-specific-enolase. Ultrastructural features are neuron-like cells with interdigitating cytoplasmic processes, dense-core neurosecretory granules, the lack of basement membranes and the presence of interstitial skeinoid fibers. Pain, chronic and acute bleeding are the most frequent but not specific symptoms and the diagnostic delay is reflected by a large average diameter of these tumors. For even smaller tumors and those with a low mitotic rate may metastasize, GAN-tumors must be considered malignant and need a radical surgical resection.
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Flückiger R, Huber A. [Sigmoid volvulus--clinical, radiological and therapeutic aspects of rare disease]. PRAXIS 1995; 84:826-830. [PMID: 7631098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Volvulus of the sigmoid colon is a common cause of colonic obstruction in many parts of the world, mainly in developing countries and in Scandinavia, but is rare in the Western Hemisphere, where it occurs in elderly patients who often have serious coexisting diseases, especially cardiovascular and neuropsychiatric disorders. Although many patients present with the typical triad of abdominal pain, distension and constipation, the disease is correctly diagnosed only in about 62%. Diagnostic delay is due in part to the relative rarity of the illness, in part to the variety of the clinical and radiologic presentation, and it might contribute to the high mortality. Treatment consists in endoscopic decompression, whenever there are no compromised intestines, followed by an elective, sigmoid resection in otherwise healthy patients, because the risk of recurrence is high after nonoperative decompression alone. Hartmann's procedure is the safest procedure in patients with ischemic necrosis of the sigmoid colon. The site of primary resection and anastomosis with viable bowel remains controversial. Knowledge of sigmoid volvulus is of general interest with respect to the growing number of elderly patients, especially those residing in nursing homes and psychiatric institutions.
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Flückiger R, Paz MA, Gallop PM. Redox-cycling detection of dialyzable pyrroloquinoline quinone and quinoproteins. Methods Enzymol 1995; 258:140-9. [PMID: 8524146 DOI: 10.1016/0076-6879(95)58043-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Abstract
A 30-year-old man with ulcerative colitis developed oral hairy leukoplakia (OHL). Serological examination for human immunodeficiency virus (HIV)-1 and HIV-2 infection showed no abnormalities. Biopsy specimen of the lateral tongue showed ballooned prickle cells, and electron microscopy revealed herpes-type viruses. Immunologic investigation of the patient showed a marked decrease in T-helper cells as a result of immunosuppressive regimen. The present report appears to be the first well-documented case of OHL in an HIV-negative patient with ulcerative colitis. OHL may be a marker for severe immunosuppression but is not necessarily associated with HIV infection. Patients with iatrogenic immunosuppression should be monitored for OHL. Concerning the marked decrease in T-helper cells in this case, the presence of OHL may imply the examination of T-lymphocyte subsets in patients such as HIV-infected individuals or in organ transplant recipients.
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Itin PH, Flückiger R, Zbinden R, Frei R. Recurrent pyogenic granuloma with satellitosis--a localized variant of bacillary angiomatosis? Dermatology 1994; 189:409-12. [PMID: 7533011 DOI: 10.1159/000246892] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
A 27-year-old male patient had recurrent pyogenic granuloma with satellitosis. Histologically, Warthin-Starry staining of the lesions revealed clumps of dark bacilli as found in patients with bacillary angiomatosis. IgG antibodies against Bartonella (Rochalimaea) henselae were elevated as shown by an indirect immunofluorescence assay. The patient did not present an obvious risk for HIV infection or immunosuppression, and no antibodies against HIV-1 and HIV-2 were found. Recurrent pyogenic granuloma with satellitosis may be a localized variant of bacillary angiomatosis.
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Itin PH, Lautenschlager S, Flückiger R, Rufli T. Oral manifestations in HIV-infected patients: diagnosis and management. J Am Acad Dermatol 1993; 29:749-60. [PMID: 8227548 DOI: 10.1016/0190-9622(93)70241-k] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Oral lesions have been observed since the beginning of the AIDS epidemic. The number of HIV-infected patients is still increasing, especially in the heterosexual population. Oral diseases in HIV-infected patients are often more difficult to diagnose because the clinical presentations may differ from the same diseases in HIV-negative patients. HIV-associated oral lesions have diagnostic, prognostic, and therapeutic impact. Approximately 10% of the HIV-infected population will have oral manifestations as a first sign of their disease. In HIV-infected men oral hairy leukoplakia and oral candidiasis are useful markers for disease progression. This article summarizes the oral manifestations and the management of oral health in persons with HIV infection.
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MESH Headings
- Acquired Immunodeficiency Syndrome/complications
- Angiomatosis, Bacillary/complications
- Angiomatosis, Bacillary/diagnosis
- Angiomatosis, Bacillary/therapy
- Candidiasis/complications
- Candidiasis/diagnosis
- Candidiasis/therapy
- Carcinoma, Squamous Cell/complications
- Carcinoma, Squamous Cell/diagnosis
- Carcinoma, Squamous Cell/therapy
- Female
- Gingivitis/complications
- Gingivitis/diagnosis
- Gingivitis/therapy
- Humans
- Leukoplakia, Hairy/complications
- Leukoplakia, Hairy/diagnosis
- Leukoplakia, Hairy/therapy
- Lymphoma, Non-Hodgkin/diagnosis
- Lymphoma, Non-Hodgkin/etiology
- Lymphoma, Non-Hodgkin/therapy
- Male
- Mouth Diseases/complications
- Mouth Diseases/diagnosis
- Mouth Diseases/therapy
- Mouth Neoplasms/complications
- Mouth Neoplasms/diagnosis
- Mouth Neoplasms/therapy
- Papilloma/complications
- Papilloma/diagnosis
- Papilloma/therapy
- Periodontitis/complications
- Periodontitis/diagnosis
- Periodontitis/therapy
- Salivary Gland Diseases/complications
- Salivary Gland Diseases/diagnosis
- Salivary Gland Diseases/therapy
- Sarcoma, Kaposi/diagnosis
- Sarcoma, Kaposi/etiology
- Sarcoma, Kaposi/therapy
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