241 results on '"Thomas, S.K."'
Search Results
202. Antibiotics: potential hazards to male fertility
- Author
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Wallach, Edward E., primary, Schlegel, Peter N., additional, Chang, Thomas S.K., additional, and Marshall, Fray F., additional
- Published
- 1991
- Full Text
- View/download PDF
203. The flow of granular material
- Author
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Hankey, W.L., primary and Thomas, S.K., additional
- Published
- 1991
- Full Text
- View/download PDF
204. Reduction of epididymal sperm motility after ablation of the inferior mesenteric plexus in the rat
- Author
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Billups, Kevin L., primary, Tillman, Shelly L., additional, and Chang, Thomas S.K., additional
- Published
- 1990
- Full Text
- View/download PDF
205. Ablation of the Inferior Mesenteric Plexus in the Rat: Alteration of Sperm Storage in the Epididymis and Vas Deferens
- Author
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Billups, Kevin L., primary, Tillman, Shelly, additional, and Chang, Thomas S.K., additional
- Published
- 1990
- Full Text
- View/download PDF
206. Focused parathyroid surgery with intraoperative parathyroid hormone measurement as a day-case procedure.
- Author
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Gurnell, E.M., Thomas, S.K., McFarlane, I., Munday, I., Balan, K.K., Berman, L., Chatterjee, V.K.K., and Wishart, G.C.
- Subjects
- *
PARATHYROID gland surgery , *HORMONES , *ADENOMA , *SURGICAL excision , *ULTRASONIC imaging , *HYPERPLASIA - Abstract
Background: This study assessed the feasibility, efficacy and safety of focused parathyroidectomy combined with intraoperative parathyroid hormone (IOPTH) measurement in a day-case setting. Methods: Over 28 months 50 consecutive patients (mean age 63 (range 33-92) years) with clear evidence of unifocal disease on sestamibi scanning or ultrasonography underwent unilateral neck exploration via a small lateral incision. Blood samples for measurement of IOPTH were taken at induction of anaesthesia, before adenoma excision and after adenoma excision (at 5, 10 and 20 min). Ten patients were discharged within 23 h and 40 patients on the day of surgery. Results: A solitary adenoma was identified in all but one patient, with a mean operating time of 30 (range 16-57) min. After parathyroidectomy, IOPTH levels fell appropriately except in one patient with multiglandular hyperplasia. No patient developed symptomatic hypocalcaemia during the 2 weeks after operation, enabling cessation of oral supplements. All patients remained normocalcaemic on follow-up (mean 26 (range 8-84) weeks) and histological examination confirmed parathyroid adenoma (48 patients), hyperplasia (one) or carcinoma (one). Conclusion: After accurate preoperative localization of uniglandular disease, patients with primary hyperparathyroidism may be managed successfully and safely by focused parathyroidectomy with IOPTH measurement as a day-case procedure. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
207. Pharmaceutical Restrictions: Possible Effect on Patient/Physician Buy-In of Disease Management Programs.
- Author
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Mullins, C.D., Thomas, S.K., and Roffman, D.S.
- Subjects
- *
DRUGS , *HEALTH maintenance organizations , *DISEASE management , *COST effectiveness , *PURCHASING - Abstract
Restrictions on the use of pharmaceuticals (such as those for low molecular weight heparins) are commonly imposed by healthcare organizations to combat rising health care costs. These restrictions can be system-based which are established by imposing specific coverage policies by insurance companies and payors or can be patient-based which are those that limit certain therapeutic agents to specified patient populations. Disease management (DM) programs are implemented by healthcare organizations to improve patient care while utilizing resources efficiently. From a payor perspective, restricted use of pharmaceuticals would conform to the goals of DM. However, from a practitioner's perspective, restrictions on the use of medications could sometimes be viewed as conflicting with their goal of providing appropriate patient care. Formularies and prior-authorization programs may sometimes impede physicians' clinical autonomy and may hinder physicians' willingness to participate in DM protocols with such drug restrictions. Furthermore, direct-to-patient advertisements and patient education are encouraging patients to participate actively in the drug selection process. When pharmaceutical restrictions prevent patients from receiving their drug of choice, patients may perceive that their treatment is suboptimal and unfavorable. Despite implementing a fine disease management protocol, imposing rigid drug-use restrictions could hinder physicians' and patients' buy-in of DM programs. [ABSTRACT FROM AUTHOR]
- Published
- 2001
208. Antibiotics: Potential hazards to male fertility
- Author
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Peter N. Schlegel, Thomas S.K. Chang, and Fray F. Marshall
- Subjects
Infertility ,Male ,medicine.medical_specialty ,medicine.drug_class ,media_common.quotation_subject ,Antibiotics ,Physiology ,Semen ,Fertility ,Biology ,Sulfasalazine ,Internal medicine ,medicine ,Animals ,Humans ,Adverse effect ,Infertility, Male ,media_common ,Obstetrics and Gynecology ,Minocycline ,General Medicine ,medicine.disease ,Anti-Bacterial Agents ,Endocrinology ,Reproductive Medicine ,Toxicity ,medicine.drug - Abstract
Individual agents within each of the major classes of antibiotics have been shown to have significant adverse effects on spermatogenesis or spermatozoal function in mammals. For humans, infertility or significant alterations in semen parameters have been well documented for the nitrofurans and for patients on sulfasalazine. Other commonly used antibiotics, such as minocycline, have been shown to be toxic to sperm at any concentration. Until further information is available, clinicians must keep in mind that treatment with antibiotics may adversely affect the fertility potential of men. It is possible that some classes of antibiotic agents, such as the penicillins or the quinolones, may have minimal effects on male fertility and maintain the clinical efficacy for patients requiring long-term antibiotic suppressive therapy. Further investigation is needed into the relative toxicity of antibiotics and the mechanisms by which antibiotics affect spermatogenesis and spermatozoal function. A background of the current state of knowledge regarding the adverse effects of antibiotics on male fertility is presented in this review.
