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1.
Sci Rep ; 13(1): 21944, 2023 12 11.
Article in English | MEDLINE | ID: mdl-38081864

ABSTRACT

Activated brown fat (aBAT) is known to affect the evaluation of 18F-FDG PET scans, especially in young patients. The aim of this study was to determine factors influencing the occurrence of aBAT, and to investigate the effectiveness of the two preventive measures, warming and beta-blocker (propranolol) administration. Five-hundred-twenty-eight 18F-FDG-PET scans of 241 EuroNet-PHL-C2 trial patients from 41 nuclear medicine departments in Germany and Czech Republic were screened for aBAT. The occurrence of aBAT was analyzed with patient characteristics (age, sex, body mass index, predisposition to aBAT), weather data at the day of 18F-FDG PET scanning as well as the preventive measures taken. Potentially important factors from univariate analyses were included into a logistic regression model. Warming as a preventive measure was used in 243 18F-FDG-PET scans, propranolol was administered in 36, warming and propranolol were combined in 84, and no preventive measures were taken in 165 scans. Whereas age, sex and body mass index had no clear impact, there was an individual predisposition to aBAT. Logistic regression model revealed that the frequency of aBAT mainly depends on the outside temperature (p = 0.005) and can be effectively reduced by warming (p = 0.004), the administration of unselective beta-blocker or the combination of both. Warming is a simple, cheap and non-invasive method to reduce the frequency of aBAT. However, the effect of warming decreases with increasing outside temperatures. Administration of propranolol seems to be equally effective and provides advantages whenever the positive effect of warming is compromised. The combination of both preventive measures could have an additive effect.


Subject(s)
Fluorodeoxyglucose F18 , Lymphoma , Humans , Adipose Tissue, Brown/diagnostic imaging , Adrenergic beta-Antagonists/pharmacology , Fluorodeoxyglucose F18/pharmacology , Positron-Emission Tomography/methods , Propranolol/pharmacology , Radiopharmaceuticals/pharmacology
2.
Genes Nutr ; 10(6): 50, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26559563

ABSTRACT

Epigenetic and posttranslational modifications of the expression of cell cycle-relevant genes or proteins like p21, e.g., by miRNAs are crucial mechanisms in the development or prevention of colon cancer. The present study investigated the influence of butyrate and trichostatin A (TSA) as histone deacetylase inhibitors on the expression of colon cancer-relevant miRNA (miR-135a, miR-135b, miR-24, miR-106b, miR-let-7a) in LT97 colon adenoma cells as a model of an early stage of colon carcinogenesis. The impact of distinct miRNAs (miR-106b, miR-135a) on butyrate-mediated regulation of p21 and Cyclin D2 gene and protein expression as well as the effect on LT97 cell proliferation (non-transfected, miR-106b and miR-135a mimic transfected) was analyzed. Butyrate and partial TSA reduced the expression of miR-135a, miR-135b, miR-24 and miR-let-7a (~0.5-fold, 24 h) and miR-24, miR-106b and miR-let-7a (~0.5-0.7-fold, 48 h) in LT97 cells. Levels of p21 mRNA and protein were significantly increased by butyrate and TSA (~threefold and 4.5-fold, respectively, 24 h) in non-transfected but not in miR-106b transfected LT97 cells. Levels of Cyclin D2 mRNA were significantly reduced by butyrate and TSA (~0.3-fold, 24 h) in non-transfected and miR-135a-transfected LT97 cells, whereas protein levels were predominantly not influenced. MiR-106b and miR-135a significantly reduced butyrate-/TSA-mediated inhibition of LT97 cell proliferation (72 h). These results indicate that butyrate is able to modify colon cancer-relevant miRNAs like miR-106b and miR-135a which are involved in the regulation of cell cycle-relevant genes like p21 and might influence inhibition of adenoma cell proliferation.

