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1.
Br J Dermatol ; 185(1): 147-152, 2021 07.
Article in English | MEDLINE | ID: mdl-33393080

ABSTRACT

BACKGROUND: Ceramide kinase-like protein (CERKL) was originally described in retinal tissue. CERKL has been shown to protect cells from oxidative stress, and mutations in CERKL underlie the inherited disease retinitis pigmentosa. CERKL expression maintains cellular sphingolipids via an unknown mechanism. OBJECTIVES: To determine whether CERKL is expressed in epidermis and cutaneous squamous cell carcinoma (cSCC) and whether CERKL expression affects cSCC sphingolipid metabolism and susceptibility to oxidative stress. METHODS: CERKL expression was determined by RNA-Seq, quantitative polymerase chain reaction and immunohistochemistry. CERKL was knocked down in cSCC cells using small interfering RNA. Sphingolipid content was analysed by liquid chromatography-mass spectrometry. Oxidative stress was induced by treatment with H2 O2 , and apoptosis was measured using flow cytometry to determine annexin V binding. RESULTS: CERKL mRNA and protein are highly expressed in actinic keratosis and cSCC in comparison with normal epidermis. CERKL is also expressed in metabolically active epithelial cells in normal hair bulbs and sebaceous glands. CERKL knockdown in cultured cSCC cells reduces cellular sphingolipid content and enhances susceptibility to oxidative stress. CONCLUSIONS: These findings suggest that CERKL may be important in cSCC progression and could lead to novel strategies for prevention and treatment of cSCC.


Subject(s)
Carcinoma, Squamous Cell , Skin Neoplasms , Carcinoma, Squamous Cell/genetics , Humans , Oxidative Stress , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Skin Neoplasms/genetics , Sphingolipids
2.
Br J Dermatol ; 2020 Dec 03.
Article in English | MEDLINE | ID: mdl-33270220

ABSTRACT

BACKGROUND: Ceramide Kinase-Like Protein (CERKL) was originally described in retinal tissue. CERKL has been shown to protect cells from oxidative stress, and mutations in CERKL underlie the inherited disease, retinitis pigmentosa. CERKL expression maintains cellular sphingolipids via an unknown mechanism. OBJECTIVES: To determine whether CERKL is expressed in epidermis and cutaneous squamous cell carcinoma (cSCC) and whether CERKL expression affects cSCC sphingolipid metabolism and susceptibility to oxidative stress. METHODS: CERKL expression was determined by RNA-Seq, qPCR and immunohistochemistry. CERKL was knocked down in cSCC cells using siRNA. Sphingolipid content was analyzed by liquid chromatography-mass spectrometry (LC-MS). Oxidative stress was induced by treatment with H2 O2 , and apoptosis was measured using flow cytometry to determine annexin v binding. RESULTS: CERKL mRNA and protein are highly expressed in actinic keratosis and cSCC in comparison with normal epidermis. CERKL also is expressed in metabolically active epithelial cells in normal hair bulbs and sebaceous glands. CERKL knockdown in cultured cSCC cells reduces cellular sphingolipid content and enhances susceptibility to oxidative stress. CONCLUSIONS: These findings suggest that CERKL may be important in cSCC progression and could lead to novel strategies for prevention and treatment of cSCC.

3.
Med Oral Patol Oral Cir Bucal ; 23(6): e639-e645, 2018 Nov 01.
Article in English | MEDLINE | ID: mdl-30341262

ABSTRACT

BACKGROUND: The objective of this study was to evaluate the dental and oral manifestations in patients with celiac disease. MATERIAL AND METHODS: The sample consisted of 40 patients with the disease and 40 without the disease matched by age in southern Brazil. The CD group included patients previously diagnosed by positive anti-endomysial (IgA) examination and confirmed by small intestine biopsy. The presence of dental enamel defects and dental caries was evaluated by a calibrated researcher according to AINE's and WHO's criteria, respectively. The history of recurrent aphthous ulcers and dry mouth was obtained through reporting. For the evaluation of the salivary flow, the saliva samples were obtained through the non-stimulated and stimulated saliva collection method. RESULTS: There was a significant association between CD and dental enamel defects (OR=2.38, P=0.045) and dry mouth (OR=9.15, P=0.002). No difference was found for the report of recurrent aphthous ulcers and caries experience between the two groups. Patients with CD had normal pattern of unstimulated and stimulated saliva flow rates (0.67 ± 0.38 ml / min and 1.14 ± 0.47 ml / min, respectively). A higher occurrence of dental enamel defects was observed in patients with classic CD (P=0.054). Of the 1,962 permanent teeth, 59 presented dental enamel defects, 71.8% of which were in patients with CD (P=0.001), predominantly in molars (P=0.009). CONCLUSIONS: CD increased the likelihood of dental enamel defects and dry mouth sensation. The oral examination can be an important auxiliary tool for the identification of cases of the disease.


