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Reassessment of doses in TLD100 by measuring the residual dose. J Radioanal Nucl Chem 2007. [DOI: 10.1007/s10967-007-0938-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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52
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Transperineal three-dimensional ultrasound in evaluating anal sphincter muscles. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2007; 30:201-9. [PMID: 17605148 DOI: 10.1002/uog.4057] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
OBJECTIVES To evaluate whether transperineal three-dimensional (3D) ultrasound can be used to depict normal anal sphincter anatomy and to measure the thickness of muscle layers and the anteroposterior length of the levator hiatus. METHODS The study included 22 normal nulliparous female volunteers. Transperineal 3D sonographic evaluation of the anal canal included assessment of sphincter shape, echogenicity, marginal definition and muscle thickness. Measurements of the thickness of the internal anal sphincter (IAS) and puborectalis muscle (PRM) were determined with the women at rest and during squeezing by two observers, and interobserver reliability was determined. The anteroposterior length of the levator hiatus at rest and during squeezing was measured. RESULTS The proximal end of the anal canal (towards the rectum) consisted of overlapping IAS and PRM, and the distal end (towards the anus) consisted of overlapping IAS and external anal sphincter (EAS). At the PRM level, the mean +/- SD IAS thickness was 2.3 +/- 0.5 mm at rest and 2.5 +/- 0.4 mm during squeezing, and at the mid-EAS level it was 2.9 +/- 0.5 mm at rest and 2.8 +/- 0.5 mm during squeezing. The PRM thickness was 6.5 +/- 1.0 mm at rest and 6.4 +/- 1.2 mm during squeezing. The difference in muscle thickness of the sphincter layers with the woman at rest and during squeezing was not significant. The anteroposterior length of the levator hiatus was 51.7 +/- 5.0 mm at rest and 47.4 +/- 4.1 mm during squeezing (P < 0.01). CONCLUSION Transperineal 3D ultrasound may be useful in evaluating the anatomy of the anal canal.
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Impact of breast cancer risk assessment in primary care: Modeling clinical outcomes and effectiveness. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.1516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
1516 Background: Breast cancer risk assessment (RA) is rarely performed in the primary care setting due to uncertainty regarding the balance of harms and benefits in high risk women subsequently offered chemoprevention. We used a decision model to assess the potential clinical impact of several strategies involving use of routine RA in primary care. Methods: We developed a decision analytic model to compare routine breast cancer RA in primary care to usual care. The RA method was the Gail model, with a 5-year risk of >1.67% being designated as high risk (varied in sensitivity analyses). We assumed that high risk women would be offered 5 years of tamoxifen and that acceptance (70%) and compliance (68%) rates would be incomplete. For women receiving tamoxifen, the relative risk (RR) of incident estrogen-receptor positive invasive breast cancer was 0.31 over the 5 years of treatment, diminishing over the next 5 years after cessation of treatment. RR’s for the other health effects associated with tamoxifen were: vertebral fracture (0.74), endometrial cancer (2.41), stroke (1.6), pulmonary embolism (PE, 3.01), and deep vein thrombosis (DVT, 1.60). The non-breast cancer health effects of tamoxifen were assumed to pertain only to the 5 years of active therapy. All RR’s were applied to age-dependent population-based incidence rates; data sources included published epidemiologic and clinical trial data; model duration was 40 years. Results: In agreement with recommended clinical use of tamoxifen, the results were sensitive to age and the Gail threshold above which chemoprevention was recommended ( Table ). The number of women needed to screen (NNS) to prevent 1 case of breast cancer is 7-fold higher among women aged 50 compared to 65 with a Gail risk of 1.67% (719 vs. 104). Conclusions: The number of women offered treatment, as well as the clinical outcomes and NNS, resulting from routine breast cancer risk assessment varies with the age at RA and treatment threshold selected. [Table: see text] No significant financial relationships to disclose.
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The quality-of-life impact of osteonecrosis of the jaw: Implications for bisphosphonate use in metastatic breast cancer. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.6620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
6620 Background: Osteonecrosis of the jaw (ONJ) has been linked to bisphosphonates used to prevent skeletal related events (SREs) in metastatic breast cancer (MBC). The primary aim of this decision-analysis study is to determine the preference threshold at which the quality of life (QOL) impact of ONJ may change bisphosphonate treatment decisions. Methods: We developed a Markov decision- analysis model of bisphosphonate use in MBC that includes the risk of ONJ. For the base case we estimated the QOL impact of ONJ by evaluating published ONJ reports with the Oral Health Impact Profile (OHIP). OHIP scores were transformed to EQ5D utilities and adjusted for MBC (published utility for MBC=0.63). We used published utility values for SRE: 0.46 for the month in which SRE occurs. Based on published data, we estimated that bisphosphonates reduce the incidence of SREs by 41% and that the incidence of SRE rises with increased bisphosphonate exposure: year 1=0.004/month; year 2=0.022/month; year 3=0.034/month. We inspected 2 treatment strategies: treat all patients with bisphosphonates (treat all) and treat no patient with bisphosphonates (treat none). Results: 18 published cases were adequate for evaluation. The mean OHIP score=27 (possible range 14–70), s.d.=1.8. We calculated that patients with MBC and ONJ have a utility=0.53 (s.d.=0.04) for the base-case. The model predicted a mean survival of 22 months for both strategies. In the treat all strategy each patient received a mean of 19 months of bisphosphonates and suffered 2.4 SREs. In the treat none strategy each patient suffered 4.0 SREs. In the base case, the treat all strategy maximized net quality-adjusted life, although by less than 1/2 month per patient. The treat all strategy was optimal for only 33% of patients. The treat all strategy does not maximize net quality-adjusted life if the risk of ONJ is 4.5 times higher than the base case or the ratio of the utility for ONJ to the utility for SRE is less than 0.4 (base-case ratio=1.152). Conclusions: The QOL impact of ONJ alters the decision to use bisphosphonates when 1) the incidence of ONJ is 4.5 times higher than published estimates; or 2) the long-term preference for ONJ is 60% lower than the short-term preference for SRE. Further QOL research may refine these estimates. No significant financial relationships to disclose.
