M.E.I. Schipper
Utrecht University
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Featured researches published by M.E.I. Schipper.
British Journal of Surgery | 2009
J. Boone; M.E.I. Schipper; W. A. Moojen; I. H. M. Borel Rinkes; G.J. Cromheecke; R. van Hillegersberg
Thoracoscopic oesophagectomy was introduced to reduce the morbidity of transthoracic oesophagectomy. The aim was to assess the short‐ and mid‐term results of robot‐assisted thoracoscopic oesophagectomy for oesophageal cancer.
Pediatric Research | 2002
Wb de Vries; Fr van der Leij; J. M. Bakker; Pjgh Kamphuis; Mfm van Oosterhout; M.E.I. Schipper; Db Smid; B Bartelds; F van Bel
Glucocorticoid treatment in preterm babies to prevent chronic lung disease causes myocardial hypertrophy and increased myocardial protein content. Although these changes are thought to be transient, there is evidence that dexamethasone (DEX) induces permanent myocardial abnormalities as well. We investigated whether a therapeutic course of neonatal DEX in rat pups produces anatomic and biochemical alterations in rat hearts during adult life. Twenty-four rat pups were treated with DEX on d 1, 2, and 3 (0.5, 0.3, and 0.1 μg/g) of life, with doses proportional to those used in preterm babies. Twenty-four control pups were treated with saline. At d 7, wk 8, or wk 45 (n = 8 per group) rats were killed. The anatomic parameters measured were body weight (Bw, in grams), heart (myocardial) weight (Hw, in milligrams), and the Hw:Bw ratio. Myocardial total protein (Prot) and DNA content were determined, and the Prot:DNA ratio was calculated. Histopathology and morphometry were performed on 45-wk-old rat hearts. In DEX-treated rat pups, at d 7, Bw and Hw were lower and the Hw:Bw ratio was increased. DNA content was lower, Prot higher, and Prot:DNA ratio was increased. In 8-wk-old rats Bw, Hw, DNA content, Prot content or Prot:DNA ratio did not differ between groups, but the Prot:DNA ratio still tended to be higher in DEX-treated rats. In 45-wk-old rats Hw and Hw:Bw ratio were significantly lower and Prot:DNA ratio higher in DEX-treated rats. Histopathologic analysis showed larger cardiomyocyte volume, length, and width, indicating hypertrophy, and increased collagen, indicating early degeneration of individual myocytes. In conclusion, neonatal DEX treatment in rat pups causes a permanent decrease in heart weight, as well as hypertrophy and early degeneration of cardiomyocytes during adulthood.
Annals of Surgical Oncology | 2000
D. van der Velde-Zimmermann; M.E.I. Schipper; R.A. de Weger; A. Hennipman; I. H. M. Borel Rinkes
Background: Immunohistochemistry (IHC) of serial sectioning is considered the gold standard for detection of melanoma activity in sentinel node (SN) biopsies. However, this is cost and labor intensive. In contrast, tyrosinase reverse transcription-polymerase chain reaction (RT-PCR) is simple and quick, but it is hampered by its extreme sensitivity. This study was performed to test whether a strategy that combines the two methods, using tyrosinase RT-PCR to preselect nodes for IHC, could be accurate and cost effective.Methods: In 36 patients, SNs were identified by scintigraphy and patent blue uptake. Of each SN, one cross section was analyzed first by hematoxylin and eosin staining. Next, all nodes were examined by serial sectioning and IHC of one-half and tyrosinase RT-PCR of the other. Before comparison, all results were documented in a blinded manner. Material costs and workload estimates were noted per SN.Results: Fifty-five SNs were retrieved from the 36 patients. Hematoxylin and eosin staining of the first cross section revealed tumor positivity in 3 patients (6 SN). Tyrosinase RT-PCR was positive in 11 of the remaining 33 patients (19 of 49 SN). Of these same 11 patients, only 5 were shown to have tumor-positive SNs by using IHC on serial sections (7 SN). All these nodes had been positive for tyrosinase on PCR. For IHC, an average of 40 sections were prepared and examined per SN at a cost of
American Journal of Transplantation | 2008
M. C. Hagemeijer; M.F.M. van Oosterhout; D.F. van Wichen; J. van Kuik; E. Siera-de Koning; F. H. J. Gmelig Meyling; M.E.I. Schipper; N. de Jonge; R.A. de Weger
200(U.S.)/SN. In contrast, routine tyrosinase RT-PCR costs
Diseases of The Esophagus | 2008
J. Boone; M.E.I. Schipper; Ronald L. A. W. Bleys; I. H. M. Borel Rinkes; R. van Hillegersberg
37(U.S.)/SN, and takes 5% of the time necessary for IHC. A strategy including hematoxylin and eosin staining on the first cross section, followed by tyrosinase RT-PCR on half of each negative (half) node, could preselect nodes to be taken through serial sectioning. In these series, such a strategy would have prevented serial sectioning and IHC of 30 SN from 22 patients. Apart from a considerable gain in efficiency, this would have reduced material costs by a minimum of
Ejso | 2004
Lidewij E. Hoorntje; M.E.I. Schipper; A Kaya; Helena M. Verkooijen; J.H.G. Klinkenbijl; I. H. M. Borel Rinkes
6000 (U.S.). This iscrepancy would be even higher if work intensity of analysts and pathologists were considered.Conclusions: In routine analysis of SN biopsies in melanoma patients, tyrosinase RT-PCR can be used effectively to preselect nodes for further IHC of serial sections. This method seems both time and cost effective.
