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M Bracko

Publications and source records attributed to M Bracko.

At least 91 records · Page 5Linked to original sources
PubMed2002

Observation of double cć production in e+e- annihilation at squareroot[s] approximately 10.6 GeV.

We report the observation of prompt J/psi via double cc; production from the e+e- continuum. In this process one cc; pair fragments into a J/psi meson while the remaining pair either produces a charmonium state or fragments into open charm. Both cases have been experimentally observed. We find cross sections of sigma[e+e- -->J/psieta(c)(gamma)]xB(eta(c)-->>or=4 charged)=(0.033(+0.007)(-0.006)+/-0.009) pb and sigma(e+e- -->J/psiD(*+)X)=(0.53(+0.19)(-0.15)+/-0.14) pb and infer sigma(e+e- -->J/psicc;)/sigma(e+e- -->J/psiX)=0.59(+0.15)(-0.13)+/-0.12. These results are obtained from a 46.2 fb(-1) data sample collected near the Upsilon(4S) resonance, with the Belle detector at the KEKB collider.

Journal Article↗
PubMed2002

Observation of the eta(c)(2S) in Exclusive B-->KK(S)K-pi(+) Decays.

We report the observation of a narrow peak in the K(S)K-pi(+) invariant mass distribution in a sample of exclusive B-->KK(S)K-pi(+) decays collected with the Belle detector at the KEKB asymmetric e(+)e(-) collider. The measured mass of the peak is M=3654+/-6(stat)+/-8(syst) MeV/c(2), and we place a 90% confidence level upper limit on the width of Gamma<55 MeV/c(2). The properties agree with heavy-quark potential model expectations for the eta(c)(2S) meson, the n=2 singlet S charmonium state.

Journal Article↗
PubMed2002

Study of CP-violating asymmetries in B0-->pi(+)pi(-) decays.

We present a measurement of CP-violating asymmetries in B0-->pi(+)pi(-) decays based on a 41.8 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We fully reconstruct one neutral B meson as a B0-->pi(+)pi(-) CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we obtain the CP-violating asymmetry parameters S(pipi)=-1.21(+0.38)(-0.27)(stat)+0.16-0.13(syst) and A(pipi)=+0.94(+0.25)(-0.31)(stat)+/-0.09(syst).

Journal Article↗
PubMed2002

Observation of chi(c2) production in B meson decay.

We report the first observation of chi(c2) production in B meson decays. We find an inclusive B-->chi(c2)X branching fraction of (1.80(+0.23)(-0.28)+/-0.26) x 10(-3). The data set, collected with the Belle detector at the KEKB e(+)e(-) collider, consists of 31.9 x 10(6) BB events. We also present branching fractions and momentum spectra for both chi(c1) and chi(c2) production.

Journal Article↗
PubMed2002

Observation of B(+/-) --> p(-)pK(+/-).

We report the observation of the decay mode B(+/-) --> p(-)pK(+/-)based on an analysis of 29.4 fb(-1) of data collected by the Belle detector at KEKB. This is the first example of a b-->s transition with baryons in the final state. The p(-)p mass spectrum in this decay is inconsistent with phase space and is peaked at low mass. The branching fraction for this decay is measured to be B(B+/--->p(-)pK+/-) = [4.3(+1.1)(-0.9)(stat)+/-0.5(syst)]x 10(-6). We also report upper limits for the decays B(0)-->p(-)pK(S) and B(+/-)-->p(-)p pi(+/-).

Journal Article↗
PubMed2002

Long term prognostic value of Nottingham histological grade and its components in early (pT1N0M0) breast carcinoma.

AIMS: To determine the prognostic usefulness of the Nottingham histological grade (NHG) and its components in a series of 270 patients with stage pT1N0M0 breast cancer with a median follow up of 12.5 years. METHODS: Microscopic slides were re-examined and the degree of tubule formation, nuclear pleomorphism, and mitotic counts were assessed and scored according to the suggested guidelines. The association with cancer specific survival (CSS) was evaluated by univariate and multivariate analyses. RESULTS: Whereas tumour size, patient age, menopausal status, type of surgery, or adjuvant treatment were not related to prognosis, histological type (p < 0.01) and NHG (p < 0.005) were associated with CSS. When evaluating the components of NHG separately, survival was not related to the score for pleomorphism, but was significantly better in tumours with score 1 or 2 for tubule formation (p < 0.007) and in those with score 1 for mitotic counts (p < 0.006). The two components retained independent significance in multivariate analysis. When the proposed cut off points for mitotic counts were replaced by lower ones based on tertile values, the mitotic index became the strongest prognostic factor (p = 0.0001) and histological type was the only additional factor of independent prognostic significance. CONCLUSIONS: These findings confirm the prognostic value of NHG in pT1N0M0 breast carcinoma, show that the evaluation of tubule formation and mitotic rate provides independent prognostic information, and suggest that the proposed cut off points for mitotic counts may be too high for this particular group of tumours.

