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Apostolou EA, Main CA, Miracolo A, Papadakis K, Paparouni K, Kanavos PG. Potential barriers in lipid-lowering treatment with PCSK9 inhibitors from a healthsystem perspective. Comparative evidence from ten countries. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.2348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Gaps between clinical guidelines and attainment of LDL-C goals are evident across jurisdictions. Despite strong evidence of benefit from PCSK9-inhibitors (PCSK9i) treatment in eligible patients, significant underuse remains, suggesting considerable unmet need in clinical outcomes optimization.
Purpose
We investigated key performance endpoints across 10 countries to provide a comparative assessment of potential barriers in PCSK9i therapeutic integration from a healthcare system perspective.
Methods
We performed secondary analysis of peer-reviewed literature, health technology assessment reports, guidelines, clinical pathways since 2015 and constructed a comparative framework of pre-defined endpoints for 10 study countries (Japan, Italy, Spain, Australia, Canada, United Kingdom, Germany, France, Netherlands, USA). We identified 8 endpoints, which were clustered in 3 domains: (a) healthcare system characteristics, (b) demand-side policies, (c) medicine reimbursement policies, pertaining to cost-sharing. Approved PCSK9i indications were in scope.
Results
PCSK9i are reimbursed in all countries. Prescribing restrictions have been applied in all countries (Table 1). PCSK9i for primary prevention are reimbursed mainly in familial hypercholesterolemia, while additional criteria may apply depending on country and condition. PCSK9i are: (a) reserved mainly for very high- or high-risk cohorts (Japan, UK, Netherlands); (b) reimbursed for secondary prevention when additional risk factors/comorbidities exist (Australia, Germany, Netherlands); (c) recommended as 3rd line in 6 countries, as 2nd line in 3 and alone or in combination with other therapies in the USA; and (d) restricted to specialist prescribing while general practitioners cannot initiate treatment in 6 countries, potentially increasing waiting times and underuse rates. Follow-up periods may apply prior to establishing eligibility and vary from 3–12 months, while prior authorization/eligibility documentation may be necessary adding to administrative burden. Age criteria may apply in determining or continuing reimbursement (e.g. max 80 years in Italy). Regional and insurance plan variations apply in Canada and USA, respectively. LDL-C reimbursement thresholds are applied in 7 countries. Their relevance to guideline-recommended goals suggests potential underuse gaps (Fig. 1). While no threshold applies in Germany, an additional criterion of indication for LDL-apheresis determines eligibility. Cost-sharing ranges between 0–30% in co-insurance models, may include a flat fee, a deductible or combination of these.
Conclusion
Restrictions in the use of PCSK9i from marketing authorization labels are implemented in all 10 countries and differ across key endpoints. Significant differences exist between guideline-recommended LDL-C goals and reimbursement thresholds, while additional prescribing and documentation restrictions apply over reimbursed indications, contributing to potential underuse.
Funding Acknowledgement
Type of funding sources: Private company. Main funding source(s): Amgen Inc.
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Affiliation(s)
- E A Apostolou
- London School of Economics and Political Science , London , United Kingdom
| | - C A Main
- London School of Economics and Political Science , London , United Kingdom
| | - A Miracolo
- London School of Economics and Political Science , London , United Kingdom
| | | | | | - P G Kanavos
- London School of Economics and Political Science , London , United Kingdom
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Alho M, Battarbee M, Pfau‐Kempf Y, Khotyaintsev YV, Nakamura R, Cozzani G, Ganse U, Turc L, Johlander A, Horaites K, Tarvus V, Zhou H, Grandin M, Dubart M, Papadakis K, Suni J, George H, Bussov M, Palmroth M. Electron Signatures of Reconnection in a Global eVlasiator Simulation. Geophys Res Lett 2022; 49:e2022GL098329. [PMID: 36249284 PMCID: PMC9541212 DOI: 10.1029/2022gl098329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/13/2022] [Accepted: 06/02/2022] [Indexed: 06/16/2023]
Abstract
Geospace plasma simulations have progressed toward more realistic descriptions of the solar wind-magnetosphere interaction from magnetohydrodynamic to hybrid ion-kinetic, such as the state-of-the-art Vlasiator model. Despite computational advances, electron scales have been out of reach in a global setting. eVlasiator, a novel Vlasiator submodule, shows for the first time how electromagnetic fields driven by global hybrid-ion kinetics influence electrons, resulting in kinetic signatures. We analyze simulated electron distributions associated with reconnection sites and compare them with Magnetospheric Multiscale (MMS) spacecraft observations. Comparison with MMS shows that key electron features, such as reconnection inflows, heated outflows, flat-top distributions, and bidirectional streaming, are in remarkable agreement. Thus, we show that many reconnection-related features can be reproduced despite strongly truncated electron physics and an ion-scale spatial resolution. Ion-scale dynamics and ion-driven magnetic fields are shown to be significantly responsible for the environment that produces electron dynamics observed by spacecraft in near-Earth plasmas.