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Use of statistical checks as maintenance tools for TLD readers. RADIATION PROTECTION DOSIMETRY 2007; 125:109-12. [PMID: 17533159 DOI: 10.1093/rpd/ncm205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Although the values of different parameters may remain within permissible limits during the operation of a thermoluminescent dosemeter (TLD) reader, certain effects can become apparent only when a long-term followup of these parameters is performed. In order to ensure an accurate and reliable operation of a TLD reader, the system characteristics must be monitored continuously. Long-term statistical checks of key system parameters may give a broader insight into the operational characteristics of the TLD reader and may help for proper maintenance of the system. The photomultipliers noise, the internal reference light source stability and the A to D reference voltage were found to be critical parameters, which have a major influence on the accuracy and stability of the system. A followup of these parameters for a period of about 10 y is presented, and some problems are seen to be reflected in the distributions.
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On the reassessment of doses in TL-dosimetry by measuring the residual dose. RADIATION PROTECTION DOSIMETRY 2007; 125:113-6. [PMID: 17449909 DOI: 10.1093/rpd/ncm195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Second readouts and the photo-transferred thermoluminscence (PTTL) method are sometimes used to reassess high doses. When using the common LiF:Mg,Ti, if the second readout is performed by a regular readout cycle of 13.3 s, its efficiency is low and the estimations cannot be obtained with acceptable accuracy for low doses in the 10-100 mSv range. By applying the PTTL method, the efficiency is much higher, but a high background is also present, deteriorating the quality of the reassessment. A simple and efficient method was studied, which consists of expanding the heating time to 30 s. Although the efficiency relative to a standard readout is improved by only a factor of 3, the low background enables to obtain results with the same uncertainty as the more complicated PTTL method. By applying region of integration discrimination, the errors can be further diminished.
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On the reassessment of thermal neutron doses in TLD-100 by measuring the residual dose. RADIATION PROTECTION DOSIMETRY 2007; 126:524-7. [PMID: 17507383 DOI: 10.1093/rpd/ncm105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
By employing second readouts and the Phototransferred thermoluminescence (PTTL) method, high doses may be reassessed on the basis of residual dose information. It was shown in the past that for TLD-100, gamma doses can be reassessed by using a simple and efficient method, which consists of expanding the heating time to 30 s. In the present study, the 'extended time' method and the PTTL residual dose evaluations are used for reassessing thermal neutron doses when using TLD-100 crystals. Reassessment characteristics are presented for relatively low thermal neutron doses, in the range between approximately 1 and 18 mSv gamma dose equivalent.
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Pre- and post-irradiation fading of 6LiF:Mg,Ti (TLD-600) exposed to thermal neutrons. RADIATION PROTECTION DOSIMETRY 2007; 126:318-21. [PMID: 17496295 DOI: 10.1093/rpd/ncm066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The results of (6)LiF:Mg,Ti (TLD-600) glow peaks fading after irradiation by thermal neutrons, as a function of pre- and post-irradiation times up to 3 months, are presented. The measured glow curves were analysed using the computerised glow curve deconvolution and region of integration methods, to study the decay characteristics of each individual peak and the sum of selected peak areas in the glow curve. The results confirm a high stability for the sum of peaks 4 + 5 and 6 + 7, whereas peaks 2 and 3 have a dominant contribution to the fading effect.
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Optimisation of the readout parameters when evaluating thermal neutron doses by TL dosimetry with LiF:Mg,Ti. RADIATION PROTECTION DOSIMETRY 2007; 126:532-5. [PMID: 17513859 DOI: 10.1093/rpd/ncm107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The location of the glow peaks depends on the heating rate. It takes some time until the crystal reaches the heater temperature, and this time lag has a direct effect on the shift of peaks towards higher temperatures. Some information on the high-temperature peaks may be lost if the readout conditions (mainly length of time) are not properly chosen. Step heating profiles to a varying final temperature between 300 degrees C and 125 degrees C were used to study the time dependence of the collected information in the glow curves of (6)LiF:Mg,Ti crystals, and the minimal heating time for evaluation of thermal neutron doses was determined.
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Global Forum of the World Federation of Hemophilia, September 26-27, 2005, Montreal, Quebec, Canada. Transfus Apher Sci 2006; 35:151-172. [PMID: 28356214 DOI: 10.1016/j.transci.2006.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Accepted: 07/05/2006] [Indexed: 10/23/2022]
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Abstract
Plica neuropathica is a rare condition involving complete matting of scalp hair. It typically occurs in otherwise healthy individuals, and in previous cases has been caused by either shampooing or neglect of hair. Cutting off the matted hair is the only solution. We present the case of a 14-year-old girl with a history of chronic illness and an acute infection presenting with plica neuropathica followed by complete hair loss. This unique case illustrates for the first time plica neuropathica in the absence of shampooing, and demonstrates that it can be associated with underlying illnesses and subsequent hair loss.
