PubMed Health⌕ Search

Biomedical subjects

A Pich

Publications and source records attributed to A Pich.

At least 37 records · Page 2Linked to original sources
PubMed1999

Androgen receptor expression in male breast carcinoma: lack of clinicopathological association.

Androgen receptor (AR) expression was retrospectively analysed in 47 primary male breast carcinomas (MBCs) using a monoclonal antibody on formalin-fixed, paraffin-embedded tissues. AR immunopositivity was detected in 16 out of 47 (34%) cases. No association was found with patient age, tumour stage, progesterone receptor (PGR) or p53 protein expression. Well-differentiated MBCs tended to be AR positive more often than poorly differentiated ones (P = 0.08). A negative association was found between ARs and cell proliferative activity: MIB-1 scores were higher (25.4%) in AR-negative than in AR-positive cases (21.11%; P = 0.04). A strong positive association (P = 0.0001) was found between ARs and oestrogen receptors (ERs). In univariate analysis, ARs (as well as ERs and PGRs) were not correlated with overall survival; tumour histological grade (P = 0.02), size (P = 0.01), p53 expression (P = 0.0008) and MIB-1 scores (P = 0.0003) had strong prognostic value. In multivariate survival analysis, only p53 expression (P = 0.002) and histological grade (P = 0.02) retained independent prognostic significance. In conclusion, the lack of association between AR and most clinicopathological features and survival, together with the absence of prognostic value for ER/PGR status, suggest that MBCs are biologically different from female breast carcinomas and make it questionable to use antihormonal therapy for patients with MBC.

Adult↗
PubMed1999

A role for intracellular immunization in chemosensitization of tumor cells?

Acquired drug resistance represents a major cause of chemotherapy failure in patients with cancer. The characterization of the molecular pathways involved in drug resistance has provided us with new targets to overcome this problem. Many of these target proteins are often overexpressed in human cancers. A number of gene therapy strategies, including antisense oligonucleotides, ribozymes and single-chain antibodies, have been developed to achieve the selective modulation and inhibition of various cellu- lar proteins. Thus, these approaches can be exploited to modulate the resistance phenotype of tumor cells. These gene therapy strategies represent a novel and unique way to enhance the sensitivity of tumor cells to chemotherapeutic drugs. This review will focus on the use of intracellular immunization as a means to modulate the expression of specific genetic determinants involved in the drug resistance phenotype.

Antibodies, Monoclonal↗
PubMed1999

Substrate-specific selenoprotein B of glycine reductase from Eubacterium acidaminophilum. Biochemical and molecular analysis.

The substrate-specific selenoprotein B of glycine reductase (PBglycine) from Eubacterium acidaminophilum was purified and characterized. The enzyme consisted of three different subunits with molecular masses of about 22 (alpha), 25 (beta) and 47 kDa (gamma), probably in an alpha 2 beta 2 gamma 2 composition. PBglycine purified from cells grown in the presence of [75Se]selenite was labeled in the 47-kDa subunit. The 22-kDa and 47-kDa subunits both reacted with fluorescein thiosemicarbazide, indicating the presence of a carbonyl compound. This carbonyl residue prevented N-terminal sequencing of the 22-kDa (alpha) subunit, but it could be removed for Edman degradation by incubation with o-phenylenediamine. A DNA fragment was isolated and sequenced which encoded beta and alpha subunits of PBglycine (grdE), followed by a gene encoding selenoprotein A (grdA2) and the gamma subunit of PBglycine (grdB2). The cloned DNA fragment represented a second GrdB-encoding gene slightly different from a previously identified partial grdBl-containing fragment. Both grdB genes contained an in-frame UGA codon which confirmed the observed selenium content of the 47-kDa (gamma) subunit. Peptide sequence analyses suggest that grdE encodes a proprotein which is cleaved into the previously sequenced N-terminal 25-kDa (beta) subunit and a 22-kDa (alpha) subunit of PBglycine. Cleavage most probably occurred at an -Asn-Cys- site concomitantly with the generation of the blocking carbonyl moiety from cysteine at the alpha subunit.

Amino Acid Oxidoreductases↗
PubMed1998

Partial purification of an iron-dependent L-serine dehydratase from Clostridium sticklandii.