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Affiliation(s)
- M. Alho
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Battarbee
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - Y. Pfau‐Kempf
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | | | - R. Nakamura
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - G. Cozzani
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - U. Ganse
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - L. Turc
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - A. Johlander
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
- Swedish Institute of Space PhysicsUppsalaSweden
| | - K. Horaites
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - V. Tarvus
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - H. Zhou
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Grandin
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Dubart
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - K. Papadakis
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - J. Suni
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - H. George
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Bussov
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
| | - M. Palmroth
- Department of PhysicsUniversity of HelsinkiHelsinkiFinland
- Finnish Meteorological InstituteHelsinkiFinland
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Ghofrani A, Simonneau G, D'armini AM, Fedullo P, Martin N, Howard L, Jais X, Jenkins D, Jing ZC, Madani M, Mayer E, Papadakis K, Richard D, Kim N. Efficacy and safety of macitentan for inoperable chronic thromboembolic pulmonary hypertension (CTEPH): Results from the randomized controlled MERIT study. Pneumologie 2018. [DOI: 10.1055/s-0037-1619324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- A Ghofrani
- Med. Klinik II/V, Universitätsklinikum Gießen und Marburg GmbH, Standort Gießen
| | - G Simonneau
- Hôpital de Bicêtre, Le Kremlin-Bicêtre, France
| | | | | | - N Martin
- Actelion Pharmaceuticals Ltd, Allschwil, Switzerland
| | | | - X Jais
- Hôpital de Bicêtre, Le Kremlin-Bicêtre, France
| | | | - ZC Jing
- Fuwai Hospital, National Center for Cardiovascular Diseases; Chinese Academy of Medical Sciences and Peking Union Medical College
| | - M Madani
- University of California San Diego Medical Center
| | - E Mayer
- Kerckhoff-Clinic, Bad Nauheim
| | | | - D Richard
- Actelion Pharmaceuticals Ltd, Allschwil, Switzerland
| | - N Kim
- University of California, San Diego
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Galie N, Landzberg M, Beghetti M, Berger R, Efficace M, Gesang S, Papadakis K, Gatzoulis M. P5462Evaluation of macitentan in patients with Eisenmenger syndrome: results from the randomised controlled MAESTRO study. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p5462] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Andersohn F, Mann H, Mitsudomi T, Mok T, Yang JCH, Papadakis K, Hoyle C. Adjusted indirect comparison using propensity score matching of osimertinib to doublet chemotherapy in patients with EGFRm T790M NSCLC who have progressed after EGFR-TKI. Ann Oncol 2016. [DOI: 10.1093/annonc/mdw383.46] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Ryden A, Lawrance R, Papadakis K, Ghiorghiu S, Walding A. 3030 Patient-reported symptom response and impact of treatment with AZD9291 for advanced non-small-cell lung cancer. Eur J Cancer 2015. [DOI: 10.1016/s0959-8049(16)31672-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Denton C, Khanna D, Krieg T, Le Brun FO, Merkel P, Papadakis K, Pope J, Matucci Cerinic M, Furst D. OP0056 Macitentan in Patients with Digital Ulcers Associated with Systemic Sclerosis: Results from the Dual-1 and Dual-2 Randomised Controlled Trials. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.1944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Liao SL, Luks FI, Piasecki GJ, Wild YK, Papadakis K, De Paepe ME. Late-gestation tracheal occlusion in the fetal lamb causes rapid lung growth with type II cell preservation. J Surg Res 2000; 92:64-70. [PMID: 10864484 DOI: 10.1006/jsre.2000.5858] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Fetal tracheal occlusion (TO) results in varying degrees of lung growth. This study examines whether gestational age influences lung growth response following TO. MATERIALS AND METHODS Fetal lambs (term = 145 days) underwent TO early (108 days, n = 6) or late (122 days, n = 6) in gestation. Aspirated lung fluid volume (LFV) and intratracheal pressure (ITP) were recorded daily. Two weeks after TO, the fetuses were sacrificed. Lung growth was assessed by lung weight and stereologic volumetry. Type II cellular density was assessed by computer-assisted morphometry using antisurfactant protein B antibody. RESULTS After early TO, ITP remained below 2 mm Hg for all but one of the first 5 days. In late TO, ITP rose to 4.8 +/- 1.7 mm Hg by Day 1 and remained elevated. LFV remained lower after early than after late TO (P < 0.05) for 8 days. Thereafter, pressure and volume reached similar levels in both TO groups; both were significantly higher than their respective controls (P < 0.05). Parenchymal fraction (1 - air-space fraction) was significantly smaller after late TO (22.8 +/- 1.2%) than after early TO (31.3 +/- 0.5%). Type II density was 38.0 +/- 12.4 x 10(6)/mL after early TO and 84.0 +/- 24.3 x 10(6)/mL in control (P < 0.05); the difference between late TO and control was not significant. CONCLUSIONS Late tracheal occlusion in fetal lambs caused more rapid lung growth than earlier TO, although ultimate lung size was similar in both groups. Late TO also resulted in greater air-space fraction and better preservation of the type II cell population than early TO. Late-gestation tracheal occlusion may therefore be preferable to prolonged occlusion initiated earlier.
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Affiliation(s)
- S L Liao
- Division of Pediatric Surgery, Brown University School of Medicine, Providence, Rhode Island 02905, USA
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De Paepe ME, Johnson BD, Papadakis K, Luks FI. Lung growth response after tracheal occlusion in fetal rabbits is gestational age-dependent. Am J Respir Cell Mol Biol 1999; 21:65-76. [PMID: 10385594 DOI: 10.1165/ajrcmb.21.1.3511] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In utero tracheal occlusion (TO) is a potent stimulus of fetal lung growth, and is currently being applied in clinical trials to treat severe forms of pulmonary hypoplasia. The aim of this study was to examine the effect of timing of TO on pulmonary growth and maturation rates. Fetal rabbits (term = 31 d) were subjected to in utero tracheal clipping at 24 (late pseudoglandular stage) or 27 d of gestation (late canalicular/early terminal sac stage). Sham-operated littermates served as controls (C). Animals were killed at time intervals ranging from 1 to 6 d (early group) or 1 to 3 d (late group) after occlusion. Lung growth was measured by computerized stereologic volumetry and 5'-bromo-2'-deoxyuridine (BrdU) pulse labeling. Pneumocyte II population kinetics were analyzed using a combination of anti-surfactant protein-A and BrdU immunohistochemistry and computer-assisted morphometry. Statistical analysis was performed using unpaired Student's t test. Early TO was followed by an initial 3-d stagnation of growth and subsequently a dramatic acceleration of growth (BrdU-labeling index [LI] 10.1 +/- 0. 6% in TO versus 2.7 +/- 0.5% in C at 29 d, P < 0.001). In contrast, late TO induced an immediate and sustained moderate increase of lung growth (BrdU-LI 2.8 +/- 0.9% in TO versus 1.1 +/- 0.2% in C at 30 d, P < 0.05), associated with relatively more pronounced air-space distension. Whereas late TO caused no significant alterations in type II cell density or proliferation, early TO was followed by a marked increase in type II cell proliferation, paradoxically associated with dramatic reduction of type II cell density after 29 d. The effects of intrauterine TO on fetal lung growth and type II cell kinetics critically depend on the gestational age, and thus on the maturity of the lungs at the time of surgery. These findings have important clinical implications with respect to the timing of fetal interventions aimed at promoting lung growth. The fetal rabbit provides an invaluable model to study the mechanics and age dependency of TO-induced lung growth.