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Determination of quality parameters from statistical analysis of routine TLD dosimetry data. RADIATION PROTECTION DOSIMETRY 2006; 119:306-9. [PMID: 16709715 DOI: 10.1093/rpd/nci514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Following the as low as reasonably achievable (ALARA) practice, there is a need to measure very low doses, of the same order of magnitude as the natural background, and the limits of detection of the dosimetry systems. The different contributions of the background signals to the total zero dose reading of thermoluminescence dosemeter (TLD) cards were analysed by using the common basic definitions of statistical indicators: the critical level (L(C)), the detection limit (L(D)) and the determination limit (L(Q)). These key statistical parameters for the system operated at NRC-Negev were quantified, based on the history of readings of the calibration cards in use. The electronic noise seems to play a minor role, but the reading of the Teflon coating (without the presence of a TLD crystal) gave a significant contribution.
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On neutron-gamma mixed field dosimetry with LiF:Mg,Ti at radiation protection dose levels. RADIATION PROTECTION DOSIMETRY 2006; 119:314-8. [PMID: 16735561 DOI: 10.1093/rpd/nci665] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The possibility of using the specific responses of the high temperature Peaks 6 and 7 and Peaks 4 and 5 to different LET radiations was mentioned in the past mainly for very high doses. The applicability of the two regions method for thermal neutrons--gamma ray mixed field dosimetry was investigated by analysing the response of LiF:Mg,Ti dosemeters irradiated to different ratios of thermal neutrons and gamma rays at radiation protection dose levels encountered in routine work conditions, up to approximately 50 mSv. The Region of Interest method was used to define the areas of the Peaks 4 + 5 and 6 + 7. We found that a simple algorithm can be used to determine with good accuracy the separate contributions of neutron and gamma doses.
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Capsule endoscopy structured terminology (CEST): proposal of a standardized and structured terminology for reporting capsule endoscopy procedures. Endoscopy 2005; 37:951-9. [PMID: 16189767 DOI: 10.1055/s-2005-870329] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Structured terminology for capsule endoscopy: results of retrospective testing and validation in 766 small-bowel investigations. Endoscopy 2005; 37:945-50. [PMID: 16189766 DOI: 10.1055/s-2005-870266] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND STUDY AIMS Capsule endoscopy (CE) is an effective means of investigating the small bowel in patients with gastrointestinal diseases. Computerized reports are frequently used in endoscopy, and the Minimal Standard Terminology (MST) has been promoted by endoscopy societies as the official vocabulary for endoscopy. The aims of this study were to design a lexicon for CE reports based on the principles of the MST and to validate lists of terms for describing findings and reasons for performing a CE by cross-matching them with the results of CE procedures collected during ongoing clinical studies. MATERIALS AND METHODS A consensus-based Capsule Endoscopy Structured Terminology (CEST) was developed by experts involved in CE studies. Lists of terms suitable for CE were designed for the various sections of an endoscopic report. They were then correlated with the corresponding MST lists for duodenal and intestinal endoscopy. The results of 766 CE procedures, collected in an electronic case record form (eCRF), were analyzed to provide lists of reasons for performing the procedures and of the findings. The eCRF provided only a limited number of items for each data field, along with free-text facilities. Only descriptions pertaining to the small bowel were analyzed. Lists of terms were then reviewed by two experts to group obvious synonyms. The accuracy of the CEST was defined beforehand as the capability to describe 90 % of entries. RESULTS A total of 766 CE procedures were analyzed. The eCRF included 824 entries as reasons for the examination in 655 CEs (1.3 per procedure). These represented 122 different expressions. After grouping of synonyms, 28 expressions remained. Among them, 10 were matched with terms from the list of reasons for performing CE offered in the CEST. These were the most frequently used, accounting for 768 entries in this field (93.2 %). All eCRFs contained at least one description of findings. A total of 109 CE procedures were classified as normal (14.3 %). A total of 2624 entries for abnormal findings were recorded for 657 procedures (4.0 per procedure). In all, 213 different expressions were used to describe abnormal findings. After grouping of synonyms, 52 expressions remained. Among these, 27 were matched with terms from the list of findings in the CEST, covering 2403 entries (91.6 %). CONCLUSIONS In this study, CEST terms were capable of describing more than 90 % of the reasons for performance and of the findings in an unselected set of CE procedures. CEST is therefore suitable for use as the standard lexicon for CE reports. Adopted as a standard, it could significantly improve the quality of the data collected and reported in CE studies.
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Cost-effectiveness analysis of oxaliplatin/5-FU/LV in adjuvant treatment of stage III colon cancer in the U.S. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.3532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Small-bowel intussusception around a gastrojejunostomy tube resulting in ischemic necrosis of the intestine. Pediatr Radiol 2004; 34:916-8. [PMID: 15503002 DOI: 10.1007/s00247-004-1230-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2004] [Revised: 04/19/2004] [Accepted: 05/04/2004] [Indexed: 10/26/2022]
Abstract
Gastrojejunostomy (GJ) tube feeding has made a significant difference in the lives of children with oropharyngeal motor problems and severe gastroesophageal reflux disease. It may, however, also lead to small-bowel intussusception. Previously, these intussusceptions have been reported as intermittent, self limiting, and innocuous. We report a case of a GJ-tube-related small-bowel intussusception that resulted in ischemic necrosis of the bowel. This case suggests that close monitoring and confirmation of successful reduction is necessary in the treatment of GJ-tube-related small-bowel intussusception.