An oxygen-sensitive and highly unstable L-serine dehydratase was partially purified from the Gram-positive anaerobe Clostridium sticklandii. The final active preparation contained five proteins of 27, 30, 44.5, 46, and 58 kDa as judged by SDS-PAGE. The N-terminal sequence of the 30 kDa subunit showed some similarity to the alpha-subunits of the iron-containing L-serine dehydratases from Clostridium propionicum and Peptostreptococcus asaccharolyticus. Oxygen-inactivated L-serine dehydratase from C. sticklandii was reactivated by incubation with Fe2+ under reducing conditions. Furthermore, the enzyme was inactivated by iron-chelating substances like phenanthroline and EDTA. Pyridoxal-5-phosphate (PLP) did not stimulate the activity, and known inhibitors of PLP-containing enzymes such as NaBH4 had no effect on the activity of L-serine dehydratase from C. sticklandii.

Aerobiosis↗
PubMed1998

Bcl-2 expression in male breast carcinoma.

We have analysed the expression of bcl-2 protein retrospectively in 34 primary male breast carcinomas (MBC), using the monoclonal antibody bcl-2 in formalin-fixed, paraffin-embedded tissues. Bcl-2 expression was compared with tumour clinicopathological features, sex steroid hormone receptors, DNA content, p53 immunoreactivity and cell proliferative activity assessed by counts of the argyrophilic nucleolar organizer regions (AgNORs), the monoclonal antibody PC10 against proliferating cell nuclear antigen and the monoclonal antibody MIB-1. Most (28, or 82.3%) of the 34 cases of MBC were bcl-2 positive. No association was found with clinicopathological features of the tumours, although bcl-2 tended to be more frequently expressed in small tumours (P=0.09) and in cases without necrotic areas (P=0.1). Nor was any association found with hormone receptor status, p53 immunoreactivity, DNA content, cell proliferative activity or patient survival. In multivariate analysis, only proliferative activity (expressed by AgNOR counts) and p53 immunoreactivity had independent prognostic significance. Our results indicate that MBC differs from FBC in that in MBC bcl-2 protein is not related to an oestrogen-dependent transcription pathway and bcl-2 alone is not sufficient to induce increased proliferation. These characteristics, together with the high prognostic value of cell proliferation and the lack of prognostic significance for hormone receptor status, support the hypothesis that MBC is biologically different from FBC.

Adult↗
PubMed1998

Nucleolar organizer region counts predict complete remission, remission duration, and survival in adult acute myelogenous leukemia patients.

PURPOSE: The analysis of the nucleolar organizer regions (AgNORs) was performed in patients with acute myelogenous leukemia (AML) to verify the role of cell proliferation in predicting complete remission (CR) and survival. MATERIALS AND METHODS: Bone marrow biopsies from 40 adult patients with AML were stained with the argyrophilic method. The mean AgNOR number (AgNOR count) was calculated for each case. After induction therapy, patients who achieved CR received intensive consolidation; two underwent autologous and four allogeneic bone marrow transplantations (BMT). RESULTS: The mean AgNOR count for the whole series was 6.6 (SD = 1.35); it was higher in CR patients than in resistant ones (P = .02). The median duration of CR was 26 months for patients with an AgNOR count greater than 6.6, but only 6 months for those with lower counts (P = .01). Sixteen patients who achieved a CR relapsed and 14 reached a second CR; the median duration of second CR was 16 months for patients with AgNOR count greater than 6.6, but only 5 months for those with lower counts (P = .01). The median survival time for the whole series was 14 months, with 30% of patients alive and in continuous CR at 103 months. Survival was longer for patients with an AgNOR count greater than 6.6 (33 months) than for those with lower counts (6 months; P = .0009). In multivariate analysis, when CR was excluded from the model, AgNOR count appeared as an independent prognostic variable (P = .005). CONCLUSION: AgNOR analysis is a suitable method to assess cell proliferation in bone marrow biopsies and can predict CR, remission duration, and survival in AML patients.

Adolescent↗
PubMed1997

High and low risk prostate carcinoma determined by histologic grade and proliferative activity.

