Creative Math of RNA Polymerase III Termination: Sense Plus Antisense Makes More Sense.

In this issue of Molecular Cell, Arimbasseri and Maraia (2015) demonstrate that yeast RNA polymerase III integrates inputs from both strands of the DNA template and three dedicated protein subunits to trigger the highly controlled release of the nascent RNA transcript.

Lacritin proteoforms prevent tear film collapse and maintain epithelial homeostasis.

Lipids in complex, protein-enriched films at air/liquid interfaces reduce surface tension. In the absence of this benefit, the light refracting and immunoprotective tear film on eyes would collapse. Premature collapse, coupled with chronic inflammation compromising visual acuity, is a hallmark of dry eye disease affecting 7 to 10% of individuals worldwide. Although collapse seems independent of mutation (unlike newborn lung alveoli), selective proteome and possible lipidome changes have been noted. These include elevated tissue transglutaminase and consequent inactivation through C-terminal cross-linking of the tear mitogen lacritin, leading to significant loss of lacritin monomer. Lacritin monomer restores homeostasis via autophagy and mitochondrial fusion and promotes basal tearing. Here, we discover that lacritin monomer C-terminal processing, inclusive of cysteine, serine, and metalloproteinase activity, generates cationic amphipathic α-helical proteoforms. Such proteoforms (using synthetic peptide surrogates) act like alveolar surfactant proteins to rapidly bind and stabilize the tear lipid layer. Immunodepletion of C- but not N-terminal proteoforms nor intact lacritin, from normal human tears promotes loss of stability akin to human dry eye tears. Stability of these and dry eye tears is rescuable with C- but not N-terminal proteoforms. Repeated topical application in rabbits reveals a proteoform turnover time of 7 to 33 h with gradual loss from human tear lipid that retains bioactivity without further processing. Thus, the processed C-terminus of lacritin that is deficient or absent in dry eye tears appears to play a key role in preventing tear film collapse and as a natural slow release mechanism that restores epithelial homeostasis.

Rac function is crucial for cell migration but is not required for spreading and focal adhesion formation.

Cell migration is commonly accompanied by protrusion of membrane ruffles and lamellipodia. In two-dimensional migration, protrusion of these thin sheets of cytoplasm is considered relevant to both exploration of new space and initiation of nascent adhesion to the substratum. Lamellipodium formation can be potently stimulated by Rho GTPases of the Rac subfamily, but also by RhoG or Cdc42. Here we describe viable fibroblast cell lines genetically deficient for Rac1 that lack detectable levels of Rac2 and Rac3. Rac-deficient cells were devoid of apparent lamellipodia, but these structures were restored by expression of either Rac subfamily member, but not by Cdc42 or RhoG. Cells deficient in Rac showed strong reduction in wound closure and random cell migration and a notable loss of sensitivity to a chemotactic gradient. Despite these defects, Rac-deficient cells were able to spread, formed filopodia and established focal adhesions. Spreading in these cells was achieved by the extension of filopodia followed by the advancement of cytoplasmic veils between them. The number and size of focal adhesions as well as their intensity were largely unaffected by genetic removal of Rac1. However, Rac deficiency increased the mobility of different components in focal adhesions, potentially explaining how Rac - although not essential - can contribute to focal adhesion assembly. Together, our data demonstrate that Rac signaling is essential for lamellipodium protrusion and for efficient cell migration, but not for spreading or filopodium formation. Our findings also suggest that Rac GTPases are crucial to the establishment or maintenance of polarity in chemotactic migration.

Activated lymphocytes secretome inhibits differentiation and induces proliferation of C2C12 myoblasts.