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Abstract
Transforming growth factor-beta (TGF-beta) plays a complex role in skin carcinogenesis, acting as a suppressor early in tumor development but later as a promoter. Smad proteins are important intracellular mediators of TGF-beta signaling. To determine the effect of disrupting Smad genes and TGF-beta signaling on chemically induced skin carcinogenesis in mice, transgenic mice heterozygous for Smad2 or Smad3 deletions and wild-type controls were treated with topical dimethylbenzanthracene for 7 months. Tumor multiplicity, type, and degree of differentiation were assessed by histopathology and immunohistochemistry. Smad3(+/-) mice developed significantly fewer tumors than the wild-type group (P < 0.05). This indicated a possible oncogenic function for Smad3 in skin carcinogenesis. Smad2(+/-) mice formed less-differentiated tumors than their wild-type counterparts, supporting a tumor suppressor role for Smad2. There was a significant difference (P < 0.05) in tumor type between Smad2(+/-) and Smad3(+/-) groups, suggesting that Smad2 and Smad3 may regulate different targets.
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Out-of-pocket costs (OPC) and time costs (TC) for patients with stage IV non-small cell lung cancer (NSCLC) and their caregivers. J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.6021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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71
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On fading corrections for LiF:Mg,Ti irradiated by thermal neutrons. RADIATION PROTECTION DOSIMETRY 2004; 110:305-308. [PMID: 15353664 DOI: 10.1093/rpd/nch119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The phenomena of preirradiation and postirradiation fading of LiF:Mg,Ti phosphors are considered a significant practical problem in routine dosimetry because of the uncertainties introduced, especially for mixed neutron-gamma dosimetry, as different fading corrections may be necessary for the gamma and neutron contributions. We have investigated if the region of interest (ROI) method is applicable to minimizing the fading effect for thermal neutron irradiation as it is for gamma irradiation. By employing the ROI method, which consists of integration between channel 31 below the glow curve maximum and channel 16 above the glow curve maximum, a constant dose value was obtained for the period of 90 d. Thus, by employing the ROI method, a fading independent evaluation of the thermal neutron dose can be made.
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Abstract
Age at menopause is associated with a variety of health outcomes. Menstrual histories, both as markers of physiologic function and through their potential association with age at menopause, have also been investigated for their links to health outcomes. This study used data from a cohort of women from the United States who provided prospectively recorded data on their menstrual cycles for many years. Dr. Alan Treloar (University of Minnesota) originally recruited the women in the 1930s; the authors used data reported by these women from 1930 through 1977. They identified nuanced characteristics of menstrual histories that were strongly predictive of the onset of menopause, focusing on measures of central tendency (the mean), variability (standard deviation), and serial irregularity (approximate entropy), the last of which quantifies a continuum that ranges from totally ordered to completely random. They controlled for other characteristics known to affect age at menopause, including use of exogenous hormones, number of births, and extent of breastfeeding. Although cycle length and variability increased with the approach of menopause, the authors found that serial irregularity decreased and was a strong predictor of its onset. This finding constitutes an important piece of information not attainable with conventional statistical summaries of menstrual histories.
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Treatment Of Complicated Parapneumonic Effusions With Intrapleural Tissue Plasminogen Activator. Paediatr Child Health 2003. [DOI: 10.1093/pch/8.suppl_b.43ba] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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On the determination of the post-irradiation time from the glow curve of TLD-100. RADIATION PROTECTION DOSIMETRY 2003; 106:121-130. [PMID: 14653332 DOI: 10.1093/oxfordjournals.rpd.a006341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The ratio of peak 3 to the sum of peaks 4 + 5 in TLD-100 was measured for various pre-irradiation and post-irradiation time periods, under conditions characteristic of routine personal dosimetry. It was confirmed that the value of this ratio depends only on the elapsed time between the prior readout and the present one, independent of the moment when the irradiation took place during the total time interval (storage time). This effect indicates that fading of peak 3 seems to be due mainly to changes in the unoccupied traps, and not to decay of trapped charges, being almost independent of the presence of electrons or holes in the traps. This observation leads to the conclusion that the suggestions in the past to use the decay of peak 3 in TLD-100 for the measurement of the elapsed time between irradiation and readout may have been wrong. On the other hand, the decay of peak 2 can be used to measure the elapsed time from irradiation, since the rate of decay is different when related to pre-irradiation and post-irradiation times, indicating a much higher decay rate of the trapped charges (Randall-Wilkins decay). However, because of the fast decay rate of peak 2, its use for determination of the elapsed time since irradiation is of little practical significance.
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Abstract
We examine whether age at menarche affects age at first marriage or first birth using two samples of U.S. women. Data are drawn from the Tremin Trust, a longitudinal study of menstrual cycles that recruited white women who were students at the University of Minnesota and from a survey of a nationally representative sample of white women born between 1900 and 1910. Regression models with cubic splines were used to analyze the relationship between age at menarche and age at first marriage. Cox proportional hazard models were used to examine the effect of age at menarche on the interval between marriage and first birth. Unlike earlier work, we found that once secular trends in both age at marriage and age at menarche were taken into account, there was no evidence that age at menarche affects either age at marriage or the timing of first births in these U.S. women.
