Viral degradation of marine bacterial exopolysaccharides.

The identification of the mechanisms by which marine dissolved organic matter (DOM) is produced and regenerated is critical to develop robust prediction of ocean carbon cycling. Polysaccharides represent one of the main constituents of marine DOM and their degradation is mainly attributed to polysaccharidases derived from bacteria. Here, we report that marine viruses can depolymerize the exopolysaccharides (EPS) excreted by their hosts using five bacteriophages that infect the notable EPS producer, Cobetia marina DSMZ 4741. Degradation monitorings as assessed by gel electrophoresis and size exclusion chromatography showed that four out of five phages carry structural enzymes that depolymerize purified solution of Cobetia marina EPS. The depolymerization patterns suggest that these putative polysaccharidases are constitutive, endo-acting and functionally diverse. Viral adsorption kinetics indicate that the presence of these enzymes provides a significant advantage for phages to adsorb onto their hosts upon intense EPS production conditions. The experimental demonstration that marine phages can display polysaccharidases active on bacterial EPS lead us to question whether viruses could also contribute to the degradation of marine DOM and modify its bioavailability. Considering the prominence of phages in the ocean, such studies may unveil an important microbial process that affects the marine carbon cycle.

Trace element and isotope deposition across the air-sea interface: progress and research needs.

The importance of the atmospheric deposition of biologically essential trace elements, especially iron, is widely recognized, as are the difficulties of accurately quantifying the rates of trace element wet and dry deposition and their fractional solubility. This paper summarizes some of the recent progress in this field, particularly that driven by the GEOTRACES, and other, international research programmes. The utility and limitations of models used to estimate atmospheric deposition flux, for example, from the surface ocean distribution of tracers such as dissolved aluminium, are discussed and a relatively new technique for quantifying atmospheric deposition using the short-lived radionuclide beryllium-7 is highlighted. It is proposed that this field will advance more rapidly by using a multi-tracer approach, and that aerosol deposition models should be ground-truthed against observed aerosol concentration data. It is also important to improve our understanding of the mechanisms and rates that control the fractional solubility of these tracers. Aerosol provenance and chemistry (humidity, acidity and organic ligand characteristics) play important roles in governing tracer solubility. Many of these factors are likely to be influenced by changes in atmospheric composition in the future. Intercalibration exercises for aerosol chemistry and fractional solubility are an essential component of the GEOTRACES programme.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

Low dentin matrix protein 1 expression correlates with skeletal metastases development in breast cancer patients and enhances cell migratory capacity in vitro.

Small integrin-binding ligand N-linked glycoproteins (SIBLINGs) constitute a family of extracellular matrix proteins involved in bone homeostasis. Their pattern of expression has been primarily reported in bone and tooth and, more recently, in several cancer types. Dentin matrix protein 1 (DMP1), a SIBLING family member, expression was investigated by immunohistochemistry in a retrospective series of 148 primary human breast cancers. Correlations between DMP1 expression levels in the tumors and clinicopathologic features, bone metastases development and relapse of the disease were examined. DMP1 was expressed by 63.5% of the breast tumors analyzed. Significant inverse associations were found between DMP1 expression levels and the size and grade of the tumors (both, P < 0.0001). High DMP1 expression levels in the primary breast lesions were associated with a lower risk of subsequent development of skeletal metastases (P = 0.009). Patients with tumors expressing high levels of DMP1 had a significantly higher disease-free survival rate than those with low DMP1-expressing tumors (P = 0.0062). When DMP1 expression was examined in breast cancer cell lines, we found that non invasive MCF-7 and T47-D cells expressed higher levels than highly invasive MDA-MB-231 and Hs578T cells. Moreover, the specific inhibition of DMP1 expression in MCF-7 cells using siRNAs promoted significantly their migratory capability. Our data implicate for the first time DMP1 expression in breast cancer progression and bone metastases development.

Prognostic indexes in breast cancer: comparison of the Nottingham and Adelaide indexes.