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Affiliation(s)
- M E De Paepe
- Department of Pathology and Division of Pediatric Surgery, Rhode Island Hospital and Brown University School of Medicine, Providence, Rhode Island.
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De Paepe ME, Sardesai MP, Johnson BD, Lesieur-Brooks AM, Papadakis K, Luks FI. The role of apoptosis in normal and accelerated lung development in fetal rabbits. J Pediatr Surg 1999; 34:863-70; discussion 870-1. [PMID: 10359197 DOI: 10.1016/s0022-3468(99)90389-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND/PURPOSE During fetal development, the mammalian lung undergoes progressive parenchymal involution. Intrauterine tracheal occlusion induces accelerated architectural maturation of the fetal lungs associated with depletion of the surfactant-producing type II cells. This study investigates the spatiotemporal pattern of apoptosis during normal fetal lung development and its modulation in tracheal occlusion-induced accelerated fetal lung growth. METHODS Fetal rabbit lungs were studied at 25 to 31 days' gestational age (DGA; term, 31 DGA), corresponding to late pseudoglandular through terminal air sac stages of fetal lung development. Intrauterine tracheal ligation (TL) was performed at 24 DGA. TL fetuses were monitored until 29 DGA, a time-point previously shown to coincide with significant type II cell depletion. Apoptotic cells were identified by light and electron microscopy, as well as terminal deoxynucleotidyl transferase-mediated dUTP-FITC nick-end labeling (TUNEL). Epithelial (type I and II) cell apoptosis was studied by TUNEL labeling in conjunction with antisurfactant protein and anticytokeratin immunohistochemistry. DNA fragmentation was analyzed by gel electrophoresis. Sham-operated littermates served as controls. RESULTS The number of apoptotic cells progressively increased with advancing lung growth and architectural maturation (apoptotic index [Al] 1.2 +/- 0.7 x 10(-3) at 25 DGA v 4.2 +/- 1.4 x 10(-3) at 31 DGA; P< .05, analysis of variance). In TL fetuses, the apoptotic rate was significantly higher than in non-TL fetuses from the third postligation day on, coinciding with the onset of significantly increased airspace distension (Al 4.9 +/- 1.3 x 10(-3) in TL v2.6 +/- 0.4 x 10(-3) in controls at 29 DGA; P< .05, Student's ttest). Apoptosis occurred in parenchymal cells and in isolated cells within the airspaces. The apoptotic activity of type II cells was significantly higher in TL fetuses than C fetuses at 29 DGA (type II Al 25.5 +/- 6.3 x 10(-3) in TL v2.3 +/- 0.8 x 10(-3) in C; P< .001). Electron microscopic studies confirmed the presence of apoptotic nuclei in interstitial macrophages and in degenerating intraluminal type II cells. DNA analysis showed nucleosomal bands. CONCLUSIONS Normal fetal lung development is associated with a progressive increase of epithelial and interstitial apoptotic activity, a process enhanced by TL. Tracheal occlusion induces a significant increase of type II cell apoptosis, which likely contributes to the observed type II cell depletion after TL. We speculate that fetal type II cell apoptosis after TL may be induced by mechanical distension (stretch) of the airspaces.
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Affiliation(s)
- M E De Paepe
- Department of Pathology, Rhode Island Hospital and Brown University School of Medicine, Providence 02903, USA
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Abstract
Metabolic abnormalities described in pyloric stenosis are now rare, probably because of prompter recognition of the disease. This report reviews the trend in presentation over three decades. All infants treated for pyloric stenosis during three mid-decade target periods were reviewed. Comparison between the 1975 group and the 1985 group and between the 1995 group and previous decades were designed to identify the impact of ultrasonography, since this modality has only been available in the last decade. Parameters included age at diagnosis and incidence of water and electrolyte imbalance as measures of delay in presentation. Two hundred eighty-three patients were reviewed. Mean age (weeks) at presentation was 5.4+/-3.0 in 1975, 4.6+/-2.0 in 1985, and 3.4+/-1.3 in 1995 (P < .05, ANOVA). Overall, 88% had no electrolyte anomalies on admission. There was no statistical difference in frequency of abnormal results between the three decades. Total and postoperative hospitalization was significantly shorter in the recent period: in 1985, 5.34 and 4.36 days; in 1985, 4.48 and 3.4 days; and in 1995, 3.8 and 2.8 days. These data show that pyloric stenosis is now recognized earlier than in previous decades. The availability of ultrasonography cannot solely be credited for earlier diagnosis, since this trend was already apparent before its introduction. The "classic" metabolic derangements associated with pyloric stenosis have been highly uncommon for the past three decades.
