Biomedical subjects

Marguerite E I Schipper

Publications and source records attributed to Marguerite E I Schipper.

4 recordsLinked to original sources

PubMed2007

Sentinel lymph node mapping in colon cancer: current status.

BACKGROUND: The primary role of sentinel lymph node (SLN) mapping in colon cancer is to increase the accuracy of nodal staging by identifying those lymph nodes with the greatest potential for harbouring metastatic disease. Ultrastaging techniques aim to identify the otherwise undetected metastases. Until now, no consensus exists as to the most optimal procedure in patients with colon cancer. METHODS: A systematic literature search on the value of different SLN mapping techniques in patients with colon cancer was performed using the electronic search engine PubMed. Prospective studies published before 1 December 2005 were included and further articles were selected by cross-referencing. The results of different techniques using either blue dye or radiocolloid, were investigated. RESULTS: The literature search yielded 17 relevant articles. SLN mapping using blue dye was described in 15 studies. Two studies reported the results of SLN mapping using a combination of blue dye and radiocolloid. The reported results on identification rate varied between 71 and 100%. Accuracy rates were between 78 and 100%, sensitivity rates between 25 and 100% and true upstaging rates between 0 and 26%. The results were not affected by the addition of radiocolloid to blue dye. CONCLUSIONS: Sentinel lymph node mapping in patients with colon cancer remains an experimental procedure with varying results. Further evaluation may lead to a standardized technique that offers the potential for significant upstaging of stage II patients. This may have important implications as to tailor adjuvant chemotherapeutic regimens in these patients.

Colonic Neoplasms↗

PubMed2003

The finding of invasive cancer after a preoperative diagnosis of ductal carcinoma-in-situ: causes of ductal carcinoma-in-situ underestimates with stereotactic 14-gauge needle biopsy.

BACKGROUND: For the evaluation of nonpalpable lesions of the breast, image-guided 14-gauge automated needle biopsy is increasingly replacing wire-localized excision. When ductal carcinoma-in-situ (DCIS) is diagnosed at core biopsy, invasive cancer is found in approximately 17% of excision specimens. These so-called DCIS underestimates pose a problem for patients and surgeons, because they generally cause extension of treatment. We evaluated DCIS underestimates in detail to assess reasons for missing the invasive component at core biopsy. This evaluation also included a histological comparison with true DCIS (DCIS at core biopsy and excision). METHODS: Between 1997 and 2000, DCIS was diagnosed at 14-gauge needle biopsy in 255 patients. In 41 cases (16%), invasive cancer was found at excision. We performed a thorough histopathological and radiological review of all these DCIS underestimates, including a histological comparison with core biopsy specimens of 32 true DCIS cases. We assessed the main reason for missing the invasive component at core biopsy. RESULTS: Causes for DCIS underestimates were categorized into "mainly radiological" (n = 20), "mainly histopathological" (n = 15), and "histological disagreements" (n = 6). High-grade DCIS and periductal inflammation in core biopsies made a DCIS underestimate 2.9 and 3.3 times more likely, respectively. CONCLUSIONS: A variety of radiological and histopathological reasons contribute to the DCIS underestimate rate. Approximately half of these are potentially avoidable.

Adult↗

PubMed2002

Left ventricular assist device in end-stage heart failure: persistence of structural myocyte damage after unloading. An immunohistochemical analysis of the contractile myofilaments.

OBJECTIVES: We sought to evaluate the contractile proteins in cardiomyocytes of patients with end-stage heart failure (HF) before and after mechanical support with a left ventricular assist device (LVAD). BACKGROUND: Improvement of myocyte dysfunction has been suggested after LVAD support. METHODS: Fourteen patients' myocardial biopsies taken at the time of LVAD implantation and after explantation, at the time of heart transplantation, were processed for routine hematoxylin-eosin staining and immunohistochemistry using monoclonal antibodies against actin, myosin, tropomyosin, troponin C and T and titin. A grading scale from 1 (abnormal staining of all myocytes, no cross-striation) to 5 (normal fiber anatomy and striation) was used. The cross-sectional area of cardiomyocytes was also measured. RESULTS: The cardiomyocytes' cross-sectional area decreased after support, from 519 +/- 94 microm(2) to 319 +/- 53 microm(2) (p < 0.001). Actin, tropomyosin, troponin C, troponin T and titin at the time of LVAD implantation showed widespread distortion of architecture; their grades were 1.4 +/- 0.6, 2.3 +/- 1.0, 2.1 +/- 0.9, 2.1 +/- 1.2 and 2.0 +/- 0.6, respectively. In contrast, myosin morphology was preserved (4.6 +/- 0.7). After LVAD support, actin, tropomyosin, troponin C, troponin T and titin showed improvement (grades 2.7 +/- 1.3 [p = 0.004], 3.2 +/- 1.2 [p = 0.021], 3.3 +/- 0.9 [p = 0.004], 3.0 +/- 1.1 [p = 0.048] and 3.1 +/- 0.9 [p = 0.001], respectively), but no normalization. The myosin pattern deteriorated slightly (3.6 +/- 1.6 [p = 0.058]). CONCLUSIONS: After LVAD support, during a period of 213 +/- 135 days in patients with end-stage HF, despite a decrease in the size of the cardiomyocytes, severe structural myocyte damage persisted. This does not support complete recovery of myocyte histologic features.

Actin Cytoskeleton↗

PubMed2002

Alterations in adult rat heart after neonatal dexamethasone therapy.

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 micro g/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.

Animals↗