- Published
- 1992
209. Infrared spectral changes with crystallization in poly(vinylchloride): Correlations with X-ray and density data.
- Author
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Chartoff, Richard P., Lo, Thomas S.K, Harrell, E. Ray, and Roe, Ryong Joon
- Published
- 1981
- Full Text
- View/download PDF
210. Induction and enhancement of progressive motility in hamster caput epididymal spermatozoa
- Author
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Thomas B. Smyth, John C. Robinson, Gail A. Cornwall, Don Vindivich, Christine Harter, and Thomas S.K. Chang
- Subjects
Male ,endocrine system ,medicine.medical_specialty ,Hamster ,Motility ,Biology ,Cricetinae ,Internal medicine ,medicine ,Animals ,Theophylline ,Epididymal fluid ,Bovine serum albumin ,reproductive and urinary physiology ,Diamide ,Epididymis ,Mesocricetus ,urogenital system ,Albumin ,Cell Biology ,General Medicine ,Spermatozoa ,Sperm ,Kinetics ,medicine.anatomical_structure ,Endocrinology ,Reproductive Medicine ,Flagella ,Sperm Motility ,biology.protein ,medicine.drug - Abstract
Progressive motility was induced in hamster caput epididymal spermatozoa incubated in Tyrodes medium containing 50 mM theophylline, 1.0% Fraction V bovine serum albumin, and 15% (v/v) heat-treated human seminal plasma. Under these induction conditions, however, the maximum percent of caput spermatozoa exhibiting progressive motility (21%) and the time during which motility was sustained (120 min) were significantly less (p less than 0.05) than that of controls from the cauda epididymidis. Moreover, in contrast to caudal spermatozoa, the majority of the induced caput spermatozoa exhibited some degree of flagellar bending at the neck or midpiece. In subsequent experiments the procedure for motility induction was modified to achieve levels of motility in caput spermatozoa equivalent to those observed for caudal spermatozoa. The addition of 5 microM diamide, a sulfhydryl oxidant, to the induction medium prevented the flagellar angularity observed in induced caput sperm preparations. The percentage of caput spermatozoa induced to progressive motility was increased to levels characteristic of caudal spermatozoa (48%) by the addition of hamster caudal epididymal fluid (CEF) to the induction medium. Finally, the viability of the induced caput spermatozoa was significantly enhanced (p less than 0.05) by the removal of Fraction V albumin from the induction medium. In the presence of CEF and in the absence of albumin, 50% of the caput spermatozoa acquired progressive motility and sustained this motility for 4 h. Moreover, when fatty acid-free, charcoal-extracted albumin instead of Fraction V albumin was utilized in the induction procedure, a maximum of 43% of the caput spermatozoa acquired progressive motility and maintained this motility for 4 h, suggesting that the decreased sperm viability observed in the presence of Fraction V albumin was due to a contaminant of albumin, possibly fatty acids. The studies described herein demonstrate for the first time that immature quiescent caput epididymal spermatozoa can be induced to acquire progressive and sustained motility equivalent to that observed in mature caudal epididymal spermatozoa.
- Published
- 1986
211. Determination of heroin and its metabolites by high-performance liquid chromatography
- Author
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Charles E. Inturrisi, M. Schultz, Seung Uon Shin, Jason G. Umans, Thomas S.K. Chiu, and Robert Lipman
- Subjects
Male ,Morphine Derivatives ,Time Factors ,Chromatography ,Morphine ,Codeine ,Propoxyphene ,General Chemistry ,High-performance liquid chromatography ,Rats ,Heroin ,Acetic acid ,chemistry.chemical_compound ,Ammonium hydroxide ,chemistry ,medicine ,Animals ,Humans ,Levorphanol ,Chromatography, High Pressure Liquid ,Active metabolite ,medicine.drug - Abstract
A method is described for the simultaneous determination of heroin (3, 6-diacetylmorphine, DAM) and its two active metabolites 6-acetylmorphine and morphine in blood by high-performance liquid chromatography using a normal-phase column and a UV detector at 218 nm. The compounds are stabilized in blood by rapid freezing and recovered by a multistep liquid—liquid extraction. The mobile phase is acetonitrile—methanol (75:25, v/v) buffered to apparent pH 7 with ammonium hydroxide and acetic acid. Using l -α-acetylmethadol as an internal standard, UV detection and a 1-ml biofluid sample, the lower limit of sensitivity is 12.5 ng/ml. Commonly used narcotic analgesics including codeine, propoxyphene, meperidine, methadone and levorphanol do not interfere with the analysis. The method has been applied to blood samples from humans and rats. Extracts of blood from a patient who had received an intravenous dose of 14 mg of DAM contained DAM and both of its active metabolites.
- Published
- 1982
212. Spermatogenesis in the Mouse 2. Amino Acid Incorporation into Basic Nucleoproteins of Mouse Spermatids and Spermatozoa
- Author
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Barry R. Zirkin, J. F. Mayer, and Thomas S.K. Chang
- Subjects
Male ,endocrine system ,Arginine ,Spermiogenesis ,In Vitro Techniques ,Biology ,Mice ,Vas Deferens ,Prophase ,Testis ,medicine ,Animals ,Protamines ,Amino Acids ,Spermatogenesis ,Cell Nucleus ,Epididymis ,Spermatid ,urogenital system ,Spermatid differentiation ,Cell Biology ,General Medicine ,Spermatids ,Spermatozoa ,Protamine ,Sperm ,Cell biology ,Nucleoproteins ,medicine.anatomical_structure ,Reproductive Medicine ,Biochemistry ,biology.protein - Abstract
The present studies were designed to identify mouse spermatid proteins into which intratesticularly injected [3 HI arginine and �3 HI lysine were initially incorporated and to determine the fates of those proteins during subsequent spermatid differentiation. At intervals between 2 h and 7 days after injections, elongated spermatid nuclei were isolated from the testes by virtue of their resistance to sonication, and mature sperm nuclei were isolated from the epididyrnides. Basic proteins were extracted from isolated spermatid and sperm nuclei and subjected to electrophoresis on acid-urea polyacrylamide gels. Two hours after injection, [3 HI arginine was seen in a number of spennatid basic proteins, including both the “testis’specific” protein (TP) and the protainines. As expected from previous studies, only one class of these labeled proteins, protamine, was retained through the completion of spermiogenesis and sperm maturation 7 days later. In striking contrast, [3 Hi lysine was initially incorporated only into the spermatid TP protein, was retained for only 3 days, and was then lost. Our previous autoradiographic study (Mayer and Zirkin, 1979) demonstrated that intratesticularly injected [3 HI lysine was initially incorporated into elongating sperinatid nuclei at the initiation of chromatin condensation (late step 12 and step 13), was retained for 3 days through the completion of chromatin condensation (step 14), and was then lost. The present results, taken together with the results of our previous autoradiographic study, demonstrate striking temporal relationships between the first appearance of newly synthesized TP protein and the initiation of chromatin condensation in spermatid nuclei of late step 12, and between the loss of TP protein and the completion of chromatin condensation in spermatid nudei of step 14.