Journal of Heart and Lung Transplantation | 2013
Jerson R. Martina; M.E.I. Schipper; N. de Jonge; R.A. de Weger; Jaap R. Lahpor; Aryan Vink
Cardiac allograft vasculopathy (CAV) in heart transplantation (HTx) patients remains the major complication for long‐term survival, due to concentric neointima hyperplasia induced by infiltrating mononuclear cells (MNC). Previously, we showed that activated memory T‐helper‐1 (Th‐1) cells are the major component of infiltrating MNC in coronary arteries with CAV. In this study, a more detailed characterization of the MNC in human coronary arteries with CAV (n = 5) was performed and compared to coronary arteries without CAV (n = 5), by investigating MNC markers (CD1a, DRC‐1, CD3, CD20, CD27, CD28, CD56, CD68, CD69, FOXP3 and HLA‐DR), cytokines (IL‐1A, 2, 4, 10, 12B, IFN‐γ, and TGF‐β1), and chemokine receptors (CCR3, CCR4, CCR5, CCR7, CCR8, CXCR3 and CX3CR1) by immunohistochemical double‐labeling and quantitative PCR on mRNA isolated from laser microdissected layers of coronary arteries. T cells in the neointima and adventitia of CAV were skewed toward an activated memory Th‐1 phenotype, but in the presence of a distinct Th‐2 population. FOXP3 positive T cells were not detected and production of most cytokines was low or absent, except for IFN‐γ, and TGF‐β. This typical composition of T‐helper cells and especially production of IFN‐γ and TGF‐β may play an important role in the proliferative CAV reaction.
Journal of Heart and Lung Transplantation | 2008
J. van Kuik; M.F.M. van Oosterhout; W. Sohns; Erica Siera; D.F. van Wichen; N. de Jonge; M.E.I. Schipper; R.A. de Weger
The standard surgical procedure for esophageal cancer is transthoracic esophagectomy with en bloc resection of the azygos vein, thoracic duct and mediastinal lymph nodes. To reduce morbidity of esophago-lymphadenectomy, minimally invasive techniques are increasingly being applied. In (robot-assisted) thoracoscopic esophagolymphadenectomy, the azygos vein is generally left in place, as the scopic ligation of the numerous intercostal veins is technically difficult and time-consuming. This could affect the extent of mediastinal lymph node dissection. Therefore, in this study, the effect of azygos vein preservation during thoracic esophagectomy on mediastinal lymph node harvesting was assessed. In 15 human cadavers, a right-sided thoracotomy was performed, followed by esophagectomy with mediastinal lymph node dissection after ligation of the azygos arch (representing the situation in robot-assisted thoracoscopic esophagolymphadenectomy). Subsequently, the remaining azygos vein with surrounding tissue was resected. The number of lymph nodes in both specimens was determined. A mean of 17.3 (95% Poisson CI 15.3-19.6) lymph nodes was dissected en bloc with the esophagus, and 0.67 (95% Poisson CI 0.32-1.23) around the separately resected azygos vein. The additional azygos vein resection did not add to the number of lymph nodes dissected in 60% (9/15) of cadavers. In conclusion, the extent of mediastinal lymph node dissection was not substantially affected by leaving the azygos vein in situ . Time-sparing azygos vein preservation in (robot-assisted) thoracoscopic esophagolymphadenectomy may therefore be considered justified.
European Heart Journal | 2013
Manon M.H. Huibers; J. Kaldeway; Max Leenders; M.E.I. Schipper; Aryan Vink; Jaap R. Lahpor; J. H. Kirkels; C. Klöpping; N. de Jonge; R.A. de Weger
Journal of Heart and Lung Transplantation | 2012
M.E.I. Schipper; Aryan Vink; Hub F. J. Dullens; R.A. de Weger; N. de Jonge; Jaap R. Lahpor