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Affiliation(s)
- K Papadakis
- Division of Pediatric Surgery, Brown University School of Medicine and Hasbro Children's Hospital, Providence, RI 02905, USA
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Abstract
BACKGROUND/PURPOSE The choice of monitoring parameters in fetal surgery has thus far been based on feasibility rather than on predictability. Ideally, monitoring should be noninvasive, have a rapid response time and high sensitivity, and be applicable to open and endoscopic techniques. Herein, the authors studied the response of several parameters to standardized episodes of fetal ischemia and stress. METHODS Eight time-dated fetal lambs (110 days, term, 145 days) were used. Under general anesthesia, a balloon occluder was placed around the umbilical cord. Pulse oximetry (POx + heart rate, HR), electrocardiography (ECG), direct oximetry (DOx), and blood pressure (BP) were recorded continuously. After stabilization, the umbilical cord was completely occluded for 5 seconds, then released. False-negative recordings were defined as failure of a parameter to respond to umbilical occlusion; false-positive episodes were defined as 10% change in value over < or = 10 seconds during stabilization (baseline) period. RESULTS The fetuses were monitored for an aggregate of 358 minutes. Baseline DOx was 64%+/-5%, POx, 66%+/-16%; HR, 141+/-18 beats per minute (bpm); systolic BP (SBP), 51+/-3 torr; and diastolic BP (DBP), 38+/-2 torr. During umbilical occlusion (n=15), SBP increased to 56+/-3 torr and DBP to 43+/-2 torr at 0.5 seconds, then returned to baseline at 8.0 seconds. A decrease was seen in DOx (start at 3.5s, maximum delta 9.9+/-1.5% at 10.5 seconds) and POx (start at 4.2 seconds, maximum delta 7.3+/-2.4% at 20.5 seconds). Heart rate showed <10% decrease (start at 8.5 seconds, nadir 131+/-14 bpm at 19.5 seconds). No ECG changes were noted. Sensitivity was 100% for DOx, POx, and BP, but only 14% for HR; specificity was 97% for DOx and 88% for POx; positive predictive value was 58% for DOx and 37% for POx; negative predictive value was 100% for DOx and POx. CONCLUSIONS Direct intravascular oximetry and blood pressure provide a prompt and reliable response to acute fetal stress, but are too invasive for routine use. Bradycardia is an insensitive and late sign of fetal distress. Pulse oximetry has a rapid response time (<5 seconds), high sensitivity, and negative predictive value. In addition, its application is noninvasive and has proven to be feasible in open and endoscopic fetal surgical procedures. It therefore appears to be the monitoring parameter of choice for fetal surgery.
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Affiliation(s)
- F I Luks
- Division of Pediatric Surgery, Brown University School of Medicine, Providence, RI, USA
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Abstract
BACKGROUND The lungs of infants born with diaphragmatic hernia are hypoplastic, immature, and surfactant-deficient. Tracheal occlusion in utero, which is being proposed as antenatal treatment of diaphragmatic hernia by promoting compensatory lung growth, decreases surfactant production as well, through loss of type II pneumocytes. The authors studied whether temporary tracheal occlusion might cause 'catch-up' lung growth and maturation, without negative effects of prolonged tracheal occlusion on the surfactant system. METHODS Diaphragmatic hernia was created in time-dated fetal lambs (65 to 75 days). At 108 days, the trachea was occluded with an embolectomy catheter (DH + TO, n = 6). After day 14, the balloon was deflated. Six congenital diaphragmatic hernia (CDH) fetuses were left unobstructed (DH). For comparison, a group of fetuses without diaphragmatic hernia were subjected to prolonged tracheal ligation (TL; 4-week tracheal ligation, n = 3). Unoperated littermates (n = 8) were used as controls (CTR). All were killed near term. Lung tissue was processed for light and electron microscopy (computerized stereologic morphometry). Type II pneumocytes were identified with antisurfactant protein B antibody. RESULTS Four animals in DH + TO and four in DH survived to term. Lung fluid volume (LFV) at 108 days was 5.2 +/- 4.4 mL in DH and 24.6 +/- 6.8 mL in controls (P < .05, Student t test). In DH + TO, LFV increased ninefold (to 48.3 +/- 13.3 mL) by 1 week postocclusion, suggesting accelerated lung growth. At term, lung weight to body weight ratio (LW/BW) was higher in TL (9.85% +/- 1.81%) than in CTR (3.55% +/- 0.56%; P < .05, analysis of variance); LW/BW and parenchymal volume tended to be greater in DH + TO than in DH, and air-exchanging parenchymal volume in DH + TO was similar to CTR (v a 50% reduction in DH), indicating some degree of hyperplasia after temporary occlusion. Pneumocyte II numerical density was decreased more than 10-fold in TL (60 +/- 22 v 826 +/- 324 in CTR, P < .001; it was slightly lower in DH + TO than in CTR, but individual type II pneumocyte cell volume was greater in the latter, and they appeared more mature than in DH (increased granulation by light microscopy, fewer glycogen granules, and abundant lamellar bodies by electron microscopy). Surfactant was also seen in the air spaces in DH + TO and CTR; it was absent in unobstructed CDH and in TL. CONCLUSIONS Temporary tracheal occlusion in utero does not cause the dramatic decrease in type II pneumocytes seen after prolonged occlusion. Although only minimal increase in lung volume is seen in CDH, catch-up parenchymal growth and maturation occur, most notably in the surfactant-producing system.
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Affiliation(s)
- K Papadakis
- Department of Surgery, Brown University School of Medicine, Providence, Rhode Island, USA
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Abstract
BACKGROUND/PURPOSE Endoscopic fetal surgery could help avoid many of the problems associated with open fetal surgery, but the use of multiple ports may be too traumatic to the membranes. The authors describe a single-port technique of tracheoscopic surgery in the fetus. METHODS Time-dated pregnant ewes (95 to 105 days; term, 145 days) underwent midline laparotomy under general halothane anesthesia. A 5-mm-diameter balloon-tipped cannula was introduced in the uterus by Seldinger technique. A 1.2-mm semirigid mini-endoscope, fitted inside a 9F, 20 degrees curved sheath, was introduced under continuous, low-pressure irrigation, inside the fetus' mouth, and advanced into the trachea. RESULTS Endotracheal procedures, including temporary (n = 11) and permanent balloon tracheal occlusion (n = 30) and placement of a barbed guide wire for endotracheal occlusion device insertion (n = 12), were performed by introducing a 1-mm diameter instrument alongside the telescope. These were successfully performed in 52 of the 53 fetuses. The rigidity of the telescope allowed controlled access to the pharynx; its curve allowed full tracheobronchial endoscopy with the fetus in utero. CONCLUSIONS The present technique marries the control and optical quality of a rigid endoscope with the physiological curve only a flexible instrument could offer until now. The types of procedures performed with this technique illustrate its potential as a research tool; the size (1.2-mm diameter), shape, and optical qualities of the telescope should make clinical applications possible.