- Published
- 1981
213. The Effect of Sulfhdryl Oxidation on the Morphology of Immature Hamster Epididymal Spermatozoa Induced to Acquire Motility in Vitro1
- Author
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Gail A. Cornwall, Don Vindivich, Thomas S.K. Chang, and Shelly Tillman
- Subjects
chemistry.chemical_classification ,endocrine system ,urogenital system ,Glutathione reductase ,Motility ,Zoology ,Hamster ,Semen ,Cell Biology ,General Medicine ,Biology ,Sperm ,Cell biology ,chemistry.chemical_compound ,Reproductive Medicine ,chemistry ,Sulfhydryl reagent ,Thiol ,reproductive and urinary physiology ,Sodium tetrathionate - Abstract
Immotile spermatozoa from the caput epididymidis become progressively motile when incubated in medium containing theophylline, seminal plasma, and albumin. We previously reported that under these incubation conditions the spermatozoa induced to acquire motility exhibited a marked flagellar angularity, with the sperm head or midpiece bent 90-180 degrees towards the tail. In addition, we demonstrated that sperm flagellar bending did not occur when the sulfhydryl oxidant diamide was added to the motility induction medium. In the present study, we examined further the effect of sulfhydryl oxidation on the morphology and sulfhydryl content of immature caput spermatozoa induced to acquire motility in vitro. We found that flagellar bending was prevented and sperm flagellar straightness was maintained in a dose-dependent manner by diamide. Moreover, flow cytometric analysis of caput sperm sulfhydryls using the sulfhydryl reagent monobromobimane (mBBr) revealed that 1) diamide oxidizes caput sperm sulfhydryls, and 2) less than 15% of the total reactive sperm sulfhydryls were oxidized at diamide concentrations capable of preventing sperm angulation. Sodium tetrathionate (NaTT), another sulfhydryl oxidant, and hamster cauda epididymal fluid (CEF) containing sulfhydryl oxidase enzyme activity also maintained flagellar straightness in induced caput spermatozoa and oxidized sperm sulfhydryls. The flagellar straightness in caput spermatozoa treated with sulfhydryl oxidants, however, was temporary; with extended incubation, diamide- or CEF-treated spermatozoa exhibited flagellar bending. Additional studies showed that the flagellar straightness observed in sulfhydryl-oxidized spermatozoa was sustained when nitrofurantoin, an inhibitor of glutathione reductase, was included in the induction medium. Flow cytometric analysis of nitrofurantoin-treated spermatozoa showed that nitrofurantoin maintained the sperm disulfides formed by diamide and prevented the reduction of sperm disulfides back to sulfhydryls. Taken together, these studies demonstrate the significance of sulfhydryl oxidation in maintaining the morphology of immature caput epididymal spermatozoa induced to acquire motility in vitro and suggest that sulfhydryl oxidation may be important in the development of motility during sperm epididymal maturation in vivo.
- Published
- 1988
214. Infrared spectral changes with crystallization in poly(vinylchloride): Correlations with X-ray and density data
- Author
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Ryong Joon Roe, Richard P. Chartoff, Thomas S.K Lo, and E. Ray Harrell
- Subjects
Materials science ,Polymers and Plastics ,Infrared ,X-ray ,Solid-state ,General Chemistry ,Condensed Matter Physics ,law.invention ,Crystallinity ,law ,Polymer chemistry ,Materials Chemistry ,Physical chemistry ,Molecule ,Crystallization - Abstract
The influence of crystallinity and stereoregularity on the infrared (IR) spectrum of atactic PVC in the solid state has been studied by many researchers [1-12]. Although the molecules in commercial...
- Published
- 1981
215. Distribution of Sulfhydryl Oxidase Activity in the Rat and Hamster Male Reproductive Tract
- Author
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Barry R. Zirkin and Thomas S.K. Chang
- Subjects
Male ,medicine.medical_specialty ,Ejaculation ,Hamster ,Genitalia, Male ,Biology ,Male Reproductive Tract ,Vas Deferens ,Seminal vesicle ,Cricetinae ,Internal medicine ,Testis ,medicine ,Animals ,Distribution (pharmacology) ,Sulfhydryl oxidase activity ,Sulfhydryl Compounds ,Epididymis ,Mesocricetus ,Vesicle ,Prostate ,Seminal Vesicles ,Cell Biology ,General Medicine ,Rats ,Endocrinology ,medicine.anatomical_structure ,Reproductive Medicine ,Oxidoreductases - Abstract
Rat and hamster testes, epididymides, vas deferentia, seminal vesicles, prostates and coagulating glands were assayed for sulfhydryl oxidase activity. The activity, present primarily in the fluids of these organs, was lowest in the testis, increased through the epididymis and was highest in the seminal vesicle. The localization and reactivity of sulfhydryl oxidase activity suggests that it may play a role in regulating the degree of disulfide bonding in spermatozoa during epididymal maturation and storage and after ejaculation.