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Calibration of the Ph. Eur. BRP Batch 3/Mega 2 (US/FDA) standard for human coagulation factor VIII concentrate for use in the potency assay. PHARMEUROPA. SPECIAL ISSUE BIOLOGICALS 2002; 2002:31-64. [PMID: 12448031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
The European Pharmacopoeia Biological Reference Preparation Batch 3/Mega 2 (United States/Food and Drug Administration) (Ph. Eur. BRP Batch 3/Mega 2 (US/FDA)) was developed as an internationally available, common working standard to replace the dwindling stocks of Mega 1 (the current US standard) and Ph. Eur. BRP Batch 2 (the current European standard). The potency was assigned in an international collaborative study with reference to four currently established standards, Ph. Eur. BRP batch 2, WHO 5th and 6th International Standard and Mega 1. Thirty-eight laboratories participated in the collaborative study. Each laboratory was asked to perform four independent assays. Participants used either the one stage clotting assay or the chromogenic assay or both. This publication reports the results obtained with both assays. The summary and conclusion, however highlight the results mainly with respect to the chromogenic assay, which is the assay prescribed in the European Pharmacopoeia. Data were analysed for both assays separately. A consensus potency value was calculated as the unweighted average of mean potencies determined against the four standards. A potency of 8.6 IU/vial as determined in the chromogenic substrate method was assigned to the candidate standard. Inter-laboratory agreement as assessed by calculation of the geometric coefficient of variation was below 10% for mean potencies against all four calibrators for the chromogenic assay. Ph. Eur. BRP Batch 3/Mega 2 (US/FDA) is a freeze-dried, plasma derived, high-purity concentrate. The material was filled into approximately 100,000 vials and lyophilised to a final residual moisture of < or = 2%. Approximately 90,000 vials of the standard are available, equally shared between the two co-ordinating centers. Based on the stability studies, the predicted mean percentage loss per year at -20 degrees C is 0.000% and thus the candidate standard appears to be stable. The Ph. Eur. BRP batch 3 was adopted by the European Pharmacopoeia Commission in November 2001.
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Medicare in the 21st century. BENEFITS QUARTERLY 2002; 17:14-23. [PMID: 11727476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
The authors provide an overview of the Medicare program in terms of how the current program operates, the current issues it faces that may shape possible options for reform, and the implications of these features and issues for employment-based health plans. Current issues include adoption of a premium support model, changes in the eligibility age for Medicare benefits, Medigap insurance, benefits covered and customer service.
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Abstract
One source of background signals, which are non-radiation related, is the reader system and it includes dark current, external contaminants and electronic spikes. These factors can induce signals equivalent to several hundredths of mSv. Mostly, the effects are minimised by proper design of the TLD reader, but some effects are dependent on proper operation of the system. The other main group of background signals originates in the TL crystal and is due to tribothermoluminescence, dirt, chemical reactions and stimulation by visible or UV light. These factors can have a significant contribution, equivalent to over several mSv, depending on whether the crystal is bare or protected by PTFE. Working in clean environments, monitoring continuously the glow curves and performing glow curve deconvolution are suggested to minimise non-radiation induced spurious signals.
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Abstract
PURPOSE We evaluated the ability of previously defined risk groups to predict prostate specific antigen (PSA) outcome 10 years after radical prostatectomy in patients diagnosed with clinically localized prostate cancer during the PSA era. MATERIALS AND METHODS Between 1989 and 2000, 2,127 men with clinically localized prostate cancer underwent radical prostatectomy, including 1,027 at Hospital of the University of Pennsylvania (study cohort) and 1,100 at Brigham and Women's Hospital (validation cohort). Cox regression analysis was done to calculate the relative risk of PSA failure with the 95% confidence interval (CI) in patients at intermediate and high versus low risk. The Kaplan-Meier actuarial method was used to estimate PSA outcome 10 years after radical prostatectomy. RESULTS Compared with low risk patients (stages T1c to 2a disease, PSA 10 ng./ml. or less and Gleason score 6 or less) the relative risk of PSA failure in those at intermediate (stage T2b disease or PSA greater than 10 to 20 ng./ml. or less, or Gleason score 7) and high (stage T2c disease, or PSA greater than 20 ng./ml. or Gleason score 8 or greater) risk was 3.8 (95% CI 2.6 to 5.7) and 9.6 (95% CI 6.6 to 13.9) in the study cohort, and 3.3 (95% CI 2.3 to 4.8) and 6.3 (95% CI 4.3 to 9.4) in the validation cohort. The 10-year PSA failure-free survival rate in the 1,020 patients in the low, 693 in the intermediate and 414 in the high risk groups was 83%, 46% and 29%, respectively (p <0.0001). CONCLUSIONS Based on 10-year actuarial estimates of PSA outcome after radical prostatectomy 3 groups of patients were identified using preoperative PSA, biopsy Gleason score and 1992 clinical T category.
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81
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Abstract
This paper reports a panel discussion--Opportunities for and Limitations to Greater Collaboration Across the Disciplines--held at the conference. It highlights the need for greater collaboration between demographers and epidemiologists and notes the institutional and disciplinary challenges to and opportunities for promoting greater cooperation.