Subject(s)
Celiac Disease/complications , Mouth Diseases/etiology , Tooth Diseases/etiology , Adolescent , Child , Female , Humans , Male , Mouth Diseases/epidemiology , Prevalence , Tooth Diseases/epidemiology
5.
Musculoskelet Surg ; 100(Suppl 1): 73-83, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27900699

ABSTRACT

BACKGROUND: The posterior approaches to the elbow are considered as to allow an excellent joint exposure for total elbow arthroplasty. One complication that is well recognized is the insufficiency of the extensor mechanism in particular with the patients with poor tendon quality as in the rheumatoid diseases. The purpose of this paper is to present a new triceps-splitting exposure for total elbow arthroplasty used in rheumatoid patients with their preliminary results. METHODS: Fifteen consecutive patients with rheumatoid disease at grades III to V of the Larsen grading scale underwent total elbow replacement using the new triceps-splitting exposure called anconeus-triceps lateral flap and it preserves the integrity of the medial proper triceps tendon. The assessments were performed with a minimum follow-up of 2 years. RESULTS: The mean Mayo Elbow Performance Score increased from 24 points to 95 points at a mean follow-up of 38 months. The pain was calculated using the visual analogue score, it had a mean pre-operative value of 8.9 points and it became 0.5 points. Although elbow motion in flexion-extension and pronosupination was allowed from the day after surgery, we did not observe any insufficiency or secondary detachments of the triceps tendon reporting grade 4 to 5 according to the Medical Research Council scale. CONCLUSIONS: These preliminary outcomes suggest that the decision to preserve the medial proper triceps tendon insertion allows to start an earlier active unrestricted rehabilitation programme. This new triceps management improves the surgical exposure of the olecranon surface. LEVEL OF EVIDENCE: Level IV.


Subject(s)
Arthritis, Rheumatoid/surgery , Arthroplasty, Replacement , Elbow Joint/surgery , Muscle, Skeletal/surgery , Aged , Arthritis, Rheumatoid/diagnostic imaging , Arthroplasty, Replacement/methods , Female , Follow-Up Studies , Humans , Male , Middle Aged , Range of Motion, Articular , Retrospective Studies , Treatment Outcome
6.
Musculoskelet Surg ; 99 Suppl 1: S57-66, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25957546

ABSTRACT

Triceps injuries are relatively uncommon in most traumatic events, and the distal triceps tendon ruptures are rare. Recently, the knowledge of this tendon lesion has increased, and it seems to be related to more precise diagnostic and clinical assessments. The most common mechanism of injury remains a forceful eccentric contraction of the muscle, while several other risk factors have been studied as chronic renal failure, endocrine disorders, metabolic bone diseases as well as steroid use. Olecranon bursitis and local corticosteroid injections may also play a role. The commonest site of rupture is at the tendon's insertion into the olecranon and rarely at the myotendinous junction or intramuscularly. The surgical intervention is recommended in acute complete ruptures, and non-operative treatment is reserved for patients with major comorbidities, as well as for partial ruptures with little functional disability and in low demanding patients. Various techniques and approaches as the direct repair to bone, the tendon augmentation, the anconeus rotation flap and the Achilles tendon allograft have been proposed for the management of these challenging injuries. The goal of surgical management should be an anatomical repair of the injured tendon by selection of a procedure with a low complication rate and one that allows early mobilization. This manuscript focuses the triceps tendon ruptures starting from the anatomy to the diagnosis and entity of the triceps tendon injuries, as well as the indications and guidelines for the management.