- Published
- 1978
216. Characterization and Localization of in Vivo Phospholipid Methylation in the Hamster Testis
- Author
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William W. Wright, Thomas S.K. Chang, and Peter N. Schlegel
- Subjects
Male ,endocrine system ,Time Factors ,Urology ,Cell ,Phospholipid ,Hamster ,Biology ,Tritium ,Methylation ,chemistry.chemical_compound ,Methionine ,Spermatocytes ,Cricetinae ,Testis ,medicine ,Protein methylation ,Animals ,Spermatogenesis ,Phospholipids ,Spermatogenic Cell ,Leydig cell ,Leydig Cells ,Molecular biology ,medicine.anatomical_structure ,Biochemistry ,chemistry - Abstract
Although previous studies have demonstrated that phospholipid methylation occurs in the testis and may be involved in Leydig cell function, phospholipid methylation in spermatogenic cells has not been characterized. In this study we describe the occurrence, time course, and localization of phospholipid methylation in the hamster testis following intratesticular injection of radioactive methyl precursor. Adult and pubertal (seven day old) hamsters were injected intratesticularly with [3H-methyl]-methionine and sacrificed 10 min. to 31 hours thereafter. The testes were then removed and homogenized or dispersed into cell suspensions. Spermatogenic cell and Leydig cell enriched preparations were isolated from the dispersed cell preparations using elutriation and Percoll gradient centrifugation and assayed for methylated phospholipids and proteins. These experiments demonstrated that 1) phospholipid methylation occurs in the hamster testis at a level seven-fold greater than protein methylation, 2) the incorporation of radioactivity associated with phospholipid methylation is progressive over time, and 3) in vivo, spermatogenic cell preparations enriched with pachytene spermatocytes have an almost four-fold higher level of measurable phospholipid methylation when compared to whole testis preparations. Taken together, these results suggest that phospholipid methylation may play an important stage-specific role in spermatogenesis.
- Published
- 1989
217. Preliminary investigations on the synthesis and antitumor activity of 3(2 H)-furanones
- Author
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Rappai, J.P., Raman, V., Unnikrishnan, P.A., Prathapan, S., Thomas, S.K., and Paulose, C.S.
- Published
- 2009
- Full Text
- View/download PDF
218. Microsurgical vasoepididymostomy to corpus epididymidis in treatment of inflammatory obstructive azoospermia
- Author
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Thomas S.K. Chang, Fray F. Marshall, and Donald Vindivich
- Subjects
Adult ,Epididymis ,Epididymitis ,Male ,Corpus epididymidis ,Microsurgery ,medicine.medical_specialty ,Pregnancy ,business.industry ,Urology ,medicine.medical_treatment ,Vasovasostomy ,Obstructive azoospermia ,Semen ,Oligospermia ,medicine.disease ,Gonorrhea ,Vasoepididymostomy ,medicine ,Humans ,Epididymal obstruction ,business - Abstract
A unilateral microsurgical vasoepididymostomy utilizing 35 mm of epididymas was performed in a patient with postinflammatory epididymal obstruction. Success was verified with multiple semen analyses, the hamster egg penetration test, and a pregnancy. These results demonstrate that surgical bypass of inflammatory tubal obstruction in the distal epididymas can result in the return of normal epididymal function and fertility.
- Published
- 1987
219. In vitro fertilization and embryo transfer: The Johns Hopkins Hospital, Baltimore, Maryland
- Author
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Beverly R. Smith, John D. Gearhart, Thomas S.K. Chang, Marian D. Damewood, Neil B. Rosensbein, Allen W. Schuetz, John A. Rock, Wiliam D. Schlaff, Giraud V. Foster, and Howard A. Zacur
- Subjects
Gerontology ,Gynecology ,Embryology ,medicine.medical_specialty ,In vitro fertilisation ,Maryland ,business.industry ,medicine.medical_treatment ,Reproductive medicine ,Obstetrics and Gynecology ,Fertilization in Vitro ,General Medicine ,Embryo Transfer ,Human genetics ,Embryo transfer ,Reproductive Medicine ,Genetics ,medicine ,Humans ,business ,Genetics (clinical) ,Developmental Biology - Published
- 1985
220. A Critical Method of Evaluating Tests for Male Infertility
- Author
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Albertsen, Peter C., Chang, Thomas S.K., Vindivich, Donald, Robinson, John C., and Walter Smyth, J.
- Abstract
Considerable uncertainty surrounds the selection of test values that separate infertile from fertile men in the evaluation of male infertility. We herein describe an objective method of determining these values, referred to as threshold values, for different infertility tests. Using test results from fertile men threshold values were chosen such that 96 per cent of the semen samples from the fertile men were scored as fertile. These threshold values then were used to evaluate 100 semen samples from 74 men presenting for evaluation of infertility.
- Published
- 1983
- Full Text
- View/download PDF
221. Characterization and Localization of in Vivo Phospholipid Methylation in the Hamster Testis
- Author
-
Schlegel, Peter N., Wright, William W., and Chang, Thomas S.K.
- Abstract
Although previous studies have demonstrated that phospholipid methylation occurs in the testis and may be involved in Leydig cell function, phospholipid methylation in spermatogenic cells has not been characterized. In this study we describe the occurrence, time course, and localization of phospholipid methylation in the hamster testis following intratesticular injection of radioactive methyl precursor. Adult and pubertal (seven day old) hamsters were injected intratesticularly with [3H-methyl]-methionine and sacrificed 10min. to 31 hours thereafter. The testes were then removed and homogenized or dispersed into cell suspensions. Spermatogenic cell and Leydig cell enriched preparations were isolated from the dispersed cell preparations using elutriation and Percoli gradient centrifugation and assayed for methylated phospholipids and proteins. These experiments demonstrated that 1) phospholipid methylation occurs in the hamster testis at a level seven-fold greater than protein methylation, 2) the incorporation of radioactivity associated with phospholipid methylation is progressive over time, and 3) in vivo, spermatogenic cell preparations enriched with pachytene spermatocytes have an almost four-fold higher level of measurable phospholipid methylation when compared to whole testis preparations. Taken together, these results suggest that phospholipid methylation may play an important stage-specific role in spermatogenesis.
- Published
- 1989
- Full Text
- View/download PDF
222. A novel NUP98-JADE2fusion in an acute myeloid leukemia patient resembling acute promyelocytic leukemia
- Author
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Cheng, Chi-Keung, Chan, Hoi-Yun, Yung, Yuk-Lin, Wan, Thomas S.K., Leung, Alex W.K., Li, Chi-Kong, Tian, Ke, Chan, Natalie P.H., Cheung, Joyce S., and Ng, Margaret H.L.