The search for single independent prognostic factors in breast cancer has often produced conflicting results. Therefore, prognostic indexes have been compiled by combining several parameters. In this study we compare the Nottingham Prognostic Index (NPI), which is based on traditional prognostic factors (diameter of the neoplasm, lymph node status and histological grade) with the Adelaide Prognostic Index (API), which is based on the tumour diameter and two biological parameters: oestrogen receptors and cell kinetics. We considered 82 cases of breast cancer observed over the period 1987-1990 with a minimum follow-up of 60 months. The NPI gives a better definition of the prognostic profile for each patient. Our results indicate three prognostic groups (good, moderate, unfavourable), which differ with respect to disease-free survival (DFS; P=0.0024) and overall survival (OS; P=0.0033). In contrast, the API scores showed no significant correlation with OS or DFS. The use of prognostic indexes, especially when compiled using traditional parameters, is a useful aid to the clinician, since they can provide a reliable indication of how individual tumours will evolve.

Breast cancer in young women: clinicopathological features and biological specificity.

Literature data suggest that breast cancers occurring in young patients may be different from those arising in older women. In this study the clinicopathologic characteristics of 50 patients under 40 years of age were compared with those of patients aged over 60. Patients under 40 years old more frequently had a family history of breast cancer than did older patients (24% vs 17%) and had more often used oral contraceptives (29% vs 13%); on average they had experienced menarche 1 year earlier. For early onset breast carcinomas there was a higher frequency of grade 3 tumours (38% vs 17%) and oestrogen receptor negativity (46% vs 20%). In addition, in younger patients the carcinomas were mostly DNA aneuploid (78% vs 58%), with a higher proliferation rate (48% vs 26%) and more frequent c-erbB-2 overexpression (48% vs 26%) and p53 alteration (30% vs 8%). Our data demonstrate that breast cancers arising in young women have a significantly different biopathological profile from those in older patients, with a predominance of unfavourable prognostic parameters.

Evaluation of the prognostic role of vascular endothelial growth factor and microvessel density in stages I and II breast cancer patients.

In this study, we retrospectively evaluated the expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) in 228 and 213 specimens, respectively, from stages I and II breast cancer patients (pts) enrolled in a randomized phase III adjuvant chemotherapy trial comparing epirubicin to CMF, while tamoxifen was given to all postmenopausal pts. The expression of VEGF and MVD was assessed on tissue sections formalin-fixed and paraffin-embedded by immunohistochemical staining using anti-VEGF antibody of human origin and anti-CD34 monoclonal antibody. Univariate and multivariate analysis were performed using chi squared test, log-rank test and Cox's regression model. Sixty four of 228 pts were classified as VEGF positive (28%) with no significant difference in the two treatment arms. In 213 pts evaluated for CD34, 103 pts (48%) were classified as MVD high. No significant association between VEGF and MVD was found, and neither were they correlated with many known prognostic factors such as age, tumor size, nodal status, and histological grade. The only significant correlations observed were between VEGF and estrogen receptor (ER) status (p = 0.013) and between MVD and HER2 overexpression (p = 0.023). At a median follow up of 96 months VEGF and MVD were not correlated with relapse-free survival (RFS) and overall survival (OS) in all pts and in pts assigned to one of the two treatment arms. In conclusion, VEGF and MVD retrospectively evaluated, cannot be considered prognostic factors in node negative (N-) high risk and node positive (N+) breast cancer pts treated with two different regimens of adjuvant chemotherapy.

5S ribosomal and U1 small nuclear RNA genes: a new linkage type in the genome of a crustacean that has three different tandemly repeated units containing 5S ribosomal DNA sequences.

We investigated the 5S ribosomal RNA (rRNA) genes of the isopod crustacean Asellus aquaticus. Using PCR amplification, three different tandemly repeated units containing 5S rDNA were identified. Two of the three sequences were cloned and sequenced. One of them was 1842 bp and presented a 5S rRNA gene and a U1 small nuclear RNA (snRNA) gene. This type of linkage had never been observed before. The other repeat consisted of 477 bp and contained only an incomplete 5S rRNA gene lacking the first eight nucleotides and a spacer sequence. The third sequence was 6553 bp long and contained a 5S rRNA gene and the four core histone genes. The PCR products were used as probes in fluorescent in situ hybridization (FISH) experiments to locate them on chromosomes of A. aquaticus. The possible evolutionary origin of the three repeated units is discussed.