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82
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Antagonistic effects of Smad2 versus Smad7 are sensitive to their expression level during tooth development. J Biol Chem 2001; 276:44163-72. [PMID: 11557747 DOI: 10.1074/jbc.m011424200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Members of the transforming growth factor-beta (TGF-beta) superfamily regulate cell proliferation, differentiation, and apoptosis, controlling the development and maintenance of most tissues. TGF-beta signal is transmitted through the phosphorylation of Smad proteins by TGF-beta receptor serine/threonine kinase. During early tooth development, TGF-beta inhibits proliferation of enamel organ epithelial cells but the underlying molecular mechanisms are largely unknown. Here we tested the hypothesis that antagonistic effects between Smad2 and Smad7 regulate TGF-beta signaling during tooth development. Attenuation of Smad2 gene expression resulted in significant advancement of embryonic tooth development with increased proliferation of enamel organ epithelial cells, while attenuation of Smad7 resulted in significant inhibition of embryonic tooth development with increased apoptotic activity within enamel organ epithelium. These findings suggest that different Smads may have differential activities in regulating TGF-beta-mediated cell proliferation and death. Furthermore, functional haploinsufficiency of Smad2, but not Smad3, altered TGF-beta-mediated tooth development. The results indicate that Smads are critical factors in orchestrating TGF-beta-mediated gene regulation during embryonic tooth development. The effectiveness of TGF-beta signaling is highly sensitive to the level of Smad gene expression.
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83
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Gluteal necrotizing myofascitis: an unusual delayed complication of abdominal sacrocolpopexy. Am J Obstet Gynecol 2001; 185:1273-4. [PMID: 11717673 DOI: 10.1067/mob.2001.118154] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Persistent low back pain developed in a 51-year-old woman after she had undergone abdominal sacrocolpopexy. Four months postoperatively, necrotizing myofascitis developed in her gluteal muscles. The infected mesh, which had eroded into the vagina, was removed. Cultures of the infected mesh and abscesses grew common vaginal flora, including Gardnerella vaginalis and Actinomyces.
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84
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Utilizing PSA, biopsy gleason score, clinical stage, and the percentage of positive biopsies to identify optimal candidates for prostate only radiation therapy. Int J Radiat Oncol Biol Phys 2001. [DOI: 10.1016/s0360-3016(01)02033-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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85
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Abstract
The childhood respiratory consequences of very low birth weight (birth weight < or =1,500 g) are incompletely understood, especially since the introduction of recent changes in neonatal care. To assess prevalence, trends, and risk factors for respiratory symptoms, the authors followed to age 8 years a cohort of 384 very low birth weight children from six regional neonatal intensive care units in Wisconsin and Iowa who were born between August 1, 1988, and June 30, 1991. A control group of 154 Wisconsin schoolchildren was also assembled. Respiratory symptoms in the past 12 months and history of asthma ("asthma ever") were reported by parents on a questionnaire used in the International Study of Asthma and Allergies in Childhood (ISAAC). Control group prevalence resembled ISAAC prevalence worldwide and in Canada, but respiratory symptoms were twice as common among very low birth weight children. With advent of the availability of pulmonary surfactants, the prevalence of wheezing at age 8 decreased from 50% to 16% (p = 0.002) among children with bronchopulmonary dysplasia, but it increased from 14% to 38% among those with milder neonatal respiratory disease. Bronchopulmonary dysplasia, family history of asthma, smoking in the household, and patent ductus arteriosus were predictive of wheezing in the previous 12 months. Antenatal steroid therapy had a borderline-significant protective association with wheezing (odds ratio = 0.56, 95% confidence interval: 0.29, 1.1). There were interaction effects between several of the predictors.
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86
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Fibroblast growth factors in regenerating limbs of Ambystoma: cloning and semi-quantitative RT-PCR expression studies. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 2001; 290:529-40. [PMID: 11555861 DOI: 10.1002/jez.1097] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Urodele amphibians (newts and salamanders) have the ability to regenerate amputated limbs throughout their life span. Because fibroblast growth factors (Fgfs) play important roles in developing limbs, we initiated studies to investigate these growth factors in regenerating limbs. Partial cDNAs of Fgf4, 8, and 10 were cloned from both the Mexican axolotl, Ambystoma mexicanum, and locally collected spotted salamander, Ambystoma maculatum, two salamanders well recognized for their regenerative capabilities. cDNAs from the two Ambystoma species were virtually identical, ranging from 97-100% nucleotide identity. Axolotl Fgf4, 8, and 10 showed nucleotide sequence identity with chick Fgf4, 8, and 10 of 79%, 83%, and 72%, respectively. RT-PCR showed that these growth factors are expressed in regenerating axolotl limbs as well as in developing salamander larvae at the three-digit forelimb stage. Fgf8 and 10 are upregulated during regeneration and thus may be involved in distal signaling similar to that of the developing chick limb. Fgf4, however, was undetectable by RT-PCR in the distal tips of regenerates, suggesting that it does not play the same role in limb regeneration that it does in limb development. We also investigated the role these Fgfs may have in the nerve-dependence of regeneration. They were expressed similarly in aneurogenic and innervated limbs, suggesting that they are not the neurotrophic factors responsible for nerve-dependence. Denervation prevented Fgf8 and 10 upregulation, suggesting Fgf pathways are downstream of nerve-dependence. These data highlight important similarities and differences in Fgf expression between limb development and limb regeneration. J. Exp. Zool. 290:529-540, 2001.