- Abstract
Acute promyelocytic leukemia (APL) is a specific subtype of acute myeloid leukemia (AML) characterized by block of differentiation at the promyelocytic stage and the presence of PML-RARAfusion. In rare instances, RARAis fused with other partners in variant APL. More infrequently, non-RARAgenes are rearranged in AML patients resembling APL. However, the underlying disease pathogenesis in these atypical cases is largely unknown. Here, we report the identification and characterization of a NUP98-JADE2fusion in a pediatric AML patient showing APL-like morphology and immunophenotype. Mechanistically, we showed that NUP98-JADE2 could impair all-transretinoic acid (ATRA)-mediated transcriptional control and myeloid differentiation. Intriguingly, NUP98-JADE2 was found to alter the subcellular distribution of wild-type JADE2, whose down-regulation similarly led to attenuated ATRA-induced responses and myeloid activation, suggesting that NUP98-JADE2 may mediate JADE2 inhibition. To our knowledge, this is the first report of a NUP98-non-RARrearrangement identified in an AML patient mimicking APL. Our findings suggest JADE2as a novel myeloid player involved in retinoic acid-induced differentiation. Despite lacking a rearranged RARA, our findings implicate that altered retinoic acid signaling by JADE2 disruption may underlie the APL-like features in our case, corroborating the importance of this signaling in APL pathogenesis.
- Published
- 2021
- Full Text
- View/download PDF
223. Involvement of endogenous proteolytic activity in thiol-induced release of DNA template restrictions in rabbit sperm nuclei
- Author
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Barry R. Zirkin and Thomas S.K. Chang
- Subjects
Male ,Proteolysis ,Trypsin inhibitor ,Endogeny ,Biology ,Dithiothreitol ,Polyethylene Glycols ,chemistry.chemical_compound ,medicine ,Thymidine Monophosphate ,Animals ,chemistry.chemical_classification ,Kunitz STI protease inhibitor ,DNA synthesis ,medicine.diagnostic_test ,Proteins ,Cell Biology ,General Medicine ,DNA ,Templates, Genetic ,Sperm ,Spermatozoa ,Benzamidines ,Quaternary Ammonium Compounds ,Reproductive Medicine ,Biochemistry ,chemistry ,Thiol ,Autoradiography ,Sperm Head ,Rabbits ,Trypsin Inhibitors - Abstract
Treatment of rabbit spermatozoa with Triton X-100 and dithiothreitol for increasing periods of time results in progressive increases in both the percentages of spermatozoa with swollen nuclei and in the ability of the swollen nuclei to serve as template for DNA synthesis. The inwilvement of endogenous proteolytic activity in this thiol-induced swelling and release of template restrictions is suggested by the fact that when spermatozoa are incubated in solutions containing various inhibitors of proteolysis (soybean trypsin inhibitor, lima bean trypsin inhibitor, or p-arninobenzamidine) in addition to Triton X-100 and dithiothreitol, inhibition of nuclear swelling and DNA template activity occur. The degree of inhibition is dependent upon the concentration of inhibitor employed. These results demonstrate a direct relationship between release of DNA template restrictions and nudear swelling, and suggest that both processes depend upon some degree of endogenous proteolytic activity as well as upon disulfide reduction.
- Published
- 1977
224. Determination of heroin and its metabolites by high-performance liquid chromatography
- Author
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Umans, Jason G., primary, Chiu, Thomas S.K., additional, Lipman, Robert A., additional, Schultz, Michael F., additional, Shin, Seung-Uon, additional, and Inturrisi, Charles E., additional
- Published
- 1982
- Full Text
- View/download PDF
225. PRM85 A DE-NOVO Model to Predict Outcomes of a New Hypothetical Intervention to Reduce CV Risk in Post Mi Patients
- Author
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Jain, M., Sonathi, V., Rathi, H., Bakuli, A., Thomas, S.K., and Mollon, P.
- Full Text
- View/download PDF
226. PRM47 A De-Novo Economic Model to Assess Clinical and Economic Consequences of Bronchiectasis
- Author
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Bhattacharyya, S.B., Calado, F., Priedane, E., Shirore, R.M., Haworth, C.S., Flume, P.A., Sonathi, V., and Thomas, S.K.
- Full Text
- View/download PDF
227. Is ambulatory parathyroid surgery safe?
- Author
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Thomas, S.K., Gurnell, E.M., McFarlene, I., Munday, I., Raggatt, P.R., Balan, K.K., Berman, L., Chatterjee, V.K.K., and Wishart, G.C.
- Subjects
- *
OPERATIVE surgery , *PARATHYROID glands , *INPATIENT care , *IMAGING systems , *AMBULATORY surgery - Abstract
Introduction: Parathyroid surgery, is routinely performed as an inpatient procedure in the UK. Recent advances in parathyroid imaging have encouraged the adoption of a minimally invasive surgical technique. We have assessed the feasibility and safety of parathyroid surgery as an ambulatory procedure. Method: Thirty consecutive patients (mean age 66, range 42-88) with primary hyperparathyroidism (pHPT) were admitted to the ambulatory surgery unit for excision of a parathyroid adenoma. All patients had unilateral neck exploration under general anaesthesia, with either sevoflurane or a target-controlled propofol infusion used for maintenance. Results: ASA scores were as follows: 1 (2/30), 2 (19/30), 3 (9/30). The mean operating time was 29 minutes (range 19-40) and the mean time to meet discharge criteria was 109 minutes (range 85-130). No patients needed any treatment for nausea and vomiting and no serious adverse events were recorded. Two-week post-operative questionnaire revealed mild symptoms related to swallowing (68%), voice changes (48%), neck restriction (42%) and sleep disturbance (50%). There was one unplanned admission for excessive drowsiness and the same patient was re-admitted after 5 days with a myocardial infarction and needed angioplasty for LAD stenosis. Another patient was admitted for assessment of chest pain after 21 days. Discussion: Patients with pHPT are predominantly elderly, with several comorbidities. The occurrence of a myocardial infarction is an important adverse event but it seems unlikely that an operation performed as an inpatient procedure would have prevented this complication. The study confirms that parathyroid surgery can be successfully and safely performed in an ambulatory surgery unit. [ABSTRACT FROM AUTHOR]
- Published
- 2003
228. A pilot study of minimally invasive parathyroid surgery, with intra-operative parathyroid hormone (PTH) measurement, as a day case procedure.