BACKGROUND: Histologic grade of differentiation is a strong prognostic factor for prostate carcinoma. However, most tumors fall in the intermediate group. Nuclear and nucleolar morphometry and analysis of the argyrophilic nucleolar organizer regions (AgNORs) were performed to improve prognosis, especially for patients with intermediate histologic grade tumors. METHODS: Core needle biopsies from 65 patients with primary prostate carcinoma at diagnosis were studied. Patients received only hormone therapy. Formalin fixed and paraffin embedded sections were stained with the method of Ploton. The mean AgNOR count was calculated in 100 tumor cells for each case. Nuclear and nucleolar areas from 100 cells were measured with an automated image analyzer. One-way analysis of variance and uni- and multivariate survival analyses were used for statistical evaluation. RESULTS: In the whole series, World Health Organization (WHO) tumor grade, nuclear and nucleolar areas, and AgNOR counts were correlated with survival time. By multivariate analysis, only AgNOR counts retained independent prognostic significance. In WHO Grade 2 carcinoma, the 5-year survival rate for patients with AgNOR/cell < or = 7.84 was 77%, but was only 12% for those with higher counts (P < 0.0001). These survival rates were similar to those obtained when patients with WHO Grade 1 carcinoma and Grade 2 carcinoma plus low AgNOR counts were compared with patients with Grade 3 carcinoma and Grade 2 carcinoma plus high AgNOR counts. In Gleason intermediate Grade 6 and 7 carcinomas, the 5-year survival rate for patients with AgNOR/cell < or = 7.84 was 71%, but was only 7% for those having higher counts (P = 0.0001). CONCLUSIONS: Nuclear and nucleolar areas, as well as AgNOR counts, supplement histologic grading in the prognostic assessment of prostate carcinoma in patients receiving only hormone therapy. AgNOR count also is a prognostic factor for patients with intermediate grade tumors. The combination of histologic grade and proliferative activity allows the stratification of patients into low and high risk groups.

Aged↗
PubMed1997

Risk groups of myeloma patients by histologic pattern and proliferative activity.

We investigated the histologic pattern and the cell proliferative activity of myeloma cells by the analysis of the nucleolar organizer regions (AgNORs) in bone marrow biopsy specimens from 150 multiple myelomas at diagnosis. The objective was an attempt to define risk groups of myeloma patients. On univariate analysis, the percentage of bone marrow plasma cells (BMPC%), the pattern of infiltration, the degree of plasma cell (PC) atypia, the marrow fibrosis, and the number of AgNOR/PC were correlated with survival time. On multivariate analysis, only AgNOR counts and pattern of infiltration retained independent prognostic significance. At 4-year followup, all patients with BMPC% < or = 20, interstitial pattern of invasion, and well-differentiated (G1) PC plus AgNOR/cell < or = 3.32 were alive, while no patient with BMPC% >50, diffuse pattern of infiltration, and poorly differentiated (G3) PC plus AgNOR/cell >5.15 survived (p < 0.0001). In conclusion, the histologic pattern and proliferative activity of myeloma cells, evaluated by AgNOR counts, are reliable predictors of survival in myeloma. Both parameters can be easily assessed in the same biopsy specimen, are reproducible, and permit identification of a group of patients with favourable outcome at 4-year followup. Thus, bone marrow biopsy should always be included in the diagnostic procedures for myeloma patients.

Adult↗
PubMed1997

Cell proliferation, bcl-2, c-myc, p53 and apoptosis as indicators of different aggressiveness in small lymphocytic lymphoma (SLL).

Cell proliferation activity, by MIB1 mAb, expression of bcl-2, c-myc and p53 gene proteins and apoptotic index (AI) were assessed in 54 cases of SLL and compared to the morphological subtypes of this disorder, defined by Lennert on the basis of amount and distribution of small and larger activated lymphocytes as diffuse, tumor-forming and pseudofollicular subtypes (DS, TFS, PFS). MIB1 scores showed significant differences between DS, PFS and TFS (5.5%, 16.61% and 24.14%, respectively; p < 0.0001). Worth noting, the MIB1 score did not differ significantly when comparing DS with the diffuse areas of PFS, or TFS with the pseudofollicles of PFS. The mean bcl-2 gene protein score was displayed to a high extent in all subtypes, but less extensively by larger activated lymphocytes that, conversely, expressed c-myc. MIB1 score correlated negatively with bcl-2 and positively with c-myc protein scores. These findings suggest that lymphocytes protected from apoptosis by bcl-2 would be exponed to cell activation and growth acceleration provided by c-myc. This condition would account for a different aggressiveness of morphologically activated subtypes, such as TFS and PFS with larger pseudofollicles. The survival analysis, performed in 23 cases, showed a trend of association of cell proliferation and c-myc expression with a more aggressive progression of the disease. Overexpression of p53 and apoptosis were found only in a minority of cases, unrelated to the subtypes. In conclusion, cell growth fraction, bcl-2 and c-myc assessment may be of help in predicting the aggressiveness of different subtypes of SLL. This approach should be most conveniently applied to PFS, which represents a continuum between DS and TFS, in order to distinguish, in this heterogeneous subtype, more indolent from more aggressive disorders.