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Affiliation(s)
- K Papadakis
- Division of Pediatric Surgery, Brown University School of Medicine, Providence, Rhode Island, USA
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De Paepe ME, Johnson BD, Papadakis K, Sueishi K, Luks FI. Temporal pattern of accelerated lung growth after tracheal occlusion in the fetal rabbit. Am J Pathol 1998; 152:179-90. [PMID: 9422535 PMCID: PMC1858114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Tracheal occlusion in utero is a potent stimulus of fetal lung growth. We describe the early growth mechanics of fetal lungs and type II pneumocytes after tracheal ligation (TL). Fetal rabbits underwent TL at 24 days gestational age (DGA; late pseudoglandular stage; term = 31 to 33 days) and were sacrificed at time intervals ranging from 1 to 5 days after TL. Lung growth was measured by stereological volumetry and bromodeoxyuridine (BrdU) pulse labeling. Pneumocyte II population kinetics were analyzed using a combination of anti-surfactant protein A and BrdU immunohistochemistry and computer-assisted morphometry. Nonoperated littermates served as controls. TL resulted in dramatically enhanced lung growth (lung weight/body weight was 5.00 +/- 0.81% in TL versus 2.52 +/- 0.13% in controls at 29 DGA; P < 0.001, unpaired Student's t-test). Post-TL lung growth was characterized by a 3-day lag-phase typified by relative stagnation of growth, followed by distension of airspaces, increased cell proliferation, and accelerated architectural and cellular maturation by postligation days 4 and 5. During the proliferation phase, the replicative activity of type II cells was markedly increased (type II cell BrdU labeling index was 10.0 +/- 4.1% in TL versus 1.1 +/- 0.3% for controls at 29 DGA; P < 0.02), but their numerical density decreased (3.0 +/- 0.5 x 10(-3)/microm2 in TL versus 4.5 +/- 0.3 x 10(-3)/microm2 in controls at 29 DGA; P < 0.02), suggesting accelerated terminal differentiation to type I cells. In conclusion, post-TL lung development is characterized by a well defined temporal pattern of lung growth and maturation. The rabbit model lends itself well to study the regulatory mechanisms underlying accelerated fetal lung growth after TL.
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Affiliation(s)
- M E De Paepe
- Department of Pathology, Rhode Island Hospital and Brown University School of Medicine, Providence 02903, USA.
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De Paepe ME, Papadakis K, Johnson BD, Luks FI. Fate of the type II pneumocyte following tracheal occlusion in utero: a time-course study in fetal sheep. Virchows Arch 1998; 432:7-16. [PMID: 9463582 DOI: 10.1007/s004280050128] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tracheal occlusion in utero has been shown to cause accelerated fetal lung growth and is now being considered as a therapeutic modality for pulmonary hypoplasia. We report the effects of tracheal ligation on the surfactant-producing type II pneumocyte population. Three groups of fetal lambs underwent tracheal ligation of 2 weeks', 4 weeks' and 6 weeks' duration, respectively, and all were sacrificed at 136 days' gestation (9 days pre-term). Nonoperated twins served as controls. The type II pneumocyte population was studied morphometrically using a combination of anti-surfactant protein B immunohistochemistry and computer-assisted stereologic morphometry at light and electron microscopic levels. Single-factor ANOVA was used for statistical analysis. Two weeks of tracheal ligation resulted in doubling of the total lung volume as a result of airspace distension and, to lesser extent, growth of the tissue compartment. With increasing duration of tracheal ligation, there was no additional lung growth. However, more prolonged tracheal occlusion was found to result in significant reduction of the surfactant system, as reflected in the marked decrease of total pneumocyte type II volume (3.14 cm3, 0.95 cm3, and 0.46 cm3, after 2, 4, and 6 weeks of ligation, compared with 5.96 cm3 for controls) and total pneumocyte type II number (13.9 x 10(9), 3.8 x 10(9), and 2.4 x 10(9), compared with 53.2 x 10(9) for controls). Ultrastructural analysis of the type II cells in obstructed lungs showed vacuolar degenerative changes that, after 6 weeks of ligation, were apparently irreversible. In utero tracheal ligation causes fetal lung hyperplasia, but results in reduction of and injury to the surfactant-producing cell population. Before tracheal occlusion can find wide-spread clinical application, its pathophysiology needs to be further elucidated.
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Affiliation(s)
- M E De Paepe
- Rhode Island Hospital, Department of Pathology, Providence 02903, USA.