3.
Oncogene ; 33(15): 1964-74, 2014 Apr 10.
Article in English | MEDLINE | ID: mdl-23604128

ABSTRACT

Malignant melanoma is a cancer characterized by high chemoresistance although p53 is rarely mutated. Here, we show that p53 wild-type melanoma cells acquire resistance to cell death induced by fotemustine (FM), which is a representative of alkylating DNA interstrand cross-linking agents used in melanoma therapy. We show that drug-induced resistance is a result of p53-dependent upregulation of the nucleotide excision repair (NER) genes xeroderma pigmentosum complementation group C (XPC) and damaged DNA-binding protein 2 (DDB2), which stimulate the repair of DNA interstrand cross-links (ICLs) arising from O(6)-chloroethylguanine. Consequently, TP53 mutated cells are unable to repair ICLs, leading to prolonged ATM, ATR and checkpoint kinase 1 (CHK1) activation, and finally apoptosis. The roles of p53 and NER in ICL-triggered cell death were confirmed by knockdown of p53 and XPC. Upregulation of XPC and DDB2 in p53wt cells following a single drug treatment is a robust and sustained response that lasts for up to 1 week. Pretreatment with an inducing dose followed by a high and toxic dose of FM provoked an adaptive response as the killing outcome of the challenge dose was reduced. Upregulation of XPC and DDB2 was also observed in a melanoma mouse xenograft model following systemic administration of FM. Additionally, XPC and DDB2 induction occurred upon treatment with other cross-linking anticancer drugs, such as cisplatin and mafosfamide, indicating it is a general response of cancer cells to this group of chemotherapeutics. Collectively, the data indicate that p53-dependent upregulation of XPC and DDB2 is a key mechanism upon genotoxic stress, whereby melanoma cells acquire resistance towards DNA cross-linking agents. To our knowledge, this is the first demonstration of upregulation of NER following a single dose of a DNA interstrand cross-linker, which is a robust and long-lasting effect that impacts the killing response of cancer cells to subsequent treatments.


Subject(s)
DNA Repair/genetics , Drug Resistance, Neoplasm/genetics , Melanoma/genetics , Tumor Suppressor Protein p53/metabolism , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , DNA Damage/genetics , DNA-Binding Proteins/biosynthesis , DNA-Binding Proteins/genetics , Flow Cytometry , Fluorescent Antibody Technique , Gene Expression Regulation, Neoplastic , Heterografts , Humans , Immunoblotting , Melanoma/metabolism , Mice , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Tumor Suppressor Protein p53/genetics , Up-Regulation
4.
Skin Pharmacol Physiol ; 27(2): 97-105, 2014.
Article in English | MEDLINE | ID: mdl-24335336

ABSTRACT

The effect of the lipophilicity of a carrier on human skin penetration of an extremely lipophilic active model substance was evaluated by using Franz type diffusion cells. Oil-in-water model emulsions containing different amounts of the oily phase were prepared, and Myritol® PC (M-PC) was selected as lipophilic marker component of the oily phase. The penetrated amounts of the lipophilic model substance salicyloyl phytosphingosine (SP) were determined by high-performance liquid chromatography with ultraviolet detection, while M-PC was detected using gas chromatography coupled with mass spectrometry. It has been ascertained that the amount of the lipid phase within the emulsion influenced the penetration profile of the active ingredient SP. The emulsion containing the lowest proportion of the lipid phase provides the best conditions for SP penetration. Surprisingly, the penetration behavior of M-PC was influenced by the oily phase in the same way. Regarding the M-PC and the SP penetration profiles from each emulsion, a solvent drag mechanism can be assumed whereby M-PC acts as penetration enhancer. In conclusion, the penetration rate of the active ingredient SP and the marker component M-PC are in reverse proportion to the oil content of the formulations. The lipophilicity of SP and M-PC, their solubility and their thermodynamic activity within the vehicle could have an effect on their penetration behavior. Additionally, M-PC has the property to enhance the penetration rates of extremely lipophilic substances even at low concentrations.


Subject(s)
Caprylates/metabolism , Skin/metabolism , Sphingosine/analogs & derivatives , Sphingosine/metabolism , Caprylates/chemistry , Chemistry, Pharmaceutical , Emulsions , Humans , In Vitro Techniques , Skin Absorption , Sphingosine/chemistry , Water
5.
Br J Cancer ; 100(2): 322-33, 2009 Jan 27.
Article in English | MEDLINE | ID: mdl-19127257