Subject(s)
Achilles Tendon/transplantation , Tendon Injuries/pathology , Tendon Injuries/surgery , Adolescent , Adult , Aged , Arm , Child , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Rupture/diagnostic imaging , Rupture/pathology , Rupture/surgery , Tendon Injuries/diagnostic imaging
7.
Br J Dermatol ; 164(1): 16-25, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20846312

ABSTRACT

BACKGROUND: Endoplasmic reticulum (ER) Ca(2+) depletion, previously shown to signal pathological stress responses, has more recently been found also to trigger homeostatic physiological processes such as differentiation. In keratinocytes and epidermis, terminal differentiation and barrier repair require physiological apoptosis and differentiation, as evidenced by protein synthesis, caspase 14 expression, lipid secretion and stratum corneum (SC) formation. OBJECTIVES: To investigate the role of Ca(2+) depletion-induced ER stress in keratinocyte differentiation and barrier repair in vivo and in cell culture. METHODS: The SERCA2 Ca(2+) pump inhibitor thapsigargin (TG) was used to deplete ER calcium both in cultured keratinocytes and in mice. Levels of the ER stress factor XBP1, loricrin, caspase 14, lipid synthesis and intracellular Ca(2+) were compared after both TG treatment and barrier abrogation. RESULTS: We showed that these components of terminal differentiation and barrier repair were signalled by physiological ER stress, via release of stratum granulosum (SG) ER Ca(2+) stores. We first found that keratinocyte and epidermal ER Ca(2+) depletion activated the ER-stress-induced transcription factor XBP1. Next, we demonstrated that external barrier perturbation resulted in both intracellular Ca(2+) emptying and XBP1 activation. Finally, we showed that TG treatment of intact skin did not perturb the permeability barrier, yet stimulated and mimicked the physiological processes of barrier recovery. CONCLUSIONS: This report is the first to quantify and localize ER Ca(2+) loss after barrier perturbation and show that homeostatic processes that restore barrier function in vivo can be reproduced solely by releasing ER Ca(2+), via induction of physiological ER stress.


Subject(s)
Calcium/metabolism , Cell Differentiation/physiology , DNA-Binding Proteins/metabolism , Endoplasmic Reticulum/metabolism , Epidermis/metabolism , Keratinocytes/cytology , Transcription Factors/metabolism , Animals , Caspase 14/metabolism , Cell Differentiation/drug effects , Cells, Cultured , Endoplasmic Reticulum/drug effects , Endoplasmic Reticulum/pathology , Enzyme Inhibitors/pharmacology , Epidermis/drug effects , Epidermis/pathology , Humans , Immunoblotting , Keratinocytes/drug effects , Keratinocytes/pathology , Lipids/analysis , Membrane Proteins/metabolism , Mice , Polymerase Chain Reaction , Regulatory Factor X Transcription Factors , Thapsigargin/pharmacology , X-Box Binding Protein 1
8.
Biophys J ; 98(5): 911-21, 2010 Mar 03.
Article in English | MEDLINE | ID: mdl-20197045

ABSTRACT

Ionic gradients are found across a variety of tissues and organs. In this report, we apply the phasor representation of fluorescence lifetime imaging data to the quantitative study of ionic concentrations in tissues, overcoming technical problems of tissue thickness, concentration artifacts of ion-sensitive dyes, and calibration across inhomogeneous tissue. We used epidermis as a model system, as Ca(2+) gradients in this organ have been shown previously to control essential biologic processes of differentiation and formation of the epidermal permeability barrier. The approach described here allowed much better localization of Ca(2+) stores than those used in previous studies, and revealed that the bulk of free Ca(2+) measured in the epidermis comes from intracellular Ca(2+) stores such as the Golgi and the endoplasmic reticulum, with extracellular Ca(2+) making a relatively small contribution to the epidermal Ca(2+) gradient. Due to the high spatial resolution of two-photon microscopy, we were able to measure a marked heterogeneity in average calcium concentrations from cell to cell in the basal keratinocytes. This finding, not reported in previous studies, calls into question the long-held hypothesis that keratinocytes increase intracellular Ca(2+), cease proliferation, and differentiate passively in response to changes in extracellular Ca(2+). The experimental results obtained using this approach illustrate the power of the experimental and analytical techniques outlined in this report. Our approach can be used in mechanistic studies to address the formation, maintenance, and function of the epidermal Ca(2+) gradient, and it should be broadly applicable to the study of other tissues with ionic gradients.