Adult↗
PubMed1997

Copurification of ribosomal protein S2 and DNA-dependent RNA polymerase from heat-shocked cells of Bacillus subtilis.

The DNA-dependent RNA polymerases from heat-shocked and vegetatively grown cells of Bacillus subtilis were isolated and compared. The RNA polymerase from non-stressed cells had the well known alpha, beta, beta' and sigma composition of eubacterial RNA polymerases. The RNA polymerase from heat-shocked cells exhibited one additional band shown by SDS-PAGE. N-terminal sequencing of the first 16 amino acids of the associated protein demonstrated its identity with the ribosomal protein S2.

Amino Acid Sequence↗
PubMed1996

Genetic analysis of two tomato mutants affected in the regulation of iron metabolism.

Iron is one of the most important micronutrients for plants. Like other organisms, plants have developed active mechanisms for the acquisition of sufficient iron from the soil. Nevertheless, very little is known about the genetic mechanisms that control the active uptake. In tomato, two spontaneously derived mutants are available, which are defective in key steps that control this process. The recessive mutation chloronerva (chln) affects a gene which controls the synthesis of the non-protein amino acid nicotianamine (NA), a key component in the iron physiology of plants. The root system of the recessive mutant fer is unable to induce any of the characteristic responses to iron deficiency and iron uptake is thus completely blocked. We present a characterization of the double mutant, showing that the fer gene is epistatic over the chln gene and thus very likely to be one of the major genetic elements controlling iron physiology in tomato. In order to gain access to these two genes at the molecular level, both mutants were precisely mapped onto the high density RFLP map of tomato. The chln gene is located on chromosome 1 and the fer gene is on chromosome 6 of tomato. Using this high-resolution map, a chromosome walk has been started to isolate the fer gene by map-based cloning. The isolation of the fer gene will provide new insights into the molecular mechanisms of iron uptake control in plants.

Algal Proteins↗
PubMed1996

p53 expression and proliferative activity predict survival in non-invasive thymomas.

We performed p53 immunohistochemistry, DNA flow cytometry and analysis of the argyrophilic nucleolar organizer regions (AgNORs) in formalin-fixed, paraffin-embedded sections from 46 non-invasive thymomas and correlated the results with the traditional clinicopathologic features of the tumor. p53 immunopositivity was detected in 21 of 46 cases; it was not associated with any clinicopathologic features nor DNA content but significantly correlated with AgNOR counts. On univariate analysis, 10-year survival rates were 100% for p53-negative cases but only 71% for p53-positive cases and 93% for patients with low AgNOR counts but only 77% for patients with high AgNOR counts. Age, sex, histologic type, myasthenia gravis and DNA content did not correlate with survival. Our results indicate that p53 staining and evaluation of proliferative activity allow assessment of prognosis in non-invasive thymomas, when all of the other parameters are insufficient. Furthermore, the high rate of p53 expression in non-invasive thymomas suggests that abnormal p53 immunoreactivity may occur early in the neoplastic process.

Adolescent↗
PubMed1996

DNA ploidy and p53 expression correlate with survival and cell proliferative activity in male breast carcinoma.