ABSTRACT

Malignant melanomas are highly resistant to chemotherapy. First-line chemotherapeutics used in melanoma therapy are the methylating agents dacarbazine (DTIC) and temozolomide (TMZ) and the chloroethylating agents BCNU and fotemustine. Here, we determined the mode of cell death in 11 melanoma cell lines upon exposure to TMZ and fotemustine. We show for the first time that TMZ induces apoptosis in melanoma cells, using therapeutic doses. For both TMZ and fotemustine apoptosis is the dominant mode of cell death. The contribution of necrosis to total cell death varied between 10 and 40%. The O(6)-methylguanine-DNA methyltransferase (MGMT) activity in the cell lines was between 0 and 1100 fmol mg(-1) protein, and there was a correlation between MGMT activity and the level of resistance to TMZ and fotemustine. MGMT inactivation by O(6)-benzylguanine sensitized all melanoma cell lines expressing MGMT to TMZ and fotemustine-induced apoptosis, and MGMT transfection attenuated the apoptotic response. This supports that O(6)-alkylguanines are critical lesions involved in the initiation of programmed melanoma cell death. One of the cell lines (MZ7), derived from a patient subjected to DTIC therapy, exhibited a high level of resistance to TMZ without expressing MGMT. This was related to an impaired expression of MSH2 and MSH6. The cells were not cross-resistant to fotemustine. Although these data indicate that methylating drug resistance of melanoma cells can be acquired by down-regulation of mismatch repair, a correlation between MSH2 and MSH6 expression in the different lines and TMZ sensitivity was not found. Apoptosis in melanoma cells induced by TMZ and fotemustine was accompanied by double-strand break (DSB) formation (as determined by H2AX phosphorylation) and caspase-3 and -7 activation as well as PARP cleavage. For TMZ, DSBs correlated significantly with the apoptotic response, whereas for fotemustine a correlation was not found. Melanoma lines expressing p53 wild-type were more resistant to TMZ and fotemustine than p53 mutant melanoma lines, which is in marked contrast to previous data reported for glioma cells treated with TMZ. Overall, the findings are in line with the model that in melanoma cells TMZ-induced O(6)-methylguanine triggers the apoptotic (and necrotic) pathway through DSBs, whereas for chloroethylating agents apoptosis is triggered in a more complex manner.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Apoptosis/drug effects , DNA Breaks, Double-Stranded/drug effects , DNA Mismatch Repair/drug effects , DNA Modification Methylases/metabolism , DNA Repair Enzymes/metabolism , Melanoma/pathology , Tumor Suppressor Protein p53/metabolism , Tumor Suppressor Proteins/metabolism , Blotting, Western , Caspases/metabolism , Collagen Type XI/metabolism , Dacarbazine/administration & dosage , Dacarbazine/analogs & derivatives , Enzyme Activation/drug effects , Everolimus , Humans , Melanoma/metabolism , Necrosis , Phosphorylation/drug effects , Sirolimus/administration & dosage , Sirolimus/analogs & derivatives , Temozolomide , Tumor Cells, Cultured
6.
Oncogene ; 26(2): 186-97, 2007 Jan 11.
Article in English | MEDLINE | ID: mdl-16819506

ABSTRACT

Methylating drugs such as temozolomide (TMZ) are widely used in the treatment of brain tumours (malignant gliomas). The mechanism of TMZ-induced glioma cell death is unknown. Here, we show that malignant glioma cells undergo apoptosis following treatment with the methylating agents N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and TMZ. Cell death determined by colony formation and apoptosis following methylation is greatly stimulated by p53. Transfection experiments with O(6)-methylguanine-DNA methyltransferase (MGMT) and depletion of MGMT by O(6)-benzylguanine showed that, in gliomas, the apoptotic signal originates from O(6)-methylguanine (O(6)MeG) and that repair of O(6)MeG by MGMT prevents apoptosis. We further demonstrate that O(6)MeG-triggered apoptosis requires Fas/CD95/Apo-1 receptor activation in p53 non-mutated glioma cells, whereas in p53 mutated gliomas the same DNA lesion triggers the mitochondrial apoptotic pathway. This occurs less effectively via Bcl-2 degradation and caspase-9, -2, -7 and -3 activation. O(6)MeG-triggered apoptosis in gliomas is a late response (occurring >120 h after treatment) that requires extensive cell proliferation. Stimulation of cell cycle progression by the Pasteurella multocida toxin promoted apoptosis whereas serum starvation attenuated it. O(6)MeG-induced apoptosis in glioma cells was preceded by the formation of DNA double-strand breaks (DSBs), as measured by gammaH2AX formation. Glioma cells mutated in DNA-PK(cs), which is involved in non-homologous end-joining, were more sensitive to TMZ-induced apoptosis, supporting the involvement of DSBs as a downstream apoptosis triggering lesion. Overall, the data demonstrate that cell death induced by TMZ in gliomas is due to apoptosis and that determinants of sensitivity of gliomas to TMZ are MGMT, p53, proliferation rate and DSB repair.