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87
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Subcutaneous emphysema in a pediatric patient after radiologic placement of a percutaneous gastrostomy tube. AJR Am J Roentgenol 2001; 177:693-4. [PMID: 11517077 DOI: 10.2214/ajr.177.3.1770693] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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88
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Provider-sponsored networks in public sector behavioral health. ADMINISTRATION AND POLICY IN MENTAL HEALTH AND MENTAL HEALTH SERVICES RESEARCH 2001; 29:3-20. [PMID: 11811771 DOI: 10.1023/a:1013161630661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Numerous behavioral health and social service providers (primarily not-for-profit community mental health and chemical dependency treatment centers) have been joining forces on a local and regional basis to create their own managed care contracting entities, referred to as provider-sponsored networks. Even though these networks are emerging as an alternative managed care model, little is known about them. This descriptive survey provides baseline information about the status of these networks. Using a structured interview questionnaire, a random sample of 15 networks from 12 states was surveyed. Participants were asked about various organizational characteristics of networks, reasons for formation, managed care readiness, obstacles to success, differential value of networks, and recommendations for success. Findings suggest that regional networks are making gradual progress, although many of the assumed benefits have been elusive.
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89
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Abstract
Scurvy has been known since ancient times, but the discovery of the link between the dietary deficiency of ascorbic acid and scurvy has dramatically reduced its incidence over the past half-century. Sporadic reports of scurvy still occur, primarily in elderly, isolated individuals with alcoholism. The incidence of scurvy in the pediatric population is very uncommon, and it is usually seen in children with severely restricted diets attributable to psychiatric or developmental problems. The condition is characterized by perifollicular petechiae and bruising, gingival inflammation and bleeding, and, in children, bone disease. We describe a case of scurvy in a 9-year-old developmentally delayed girl who had a diet markedly deficient in vitamin C resulting from extremely limited food preferences. She presented with debilitating bone pain, inflammatory gingival disease, perifollicular hyperkeratosis, and purpura. Severe hypertension without another apparent secondary cause was also present, which has been previously undescribed. The signs of scurvy and hypertension resolved after treatment with vitamin C. The diagnosis of scurvy is made on clinical and radiographic grounds, and may be supported by finding reduced levels of vitamin C in serum or buffy-coat leukocytes. The response to vitamin C is dramatic. Clinicians should be aware of this potentially fatal but easily curable condition that is still occasionally encountered among children.
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90
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An antibiotic with activity against gram-positive bacteria from the gentamicin-producing strain of Micromonospora purpurea. Appl Microbiol Biotechnol 2001; 56:502-3. [PMID: 11549027 DOI: 10.1007/s002530100671] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A mixture of polycyclic aromatic compounds with activity against gram-positive bacteria was isolated from a gentamicin-producing species of Micromonospora.
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91
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Smad proteins and hepatocyte growth factor control parallel regulatory pathways that converge on beta1-integrin to promote normal liver development. Mol Cell Biol 2001; 21:5122-31. [PMID: 11438667 PMCID: PMC87237 DOI: 10.1128/mcb.21.15.5122-5131.2001] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Smads serve as intracellular mediators of transforming growth factor beta (TGF-beta) signaling. After phosphorylation by activated type I TGF-beta receptors, Smad proteins translocate to the nucleus, where they serve as transcription factors and increase or decrease expression of TGF-beta target genes. Mice lacking one copy each of Smad2 and Smad3 suffered midgestation lethality due to liver hypoplasia and anemia, suggesting essential dosage requirements of TGF-beta signal components. This is likely due to abnormal adhesive properties of the mutant hepatocytes, which may result from a decrease in the level of the beta1-integrin and abnormal processing and localization of E-cadherin. Culture of mutant livers in vitro revealed the existence of a parallel developmental pathway mediated by hepatocyte growth factor (HGF), which could rescue the mutant phenotype independent of Smad activation. These pathways merge at the beta1-integrin, the level of which was increased by HGF in the cultured mutant livers. HGF treatment reversed the defects in cell proliferation and hepatic architecture in the Smad2(+/-); Smad3(+/-) livers.
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92
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Functional characterization of transforming growth factor beta signaling in Smad2- and Smad3-deficient fibroblasts. J Biol Chem 2001; 276:19945-53. [PMID: 11262418 DOI: 10.1074/jbc.m102382200] [Citation(s) in RCA: 335] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A prominent pathway of transforming growth factor (TGF)-beta signaling involves receptor-dependent phosphorylation of Smad2 and Smad3, which then translocate to the nucleus to activate transcription of target genes. To investigate the relative importance of these two Smad proteins in TGF-beta1 signal transduction, we have utilized a loss of function approach, based on analysis of the effects of TGF-beta1 on fibroblasts derived from mouse embryos deficient in Smad2 (S2KO) or Smad3 (S3KO). TGF-beta1 caused 50% inhibition of cellular proliferation in wild-type fibroblasts as assessed by [(3)H]thymidine incorporation, whereas the growth of S2KO or S3KO cells was only weakly inhibited by TGF-beta1. Lack of Smad2 or Smad3 expression did not affect TGF-beta1-induced fibronectin synthesis but resulted in markedly suppressed induction of plasminogen activator inhibitor-1 by TGF-beta1. Moreover, TGF-beta1-mediated induction of matrix metalloproteinase-2 was selectively dependent on Smad2, whereas induction of c-fos, Smad7, and TGF-beta1 autoinduction relied on expression of Smad3. Investigation of transcriptional activation of TGF-beta-sensitive reporter genes in the different fibroblasts showed that activation of the (Smad binding element)(4)-Lux reporter by TGF-beta1 was dependent on expression of Smad3, but not Smad2, whereas activation of the activin response element-Lux reporter was strongly suppressed in S2KO fibroblasts but, on the contrary, enhanced in S3KO cells. Our findings indicate specific roles for Smad2 and Smad3 in TGF-beta1 signaling.