DNA flow cytometry and the monoclonal antibody DO7 were applied in formalin-fixed, paraffin-embedded specimens from 34 primary male breast carcinomas to verify whether DNA ploidy and p53 expression were associated with survival and proliferative activity. They were compared with tumor clinicopathologic features, sex steroid hormone receptors and cell proliferative activity, assessed by the counts of the argyrophilic nucleolar organizer regions (AgNORs), the monoclonal antibody PC10 against the proliferating cell nuclear antigen and the monoclonal antibody MIB-1. A significant correlation was found between survival and tumor ploidy (median survival, 77 months for diploid but only 38 months for aneuploid cases; P = .03) and p53 expression (median survival, 95 months for cases with p53 scores < or = 14.06% versus 33 for cases with P53 scores > 14.06%; P = .0004; median survival, 99 months for p53 negative vs 39 for positive cases; P = .007). Tumor histological grade (P = .006), AgNOR counts (P = .0001), PC10 scores (P = .002), and MIB-1 scores (P = .001) were also associated with prognosis. In the multivariate analysis, only p53 scores (P = .001) or p53 immunopositivity (P = .003) and AgNOR counts (P = .022) retained an independent prognostic significance. Aneuploid tumors had higher AgNOR counts (P = .002), PC10 (P = .007), MIB-1 (P = .006), and p53 scores (P = .01) than diploid cases. A linear relationship was observed between p53 scores and AgNOR counts (r = .41; P = .014), PC10 (r = .46; P = .005), and MIB-1 scores (r = .44; P = .011). These results indicate that DNA ploidy and p53 expression are associated with survival and cell proliferative activity in male breast carcinoma. Quantitative parameters, such as DNA ploidy, p53 scores, AgNOR counts, PC10, and MIB-1 scores substantially improve the prognostic significance of the traditional parameters in male breast carcinoma.

Adult↗
PubMed1996

Malignant cellular blue nevus: a clinicopathological study of 6 cases.

BACKGROUND: Malignant cellular blue nevus (MCBN) is a rare entity due to the malignant transformation of a preexisting cellular blue nevus (CBN). OBJECTIVE AND METHODS: The clinical and pathologic features of 6 patients with MCBN are described. RESULTS: Three tumors were located on the scalp, 2 on the trunk and 1 on the neck. The lesions, present from birth or childhood, had enlarged rapidly in the last months before excision. Histologically, there was a dermal proliferation of spindle and epithelioid atypical melanocytic cells. Some of them were heavily pigmented. Numerous atypical mitoses were seen. In 2 cases, foci of necrosis were detected. In 2 cases, remnants of CBN were also noted. MCBN has a poor prognosis and may be difficult to differentiate from so-called atypical blue nevus, metastasis of malignant melanoma and malignant transformation of combined nevus. CONCLUSIONS: CBN may represent a precursor of malignant melanoma. In MCBN, malignant changes seem to occur in clear cells.

Adult↗
PubMed1995

Long-term survival of thymoma patients by histologic pattern and proliferative activity.

We performed DNA flow cytometry and analysis of the argyrophilic nucleolar organizer regions (AgNORs) in formalin-fixed, paraffin-embedded sections from 60 surgically resected thymomas. The results were correlated with histologic pattern, stage, associated clinical features, and survival to assess which parameters could best predict prognosis. On univariate analysis, the 10-year survival rates were 86% for predominantly lymphocytic type but only 42% for predominantly epithelial, mixed lymphoepithelial, or spindle cell thymomas (p = 0.006); survival rates were 85% for noninvasive but only 34% for invasive thymomas (p = 0.0002); 73% for diploid but only 38% for aneuploid cases (p = 0.005); 88% for thymomas with 5.75 AgNORs per cell or fewer but only 34% for thymomas with more than 5.75 AgNORs per cell (p < 0.0001). On multivariate survival analysis, tumor stage (p < 0.001) and AgNOR counts (p = 0.009) retained independent prognostic significance. The 16 patients with predominantly lymphocytic type and 5.75 AgNORs per cell or fewer were all alive at the end of the observation period. In conclusion, the histologic type of the American classification and the proliferative activity evaluated by AgNOR analysis are the best predictors of long-term survival for patients with thymoma. Both predictors can be easily evaluated in the same histologic section, are highly reproducible, and permit identification of a group of patients with a favorable outcome regardless of other clinicopathological features.

Adolescent↗
PubMed1995

Biological heterogeneity of diffuse mixed small and large cell non-Hodgkin's lymphomas assessed by DNA flow cytometry and Ki67.