Subject(s)
Antineoplastic Agents, Alkylating/pharmacology , Apoptosis/drug effects , Brain Neoplasms/pathology , DNA Damage/drug effects , Dacarbazine/analogs & derivatives , Glioma/pathology , Guanine/analogs & derivatives , Blotting, Western , Brain Neoplasms/metabolism , Caspases/metabolism , Cell Cycle/drug effects , Cell Proliferation/drug effects , DNA Breaks, Double-Stranded , Dacarbazine/pharmacology , Fas Ligand Protein/metabolism , Fas-Associated Death Domain Protein/metabolism , Flow Cytometry , Glioma/metabolism , Guanine/metabolism , Humans , Methylnitronitrosoguanidine/pharmacology , O(6)-Methylguanine-DNA Methyltransferase/genetics , O(6)-Methylguanine-DNA Methyltransferase/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Small Interfering/pharmacology , Temozolomide , Tumor Cells, Cultured , Tumor Stem Cell Assay , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
7.
J Clin Pathol ; 57(11): 1172-8, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15509679

ABSTRACT

BACKGROUND: Cytogenetic studies of malignant peripheral nerve sheath tumours (MPNSTs) and malignant triton tumours (MTTs) are rare. AIMS: To undertake cytogenetic analysis of these tumours. METHODS: Conventional cytogenetic analysis of 21 MPNSTs and MTTs from 17 patients (nine with peripheral neurofibromatosis (NF1)) was carried out using standard culture and harvesting procedures. For a more precise identification of composite structural rearrangements and marker chromosomes, spectral karyotypic analysis (SKY) was applied to a subset of cases. In addition, EGFR gene copy number was assessed by fluorescence in situ hybridisation (FISH) analysis in a subset of cases. RESULTS: Cytogenetic analysis revealed predominantly complex karyotypes. SKY analysis was useful in further defining many structural anomalies. Structural aberrations most frequently involved chromosomal bands or regions 1p31-36, 4q28-35, 7p22, 11q22-23, 19q13, 20q13, and 22q11-13. Overall, loss of chromosomal material was much more common than gain. Loss of chromosomes or chromosomal regions 1p36 (48%), 3p21-pter (52%), 9p23-pter (57%), 10 (48%), 11q23-qter (48%), 16/16q24 (62%), 17(43%), and 22/22q (48%), and gains of 7/7q (29%) and 8/8q (29%) were most prominent. These gains and losses were distributed equally between MPNST and MTT, demonstrating that these entities are similar with respect to recurrent genomic imbalances. Similarly, none of the recurrent chromosomal breakpoints or imbalances was restricted to either NF1 associated or sporadic MPNSTs. FISH analysis was negative for amplification. CONCLUSIONS: These cytogenetic and molecular cytogenetic findings expand the knowledge of chromosomal alterations in MPNST and MTT, and point to possible recurring regions of interest.


Subject(s)
Chromosome Aberrations , Nerve Sheath Neoplasms/genetics , Adolescent , Adult , Aged , Cell Transformation, Neoplastic/genetics , Chromosome Deletion , Female , Gene Amplification/genetics , Humans , In Situ Hybridization, Fluorescence/methods , Karyotyping/methods , Male , Middle Aged , Neurofibromatosis 1/genetics , Rhabdomyosarcoma/genetics , Translocation, Genetic/genetics
8.
Med Biol Eng Comput ; 41(3): 290-5, 2003 May.
Article in English | MEDLINE | ID: mdl-12803293

ABSTRACT

Silicon soft suction sockets (roll-on sleeves) currently used in passive prostheses for below-elbow amputees could also be used in externally powered prostheses, enhancing their functionality and comfort. However, as it is extremely difficult to hold currently used electromyography (EMG) sensors in place reliably within a silicon socket, an alternative measurement of muscular activity as the control input is necessary. Mechanomyography (MMG) is the epidermal measurement of the low-frequency vibrations produced by a contracting muscle. MMG sensors do not have to be in direct contact with the skin. Moreover, the embedding of sensors in the roll-on sleeve may also solve attachment issues, making sensor placement flexible. Therefore the objective was to determine the feasibility of recording MMG signals using silicon-embedded, micro-machined accelerometers. Fifteen embedded accelerometers were excited with predefined vibration patterns. The signal-to-noise ratio (SNR) and frequency response of each sample were measured and compared with those of non-embedded accelerometers. The SNR of embedded samples (approximately equal to 19 dB) was significantly higher than that of non-embedded samples (approximately equal to 12 dB), owing to the considerable mechanical damping effect of the silicon in the 300-900 Hz bandwidth (p=0.0028). This has implications for the application of silicon-embedded accelerometers for externally powered prosthesis control.