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Abstract
Fetal tracheal ligation increases lung growth in utero, making it potentially applicable for antenatal treatment of diaphragmatic hernia. This phenomenon has been ascribed to increased intratracheal pressure, which activates as yet unidentified pulmonary stretch receptors. The purpose of this study was to determine whether the composition of lung fluid has any effect on fetal lung development after tracheal obstruction. Six sets of fetal lamb twins underwent tracheal ligation with placement of intratracheal catheters at 122 days' gestation (term, 145 days). In group 1 (n = 6), tracheal fluid was aspirated daily, measured, and replaced with equal volumes of saline. Their respective twins (group 2, n = 6) had daily reinfusion of their own tracheal aspirates. Intratracheal pressure was recorded daily in both groups. Unobstructed fetal lambs (n = 7) were used as negative controls. Animals were killed on postoperative day 14 (136 days). Lungs were weighed, perfusion fixed at 25 cm H2O, and processed for standard morphometric analysis. Intratracheal pressure remained between 3 and 5 torr in both experimental groups throughout the entire postoperative period. In all 12 experimental fetuses, tracheal ligation resulted in an almost threefold increase in lung fluid volume by day 1; a slight decrease at a mean of 2.4 days; and a second surge from day 4 on. Lung fluid volume was significantly higher in group 2 than in group 1 at all measured time points (P < .05, Wilcoxon rank sum test) except on days 3, 4, and 8 (P = .06). Lung weight per body weight (LW/BW) at delivery was 0.045 +/- 0.008 in group 1, not significantly different from unobstructed controls (0.038 +/- 0.006). LW/BW in group 2 was 0.055 +/- 0.010, significantly larger than either group 1 or control (P < .05, single factor analysis of variance). Air space fraction was comparable between the three groups. Alveolar numerical density was significantly lower in groups 1 and 2 than in unobstructed controls (P < 0.05). Replacement of tracheal fluid with saline inhibits the lung hypertrophy seen after tracheal ligation. This phenomenon therefore appears more dependent on tracheal fluid growth factors than on increased intratracheal pressure after obstruction. The immediate decrease in net lung fluid production after saline exchange suggests that these humoral factors play an important role in the initiation of lung cell proliferation.
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Affiliation(s)
- K Papadakis
- Division of Pediatric Surgery, Brown University School of Medicine, Hasbro Children's Hospital, Providence, RI 02905, USA
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Abstract
BACKGROUND Endometrial cancer is the most common female genital cancer and approximately 90% of the cases are diagnosed while they are still confined to the uterus. However, the frequency and the pattern of pulmonary metastasis (PM) have not been studied systematically. PATIENTS AND METHODS From 1962 to 1989, 90 patients wit PM were identified by computerized search of the medical records of the 1,550 (5.8%) patients admitted to the Massachusetts General Hospital with the diagnosis of uterine cancer. The median age of the patients was 67 years (range from 42 to 88 years). The histology of the uterine neoplasms included 53 adenocarcinomas (59%), 19 sarcomas (21%), 12 adenosqamous carcinomas (13.5%), 4 adenoacanthomas (4.5%), and 2 clear cell adenocarcinomas (2%). Chest radiographs were retrospectively reviewed by two experienced readers. RESULTS Lung metastases were found at the time of diagnosis of the primary tumor in 20 patients (22%). The usual pattern of PM involved multiple pulmonary nodules in 65 patients (72%); solitary pulmonary nodules were found in 16 (18%), mass lesion in 10 (11%), lymphangitic spread in 3, and pleural effusion in 6 (6.7%). Cavitation and tracheal metastasis were observed in one case each. CONCLUSION Pulmonary metastases represent a common site of extrapelvic spread of disease for the small number of patients with advanced or recurrent endometrial carcinoma. The usual type of PM is multiple bilateral nodules.
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Affiliation(s)
- D Bouros
- Department of Obstetrics and Gynecology, Massachusetts General Hospital, Harvard Medical School, Boston, USA
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Anaissie EJ, Vartivarian SE, Abi-Said D, Uzun O, Pinczowski H, Kontoyiannis DP, Khoury P, Papadakis K, Gardner A, Raad II, Gilbreath J, Bodey GP. Fluconazole versus amphotericin B in the treatment of hematogenous candidiasis: a matched cohort study. Am J Med 1996; 101:170-6. [PMID: 8757357 DOI: 10.1016/s0002-9343(96)80072-6] [Citation(s) in RCA: 138] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE To compare the efficacy and toxicity of fluconazole and amphotericin B in the treatment of hematogenous candidiasis in cancer patients. PATIENTS AND METHODS A matched cohort study of cancer patients with hematogenous candidiasis was conducted. Forty-five patients with hematogenous candidiasis who received fluconazole (200 to 600 mg/day) in an open-label trial at the University of Texas M. D. Anderson Cancer Center, Houston, Texas, between February 1990 and June 1992 were matched to 45 patients treated with amphotericin B (0.3 to 1.2 mg/kg/day) for the same diagnosis. Criteria for matching included the following prognostic variables at the initiation of therapy: pneumonia, neutropenia (< 1,000 cells/mm3), number of positive blood cultures before therapy, infecting Candida species, underlying disease, and the simplified acute physiology score. Response and survival at 48 hours, after 5 days of therapy, and at the end of therapy, as well as toxicity rates were obtained. Other post hoc analyses were performed. Differences in outcomes were assessed by the McNemar, the sign, and the log rank tests. RESULTS Patients were similar with respect to the matching criteria, age, sex, status of underlying disease, use of antibiotics and growth factors, duration of treatment, presence and removal of central venous catheters, disseminated disease, and concomitant infections. Response rates at 48 hours and 5 days were similar between the two study groups. Overall response rates at the end of therapy were 73% for patients treated with fluconazole and 71% for patients treated with amphotericin B (P = 0.78). There were no differences in survival rates or causes of death. Toxicity was observed in 9% of patients treated with fluconazole and in 67% of patients treated with amphotericin B (P < 0.0001). Toxic effects of amphotericin B included nephrotoxicity, hypokaliemia, and fever and chills. CONCLUSION Fluconazole is effective and better tolerated than amphotericin B for the treatment of hematogenous candidiasis in cancer patients.
