[Intestinal stromal tumors with skenoid fibers in patients with type I neurofibromatosis: histological and ultrastructural evaluation of a case].
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Biomarkers, Tumor↗
Biomedical subjects
M Leutner
Publications and source records attributed to M Leutner.
Which kinds of lymph node metastases can FDG PET detect? A clinical study in melanoma.
UNLABELLED: The purposes of this study were to establish the diagnostic accuracy of FDG PET for lymph node metastases and to determine the smallest detectable volume of disease. METHODS: Using FDG PET, we preoperatively studied 56 lymph node basins in 38 patients with a clinical or instrumental diagnosis of lymph node metastases from melanoma. All lymph node basins underwent node dissection. The FDG PET results were compared with the postoperative histopathology results. PET images were obtained using a GE 4096 WB scanner, after injection of a mean activity of 496 MBq (range, 366-699 MBq) of FDG. RESULTS: The efficacy of FDG PET in the diagnosis of involved lymph node basins was good. Sensitivity was 95% (35/37); specificity, 84% (16/19); accuracy, 91% (51/56); positive predictive value, 92% (35/38); and negative predicative value, 89% (16/18). Metastases were shown histologically in 114 of 647 surgically removed lymph nodes. FDG PET detected 100% of metastases > or = 10 mm, 83% of metastases 6-10 mm, and 23% of metastases < or = 5 mm. Moreover, FDG PET had high sensitivity (> or = 93%) only for metastases with more than 50% lymph node involvement or with capsular infiltration. CONCLUSION: Our study shows that FDG PET has a reasonable sensitivity and specificity for detecting the presence or absence of lymph node metastases in patients with melanoma. However, even if able to detect small volumes of subclinical macroscopic disease, FDG PET cannot detect subclinical microscopic disease with acceptable sensitivity. The specificity of FDG PET is good, but some false-positive results may occur.
Adult↗
Bcl-2 protein and prognosis in patients with potentially curable non-small-cell lung cancer.
The bcl-2 proto-oncogene functions as a cell death suppressor, and its expression prolongs cell survival by blocking apoptosis. Data available on the clinical relevance of bcl-2 protein expression in patients with non-small-cell lung cancer (NSCLC) are controversial. We analysed the role of bcl-2 protein expression on 6-year relapse-free survival in 229 patients with stage I-IIIa NSCLC (101 squamous cell carcinomas and 128 adenocarcinomas) subjected to surgery, with curative intent. Immunohistochemical analysis was performed on archival material by using a monoclonal antibody anti-bcl-2 (clone 124). Bcl-2 protein expression, which was detected in 22% of the cases, was significantly related to stage, histology and grading, and was an indicator of clinical outcome. The probability of relapse-free survival at 6 years was longer for patients with bcl-2-positive tumours (74%) than for those with bcl-2-negative tumours (57%) (P=0.02). This finding was mainly evident for the subgroups of patients with stage IIIa tumours (P=0.05), squamous cell carcinoma (P=0.03) or moderately/poorly differentiated tumours (P=0.02). However, multivariate analysis by Weibull's regression model indicated that bcl-2 protein expression was not an independent prognostic risk factor in patients with curable NSCLC when the information provided by stage was available.
Adult↗
Automated backbone assignment of labeled proteins using the threshold accepting algorithm.
The sequential assignment of backbone resonances is the first step in the structure determination of proteins by heteronuclear NMR. For larger proteins, an assignment strategy based on proton side-chain information is no longer suitable for the use in an automated procedure. Our program PASTA (Protein ASsignment by Threshold Accepting) is therefore designed to partially or fully automate the sequential assignment of proteins, based on the analysis of NMR backbone resonances plus C beta information. In order to overcome the problems caused by peak overlap and missing signals in an automated assignment process, PASTA uses threshold accepting, a combinatorial optimization strategy, which is superior to simulated annealing due to generally faster convergence and better solutions. The reliability of this algorithm is shown by reproducing the complete sequential backbone assignment of several proteins from published NMR data. The robustness of the algorithm against misassigned signals, noise, spectral overlap and missing peaks is shown by repeating the assignment with reduced sequential information and increased chemical shift tolerances. The performance of the program on real data is finally demonstrated with automatically picked peak lists of human nonpancreatic synovial phospholipase A2, a protein with 124 residues.