Adult↗
PubMed2001

Correlation of MTS1/p16 and nm23 mRNA expression with survival in patients with peripheral synovial sarcoma.

BACKGROUND AND OBJECTIVES: Tumor suppressor gene MTS1/p16 (cyclin-dependent kinase-4 inhibitor) and a putative tumor metastasis suppressor gene nm23 (nucleoside diphosphate A kinase) have been identified in a variety of human tumors but have not been well studied in mesenchymal neoplasms. METHODS: Expression of nm23 and MTS1 mRNA was determined by quantitative analysis from paraffin-embedded tumor tissue. The series comprised 31 patients with localized primary synovial sarcoma of soft tissues who were followed for a median of 83 months. RESULTS: Neither MTS1 nor nm23 expression levels correlated with the patient's age or sex, tumor type, depth, size, mitotic rate, or extent of tumor necrosis. In addition, there was no correlation between MTS1 and nm23 levels. Patients' survival was not related to sex, age, tumor type, location, mitotic rate, or MTS1 mRNA level. The only factors that correlated with poor survival in multivariate analysis were the presence of extensive tumor necrosis (> 15%) and higher levels of nm23 mRNA. CONCLUSIONS: Our results suggest that increased expression level of nm23 mRNA may be implicated in the mechanism of tumor progression and is associated with poor survival in patients with synovial sarcoma.

Adolescent↗
PubMed2001

Myeloid metaplasia of the breast.

Hereby, we present the case of a 50-year-old woman with 5-year history of chronic idiopathic myelofibrosis who was referred to our institution after she had noted a lump in the breast. Histological examination of the lesion removed from her left breast yielded the diagnosis of extramedullary hematopoiesis in the breast. On the basis of our experience in this particular patient and on the basis of the data in the literature, we discuss the value of different more or less invasive diagnostic procedures, such as sonography, mammography, fine needle aspiration biopsy and surgical excision with histological examination of removed tissue in obtaining the diagnosis of myeloid metaplasia in breast.

Biopsy, Needle↗
PubMed2001

Prognostic significance of DNA ploidy determined by high-resolution flow cytometry in breast carcinoma.

OBJECTIVE: To assess the prognostic value of DNA ploidy in breast carcinoma and its relation to other established prognostic factors. STUDY DESIGN: We evaluated DNA ploidy in 303 breast carcinoma patients with a median follow-up of 63 months. Flow cytometry was performed on frozen tumor material, yielding histograms with narrow peaks (median coefficient of variation of 2.08). DNA ploidy pattern was classified as either diploid versus nondiploid, euploid (diploid and tetraploid) versus aneuploid or diploid/near-diploid (DNA index < 1.2) versus other, and correlated with relapse-free (RFS) and cancer-specific survival (CSS) along with tumor size, histologic grade and type, axillary lymph node involvement, menopausal and steroid receptor status, age and type of treatment. RESULTS: Seventy-one percent of tumors were DNA nondiploid (14% tetraploid and 57% aneuploid). There was a strong association between DNA ploidy and histologic grade. Histologic grade, lymph node status, tumor size and DNA ploidy (regardless of the classification used) were all significantly associated with RFS and CSS in multivariate analysis. CONCLUSION: These results suggest that DNA ploidy, at least when determined from frozen tumor tissue, is an independent prognostic factor in breast carcinoma; however, its prognostic power seems to be inferior to that of histologic grade, with which it strongly correlates.

Adult↗
PubMed1998

Nonsporadic cases and unusual morphological features in pheochromocytoma and paraganglioma.