Drosophila male meiosis as a model system for the study of cytokinesis in animal cells.

Drosophila male meiosis offers unique opportunities for mutational dissection of cytokinesis. This system allows easy and unambiguos identification of mutants defective in cytokinesis through the examination of spermatid morphology. Moreover, cytokinesis defects and protein immunostaining can be analyzed with exquisite cytological resolution because of the large size of meiotic spindles. In the past few years several mutations have been isolated that disrupt meiotic cytokinesis in Drosophila males. These mutations specify genes required for the assembly, proper constriction or disassembly of the contractile ring. Molecular characterization of these genes has identified essential components of the cytokinetic machinery, highlighting the role of the central spindle during cytokinesis. This structure appears to be both necessary and sufficient for signaling cytokinesis. In addition, many data indicate that the central spindle microtubules cooperatively interact with elements of the actomyosin contractile ring, so that impairment of either of these structures prevents the formation of the other.

Biopathological significance of single cell DNA aneuploidy measured by static cytometry in breast cancer.

DNA ploidy image analysis in breast carcinomas has occasionally revealed cases with a diploid DNA content but with a single hypertetraploid element, the so-called single cell aneuploidy (SCA). To identify the biologic significance of this little known phenomenon, we selected 40 cases with SCA from a series of 599 consecutive operable breast carcinomas. The clinical, pathological and biological characteristics of SCA cases were compared with those of a control group of 40 pure diploid breast carcinomas. Hormonal receptor status, proliferative indexes (Ki-67) and p53 overexpression were determined immunohistochemically and quantitatively evaluated by image analysis. The overexpression of c-erbB-2 was determined semiquantitatively. SCA was observed in 6.6% of cases (40 of 599) and in 17% of otherwise diploid cases (40 of 236). Breast cancers with SCA occur in younger women (mean age 54.75 y vs 61.12 y, P<0.05), are smaller (mean diameter 20.00 vs 21.62 mm), less differentiated (percentage of G3 cases 13.2 vs 2.9), more frequently hormone independent (ER positivity 70.0 vs 77.5%; PgR positivity 57.5 vs 77.5%) and have a greater cell proliferative activity (mean S-phase: 4.6 vs 2.8, P<0.05), (percentage of Ki-67 immunostaining: 24.1 vs 19.7%). There is also more overexpression of c-erbB-2 and P53, particularly in pT1 cases in which the percentage of c-erbB-2 positive cells is 54 vs 32 (P value is not significant) and the percentage of p53 is 29 vs 4 (P<0.05). According to these results SCA may be a reliable marker of genetic instability and of greater biologic aggressiveness. Image cytometry of DNA content may be a cost effective means of identifying breast cancer patients with an increased risk of tumour recurrences despite otherwise favourable prognostic parameters.

Biological prognostic factors for early stage completely resected non-small cell lung cancer.

BACKGROUND AND OBJECTIVES: The different and unpredictable outcomes in early-stage non-small cell lung cancer patients requires urgent research concerning the biological pathway of this neoplasm. Our study investigated the frequency of expression and the clinicopathologic and prognostic significance of a series of biological markers in stage I and II resected non-small cell lung cancer. METHODS: A total of 99 cases of pathologic stage I and II were analyzed. The mean follow-up of surviving patients was 41 months. The expressions of the following biological markers were tested: bcl-2, p53, Ki-67, angiogenesis, and tumor vessel invasion. Kaplan-Meier estimates of survival and time to recurrence were calculated for clinical variables and biological markers using Cox's model for multivariate analysis. RESULTS: Tumoral vessel invasion was present in 22 (22%) pathologic samples, the angiogenesis mean value was 37 +/- 13, and median was 35; 13 (13%) patients showed positive immunostaining for bcl-2 oncoprotein. P53 oncoprotein expression was present in 48 patients (48.5%). All samples presented Ki-67 expression (mean value = 25.3 +/- 19.3, median = 20). The pathologic staging of the tumor was the most important independent prognostic factor for survival (P = 0.037) and for recurrence of disease (P = 0.040). Tumoral vessel invasion was the only marker with an independent predictive factor for survival and recurrence of disease in the group of patients without lymph node involvement (P = 0.02). CONCLUSION: Our data do not support a relevant prognostic role for p53, bcl-2, or Ki-67 immunohistochemical markers in non-small cell cancer. Tumor vessel invasion was an independent predictive factor of poor outcome in the group of patients without lymph node involvement. Pathological stage was confirmed as the most important independent prognostic factor.