Subject(s)
Biophysical Phenomena , Calcium/metabolism , Epidermis/metabolism , Imaging, Three-Dimensional/methods , Adult , Calibration , Epidermal Cells , Extracellular Space/metabolism , Fluorescence , Humans , Organic Chemicals/metabolism , Time Factors , Tissue Fixation
9.
Cell Mol Life Sci ; 63(24): 3061-71, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17131054

ABSTRACT

To clarify the role of poly(ADP-ribose)polymerase-1 (PARP-1) in myocardial ischemia-reperfusion injury, we explored some effects of PJ34, a highly specific inhibitor of this enzyme, in hypoxic-reoxygenated (HR) H9c2 cardiomyoblasts. Compared to the control, HR cells showed signs of oxidative stress, marked PARP-1 activation, NAD(+) and ATP depletion and impaired mitochondrial activity. HR cardiomyoblasts were affected by both necrosis and apoptosis, the latter involving the nuclear translocation of apoptosis-inducing factor. In HR cardiomyoblasts treated with PJ34, oxidative stress and PARP-1 activity were decreased, and NAD(+) and ATP depletion, as well as mitochondrial impairment, were attenuated. Above all, PJ34 treatment improved the survival of HR cells; not only was necrosis significantly diminished, but apoptosis was also reduced and shifted from a caspase-independent to a caspase-dependent pathway. These results suggest that PARP-1 modulation by a selective inhibitor such as PJ34 may represent a promising approach to limit myocardial damage due to post-ischemic reperfusion.


Subject(s)
Myoblasts, Cardiac/drug effects , Phenanthrenes/pharmacology , Poly(ADP-ribose) Polymerase Inhibitors , Adenosine Triphosphate/metabolism , Animals , Apoptosis , Cell Hypoxia , Cell Line , Cell Survival , Coloring Agents/pharmacology , NAD/metabolism , Necrosis , Oxidative Stress , Poly (ADP-Ribose) Polymerase-1 , Rats , Reactive Oxygen Species , Tetrazolium Salts/pharmacology , Thiazoles/pharmacology
10.
Biochim Biophys Acta ; 1741(1-2): 173-82, 2005 Jun 30.
Article in English | MEDLINE | ID: mdl-15894467

ABSTRACT

Oxidative stress stimulates both growth and apoptosis in cardiac myocytes in vitro. We investigated the role of oxidative stress in the initial phases of cardiac remodeling induced in an animal model by volume overload. As plausible candidates for a connection between oxidative stress and cardiomyocyte apoptosis or hypertrophy, we explored the behaviour of two MAPKs, specifically JNK and ERK. At 48 h of overload, the greatest increase in oxidative stress coincided with a peak of cardiomyocyte apoptosis. This was possibly induced through the mitochondrial metabolism, as evidenced by the release of cytochrome c and a significant increase in the active forms of caspase-9 and -3, but not caspase-8. Oxidative stress markers significantly decreased at 96 h of overload, combined with a marked attenuation of apoptosis and the appearance of hypertrophy. The highest levels of JNK and the lowest levels of ERK phosphorylation were observed at 48 h of overload. Conversely, a sharp increase in ERK phosphorylation was detected at 96 h of overload coinciding with the hypertrophic response. Together these results show that oxidative stress is an early and transient event in myocardial volume overload. They suggest that oxidative stress mediates amplitude dependent apoptotic and hypertrophic responses in cardiomyocytes through the selective activation of, respectively, JNK and ERK.