Algorithms↗
Effects of short-term pre-operative tamoxifen on steroid receptor and Ki-67 expression in primary breast cancer: an immunocytochemical study.
The effects of the short-term pre-operative administration of tamoxifen (TAM, 20 mg once daily) on the tumor levels of steroid receptors and the nuclear proliferation Ki-67 antigen, were investigated in 32 elderly patients with hormone-sensitive, operable primary breast cancer by means of fine-needle aspiration biopsy (FNAB). The FNAB smears before (pre-TAM) and after six weeks of treatment (post-TAM) were stained immunocytochemically in order to obtain an H-score for steroid receptors, and the percentage of cellular nuclei containing Ki-67. The mean oestrogen receptor (ER) score between the pre- and post-TAM specimens fell from 181.2 9.7 ( SEM) to 148.1 7.9 (Wilcoxon's matched-pairs signed-rank test, p=0. 01) and there was also a significant decrease in both the mean progesterone receptor (PgR) score (178.4 10.6 vs 148.5 10.6; p=0.01) and mean Ki-67 index (8.2% 1.2 vs 4.9% 0.9; p=0.0002). The reliability of FNAB as a sampling method was checked by comparing the results of the immunocytochemical assay (ICA) of the post-TAM biopsies with those of the immunohistochemical assay (IHA) of the corresponding excised tumors. There was a positive correlation between the ICA and IHA scores: ER (Spearman's correlation coefficient, rho=0.66, p<0.001), PgR (rho=0.84, p<0.001) and Ki-67 (rho=0.96, p<0.001). We conclude that the sequential use of FNAB is a reliable means of assessing the behaviour of within-tumor biomarkers during endocrine therapy.
Aged↗
The effects of bone resorption inhibitors on the growth plate and proximal tibial metaphysis of rats: clinical implications.
This study investigated the effects of diphosphonates at scalar doses in a high bone turnover structure, namely, the proximal tibial metaphysis of rats. Arrest of bone modeling was represented by cylindrical-shaped metaphyses, increased height of the perichondrial bone bark, and persistence of primary metaphyseal trabeculae; these changes were dose-related. Higher doses of the inhibitors produced extension of the growth plate and arrest of the mineralization process. The dose-related dissociation between the effects on bone resorption and mineralization allows the therapeutic use of this class of drugs.
Animals↗
Prospective evaluation of fluorine-18-FDG PET in presurgical staging of the axilla in breast cancer.
METHODS: The presurgical, noninvasive staging of axillary nodes for metastases was prospectively investigated in 68 patients who were diagnosed with primary breast cancer using PET with 18F-fluorodeoxyglucose (FDG). Four patients had bilateral nodules; therefore, the total number of evaluable cases was 72. Visual analyses of attenuation-corrected PET images and standardized uptake values (SUVs) of FDG uptake in carcinomas were compared with histopathological surgical findings. The SUV distribution differences between carcinomas with and without axillary metastases were evaluated by means of statistical and receiver operating characteristics analyses. RESULTS: PET correctly classified 64 of the 72 cases; four false-positive and four false-negative PET results were found. The overall sensitivity, specificity and accuracy of PET for axillary metastases were 85%, 91% and 89%, respectively. With respect to the clinical axillary stage of the patients (TNM, or tumor-node-metastasis, classification), we obtained the following results: N0 patients, sensitivity = 70%, specificity = 92%, accuracy = 86%; N1a patients, sensitivity = 85.5%, specificity = 100%, accuracy = 95%; and N1b-2 patients, sensitivity = 100%, specificity = 67%, accuracy = 87%. The median SUV in carcinomas with axillary metastases (4.6) was significantly higher than that in carcinomas without metastases (2.9), but there was a great SUV overlap between the two groups (interquartile ranges = 2.7-7.2 and 1.9-4.5, respectively). Analysis of the receiver operating characteristics curve showed that a high sensitivity of SUV in predicting axillary metastases was associated with a very low specificity and vice versa. With the best SUV cutoff value of 2.9, the sensitivity and specificity were 74% and 56%, respectively. CONCLUSION: PET showed good overall diagnostic accuracy in the detection of axillary metastases (86%). The very high accuracy (95%) in N1a patients is of particular importance. False-negative PET findings, however, can be encountered. SUVs of breast carcinoma cannot predict the spread of the disease to the axilla, even if higher values are often associated with axillary metastases. Any decision on the use of PET in the presurgical staging of breast cancer should be incorporated into a more general debate on axillary management. In selected patients with a very low probability of axillary metastases (T1a), in whom axillary surgery can already be avoided according to data from follow-up studies, 18F-FDG PET could be proposed as a noninvasive imaging modality to improve the diagnosis of axillary relapses.