- Author
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Thomas, S.K., Gurnell, E.M., McFarlene, I., Munday, I., Raggatt, P.R., Balan, K.K., Berman, L., Chatterjee, V.K.K., and Wishart, G.C.
- Subjects
- *
OPERATIVE surgery , *PARATHYROID hormone , *HYPERPARATHYROIDISM , *ADENOMA , *PARATHYROID glands - Abstract
Background: The aim of this pilot study was to assess the feasibility of unilateral, minimally invasive surgery (MIS), combined with intra-operative parathyroid hormone (IOPTH) measurement, in the surgical management of patients with primary hyperparathyroidism. Methods: With local ethical committee approval 36 consecutive patients (mean age 65, range 32-88 years) with clear evidence of a parathyroid adenoma on SestaMIBI scan ± neck ultrasound were selected for study. Following informed consent these patients underwent a unilateral neck exploration performed through a 2·5 cm incision lateral to sternomastoid. Blood samples for PTH measurement were taken at induction of anaesthesia, pre adenoma excision, post adenoma excision (+5 mins, +10 mins, ± 20 mins). Patients were discharged within 23 hours (n = 10) or on the day of surgery (n = 20) on calcium and vitamin D supplementation until outpatient review at two weeks. Results: The adenoma was easily identified using this approach in all patients with a mean operating time of 31 minutes (range 19-57 min). The plasma PTH fell by > 50% of baseline levels at 5 min (n = 32), 10 min (n = 3) or 20 min (n = 1) post adenoma excision. None of the patients developed symptomatic hypocalcaemia during the two post-operative weeks enabling cessation of oral supplements. Following this all patients (100%) were normocalcaemic (mean 2·23 mM; range 2·13-2·47). Histology confirmed a parathyroid adenoma (n = 34), hyperplasia (n = 1) or carcinoma (n = 1). Conclusions: The results of this pilot study suggest that, following accurate pre-operative localization of uniglandular disease, patients with primary hyperparathyroidism may be successfully and safely managed by MIS with IOPTH measurement in the day case unit. [ABSTRACT FROM AUTHOR]
- Published
- 2003
229. Studies of a sulfhydryl oxidase from the male reproductive tract : a sperm-protective enzyme
- Author
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Chang, Thomas S.K.
- Subjects
- Sulfhydryl oxidase, Spermatozoa, Enzymes
- Published
- 1976
230. Functional Alterations of Lin−CD34+CD38+Progenitors in Chronic Myelomonocytic Leukaemia and on Progression to Acute Leukaemia.
- Author
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Sun, Qian, So, Chi-Chiu, Yip, Sze-Fai, Wan, Thomas S.K., Ma, Edmond Shiu Kwan, and Chan, LiChong
- Abstract
Chronic myelomonocytic leukaemia (CMML) is a clonal bone marrow stem cell disorder based on the presence of trilineage involvement, the association of myelodysplastic and myeloproliferative features and its ability to transform into acute myeloid leukaemia. The objectives of our study are to identify the cell population and its functional characteristics involved in evolution from CMML phase to acute myeloid leukaemia. We analysed Lin−CD34+stem/progenitor population and performed cell proliferation, apoptotic assays, self-renewal ability and differentiation potential studies in purified populations of Lin−CD34+CD38−stem cells and Lin−CD34+CD38+committed progenitors from peripheral blood of 16 patients with CMML and in six of the 16 after transformation to acute myeloid leukaemia (AML-t). We observed an expansion of the stem cell/progenitor pool (Lin−CD34+cells) in AML-t comprising mainly of Lin−CD34+CD38+committed progenitors within Lin−CD34+cells. The Lin−CD34+CD38+committed progenitors displayed highly proliferative activity in CMML and in AML-t; and additionally acquired resistance to apotosis and myeloid colony self-renewing ability in AML-t. Impairment of dendritic cell (DC) differentiation was observed with complete block in AML-t. Our findings suggest Lin−CD34+CD38+committed progenitors instead of Lin−CD34+CD38−stem cells could be the target(s) of secondary genetic lesions underpinning progression from CMML to AML. These results have implications for the further study of the biology of leukaemic transformation and the design of new strategies for the effective treatment of CMML.
- Published
- 2007
- Full Text
- View/download PDF
231. The spectrum of acute lymphoblastic leukemia with mature B-cell phenotype
- Author
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Chan, Natalie P.H., Ma, Edmond S.K., Wan, Thomas S.K., and Chan, Li Chong
- Subjects
- *
LYMPHOBLASTIC leukemia , *B cells - Abstract
We showed heterogeneous disease spectrum among 15 acute lymphoblastic leukemia (ALL) cases with mature B-cell phenotype diagnosed over the past 7 years at our institution. Besides those with typical L3 morphology and 8q24 (c-myc) translocation (
n=6 ), there were cases showing L1 or L2 morphology without 8q24 translocation (n=6 ), unusually large L3 blasts in hyperdiploid clone (n=2 ) and blastoid variant of mantle cell lymphoma (n=1 ). The expression of CD5 and cyclin D1 may need to be routinely determined on ALL cases with mature B-cell phenotype and non-L3 morphology to facilitate timely diagnosis of blastoid MCL and institution of suitable management. [Copyright &y& Elsevier]- Published
- 2003
- Full Text
- View/download PDF
232. Rapid detection of chromosomal translocation and precise breakpoint characterization in acute myeloid leukemia by nanopore long-read sequencing.
- Author
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Au, Chun Hang, Ho, Dona N., Ip, Beca B.K., Wan, Thomas S.K., Ng, Margaret H.L., Chiu, Edmond K.W., Chan, Tsun Leung, and Ma, Edmond S.K.