Subject(s)
Amputation, Surgical/rehabilitation , Artificial Limbs , Myography/methods , Electronics, Medical/instrumentation , Humans , Prosthesis Design , Silicon , Transducers
9.
Cytogenet Cell Genet ; 93(3-4): 221-7, 2001.
Article in English | MEDLINE | ID: mdl-11528115

ABSTRACT

Comparative genomic hybridization (CGH) has been applied to characterize 61 primary renal cell carcinomas derived histogenetically from the proximal tubulus. The tumor samples comprised 46 clear-cell renal cell carcinomas (ccRCCs) and 15 papillary renal cell carcinomas (pRCCs). Changes in the copy number of entire chromosomes or subregions were detected in 56 tumors (92%). In ccRCCs, losses of chromosome 3 or 3p (63%); 14q (30%); 9 (26%); 1 and 6 or 6q (17% each); 4 and 8 or 8p (15% each); 22 (11%); 2 or 2q and 19 (9% each); 7q, 10, 16, 17p, 18, and Y (7% each); and 5, 11, 13, 15, and 21 (4% each) were detected. Most frequent genomic gains in ccRCC were found on chromosome 5 (63%); 7 (35%); 1 or 1q (33%); 2q (24%); 8 or 8q, 12, and 20 (20% each); 3q (17%); 16 (15%); 19 (13%); 6 and 17 or 17q (11% each); and 4, 10, 11, 21, and Y (9% each). In pRCCs, gains in the copy number of chromosomes 7 and 17 (7/15, each) and 16 and 20 (6/15, each) were frequent. One pRCC showed amplification of subchromosome regions 2q22-->q33, 16q, 17q and the entire X chromosome. In pRCC, losses were less frequently seen than gains. Losses of chromosomes 1, 14, 15, and Y (3/15 each) and 2, 4, 6, and 13 (2/15 each) were observed. In ccRCCs, statistical evaluation revealed significant correlations of chromosomal imbalances with tumor stage and grade, i.e., a gain in copy number of chromosome 5 correlated positively with low tumor grade, whereas a gain of chromosomes 10 and 17 correlated positively with high tumor grade. Furthermore, loss of chromosome 4 correlated positively with high tumor stage.


Subject(s)
Chromosome Aberrations/genetics , Kidney Neoplasms/genetics , Kidney Neoplasms/pathology , Kidney Tubules, Proximal/pathology , Adenocarcinoma, Clear Cell/genetics , Adenocarcinoma, Clear Cell/mortality , Adenocarcinoma, Clear Cell/pathology , Adenocarcinoma, Clear Cell/secondary , Adult , Aged , Aged, 80 and over , Bone Neoplasms/secondary , Carcinoma, Papillary/genetics , Carcinoma, Papillary/mortality , Carcinoma, Papillary/pathology , Carcinoma, Papillary/secondary , Female , Genome, Human , Humans , Kidney Neoplasms/mortality , Kidney Tubules, Proximal/metabolism , Lung Neoplasms/secondary , Male , Middle Aged , Neoplasm Recurrence, Local , Neoplasm Staging , Nucleic Acid Hybridization , Recurrence , Survival Rate
10.
J Hand Ther ; 14(2): 91-104, 2001.
Article in English | MEDLINE | ID: mdl-11382260

ABSTRACT

The Prosthetic Upper Extremity Functional Index (PUFI) was developed by the authors' clinical research group to evaluate the extent to which a child actually uses a prosthetic limb for daily activities, the comparative ease of task performance with and without the prosthesis, and its perceived usefulness. The PUFI's test-retest and interrater reliability were evaluated with 24 children. Intraclass coefficients (ICCs) were calculated for each of four subscales of the PUFI--specifically, method of performance, ease of prosthetic use, usefulness of the prosthesis, and ease of performance without the prosthesis. The ICCs were greater than 0.65, indicating good test-retest reliability for the older-child respondents (n = 10) and fair to good reliability (ICCs, 0.40 to 0.84) for the parent respondents overall (n= 21). Interrater (child-parent) reliability was lower, with ICCs from 0.30 to 0.77. This finding was not unexpected, since a child and parent may rate in the context of different functional environments. The prosthesis was used 53% of the time by older children and more than 75% of the time by younger children. The results provide evidence that the PUFI has good test-retest reliability overall as a measure of a child's ability to perform upper extremity activities with a prosthesis.


Subject(s)
Artificial Limbs , Surveys and Questionnaires , Activities of Daily Living , Adolescent , Arm , Child , Child, Preschool , Female , Humans , Infant , Male , Reproducibility of Results , Task Performance and Analysis
11.
Leuk Res ; 25(4): 313-22, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11248328

ABSTRACT

This study combines conventional cytogenetics, fluorescence in situ hybridization (FISH), multiplex-FISH and comparative genomic hybridization (CGH). In applying this multimodal approach on the human leukemia cell line K562, the chromosome composition was refined in detail and compared with data from the literature. A hypotriploid karyotype with a modal chromosome number of 67, and 21 unique marker chromosomes were identified. The classification of six markers was identical to published data and the composition of five further markers from the literature could be fully clarified for the first time. The composition of another five markers, which have been interpreted in divergent ways in different studies, were elucidated without doubt. Finally, five new markers of our study seem to have no equivalents in former studies, very likely due to limitations of conventional cytogenetics. The combinatory application of complementary techniques as shown in this study will be very useful to provide the basis of a refined genotype analysis on the chromosomal level.