BACKGROUND: Pheochromocytomas and paragangliomas are well-defined entities. Some of their nonsporadic associations and unusual morphological appearances are not universally appreciated. DESIGN: We reevaluated all adrenal pheochromocytomas and extra-adrenal paragangliomas seen at our institution in the period from 1980 through 1995 for their nonsporadic presentation or unusual morphological features and for the presence of sustentacular cells. RESULTS: Among 71 pheochromocytomas and paragangliomas in 60 patients, there were seven nonsporadic cases (11.5%), including three familial cases, two cases of multiple endocrine neoplasia 2a syndrome, one case associated with neurofibromatosis type 1, and one case of incomplete Carney's triad. In addition, we saw two cases of pheochromocytoma associated with metachronous malignant melanoma and one case of multicentric paraganglioma in a patient with Maffucci's syndrome. Unusual morphological features were as follows: some degree of coexisting cortical hyperplasia (eight cases), vacuolar degeneration of tumor cells (three cases), composite pheochromocytoma (one case), presence of pheochromoblasts and calcospherites (one case), melanin pigmentation (two cases), and insular growth pattern (four cases); the latter was associated with malignant behavior in two cases. Sustentacular cells varied in number but were consistently numerous in all nonsporadic cases. CONCLUSIONS: Nonsporadic cases of pheochromocytoma comprise around 10% of all cases in this as in other series. Some other, less well-recognized associations, eg, with malignant melanoma, may also belong to this group. Unusual morphological features occur in a substantial number of cases and may cause diagnostic problems.

Adolescent↗
PubMed1998

[Malignant melanoma with pseudoepitheliomatous reaction marker. A case report].

Pseudoepitheliomatous hyperplasia or pseudocarcinomatous hyperplasia (PEH) is characterized by a downward expansion of the epidermis, which can simulate a squamous cell carcinoma (SC). It is usually associated to chronic inflammatory conditions, but rarely it can hide a tumour. In the present paper a case of melanoma (M) associated with a prominent PEH is described. The patient is a 79-year old woman who presented a polypoid, ulcerated lesion of the left thigh. The lesion was entirely removed. The patient is free of disease 5-years after surgery. On histology, the malignant melanomatous proliferation was closely admixed to sheets of squamous cells. The possibility of SC was excluded as the squamous component did not show architectural disarray, prominent nucleoli and atypical mitoses. Siringomatous metaplasia was observed in the deeper portion of the lesion. On the basis of these findings the diagnosis of melanoma (M) associated to prominent PEH was considered the most likely.

Aged↗
PubMed1997

DNA flow cytometry in gastric carcinoma: implication in patients with potentially curative resection.

BACKGROUND AND OBJECTIVES: The relevance of DNA ploidy as a prognostic factor in patients with gastric cancer is controversial. The prognostic significance of DNA ploidy and its relationship to conventional histological grading and staging of the tumor (TNM stage, Lauren, Ming and WHO classification) were evaluated. METHODS: DNA ploidy of the tumor was determined by flow cytometry on archival material from 76 patients who underwent R0, D2 stomach resection. RESULTS: DNA aneuploidy was found in 39 cases (51%). No significant association between DNA aneuploidy and either patients' sex, pT, pN, type according to Ming or Borrmann and tumor localization was found. The incidence of DNA aneuploidy was significantly lower in tumors of diffuse type according to Lauren, in signet-ring cell or undifferentiated type (WHO), in grade 3/4 tumors, and in patients younger than 50 years. We found no significant difference in survival of patients with DNA aneuploid when compared to DNA diploid tumors, although the prognosis of the patients with lower DNA index (DI < 1.2) tended to be better than that of higher DNA index (DI > 1.2). CONCLUSIONS: DNA ploidy appears to be of limited prognostic value after R0, D2 resection of stomach cancer.

DNA, Neoplasm↗
PubMed1997

Comparison of standardized immunohistochemical and biochemical assays for estrogen and progesterone receptors in breast carcinoma.

The purpose of this study was to determine estrogen receptor (ER) and progesterone receptor (PR) expression assessed by dextran-coated charcoal method (DCC) and standardized immunohistochemical method (IHC) in a prospective series of 557 primary breast carcinomas, to assess the concordance between the two assays, and to evaluate the association between hormone receptor expression and various clinicopathological parameters. For ER, results of both methods were in agreement in 73.6% of the cases (277 positive, 133 negative), 74 tumors (13.3%) where IHC+/DCC- and 73 (13.1%) were IHC-/DCC+. For PR, concordant results were observed in 72.7% of the cases (201 positive and 204 negative), 127 tumors (22.8%) were IHC+/DCC- and 25 (4.5%) were IHC-/DCC+. Irrespective of the method used, ER and PR positivity showed a strong negative association with tumor grade. ER+ tumors were significantly more common among older patients. With IHC, PR+ cases were more common among tumors of lobular and mucinous type and among node positive tumors. The only parameter that was related to the concordance rate of ER determination by the DCC and IHC method was the age of the patients, with agreement being significantly lower in the group of patients younger than 50 years. On the other hand, discordant PR determination was more often observed in tumors of lower grade, node positive tumors and in tumors of lobular and mucinous type.

Adult↗
PubMed1997

Evaluation of DNA content in epithelial hyperplastic lesions of the larynx.