Organization, nucleotide sequence, and chromosomal mapping of a tandemly repeated unit containing the four core histone genes and a 5S rRNA gene in an isopod crustacean species.

A tandemly repeated unit of 6553 bp containing a copy of the four core histone genes H2B, H2A, H3, and H4, and also a 5S rRNA gene, was amplified by PCR from genomic DNA of the isopod crustacean Asellus aquaticus. The linkage between 5S rRNA genes and histone genes has been so far observed in only one other organism, the anostrac crustacean Artemia salina. The gene cluster was cloned and sequenced. The histone genes, in their 3' flanking region, have the interesting feature of possessing two different mRNA termination signals, the stem-loop structure and the AATAAA sequence. A part of the PCR product was used as a probe in FISH experiments to locate the gene cluster on an inter-individually variable number of chromosomes from 6 to 12 per diploid cell, always in a terminal position and never associated with the heterochromatic areas. Fluorescence in situ hybridization (FISH) was also performed on preparations of released chromatin and the reiteration level of the gene cluster was determined as approximately 200-300 copies per haploid genome.

Primary mucinous carcinoma of the skin.

Primary mucinous carcinomas of the skin are very rare. To date, 120 cases have been described in the literature. This tumor is a histologic subtype of sweat gland carcinoma. Because of the histopathologic appearance, primary mucinous carcinoma of the skin can be mistaken for metastasis from extracutaneous sites. We report on the cases of two elderly women with mucinous carcinomas arising in the scalp. Immunohistochemical staining of both tumors was positive for low-molecular-weight cytokeratin and epithelial membrane antigen. Carcinoembryonic antigen was positive in Case 2. Neuroendocrine features represented by neuron-enolase-specific positivity were also observed in both cases, and Grimelius and chromogranin A positivity were observed in Case 2. In both cases, there was strong positivity for estrogen receptor and progesterone receptor. Image analysis cytometry showed a diploid DNA content with a low rate of proliferative cells and negativity for p53 and c-erbB-2 proteins in agreement with the low aggressiveness of these neoplasms.

Computer-assisted immunocytochemical determination of breast cancer steroid receptors on cytological smears of excised surgical specimens compared with frozen sections.

BACKGROUND: Due to the widespread use of fine needle aspirate biopsy the practice of determining estrogen (ER) and progesterone (PR) receptors in breast carcinoma from cytological smears (CS) is becoming very common. The aim of this study was to determine concordance between ER and PR assessed by immunocytochemical assay (ICA) on CS and FS both evaluated by image analysis since we have found no data in literature on this. METHODS: 104 breast carcinoma cases were selected. For all cases ER and PR determination was performed on CS, obtained by light scraping of the freshly cut surface of the excised surgical tumors at the time of frozen section diagnosis, and FS using the same monoclonal antibodies. Computer-assisted image analysis was performed in all cases using CAS 200. Results were expressed as percent positive area of neoplastic nuclei compared with total nuclear area of the examined neoplastic cells. RESULTS: Good correlation was demonstrated between percent positive nuclear neoplastic area by ER-ICA on CS and FS (r = 0.759; P < 0.0001). Concordance of results was 90.19% (P < 0.001). Good correlation was also demonstrated between percent positive nuclear neoplastic area by PR-ICA in CS and FS (r = 0.889; P < 0. 0001). Concordance of results was 97.02% (P < 0.0001). CONCLUSIONS: Our data suggest that ICA on CS with automated image analysis is efficient in evaluating ER and PR content in human breast cancer, especially when CS is the only method pathologists have to evaluate receptor status e.g. in advanced breast cancer cases when neoadjuvant therapy is necessary before surgery or when surgery is impossible.