Axilla↗
Expression of p53, glutathione S-transferase-pi, and Bcl-2 proteins and benefit from adjuvant radiotherapy in breast cancer.
BACKGROUND: In clinical breast cancer research, the utility of certain biomarkers as predictors of response to surgery, chemotherapy, or hormonal therapy has been studied intensively. Much less research has been done on the relevance of biologic predictors of response to radiotherapy, which represents an effective local-regional treatment for breast cancer. PURPOSE: The utility of biomarkers involved in DNA damage repair (p53 protein), control of programmed cell death (p53 and Bcl-2 proteins), and cellular detoxification (glutathione S-transferase-pi [GST-pi] enzyme) in predicting local breast cancer recurrence was analyzed retrospectively in two cohorts of breast cancer patients. These patients had had no detectable metastases in the axillary lymph nodes (i.e., node-negative) or in distant sites and had had similar distributions of clinicopathologic and biologic prognostic features. They had been treated by conservative surgery alone (139 case patients) or by conservative surgery followed by adjuvant radiotherapy (496 case patients) during the period from 1984 through 1990. METHODS: The expression of the p53, GST-pi, and Bcl-2 proteins in the specimens of primary breast tumor obtained from these patients was determined by use of immunohistochemistry; cell proliferation activity and levels of steroid receptors were determined by use of a [3H]thymidine-labeling index assay and the dextran-coated charcoal technique, respectively. The median time of follow-up of patients was 6 years. In the analyses of patient outcomes, only local failures that presented as first events were considered. RESULTS: After surgery alone, the risk of local recurrence at 6 years was higher for patients with tumors exhibiting elevated levels of p53 and GST-pi protein expression than for patients with low levels (hazard ratio [HR] = 3.1, 95% confidence interval [CI] = 1.3-7.7, two-sided P = .012; HR = 2.7, 95% CI = 1.1-6.4, two-sided P = .026, respectively). Weak or no observable expression of Bcl-2 protein was only suggestive of a higher frequency of local failures. Adjustment for patient age, tumor size, cell proliferation, and estrogen receptor status did not change these findings. Conversely, in the series of patients given conservative surgery followed by radiotherapy, there was no difference in local tumor recurrence between patients with tumors expressing or not expressing each of the three markers. CONCLUSIONS: Our study provides indirect evidence of a benefit from radiation therapy in preventing local breast cancer relapse, particularly among node-negative patients with tumors that express elevated levels of the p53 or GST-pi proteins or that express little or no Bcl-2 protein.
Biomarkers, Tumor↗
Secondary structure of the IIB domain of the Escherichia coli mannose transporter, a new fold in the class of alpha/beta twisted open-sheet structures.
The mannose transporter of the Escherichia coli bacterial phosphotransferase system consists of three subunits: IIAB, IIC and IID. IIABMan transfers phosphoryl groups to the transported substrate via phosphohistidine intermediates. Its IIB domain was overexpressed and isotopically labelled with 13C, 15N and 2H. Heteronuclear 3D triple-resonance NMR experiments combined with a semi-automatic assignment procedure yielded the sequential assignment of the 1H, 13C and 15N backbone resonances. Based on the evaluation of conformationally sensitive parameters, the secondary structure of the IIBMan domain has been determined as an alpha/beta twisted open-sheet structure consisting of a six-stranded parallel beta-sheet with the novel strand order 3-2-4-1-5-6, six helices and a short two-stranded antiparallel beta-sheet.
Amino Acid Sequence↗
Cell proliferation in 3,800 node-negative breast cancers: consistency over time of biological and clinical information provided by 3H-thymidine labelling index.