Subject(s)
Apoptosis , Cardiac Volume/physiology , Myocytes, Cardiac/metabolism , Oxidative Stress , Animals , Caspase 3 , Caspase 9 , Caspases/analysis , Caspases/metabolism , Cell Size , Cytochromes c/metabolism , Echocardiography , Enzyme Activation , Hemodynamics , Hypertrophy , JNK Mitogen-Activated Protein Kinases/metabolism , Malondialdehyde/analysis , Malondialdehyde/metabolism , Mitogen-Activated Protein Kinases/metabolism , Myocytes, Cardiac/pathology , Phosphorylation , Poly(ADP-ribose) Polymerases/analysis , Poly(ADP-ribose) Polymerases/metabolism , Subcellular Fractions/metabolism , Sus scrofa , Time Factors
11.
Chir Organi Mov ; 90(2): 121-32, 2005.
Article in English, Italian | MEDLINE | ID: mdl-16422237

ABSTRACT

Purpose of this study is to evaluate the effectiveness of muscle transfer of the teres major in the treatment of irreparable posterosuperior injuries of the rotator cuff. Long-term monitoring of the results obtained in 20 patients treated at our clinic using this method are reported, comparing the data obtained in evaluations of results with preoperative values. Clinical evaluations were obtained using the Constant Score System, while X-ray examination showed the presence of osteoarticular modifications, and MRI and electromyography the preserved morphology and function of transplant. The mean Constant Score increased from 31.6 points preoperatively to 66.1 points postoperatively at the time of follow-up. At follow-up, MRI allowed us to evaluate any fatty degeneration of the muscle fibers of transfer and the integrity of tendinous insertion on the humeral greater tuberosity. The obtained results allowed us to reveal the advantages and the disadvantages of teres major transplant in irreparable posterosuperior ruptures of the cuff.


Subject(s)
Muscle, Skeletal/transplantation , Rotator Cuff Injuries , Rotator Cuff/surgery , Adult , Aged , Electromyography , Female , Humans , Male , Middle Aged , Radiography , Retrospective Studies , Rotator Cuff/diagnostic imaging , Rupture , Shoulder Injuries , Shoulder Joint/surgery
12.
Chir Organi Mov ; 89(1): 7-19, 2004.
Article in English, Italian | MEDLINE | ID: mdl-15382581

ABSTRACT

Fractures of the radial head associated with dislocation of the elbow constitute a pathology for which it is difficult to choose treatment, and that has a high failure rate. A retrospective study of the literature and of a series of cases was conducted: 31 patients came to our observation between 1990 amd 2001 and were analyzed by clinical (Broberg and Morrey Score and SECEC Score) and radiographic testing. Based on the Broberg and Morrey Score the results were excellent in 4 patients (13%), good in 8 (26%), fair in 12 (39%), and poor in 7 (22%) with a success rate of 39% and a failure rate of 61% principally due to secondary stiffness and instability. In an attempt to reduce the number of failures, a treatment protocol aimed at restoring a stable, mobile and painless elbow was devised.


Subject(s)
Elbow Joint , Joint Dislocations/complications , Joint Dislocations/surgery , Radius Fractures/complications , Radius Fractures/surgery , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Range of Motion, Articular , Recovery of Function , Retrospective Studies
13.
Biochim Biophys Acta ; 1638(3): 217-26, 2003 Jul 30.
Article in English | MEDLINE | ID: mdl-12878322

ABSTRACT

To identify early adaptive processes of cardiac remodeling (CR) in response to volume overload, we investigated the molecular events that may link intracellular Ca(2+) homeostasis alterations and cardiomyocyte apoptosis. In swine heart subjected to aorto-cava shunt for 6, 12, 24, 48 and 96 h sarcoplasmic reticulum (SR) Ca(2+) pump activity was reduced until 48 h (-30%), but a recovery of control values was found at 96 h. The decrease in SR Ca(2+)-ATPase (SERCA2a) expression at 48 h, was more marked (-60%) and not relieved by a subsequent recovery, while phospholamban (PLB) concentration and phosphorylation were unchanged at all the considered times. Conversely, acylphosphatase activity and expression significantly increased from 48 to 96 h (+40%). Bcl-2 expression increased significantly from 6 to 24 h, but at 48 h, returned to control values. At 48 h, microscopic observations showed that overloaded myocardium underwent substantial damage and apoptotic cell death in concomitance with an enhanced Fas/Fas-L expression. At 96 h, apoptosis appeared attenuated, while Fas/Fas-L expression was still higher than control values and cardiomyocyte hypertrophy became to develop. These data suggest that in our experimental model, acylphosphatase could be involved in the recovery of SERCA2a activity, while cardiomyocyte apoptosis might be triggered by a decline in Bcl-2 expression and a concomitant activation of Fas.