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Affiliation(s)
- E J Anaissie
- Department of Medical Specialties, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA
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Abstract
BACKGROUND Endometrial cancer is the most common female genital cancer and approximately 90% of the cases are diagnosed while they are still confined to the uterus. However, the natural history and treated course after the development of pulmonary metastasis (PM) have not been studied systematically in a large series of patients. METHODS Between 1962 and 1992, 100 patients (6%) with PM were identified by computerized search of the medical records from 1.665 patients admitted to our hospitals with the diagnosis of uterine cancer. The median age of the patients was 65.5 years (range: 42-87 yrs). The usual histologic types of the uterine neoplasms were 59 adenocarcinomas (59%), 21 sarcomas, and 14 adenosquamous carcinomas. Of the 83 patients with reported tumor grade, 11 had Grade 1 tumor, 12 Grade II, and 60 Grade III. RESULTS Lung metastases were found at the time of diagnosis of the primary tumor in 22 patients. Hemoptysis was the first symptom of 3 of the 22; the majority had no respiratory symptoms. In the remaining 78 patients with PM appearing after primary therapy, the mean interval time between primary diagnosis and PM was 29.4 months, whereas between PM and death was 15.7 months. Of all patients with lung metastases, 75% did not survive 1 year; however 6% survived more than 5 years after diagnosis of metastatic disease. Patients with isolated PM had prolonged survival (36.1 mos, P=0.001), whether treated medically or with pulmonary resection. Progestin therapy was given to 39 patients, with complete response consisting of radiographic resolution of all disease in 6 patients (15%) and prolonged stabilization in an additional 5 (13%). The histologic grade of the primary tumor was predictive of clinical response to progestine therapy. CONCLUSIONS Asymptomatic pulmonary metastases represent a common site of extra pelvic spread of disease. The majority of patients with PM (75%) do not survive 1 year. Low grade uterine tumors are more likely to respond to progestin therapy and do so for extended periods of time.
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Affiliation(s)
- D Bouros
- Department of Thoracic Medicine, Medical School, University of Crete, Heraklion Greece
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Muder RR, Harris AP, Muller S, Edmond M, Chow JW, Papadakis K, Wagener MW, Bodey GP, Steckelberg JM. Bacteremia due to Stenotrophomonas (Xanthomonas) maltophilia: a prospective, multicenter study of 91 episodes. Clin Infect Dis 1996; 22:508-12. [PMID: 8852971 DOI: 10.1093/clinids/22.3.508] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We identified 91 cases of bacteremia due to Stenotrophomonas (Xanthomonas) maltophilia in a prospective, multicenter observational study. The patients were highly compromised; the majority had an underlying malignancy, had received immunosuppressive therapy, and had indwelling venous catheters. Although 94% of patients received an antimicrobial agent to which the blood isolate was susceptible, the mortality among these patients 14 days after the onset of bacteremia was 21%. Mortality was significantly correlated with the presence of a hematologic malignancy or neutropenia or transplantation, immunosuppressive therapy, and a severity-of-illness score of > 4. S. maltophilia infection is associated with substantial morbidity and mortality among highly compromised patients. The organism is typically resistant to expanded spectrum beta-lactam agents and aminoglycoside antibiotics. Trimethoprim-sulfamethoxazole should be administered if the isolate is susceptible to this combination; addition of another agent to which the isolate is susceptible should be considered in treating patients who are neutropenic, immunocompromised, or critically ill.
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Affiliation(s)
- R R Muder
- Veterans Affairs Medical Center and University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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Sonecha TN, Nicolaides AN, Salmasi AM, Nicolaides EP, Papadakis K, Nissiotis T. Noninvasive detection of coronary artery disease in patients presenting with claudication. INT ANGIOL 1990; 9:79-83. [PMID: 2254679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
ECG chest wall mapping with bicycle ergometry which can detect not only myocardial ischaemia but also individual coronary artery territories involved has been used to screen 100 consecutive patients presenting with claudication. Fifty-three had a positive history and/or evidence of ischaemic heart disease on a resting ECG. The test was positive in 38, negative in 38 and inconclusive in 24, the latter because of inadequate heart rate response. In 11 out of 38 (29%) with a positive test there was no history or evidence of myocardial ischaemia on a conventional resting ECG. ECG changes suggestive of three vessel coronary disease were found in three, single vessel coronary disease in 16 and two vessel disease in 19. Of the latter, eight had changes in the LAD/circumflex distribution, indicating left main stem or equivalent disease. These together with the three with triple vessel coronary disease constituted a subset of 11 (11%) high risk patients who merited coronary angiography with a view to confirming the presence of severe coronary disease.
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Affiliation(s)
- T N Sonecha
- Irvine Laboratory for Cardiovascular Investigation and Research, St. Mary's Hospital Medical School, London, U.K
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Sonecha TN, Nicolaides AN, Kyprianou P, Zukowski A, Papadakis K, Vasdekis S, Salmasi AM. The effect of enalapril on leg muscle blood flow in patients with claudication. INT ANGIOL 1990; 9:22-4. [PMID: 2212796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In the percent study the authors have demonstrated that the peripheral blood flow and resistance as measured by strain-gauge venous occlusion plethysmography were favourably altered by enalapril. The peripheral blood flow increased significantly and since there was no detectable change in ankle pressure this indicated a decrease in resistance during administration of the drug.
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Affiliation(s)
- T N Sonecha
- Irvine Laboratory for Cardiovascular Investigation and Research, St Mary's Hospital Medical School, London, UK
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25
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Abstract
A randomised double-blind, three-way cross-over trial comparing oral thymoxamine 40 mg, oral thymoxamine 80 mg with a matched placebo was performed in 24 patients with primary Raynaud's phenomenon. The response to treatment was objectively assessed by monitoring digital skin temperature response for 7 min after exposure to a mild cold stimulus (20 C for 1 min). Thymoxamine treatment "normalised" rewarming responses in a statistically significant number of patients (P less than 0.01). Absolute digital temperatures and maximum rewarming rates were increased and the length of the latent period reduced (P less than 0.001). These effects were more pronounced with thymoxamine 80 mg than with thymoxamine 40 mg.