Subject(s)
Cytogenetics/methods , K562 Cells/metabolism , Chromosome Mapping/methods , Chromosome Painting/methods , Genetic Markers/genetics , Humans , In Situ Hybridization, Fluorescence/methods , K562 Cells/pathology , K562 Cells/ultrastructure , Karyotyping/methods , Nucleic Acid Hybridization/methods
12.
J Manag Med ; 15(4-5): 376-86, 2001.
Article in English | MEDLINE | ID: mdl-11765320

ABSTRACT

In a study of 195 patients visiting the urgent care department of a hospital in the UK, we examined the effects of three elements of process control on patients' fairness and satisfaction perceptions. Patients who believed they had a voice in the triage process had higher fairness perceptions and waited a shorter period of time than those who believed they did not have a voice in the triage process. In addition, patients who were told the expected waiting time and were kept busy while waiting had higher satisfaction perceptions. We identify implications for hospital employees in managing the patient waiting process.


Subject(s)
Emergency Service, Hospital/organization & administration , Patient Satisfaction/statistics & numerical data , Process Assessment, Health Care , Time Management , Waiting Lists , Adult , Emergency Service, Hospital/standards , Emergency Service, Hospital/statistics & numerical data , Female , Health Care Surveys , Health Services Accessibility/organization & administration , Hospital-Patient Relations , Hospitals, Public/standards , Hospitals, Rural/standards , Humans , Male , Middle Aged , Social Justice , Total Quality Management , United Kingdom
13.
J Biomol Struct Dyn ; 18(2): 199-208, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11089641

ABSTRACT

Several 2.7-bis-[(dialkylamino)-acetylamino]-fluoren-9-one derivatives (fluoramides) were synthesized as analogues of the DNA binding compound tilorone (2,7-bis[(diethylamino)-ethoxy]-fluoren-9-one). Previous studies showed the drugs to induce cytokines and inhibit reverse transcription. Here, their binding to DNA was evaluated using UV and circular dichroism studies. Like tilorone, the fluoramides derivatives also intercalate resulting in increased Tm values and new CD signatures. A preference to alternating A-T and G-C sequences was detected; only minor interaction to homologous sequences was observed. Moreover, no upper limit in the drug/DNA ratio was found, testing limit being the precipitation of the drug. However, surface plasmon resonance (SPR) studies of tilorone and 2,7-bis-[(dipropylamino)-acetyl-amino]-fluoren-9-one, indicate an astonishing drug/base pair ratio (r > 1), which point to a multitude of interactions under SPR conditions. Molecular modeling calculations, where the geometries of the complexes optimized under the assumption of intercalative and multitude of suprahelical arrangements, rationalize the observations. Based on the thermodynamic and biological studies, a structure-function model is proposed.


Subject(s)
DNA/metabolism , Fluorenes/chemistry , Nucleic Acids/chemistry , Animals , Cattle , Circular Dichroism , Computer Simulation , Ligands , Models, Chemical , Models, Molecular , Spectrophotometry , Structure-Activity Relationship , Surface Plasmon Resonance , Thermodynamics , Thymus Gland/metabolism , Ultraviolet Rays
14.
Am J Orthod Dentofacial Orthop ; 117(4): 486-95, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10756276

ABSTRACT

The purpose of this study was to better understand the multidimensional nature of overbite changes that occur during adolescence. The study used longitudinal cephalograms of 181 untreated children (102 males, 79 females) taken at ages 10 and 15. Four major components that directly affect overbite were measured: (1) maxillary vertical displacement, (2) mandibular vertical displacement, (3) upper incisor vertical change within the bone, (4) lower incisor vertical change within the bone. Cranial base, maxillary, and mandibular superimpositions were performed for each subject to assess the vertical changes that occurred in these 4 components and to assess overbite. A multiple regression analysis was used to develop a mathematical model describing the relationships of these components to changes in overbite. The model was validated with an independent subsample and a comparison of subjects whose overbites decreased and those whose overbites increased. The results showed that overbite changed minimally (0.2 mm) over the 5-year period; variation ranged from a 2.4 mm decrease to a 5.6 mm increase. The regression model indicated that the mandibular skeletal changes were twice as important as the mandibular dental changes and about 2.5 times as important as the maxillary changes in effecting overbite change. Within the mandibular skeletal component, vertical growth was more important than mandibular rotation in determining overbite change. The model demonstrated that a multivariate approach is necessary to understand overbite changes. More effective orthodontic treatment might be achieved by focusing on the primary components effecting overbite change, especially those with the greatest potential for therapeutic modification.