Quantification of cellular DNA by image or flow cytometry has achieved acceptance as an objective and reproducible component of diagnostic pathology. Although the majority of investigations have focused on the prognostic utility of DNA content measurements in malignant neoplasms, the detection of abnormal DNA content can also be useful for the detection of early neoplasia or premalignant change. Several studies of laryngeal epithelial hyperplastic lesions by image cytometry have shown that a proportion of these lesions exhibit abnormal DNA content and that the incidence of this finding correlates with the degree of dysplasia or atypia. Similar results were obtained by flow cytometry, which has only rarely been used for investigation of these lesions. Although there is some evidence that lesions with abnormal DNA content are more likely to progress to carcinoma, additional studies are needed to define the clinical importance of DNA cytometry in hyperplastic epithelial lesions of the larynx.

DNA↗
PubMed1997

Prognostic value of DNA ploidy in breast cancer stage I-II.

The DNA content of paraffin-embedded tumor tissue has been measured by flow cytometry in 169 patients with operable breast cancer Stage I-II. The medium follow-up period was 123 months. Aneuploid primary tumors were found in 49% of patients. Tumor ploidy significantly correlated with histological type of tumor (p < 0.05), whereas no clear correlation between DNA ploidy and tumor size, histological grade and lymph node involvement was found. After 10-year follow-up, recurrence-free survival (RFS) of patients with diploid tumors was slightly better than the survival of those with aneuploid tumors, but the difference was not statistically significant (p = 0.39). In a Cox multivariate analysis only the axillary lymph node involvement and tumor size proved to be independent prognostic factors for recurrence, whereas DNA ploidy lost its prognostic value already in the univariate analysis. Therefore, we can conclude that the information on DNA ploidy, obtained from archival material, does not contribute significantly to better discrimination between good-risk and poor-risk operable breast cancer patients.

Aged↗
PubMed1997

Is DNA aneuploidy a prognostic factor in gastric cancer?

Flow cytometric analysis of DNA ploidy was performed on an archival material obtained from 79 patients with gastric cancer who underwent a potentially curative (R0) stomach resection with D2 lymphadenectomy, and evaluated its relationship to conventional pathologic parameters, TNM stage and prognosis. No significant association between DNA aneuploidy and either patients' sex, depth of tumor infiltration (pT), lymph node involvement (pN), histological type according to Ming, macroscopic type according to Borrmann or tumor localization was found. However, the incidence of DNA aneuploidy was significantly lower in tumors of diffuse type according to Lauren, in tumors of signet ring cell or undifferentiated type according to WHO classification, in poorly differentiated/undifferentiated tumors and in patients younger than 50 years. We found no significant difference in survival between patients with DNA aneuploid tumors and those with DNA diploid tumors. Although the prognosis of patients with tumors of lower DNA index (DI < 1.2) tended to be better than for those of higher DNA index (DI > 1.2), the difference did not reach a statistically significant level (p = 0.09). TNM stage, depth of tumor infiltration (pT) and lymph node involvement (pN) were the only factors that significantly affected survival in univariate analysis and both pT and pN retained their independent prognostic significance in multivariate analysis.

Age Factors↗
PubMed1996

Epithelioid hemangioma of small tubular bones: a report of three cases, two of them associated with pregnancy.

We report three cases of epithelioid hemangioma of small tubular bones in women aged 20, 24, and 50 years. In two patients, the tumor appeared during or shortly after pregnancy. We studied clinical data, radiographs, and hematoxylin- and eosin-stained slides, and we performed immunohistochemical and flow cytometric DNA analysis. The tumor was in distal phalanges of the fingers in two patients and in metatarsal bone in one. Cortical bone destruction with infiltration of the surrounding soft tissue was seen in all of the patients. Light microscopic examination showed characteristic morphology, highlighted by epithelioid endothelial cells with different degrees of vasoformativity. Immunohistochemically, the epithelioid cells showed strong positive reaction for Factor VIII in all three patients, for CD31 in two, and for CD34 in one. Ulex europaeus antigen and keratins were negative. Laminin and collagen IV delineated innumerable predominantly abortive vascular structures, which were encircled by cells that presumably were pericytic and that were positive for smooth muscle actin. A relatively high degree of immunostaining for proliferating cell nuclear antigen and Ki67 contrasted with the low mitotic rate and low percentage of cells in S phase. Progesterone and estrogen receptors were negative. Epithelioid hemangiomas of small tubular bones are rare lesions that are characterized by early bone destruction and infiltration of soft tissues. Their association with pregnancy may be fortuitous; if any gestation-related proliferative stimulation exists, it does not seem to be mediated through steroid receptors.

Adult↗