- Subjects
- *
ACUTE myeloid leukemia , *CHROMOSOMAL translocation , *NUCLEOTIDE sequence , *NUCLEOTIDE sequencing , *MOLECULAR genetics - Abstract
• Low-cost nanopore whole-genome sequencing shows exact DNA translocation breakpoints of t(5;11) and t(10;12) in an acute myeloid leukemia case. • t(5;11) NUP98-NSD1 fusion is a driver event whereas t(10;12) DUSP13 - GRIN2B fusion is a non-productive passenger event. • Nanopore sequencing complements cytogenetics, next-generation sequencing and digital PCR in diagnosis and monitoring. Detection of chromosomal translocation is a key component in diagnosis and management of acute myeloid leukemia (AML). Targeted RNA next-generation sequencing (NGS) is emerging as a powerful and clinically practical tool, but it depends on expression of RNA transcript from the underlying DNA translocation. Here, we show the clinical utility of nanopore long-read sequencing in rapidly detecting DNA translocation with exact breakpoints. In a newly diagnosed patient with AML, conventional karyotyping showed translocation t(10;12)(q22;p13) but RNA NGS detected NUP98-NSD1 fusion transcripts from a known cryptic translocation t(5;11)(q35;p15). Rapid PCR-free nanopore whole-genome sequencing yielded a 26,194 bp sequencing read and revealed the t(10;12) breakpoint to be DUSP13 and GRIN2B in head-to-head configuration. This translocation was then classified as a passenger structural variant. The sequencing also yielded a 20,709 bp sequencing read and revealed the t(5;11) breakpoint of the driver NUP98-NSD1 fusion. The identified DNA breakpoints also served as markers for molecular monitoring, in addition to fusion transcript expression by digital PCR and sequence mutations by NGS. We illustrate that third-generation nanopore sequencing is a simple and low-cost workflow for DNA translocation detection. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
233. Functional alterations of Lin−CD34+CD38+ cells in chronic myelomonocytic leukemia and on progression to acute leukemia
- Author
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Sun, Qian, So, Chi-Chiu, Yip, Sze-Fai, Wan, Thomas S.K., Ma, Shiu-Kwan, and Chan, L.C.
- Subjects
- *
LEUKEMIA , *ANEMIA , *CANCER , *LEUCOCYTOSIS - Abstract
Abstract: The functional behavior of hematopoietic stem cell (HSC) and progenitors in chronic myelomonocytic leukemia (CMML) and on disease progression is little known. We performed cell proliferation, apoptosis, hematopoietic colony forming/replating and differentiation potential studies in the purified subpopulations of Lin−CD34+CD38− and Lin−CD34+CD38+ cells from 16 CMML with 6 cases after acute myeloid leukemia transformation (AML-t). We observed an expansion of the hematopoietic progenitor pool (Lin−CD34+ cells) in AML-t comprising mainly Lin−CD34+CD38+ cells. The Lin−CD34+CD38+ cells in AML-t displayed high proliferative activity, resistance to apoptosis, enhanced myeloid colony formation/replating ability and a complete dendritic cell (DC) differentiation block. Our findings suggest Lin−CD34+CD38+ cells instead of Lin−CD34+CD38− cells could be the target(s) of secondary genetic lesions underpinning progression from CMML to AML, which have implications for the further study of the biology of leukemic transformation and the design of new strategies for the effective treatment of CMML. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
234. Establishment, characterization, karyotyping, and comparative genomic hybridization analysis of HKESC-2 and HKESC-3: two newly established human esophageal squamous cell carcinoma cell lines
- Author
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Hu, Ying Chuan, Lam, King Y., Law, Simon Y., Wan, Thomas S.K., Ma, Edmond S.K., Kwong, Yok Lam, Chan, Li C., Wong, John, and Srivastava, Gopesh
- Subjects
- *
ESOPHAGEAL cancer , *SQUAMOUS cell carcinoma , *CANCER in women , *KARYOTYPES - Abstract
The establishment of esophageal cancer cell lines can facilitate the search for molecular mechanisms underlying its pathogenesis. Two novel human esophageal squamous cell carcinoma (ESCC) cell lines, HKESC-2 and HKESC-3, were established from a moderately differentiated ESCC of a 46-year-old Chinese woman and a well-differentiated ESCC of a 74-year-old Chinese man, both from Hong Kong. The pathological characteristics (morphological, immunohistochemical, and electron microscopic studies), tumorigenicity in nude mice, cytogenetic features, and DNA ploidy of the two cell lines were investigated. The two cell lines have been maintained in vitro for more than 17 months and passaged over 85 times for HKESC-2 and 58 times for HKESC-3. Both grew as monolayers, with a doubling time of 24 hours for HKESC-2 and 48 h for HKESC-3. Their squamous epithelial nature was authenticated by their strong immunopositivity with the anti-cytokeratin antibodies and the ultrastructural demonstration of tonofilaments and desmosomes. They are tumorigenic in nude mice and had DNA aneuploidy. G-banding cytogenetic analysis showed hyperdiploidy in HKESC-2 and near-tetraploidy in HKESC-3. Frequent breakpoints were noted at 1p22, 1p32, and 9q34 in HKESC-2 and at 1p31, 3p25, 3p14, 6q16, 6q21, 8p21, 9q34, 13q32, and 17q25 in HKESC-3. Comparative genomic hybridization analysis found that chromosomal gains were at 3q24∼qter, 5q21∼qter, 8q11∼qter, 13q21∼q31, 17q11∼qter, 19, 22q22 for HKESC-2 and at 3q13∼qter, 5p, 6p, 9q21∼qter, 10q21∼q22, 12q15∼pter, 14q24∼qter, 16, 17q24∼qter, 20 for HKESC-3. Chromosomal losses were at 3p13∼pter, 18q12∼qter for HKESC-3. These two newly established cell lines will be useful tools in the study of the molecular pathogenesis and biological behavior of ESCC cells and for testing new therapeutic reagents for ESCC in the future. [Copyright &y& Elsevier]
- Published
- 2002
- Full Text
- View/download PDF
235. der(Y)t(Y;1) is a nonrandom abnormality in myelodysplastic syndrome
- Author
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Wei, D.C.C., Wan, Thomas S.K., Chan, L.C., and Cheng, P.N.M.