For breast cancer, many prognostic markers that initially appeared promising have failed to maintain their clinical predictive value. Few reports have analyzed the consistency over time of biological and clinical information provided by biomarkers. Tumour cell proliferation has acquired relevance as an indicator of prognosis and of response to treatment. Since its clinical role has been investigated for some decades, cell proliferation represents an ideal marker for an over-time validation. In 3,800 node-negative breast cancers recruited between 1972 and 1991, the consistency of information provided by the 3H-thymidine labelling index (TLI), in terms of basic relations with other clinico-pathological and biological variables and clinical predictivity, was evaluated using a combined analysis of results previously published by our group for distinct series of patients. Clinical predictivity was analyzed on a subset of 2,067 patients given local-regional therapy until relapse and followed for a median time from 6 to 10 years. Over the entire period TLI maintained a weak direct relation with tumour size and an inverse strong relation with steroid receptors. An increase in TLI was observed for tumours in post-menopausal patients up to the mid 1980s. During 3 different accrual periods (1972-1983; 1984-1987; 1988-1991), TLI was a consistent and independent predictor of relapse-free time, distant metastasis and overall survival, regardless of its consideration as a continuous variable or with a cutoff value of 3%. The reproducibility of our results over time provides support to the consistency of the methodology used and of the biological and clinical information obtained when using TLI as an indicator of breast cancer cell proliferation.
Adult↗
Pathology of disappearing bone disease: a case report with immunohistochemical study.
A case of disappearing bone disease of the proximal femur is reported with histopathological and immunohistochemical studies. There was a densely packed cellular tissue, positive to endothelial antibodies, in areas of massive bone destruction. A more differentiated vascular tissue was present where trabecular cancellous or cortical bone was preserved with only focal zones of accelerated bone remodelling. The self-limited course correlates well with two phases of evolution of the histopathological lesions with neoplastic-like proliferation of endothelial cells corresponding to the rapid and massive bone destruction, and a later differentiation of the cells in mature vascular structures, but still with accelerated bone resorption which is partly compensated by appositional activity.
Arthroplasty, Replacement, Hip↗
Pituitary lesions in multiple endocrine neoplasia syndrome (MENS) type 1.
This review summarizes knowledge on pathology of proliferative lesions of the pituitary gland in multiple endocrine neoplasia syndrome type 1 (MENS 1). When compared with sporadic tumors occurring in general population, pituitary adenomas associated with MENS 1 show the following distinguishing features: (1) they are more often endocrinologically functional, (2) they are more often GH or PRL-producing and (3) they are more frequently plurihormonal. The study of autoptic cases discloses that pituitary PRL or mixed GH-PRL cell adenomas in MENS are multiple and are associated with PRL or GH cell hyperplasia of the peritumoral parenchyma.
Adenoma↗
Different expression of chromogranin A and chromogranin B in various types of pituitary adenomas.
Two hundred and nineteen (33 GH, 21 GH-PRL, 38 PRL, 16 ACTH, 1 TSH cell functioning and 38 FSH-LH, 17 alpha-chain, 8 mixed, 27 minimal glycoprotein--MIN-GLYC--, 11 small argyrophil granule--SAG--, 4 silent TSH-sTSH--and 5 silent ACTH-sACTH--cell nonfunctioning) adenomas were investigated immunohistochemically with antibodies against ACTH, GH, PRL, TSH, FSH, LH alpha-hCG, chromogranin A (CgA) and chromogranin B (CgB). For immunostaining of CgB a novel monoclonal (B 11) antibody was employed. All types of adenomas were positive for CgB. CgA was widely expressed in nonfunctioning FSH-LH, MIN-GLYC, SAG, MIXED, alpha-chain adenomas and in the single TSH cell functioning adenoma. CgA was lacking both in PRL and ACTH functioning adenomas and was poorly expressed in GH and GH-PRL functioning adenomas. The distribution of Grimelius' silver paralleled that of CgA-IR, but not that of CgB-IR. We conclude that: 1) CgB may be considered as an universal granular marker for pituitary adenomas, 2) CgA is an important marker for nonfunctioning adenomas, 3) the pattern of distribution of CgA and CgB for most nonfunctioning ("null cell" according to Kovacs et al.) adenomas favors their origin from glycoprotein producing (FSH/LH, TSH) cells.
Adenoma↗