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93
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A public culture for guinea pigs: US human research subjects after the Tuskegee study. SCIENCE AS CULTURE 2001; 10:195-223. [PMID: 15971362 DOI: 10.1080/09505430120052293] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
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94
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Abstract
A 6-week-old male infant presented to hospital with a large upper gastrointestinal hemorrhage. Endoscopic biopsies of his esophagus and duodenum showed cytomegalovirus (CMV) inclusions and CMV early antigen was detected by immunohistochemistry. There were no other signs of congenital CMV infection. This case adds to the clinical spectrum of perinatal CMV infection and may be more common than is currently recognized.
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95
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Abstract
A patient, who was not suited for ultrasound-guided biopsy, was biopsied in an interventional magnetic resonance unit at Brigham and Women's Hospital. Real-time magnetic resonance imaging provided verification of placement before tissue samples were taken. This technique successfully sampled tissue from the prostate and led to a diagnosis of cancer.
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96
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97
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Transperineal magnetic resonance image guided prostate biopsy. J Urol 2000; 164:385-7. [PMID: 10893591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
PURPOSE We report the findings of a transperineal magnetic resonance image (MRI) guided biopsy of the prostate in a man with increasing prostate specific antigen who was not a candidate for a transrectal ultrasound guided biopsy. MATERIALS AND METHODS Using an open configuration 0.5 Tesla MRI scanner and pelvic coil, a random sextant sample was obtained under real time MRI guidance from the peripheral zone of the prostate gland as well as a single core from each MRI defined lesion. The patient had previously undergone proctocolectomy for ulcerative colitis and, therefore, was not a candidate for transrectal ultrasound guided biopsy. Prior attempts to make the diagnosis of prostate cancer using a transurethral approach were unsuccessful. RESULTS The random sextant samples contained benign prostatic hyperplasia, whereas Gleason grade 3 + 3 = 6 adenocarcinoma was confirmed in 15% and 25% of the 2 cores obtained from the MRI targeted specimens of 2 defined lesions. The procedure was well tolerated by the patient. CONCLUSIONS Transperineal MRI guided biopsy is a new technique that may be useful in detecting prostate cancer in men with increasing prostate specific antigen who are not candidates for transrectal ultrasound guided biopsy.
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98
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Abstract
DESIGN A selection of primary and transformed cell types were evaluated for their susceptibility to infection with human herpesvirus 8 (HHV-8)/Kaposi's sarcoma-associated herpesvirus. METHODS Sources of HHV-8 included Kaposi's sarcoma lesion punch biopsies that were either cocultured directly with target cells or that were first cocultured with human lymphocytes to derive HHV-8-containing fluids that were inoculated onto target cells. HHV-8 was also obtained from primary effusion lymphoma-derived cell lines. Techniques to detect infection included the PCR, immunofluorescence assays and in situ hybridization. RESULTS Susceptible cells included human umbilical cord blood mononuclear cells (UCMC), adult CD19 B cells, macrophages and certain endothelial cells of human and animal origin, including some that are transformed with human papilloma virus type 16 E6 and E7 genes. The infection of lymphocytes did not yield established lymphoblastoid cell lines (LCL) and virus infection persisted for only 4-7 days. However, long-term HHV-8 infection of UCMC could be achieved by coinfection with Epstein-Barr virus. HHV-8 could also infect UCMC LCL recently derived by Epstein-Barr virus transformation, but long-established LCL could not be infected with HHV-8. CONCLUSIONS These data provide further biological evidence in cell culture for the limited cellular host range of HHV-8 to CD19 B cells, macrophages, and certain endothelial cells.
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99
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Angiosarcoma arising in a testicular teratoma. J Urol 2000; 163:1872-3. [PMID: 10799210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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100
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Elevated cholesterol metabolism and bile acid synthesis in mice lacking membrane tyrosine kinase receptor FGFR4. J Biol Chem 2000; 275:15482-9. [PMID: 10809780 DOI: 10.1074/jbc.275.20.15482] [Citation(s) in RCA: 273] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Heparan sulfate-regulated transmembrane tyrosine kinase receptor FGFR4 is the major FGFR isotype in mature hepatocytes. Fibroblast growth factor has been implicated in the definition of liver from foregut endoderm where FGFR4 is expressed and stimulation of hepatocyte DNA synthesis in vitro. Here we show that livers of mice lacking FGFR4 exhibited normal morphology and regenerated normally in response to partial hepatectomy. However, the FGFR4 (-/-) mice exhibited depleted gallbladders, an elevated bile acid pool and elevated excretion of bile acids. Cholesterol- and bile acid-controlled liver cholesterol 7alpha-hydroxylase, the limiting enzyme for bile acid synthesis, was elevated, unresponsive to dietary cholesterol, but repressed normally by dietary cholate. Expression pattern and cholate-dependent, cholesterol-induced hepatomegaly in the FGFR4 (-/-) mice suggested that activation of receptor interacting protein 140, a co-repressor of feed-forward activator liver X receptor alpha, may mediate the negative regulation of cholesterol- and bile acid-controlled liver cholesterol 7alpha-hydroxylase transcription by FGFR4 and cholate. The results demonstrate that transmembrane sensors interface with metabolite-controlled transcription networks and suggest that pericellular matrix-controlled liver FGFR4 in particular may ensure adequate cholesterol for cell structures and signal transduction.
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