The cell proliferative activity of the clinico-pathologically heterogeneous non-Hodgkin's lymphomas (NHL) included in the intermediate grade F category of the Working Formulation (WF) was investigated. S-phase fraction with flow cytometry on cell suspensions, and Ki67 on frozen tissue sections were performed in 42 F NHL. An avidin-biotin immunocomplex method was used and 1000 cells from 10 representative fields were counted. DNA content, S-phase and Ki67 were also detected in 194 NHL covering the whole spectrum of the WF. DNA content anomalies were found in 52 of 194 NHL. Their incidence, like that of S-phase fraction and Ki67 positive cells, progressively increased from low- to high-grade. A linear correlation was found between Ki67 and S-phase (r = .59). Using the median value of proliferating cells obtained with both procedures as a cut off, two very different groups of lymphomas could be distinguished within a series of 42 F-intermediate NHL: with low and high proliferative cell activity (p < .0001) that were termed F(low) and F(high), respectively. A intermediate group was placed between them. It differed significantly from the others if Ki67 was used but only from the F(high) group if the S-phase fraction analysis was applied. No significant differences were seen when comparing F(low) with the single categories of low-grade NHL and F(high) with H high-grade NHL; no significant differences were found between F(high) and G, and between G and H categories. The existence of distinct groups of NHL in the F category, as defined by biological parameters assessing the cell proliferative activity, indicates that this category includes biologically heterogeneous lymphoma subtypes with different grades of aggressiveness. The results also indicate that the G intermediate category displays proliferation indices similar to those of H high grade category.

Aneuploidy↗
PubMed1995

Role of the argyrophilic nucleolar organizer regions in tumor detection and prognosis.

The expression of the argyrophilic nucleolar organizer regions (AgNORs) has been analyzed in renal, bladder, and pharyngeal carcinomas, multiple myeloma (MM), and skin melanocytic lesions to clarify their role in tumor detection and prognosis. Sections from formalin-fixed, paraffin-embedded biopsies were stained with the method of Ploton; the mean AgNOR number per nucleus (AgNOR count) and their distribution (configuration) were assessed examining 100 neoplastic cells. AgNOR counts and histologic grade were highly associated in bladder urotheliomas (6.01 for grade 1 [G1], 7.69 for G2, 13.35 for G3; p < 0.00001) and MM (3.18 for G1, 4.36 for G2, 6.13 for G3; p < 0.0001); they were not associated in renal cell carcinomas (5.35 for G1, 5.92 for G2, 7.99 for G3; p = 0.132) and pharyngeal carcinomas (11.1 for G2, 10.27 for G3; p = 0.08). AgNOR number was also related to the degree of malignancy in melanocytic lesions (2.93 for common blue nevus, 2.89 for benign nevus [BN], 3.69 for cellular blue nevus [CBN], 7.71 for malignant melanoma, and 8.33 for malignant cellular blue nevus [MCBN]; p < 0.00001). Association between AgNOR counts and pathologic stage was found in bladder carcinomas (6.43 for pTa, 10.19 for pT1, 12.57 for pT2-4; p < 0.00001) and MM (3.06 for cases with percentage of bone marrow plasma cells [BMPC%] < or = 20, 4.28 for BMPC% 21 to 50, 5.14 for BMPC% > 50; p < 0.0001]; no correlation was found in pharyngeal (11.18 for T1, 10.08 for T2, 10.68 for T3, 11.47 for T4; p = 0.18) or renal cell carcinomas (6.06 for pT2, 6.31 for pT3; p = 0.78). Few, large and grouped AgNORs were found in well-differentiated bladder carcinomas, MM, and benign melanocytic lesions; numerous, small and dispersed AgNORs were seen in poorly differentiated bladder, renal and pharyngeal carcinomas, MM and malignant melanocytic lesions. Significant association with prognosis was found in pharyngeal carcinomas (5-year survival: 68% for cases with < or = 10.31 AgNOR/cell, 20% for cases with > 10.31 AgNORs) and MM (5-year survival: 46% for cases with < or = 4.62 AgNOR/cell, 7% for cases with > 4.62 AgNORs; in MM the configuration too was related to prognosis: median of survival 72 months for tightly grouped, 16 for partially grouped, and 11 for dispersed AgNORs). Our results indicate that AgNOR number and configuration are useful in detection and prognosis of some neoplasias. They permit a rapid evaluation of morphology and tumor cell kinetics even on small biopsies.(ABSTRACT TRUNCATED AT 400 WORDS)

Antigens↗