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Affiliation(s)
- M J Grigg
- Irvine Laboratory for Cardiovascular Investigation and Research, St. Mary's Hospital Medical School, London, U.K
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Papadakis K, Christodoulou C, Christopoulos D, Hobbs J, Malouf GM, Grigg M, Irvine A, Nicolaides A. Number and anatomical distribution of incompetent thigh perforating veins. Br J Surg 1989; 76:581-4. [PMID: 2758263 DOI: 10.1002/bjs.1800760618] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Although incompetent thigh perforating veins are considered to be a common cause of recurrence of varicose veins after high saphenous ligation, the number and distribution of such incompetent veins have not been reported. The aim of the study was to determine the number and anatomical distribution of incompetent thigh perforating veins. Sixty-five limbs in 48 patients with varicose veins who were found to have incompetent thigh perforating veins on ascending deep to superficial venography were studied. In 80 per cent of patients one incompetent thigh perforating vein was found and in 20 per cent more than one was found. Concomitant incompetent calf perforating veins were found in 92 per cent of the limbs studied. The incompetent thigh perforating veins were found to occur anywhere in the thigh, from the upper edge of the patella to a few centimetres below the saphenofemoral junction. The majority (71 per cent) were found in the middle third of the thigh. All incompetent thigh perforating veins were communicating with the long saphenous vein, including those in five patients with incomplete stripping. The surgeon should be aware of incompetent thigh perforating veins which may be multiple and occur at any site on the medial aspect of the thigh.
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Affiliation(s)
- K Papadakis
- Irvine Laboratory for Cardiovascular Investigation and Research, St. Mary's Hospital Medical School, London, UK
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Grigg MJ, Papadakis K, Nicolaides AN, Al-Kutoubi A, Williams MA, Deacon DF, Sonecha T, Eastcott HH. The significance of cerebral infarction and atrophy in patients with amaurosis fugax and transient ischemic attacks in relation to internal carotid artery stenosis: a preliminary report. J Vasc Surg 1988; 7:215-22. [PMID: 3339768 DOI: 10.1067/mva.1988.avs0070215] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
There is a growing appreciation for the high incidence of silent cerebral infarction and cerebral atrophy on CT scans in patients with amaurosis fugax (AF) and hemispheric transient ischemic attacks (TIAs). Seventy patients with AF only (no TIAs), 104 patients with hemispheric TIAs (no AF), 185 patients without focal carotid territory symptoms (i.e., vertebrobasilar TIAs or asymptomatic carotid bruit only), and 129 patients with stroke and good recovery were studied with CT scan and duplex scanning to grade the degree of stenosis of the internal carotid artery (grades: A = normal, B = 0% to 15% stenosis, C = 16% to 49%, D = 50% to 99%, and E = occlusion). In patients with AF, the incidence of infarction increased from 20% in grades A, B, and C to 40% in grade D and 58% in grade E. The incidence of atrophy increased in parallel from 10% in grade A to 30% in grade E. The increased incidence of atrophy with increasing degrees of stenosis was not the result of increasing degrees of stenosis per se, but the associated increase in the incidence of infarction (patients without CT infarcts in grades D and E had 5% and 0% incidence of atrophy). In patients with hemispheric TIAs, the incidence of CT infarction increased from 25% in grades A and B to 48% in grades D and E. The incidence of atrophy did not show a parallel increase. Our findings support the hypothesis that atrophy is associated not only with cerebral infarction but may be causally related.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M J Grigg
- Irvine Laboratory for Cardiovascular Investigation and Research, St. Mary's Hospital, London, England
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Nicolaides N, Santos EC, Papadakis K, Ruth EC, Müller L. The occurrence of long chain alpha, omega-diols in the lipids of steer and human meibomian glands. Lipids 1984; 19:990-3. [PMID: 6527617 DOI: 10.1007/bf02534741] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A group of long chain alpha, omega-diols (C29 to C34) has been identified in the lipids of steer and human meibomian gland excreta (meibum). These new lipids were isolated from the steer meibum unsaponifiables. Proof of structure was provided by 1) the column chromatographic behavior and TLC of the diols and their diacetates; 2) GLC on glass capillary columns; 3) fragmentation patterns in GC-MS; 4) NMR data, and 5) ozonolysis studies of the unsaturates. Chain types for the steer sample were 51% straight monoenes, 8.5% straight saturates, 39% iso and anteiso saturates and 1.5% iso and anteiso unsaturates. GC for the human sample gave straight monoenes 83%, straight saturates 8%, and iso plus anteiso saturates 9%. Close correspondence of the alpha, omega-diol chain lengths and types with meibum omega-hydroxy fatty acids suggests a biochemical precursor relationship.
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Abstract
Ozonolysis studies of the monoenes of the fatty chain types in lipids of steer meibomian gland excreta (meibum) have confirmed earlier structural assignments based on gas liquid chromatography (GLC) retention data and have assisted in assigning complete structures to a group of recently identified omega-hydroxy fatty acids. The omega-hydroxy acids include straight-chain monoenoic acids (85%), saturated anteiso and iso acids (13%), monoenoic acids of the latter group (1%) and, finally, saturates of the normal monoenoic acids (1%). All the fatty chains of meibum can be biosynthesized by a unified process of chain buildup to primary chain lengths of 12:0-20:0 for the straight evens, with 16:0 predominating, 13:0-21:0 for the straight odds with 17:0 predominating, i16:0 to i28:0 for the iso and ai17:0 to ai29:0 for the anteiso chain types; then delta 9 desaturation of each of these chain types: and finally chain elongation of 1-10 C2 units. Some chain degradation may also occur. The meibum lipid components involved are unsubstituted fatty acids, alpha-OH fatty acids, alpha-OH fatty acids, omega-OH fatty acids, fatty alcohols and some other lipid components incompletely characterized. The carbon skeletons are straight even, straight odd, iso and anteiso except that the alpha-OH fatty acids are only straight even and straight odd and these chains are not elongated. All fatty chains are almost entirely saturated and monoenoic, the polyenes occurring in only trace amounts. Biosynthesis of the fatty chains of human meibum evidently occurs similarly, except that considerably more 18:0 than 16:0 fatty acids are built up by the fatty acid synthetase, before desaturation and extension.
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