Subject(s)
Malocclusion/diagnosis , Models, Biological , Vertical Dimension , Adolescent , Cephalometry/statistics & numerical data , Child , Female , Humans , Male , Malocclusion/ethnology , Mandible , Maxilla , Quebec , Random Allocation , Regression Analysis
15.
Cancer Genet Cytogenet ; 117(1): 1-8, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10700858

ABSTRACT

To determine the effectiveness of different methods for the detection of tumor cell contamination of collected peripheral stem cells, we performed a study on 39 chronic myelogenous leukemia (CML) patients who were consecutively treated at our department. Analyses of tumor cell contamination by fluorescence in situ hybridization (FISH), conventional cytogenetics, and polymerase chain reaction (PCR) showed marked differences in the percentage of evaluable results: Quantitative analysis of tumor cell contamination was feasible in 60 of 105 (57%) samples evaluated with the use of conventional cytogenetic analysis and in 105 of 107 (98%) samples analyzed by FISH. PCR was evaluable in all 85 samples tested (100%). Both methods were shown to be adequate overall in determining the number of BCR-ABL positive cells, although cytogenetics tended to produce slightly higher percentages. Based on these results, we conclude that FISH performed on leukapheresis products is a rapid and reliable method for assessing the quality of these products and should be used for routine evaluation of tumor cell contamination of CML stem cell products.


Subject(s)
Bone Marrow Purging , Hematopoietic Stem Cell Transplantation , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Philadelphia Chromosome , Adult , Base Sequence , DNA Primers , Female , Humans , In Situ Hybridization, Fluorescence , Leukapheresis , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/therapy , Male , Middle Aged , Polymerase Chain Reaction , Transplantation, Autologous
16.
J Biomol Struct Dyn ; 18(3): 385-92, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11149515

ABSTRACT

The bifunctionally reactive nucleoside and distant nucleoside analogs adenosine (Ado), S-[(adenine-9-yl)methoxyethyl]-L-cysteine (Na-salt) (cysA) and 9-vinyladenine (vA) in aqueous solutions assemble on complementary polyuridylic acid templates to form complex lyomesophases. The systems are investigated by polarizing microscopy, differential scanning calorimetry (DSC) and 1H- and 31P-nmr spectroscopies, assisted by molecular modeling studies. The results indicate the importance of biomesogenic (pre)ordering in nucleic acid native and artificial matrix reactions.


Subject(s)
Polyribonucleotides/chemistry , Adenine/analogs & derivatives , Adenine/chemistry , Adenosine/chemistry , Calorimetry, Differential Scanning , Macromolecular Substances , Magnetic Resonance Spectroscopy , Microscopy, Polarization , Models, Molecular , Nucleic Acid Conformation , Poly U/chemistry , Thermodynamics
17.
Clin Anat ; 11(5): 314-9, 1998.
Article in English | MEDLINE | ID: mdl-9725575

ABSTRACT

The purpose of this study was to investigate the use of the Pearson Product-Moment correlation coefficient to quantify muscle coactivation using electromyography. The subjects were two children with spastic diplegia. Surface electrodes were used to record muscle activity from the soleus and tibialis anterior muscles during voluntary attempts at dorsiflexion and plantarflexion of the ankle against resistance. The linear envelope signals were smoothed with a Hamming filter at a cutoff frequency of 4 Hz and intervals of the resultant pairs of curves subjected to the PPM test. Both subjects demonstrated significant coactivation on their right side and independent activity on the left, indicated by high positive and negative coefficients, respectively. This method shows promise for description of side differences in diplegics and for assessing the effects of physical therapy and other interventions.


Subject(s)
Cerebral Palsy/physiopathology , Electromyography/methods , Isometric Contraction , Muscle, Skeletal/physiopathology , Cerebral Palsy/complications , Cerebral Palsy/etiology , Child , Child, Preschool , Confidence Intervals , Female , Humans , Male , Motor Neurons , Muscle, Skeletal/innervation , Sensitivity and Specificity
18.
Dev Med Child Neurol ; 40(4): 239-47, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9593495