Subject(s)
Acid Anhydride Hydrolases/physiology , Cardiomyopathies/metabolism , Ventricular Remodeling/physiology , Animals , Apoptosis , Calcium/metabolism , Calcium-Binding Proteins/metabolism , Calcium-Transporting ATPases/biosynthesis , Calcium-Transporting ATPases/metabolism , Cardiac Volume , Cardiomyopathies/pathology , Electrocardiography , Fas Ligand Protein , Hemodynamics , Membrane Glycoproteins/biosynthesis , Proto-Oncogene Proteins/biosynthesis , Sarcoplasmic Reticulum Calcium-Transporting ATPases , Swine , Time Factors , fas Receptor/biosynthesis , Acylphosphatase
14.
Histol Histopathol ; 18(2): 359-69, 2003 04.
Article in English | MEDLINE | ID: mdl-12647785

ABSTRACT

Gap-junctions are specialized regions of intercellular contacts allowing electrical impulse propagation among adjacent cardiomyocytes. Connexin43 (Cx43) is the predominant gap-junction protein in the working ventricular myocardium and its reduced expression has been extensively implicated in the genesis of conduction abnormalities and re-entry arrhythmia of chronically hypertrophied hearts. In contrast, data on the role played by this protein during cardiac remodeling and early phases of developing hypertrophy are lacking. Therefore, in the present study, we investigated this issue using an experimental model of pig left ventricle (LV) volume overloading consisting in the creation of an aorto-cava fistula. At scheduled times (6, 24, 48, 96, 168 h, and 2, 3 months after surgery) echocardiographic and haemodynamic measurements were performed and myocardial biopsies were taken for the morphological and biochemical analyses. When faced with the increased load, pig myocardium underwent an initial period (from 6 up to 48 h) of remarkable tissue remodeling consisting in the occurrence of cardiomyocyte damage and apoptosis. After that time, the tissue developed a hypertrophic response that was associated with early dynamic changes (up-regulation) in Cx43 protein expression, as demonstrated by Western blot and confocal immunofluorescence analyses. However, an initial transient increase of this protein was also found after 6 h from surgery. With the progression of LV hypertrophy (from 168 hr up to 3 months), a reduction in the myocardial Cx43 expression was, instead, observed. The increased expression of Cx43 protein during acute hypertrophic response was associated with a corresponding increase in the levels of its specific mRNA, as detected by RT-PCR. We concluded that up-regulation of Cx43 gap-junction protein could represent an immediate compensatory response to support the new working conditions in the early stages of ventricular overloading.


Subject(s)
Adaptation, Physiological/physiology , Connexin 43/biosynthesis , Heart/physiology , Myocardium/metabolism , Animals , Apoptosis/physiology , Blotting, Western , Cell Size , Densitometry , Fibrosis , Hemodynamics/physiology , Microscopy, Confocal , Microscopy, Electron , Myocardial Contraction/physiology , Myocardium/ultrastructure , RNA, Messenger/biosynthesis , Reverse Transcriptase Polymerase Chain Reaction , Swine , Ventricular Function, Left/physiology
17.
Org Lett ; 3(22): 3573-4, 2001 Nov 01.
Article in English | MEDLINE | ID: mdl-11678711

ABSTRACT

[reaction: see text]. Irradiation of 4,5-dithiophen-3-yl-[1,3]dithiol-2-one 1 at lambda > 330 nm gave the thieno[3,4-c]dithiine 2, the first example of this heterocyclic system

18.
Methods ; 25(1): 103-10, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11559001

ABSTRACT

Multiphoton fluorescence microscopy has now become a relatively common tool among biophysicists and biologists. The intrinsic sectioning achievable by multiphoton excitation provides a simple means to excite a small volume inside cells and tissues. Multiphoton microscopes have a simplified optical path in the emission side due to the lack of an emission pinhole, which is necessary with normal confocal microscopes. This article illustrates examples in which this advantage in the simplified optics is exploited to achieve a new type of measurements. First, dual-emission wavelength measurements are used to identify regions of different phase domains in giant vesicles and to perform fluctuation experiments at specific locations in the membrane. Second, we show how dual-wavelength measurements are used in conjunction with scanning fluctuation analysis to measure the changes in the geometry of the domains and the incipient formation of gel domains when the temperature of the giant vesicles is gradually lowered.