- Published
- 1993
- Full Text
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236. PRO155 COST–UTILITY ANALYSIS OF RAVULIZUMAB COMPARED WITH ECULIZUMAB IN GERMAN ADULT OUTPATIENTS WITH PAROXYSMAL NOCTURNAL HEMOGLOBINURIA.
- Author
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OConnell, T., Buessing, M.G., Tu, L., Tomazos, I., Thomas, S.K., and Myren, K.J.
- Subjects
- *
PAROXYSMAL hemoglobinuria , *ECULIZUMAB , *COST effectiveness - Abstract
PRO155 COST-UTILITY ANALYSIS OF RAVULIZUMAB COMPARED WITH ECULIZUMAB IN GERMAN ADULT OUTPATIENTS WITH PAROXYSMAL NOCTURNAL HEMOGLOBINURIA Eculizumab and ravulizumab are the only approved treatments for intravascular haemolysis caused by uncontrolled complement system activation in patients with paroxysmal nocturnal haemoglobinuria (PNH). The model demonstrated that ravulizumab is cost-saving compared with eculizumab for managing German adult outpatients with PNH, and provides moderate HRQoL benefits by reducing treatment burden and alleviating BTH and blood transfusion requirements. [Extracted from the article]
- Published
- 2019
- Full Text
- View/download PDF
237. Cytogenetic resources and information Running title: Databases for cancer cytogenetics *Corresponding authors
- Author
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de Braekeleer, H, Huret, Jl, Mossafa, H, Dessen, P, Plateforme de Bioinformatique [Gustave Roussy], Analyse moléculaire, modélisation et imagerie de la maladie cancéreuse (AMMICa), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut Gustave Roussy (IGR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut Gustave Roussy (IGR)-Institut National de la Santé et de la Recherche Médicale (INSERM), Hématopoïèse normale et pathologique (U1170 Inserm), Université Paris-Sud - Paris 11 (UP11)-Institut Gustave Roussy (IGR)-Institut National de la Santé et de la Recherche Médicale (INSERM), Thomas S.K. Wan, John M. Walker, Huret, Jean-Loup, and Université Paris-Sud - Paris 11 (UP11)-Institut Gustave Roussy (IGR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut Gustave Roussy (IGR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SDV.GEN]Life Sciences [q-bio]/Genetics ,[SDV.BIBS] Life Sciences [q-bio]/Quantitative Methods [q-bio.QM] ,COSMIC ,Mitelman database ,[SDV.CAN]Life Sciences [q-bio]/Cancer ,[SDV.GEN] Life Sciences [q-bio]/Genetics ,Ensembl ,[SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM] ,HGNC ,Database ,ICD-O ,[SDV.CAN] Life Sciences [q-bio]/Cancer ,Cytogenetic ,Atlas of Genetics and Cytogenetics in Oncology and Haematology ,UCSC ,Cancer - Abstract
International audience; The main databases devoted stricto sensu to cancer cytogenetics are the "Mitelman Database of Chromosome Aberrations and Gene Fusions in Cancer" ( http://cgap.nci.nih.gov/Chromosomes/Mitelman ), the "Atlas of Genetics and Cytogenetics in Oncology and Haematology" ( http://atlasgeneticsoncology.org ), and COSMIC ( http://cancer.sanger.ac.uk/cosmic ).However, being a complex multistep process, cancer cytogenetics are broadened to "cytogenomics," with complementary resources on: general databases (nucleic acid and protein sequences databases; cartography browsers: GenBank, RefSeq, UCSC, Ensembl, UniProtKB, and Entrez Gene), cancer genomic portals associated with recent international integrated programs, such as TCGA or ICGC, other fusion genes databases, array CGH databases, copy number variation databases, and mutation databases. Other resources such as the International System for Human Cytogenomic Nomenclature (ISCN), the International Classification of Diseases for Oncology (ICD-O), and the Human Gene Nomenclature Database (HGNC) allow a common language.Data within the scientific/medical community should be freely available. However, most of the institutional stakeholders are now gradually disengaging, and well-known databases are forced to beg or to disappear (which may happen!).
- Published
- 2017
238. How Does Uncertainty Around Costs And Effects Relate To Uncertainty Around Cost-Effectiveness?
- Author
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Jain, M., Bhattacharyya, S., Gupta, S., Sonathi, V., Mahon, R., Malakar, H., Vudumala, U., Gunda, P., Kumar, P., Partha, G., and Thomas, S.K.
- Subjects
- *
COST effectiveness , *MEDICAL technology , *HEALTH outcome assessment , *REIMBURSEMENT , *DECISION making - Published
- 2014
- Full Text
- View/download PDF
239. The Economic Impact Of Cardiovascular Events In Patients Post Myocardial Infarction: Uk Health Care Perspective.
- Author
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Jain, M., Sonathi, V., Rathi, H., Thomas, S.K., and Mollon, P.
- Subjects
- *
MYOCARDIAL infarction , *CARDIOVASCULAR diseases risk factors , *MYOCARDIAL infarction treatment , *DISEASE prevalence , *DISEASE progression , *MEDICAL care costs , *PATIENTS - Published
- 2014
- Full Text
- View/download PDF
240. A DE-NOVO Model to Predict Outcomes of a New Hypothetical Intervention to Reduce CV Risk in Post Mi Patients.
- Author
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Jain, M., Sonathi, V., Rathi, H., Bakuli, A., Thomas, S.K., and Mollon, P.
- Subjects
- *
HEALTH outcome assessment , *CARDIOVASCULAR diseases risk factors , *MYOCARDIAL infarction , *MEDICAL care , *DRUG efficacy , *RELATIVE medical risk , *PATIENTS - Published
- 2014
- Full Text
- View/download PDF
241. A De-Novo Economic Model to Assess Clinical and Economic Consequences of Bronchiectasis.
- Author
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Bhattacharyya, S.B., Calado, F., Priedane, E., Shirore, R.M., Haworth, C.S., Flume, P.A., Sonathi, V., and Thomas, S.K.
- Subjects
- *
BRONCHIECTASIS , *MEDICAL care costs , *ANTIBIOTICS , *DISEASE exacerbation , *ECONOMIC models - Published
- 2014
- Full Text
- View/download PDF
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