ABSTRACT

Selective dorsal rhizotomy (SDR) is widely used to treat spasticity in children with diplegic cerebral palsy (CP) but has never been shown conclusively to improve functional outcome. The study was designed to measure changes in gross motor function in children 1 year following rhizotomy compared with a control group receiving equivalent physiotherapy (PT) and occupational therapy (OT) with the exception that the rhizotomy group initially underwent a 6-week postoperative in-patient therapy program. Twenty-four children (mean age 58 months) with mild to moderate CP with spastic diplegia were randomly assigned to a therapy-only control group (CG) (N=12) or rhizotomy and therapy group (RG) (N=12). The Gross Motor Function Measure (GMFM) was administered at the baseline, 6-, and 12-month assessments. Extremity tone, range of motion (ROM), biomechanics of the ankle-stretch reflex, isometric contraction, and temporal gait components were also evaluated. GMFM scores in the RG improved by 12.1 percentage points versus 4.4 percentage points in the CG (P<0.02). RG knee and ankle tone was significantly reduced (P<0.005), associated with increased passive ankle ROM (P<0.001), and decreased soleus EMG reflex activity on forced dorsiflexion (P<0.008). Foot-floor contact pattern improved in the RG compared with the CG (P<0.05). In conclusion, SDR combined with PT and OT leads to significantly greater functional motor improvement at 1 year following surgery compared with PT and OT alone. This was achieved in part through reduced knee and ankle tone, increased ankle dorsiflexion ROM, and more normal foot-floor contact during walking.


Subject(s)
Cerebral Palsy/surgery , Rhizotomy/methods , Spinal Nerve Roots/surgery , Analysis of Variance , Biomechanical Phenomena , Cerebral Palsy/therapy , Child, Preschool , Electromyography/instrumentation , Female , Humans , Male , Muscle, Skeletal/innervation , Occupational Therapy , Physical Therapy Modalities , Postoperative Care , Range of Motion, Articular , Reflex, Stretch/physiology , Time Factors
19.
Assist Technol ; 8(2): 110-20, 1996.
Article in English | MEDLINE | ID: mdl-10172879

ABSTRACT

The assistive technology (AT) community has been challenged to effectively measure the outcomes of AT services. There has been much discussion recently in the literature about how to conceptualize and respond to this challenge. In this paper, we suggest that these objectives are best accomplished when AT services are understood within the contexts of the total rehabilitation of AT users and the institutional culture in which services are delivered. We provide examples of outcome priorities we have identified and the tools and approaches we have used. These include projects in the areas of clinical, functional, and psychosocial outcomes assessment of ATs.


Subject(s)
Disabled Persons/rehabilitation , Equipment and Supplies , Outcome Assessment, Health Care , Rehabilitation Centers , Activities of Daily Living , Arm Injuries/rehabilitation , Artificial Limbs , Cerebral Palsy/physiopathology , Cerebral Palsy/rehabilitation , Child , Gait , Humans , Quality of Life , Technology Assessment, Biomedical , Walkers
20.
Life Sci ; 55(23): 1823-31, 1994.
Article in English | MEDLINE | ID: mdl-7968262

ABSTRACT

Prolactin and other lactogenic hormones are mitogenic for the rat T-cell lymphoma line, Nb2. Glucocorticoids have antiproliferative effects on these cells. A limiting feature of experiments utilizing the Nb2 line is their labor-intensive nature. We therefore adapted the commonly used MTT dye proliferation assay for the Nb2 cell line. While rPRL, hPRL, oPRL, hGH, bPL, and to a lesser extent bPRL stimulated the Nb2 cells, hormones without lactogenic activity, rGH and oGH did not. Human serum and rat sera from animals bearing a PRL-secreting tumor stimulated the Nb2 cells in parallel to standards. Glucocorticoids had anti-proliferative effects on Nb2 cells in the presence of half-maximal or maximal PRL doses, as measured by the MTT proliferation assay. It has been claimed that an oxazoline steroid, deflazacort, has anti-inflammatory effects in clinical studies with fewer of the deleterious side-effects common to glucocorticoids. We therefore compared the in vitro anti-proliferative effects of deflazacort with other glucocorticoids. Deflazacort's negative effect on Nb2 cell proliferation was similar to that of cortisol and prednisolone and less than that of dexamethasone. We conclude that the MTT proliferation assay can be used to study both mitogenic and anti-proliferative substances in Nb2 cells. In addition we found that deflazacort acts similarly in vitro to other glucocorticoids.


Subject(s)
Glucocorticoids/pharmacology , Growth Hormone/pharmacology , Lymphoma/pathology , Prolactin/pharmacology , Animals , Anti-Inflammatory Agents/pharmacology , Cell Division/drug effects , Dexamethasone/pharmacology , Formazans/metabolism , Humans , Pregnenediones/pharmacology , Rats , Tetrazolium Salts/metabolism , Tumor Cells, Cultured
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