Subject(s)
Microscopy, Confocal/methods , Microscopy, Fluorescence/methods , Photons , Spectrometry, Fluorescence/methods , Fluorescence Polarization , Fluorescent Dyes , Membrane Fluidity , Microscopy, Confocal/instrumentation , Microscopy, Fluorescence/instrumentation , Quantum Theory , Spectrometry, Fluorescence/instrumentation
19.
J Steroid Biochem Mol Biol ; 77(4-5): 213-22, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11457659

ABSTRACT

This study examines the effect of 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], 24,25-dihydroxyvitamin D(3) [24,25(OH)(2)D(3)], two vitamin D analogues (KH 1060 and EB 1089, which are 20-epi-22-oxa and 22,24-diene-analogues, respectively), 9-cis retinoic acid and all-trans retinoic acid on proliferation of SH-SY5Y human neuroblastoma cells, after treatment for 7 days. Cell number did not change when the cells were incubated with 1, 10 or 100 nM 1,25(OH)(2)D(3) or its derivatives, but significantly decreased in the presence of the two retinoids (0.001--10 microM final concentration). A synergistic inhibition was observed, when SH-SY5Y cells were treated combining 0.1 microM 9-cis retinoic acid and 10 nM 1,25(OH)(2)D(3) or 10 nM KH 1060, and 1 microM 9-cis retinoic acid and 10 nM 1,25(OH)(2)D(3) or 10 nM EB 1089. Acetylcholinesterase activity showed a significant increase, in comparison with controls, after treatment of the cells for 7 days with 0.1 or 1 microM 9-cis retinoic acid, alone or combined with 10 nM 1,25(OH)(2)D(3) or 10 nM KH 1060 or 10 nM EB 1089. This increase was synergistic, combining 1 microM 9-cis retinoic acid and 10 nM 1,25(OH)(2)D(3) or EB 1089. The levels of the c-myc encoded protein remarkably decreased after treatment of SH-SY5Y cells for 1, 3, 7 days with 0.1 and 1 microM 9-cis retinoic acid, alone or combined with 10 nM 1,25(OH)(2)D(3) or 10 nM KH 1060 or 10 nM EB 1089. In particular, the association of 1 microM 9-cis retinoic acid and 10 nM 1,25(OH)(2)D(3) or 10 nM EB 1089 resulted in a synergistic c-myc inhibition, in comparison with that obtained in the presence of the retinoid alone. These findings may have therapeutic implications in human neuroblastoma.


Subject(s)
Antineoplastic Agents/pharmacology , Neuroblastoma/pathology , Steroid Hydroxylases/pharmacology , Tretinoin/pharmacology , Acetylcholinesterase/drug effects , Acetylcholinesterase/metabolism , Alitretinoin , Cell Division/drug effects , Drug Synergism , Gene Expression/drug effects , Humans , Neuroblastoma/enzymology , Proto-Oncogene Proteins c-myc/drug effects , Proto-Oncogene Proteins c-myc/genetics , Proto-Oncogene Proteins c-myc/metabolism , Tumor Cells, Cultured , Vitamin D/analogs & derivatives
20.
J Mol Spectrosc ; 199(1): 13-17, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10712865

ABSTRACT

High-resolution FTIR spectra of 1,1,1-trifluoroethane (HFC-143a) have been recorded in the region from 1370 to 1470 cm(-1) with an unapodized resolution of 0.0016 cm(-1) at room temperature and of 0.004 cm(-1) at 183 and 100 K. The two main infrared active bands of A(1) symmetry have been shown to be nu(2) at 1407.5 cm(-1) and nu(4) + nu(5) at 1440.5 cm(-1). With the aid of Raman spectra, the two infrared inactive bands of E symmetry in this spectra region have been shown to be nu(8) at 1457.5 cm(-1) and nu(6) + nu(9) at 1446.2 cm(-1). The nu(2) band was analyzed as an isolated band, whereas the nu(4) + nu(5) band was analyzed as part of the triad nu(4) + nu(5), nu(6) + nu(9), and nu(8). Copyright 2000 Academic Press.

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