Leiomyoma of the breast: case report and review of the literature.

We describe a case of leiomyoma in the breast in a 48-year-old woman. The main clinical-pathologic features together with the differential diagnosis, and the pertinent literature reviewed.

Amyloid tumours in the soft tissues of the legs. Case report and review of the literature.

We present a case of multiple amyloidomas occurring in the calves of a 61-year-old woman, without systemic amyloidosis or plasma cell dyscrasia. The disappearance of Congo red positivity after potassium permanganate treatment and immunohistochemical results showed that this was a case of reactive AA amyloidosis. True soft tissue amyloidomas are extremely rare, and this is the first case of AA amyloidoma in the soft tissues of the legs.

Spontaneous dissecting aneurysm of coronary artery in a pregnant woman at term.

We describe a case of spontaneous dissecting aneurysm of the circumflex coronary artery in a 44-year-old primigravida at term with no vascular risk factors. Spontaneous coronary artery dissection is a very rare condition with a greater prevalence in women, postpartum in particular. The left anterior descending artery is the most frequently affected. Histologically, the most common finding is a hematoma occupying the outer third of the media, resulting in complete compression of the true lumen. Arterial wall changes during pregnancy together with hemodynamic factors, a lytic action of protease released from eosinophils, and intimal tears are the main hypotheses considered to explain the etiology of spontaneous coronary artery dissection.

Nucleotide sequence and chromosomal mapping of the 5S rDNA repeat of the crustacean Proasellus coxalis.

In this investigation we analysed the 5S rRNA genes of the isopod crustacean Proasellus coxalis, 5S rDNA hybridization of digested genomic DNA and amplification by PCR demonstrate that these genes are organized in tandem repeats of 589 bp, 120 of which represent the coding sequence and 469 the spacer sequence. Proasellus coxalis is the first crustacean species in which 5S rRNA genes have been found tandemly arranged without being linked to other repeated genes. The PCR product has been used as a probe in FISH to locate the 5S rRNA genes on two chromosome pairs of the P. coxalis karyotype. Comparison of the 5S rRNA sequence of this species with previously published sequences of six other crustacean species shows the existence of a good correlation between phylogenetic relationships and sequence identity.

Ciliated cyst of the perineal skin.

Cutaneous cysts lined by ciliated epithelium are very rare, benign tumors predominantly occurring on the lower extremities of young women. We describe a ciliated cyst found in the perineum of a 60-year-old man. The location and histological features led us to attribute a primitive tailgut origin to this cyst, probably from the embryonic remnants of cloacal membrane. Only two previous examples of similar cysts were found in the literature.

Value of c-erbB-2 and p53 oncoprotein co-overexpression in human breast cancer.

p53 and c-erbB-2 protein expression was immunohistochemically examined in a consecutive series of 49 primary breast cancer patients with a 10-year follow-up. The study was performed on paraffin sections using the monoclonal antibodies DO7 and CBE1; the former recognizes both the wild-type and the mutant p53 forms, the latter recognizes the external domain of the transmembrane c-erbB-2 protein. Positive staining was expressed in 12.2% and 16.3% of cases for p53 and c-erbB-2 proteins, respectively. The results were related to clinicopathological parameters by the chi 2 test. A significant correlation was found between positive c-erbB-2 immunostaining and poor survival (P = 0.04) and between p53 and c-erbB-2 overexpression (P = 0.003); this co-overexpression correlated well with a poor clinical outcome (P = 0.040). From our results, we may speculate that simultaneous expression of p53 and c-erbB-2 oncoproteins could be a critical event in breast tumor progression, and therefore, of prognostic value to identify patients at high risk.