BACKGROUND/AIMS: ageing is associated with a marked decline in immune function which may contribute to the local environment that can influence the regenerative process of skeletal muscle cells. METHODS: Herein, we focused on determining the effect of an activated immune system secretome on myoblast differentiation and proliferation as possible means to attenuate adverse effects of muscle aging. C2C12 myoblasts were used as model to assess the impact of lymphocyte conditioned media (CM) following anti-CD3/IL-2 activation. RESULTS: Myoblasts cultured with activated lymphocytes CM exhibited reduced morphological and biochemical differentiation (98±20, p<0.005) and increased entry to the S Phase of the cell cycle (61%±7, p<0.001), when compared with myoblasts cultured with non-activated lymphocytes CM. Associated with increased proliferation and reduced differentiation, muscle specific transcription factors MyoD and myogenin were significantly reduced in C2C12 treated with activated lymphocytes CM vs control CM, respectively (myoD: 0.5±0.12 fold reduction P<0.005); myogenin: 0.38±0.08 fold reduction; p<0.005). Moreover, key protein of proliferation pERK1/2 increased (46±11U/ml, p<0.05) whereas mediator of differentiation pAkt decreased (21±12U/ml, p<0.05) in C2C12 treated with activated vs. non-activated CM. CONCLUSION: our data demonstrate that, following activation, secretome of the immune system cells elicit marked regulatory effects on skeletal muscle growth and differentiation; enhancing the former with the loss of the latter.

Phospho-tyrosine phosphatase inhibitor Bpv(Hopic) enhances C2C12 myoblast migration in vitro. Requirement of PI3K/AKT and MAPK/ERK pathways.

Muscle progenitor cell migration is an important step in skeletal muscle myogenesis and regeneration. Migration is required for muscle precursors to reach the site of damage and for the alignment of myoblasts prior to their fusion, which ultimately contributes to muscle regeneration. Limited spreading and migration of donor myoblasts are reported problems of myoblast transfer therapy, a proposed therapeutic strategy for Duchenne Muscular Dystrophy, warranting further investigation into different approaches for improving the motility and homing of these cells. In this article, the effect of protein phospho-tyrosine phosphatase and PTEN inhibitor BpV(Hopic) on C2C12 myoblast migration and differentiation was investigated. Applying a wound healing migration model, it is reported that 1 µM BpV(Hopic) is capable of enhancing the migration of C2C12 myoblasts by approximately 40 % in the presence of myotube conditioned media, without significantly affecting their capacity to differentiate and fuse into multinucleated myotubes. Improved migration of myoblasts treated with 1 µM BpV(Hopic) was associated with activation of PI3K/AKT and MAPK/ERK pathways, while their inhibition with either LY294002 or UO126, respectively, resulted in a reduction of C2C12 migration back to control levels. These results propose that bisperoxovanadium compounds may be considered as potential tools for enhancing the migration of myoblasts, while not reducing their differentiation capacity and underpin the importance of PI3K/AKT and MAPK/ERK signalling for the process of myogenic progenitor migration.

Can we predict death using scoring systems in patients with local peritonitis ? A retrospective study.

INTRODUCTION: Prognostic scores in patients with local peritonitis (LP) have not yet been studied exhaustively. AIM: We, therefore, aimed in this study to evaluate the ability of several scoring systems to predict death in LP. MATERIALS AND METHODS: A retrospective analysis including 68 patients with LP was conducted at Prof. Dr. Stoyan Kirkovich University Hospital in Stara Zagora from January 2017 to August 2021. Clinical and laboratory data needed for calculating the scoring systems were collected at admission or postoperatively. We compared the prognostic performance of WSES SSS, MPI, SIRS, and qSOFA using area under the receiver operation characteristics (AUROC) curves and bivariate correlation analysis. RESULTS: The observed mortality rate was 8.8%. Among all scores, MPI showed the best prognostic performance (AUROC=0.805, 95% CI 0.660-0.950). A threshold MPI >25 points permitted prediction of adverse outcome with a sensitivity of 66.7% and a specificity of 80.6%. The only significant correlation was found between outcome and MPI (p=0.012, r=0.302). Conclusions: The MPI has the ability to prognosticate mortality in patients with LP unlike WSES SSS, qSOFA and SIRS.

Polymorphisms in SREBF1 and SREBF2, two antipsychotic-activated transcription factors controlling cellular lipogenesis, are associated with schizophrenia in German and Scandinavian samples.

Several studies have reported structural brain abnormalities, decreased myelination and oligodendrocyte dysfunction in schizophrenia. In the central nervous system, glia-derived de novo synthesized cholesterol is essential for both myelination and synaptogenesis. Previously, we demonstrated in glial cell lines that antipsychotic drugs induce the expression of genes involved in cholesterol and fatty acids biosynthesis through activation of the sterol regulatory element binding protein (SREBP) transcription factors, encoded by the sterol regulatory element binding transcription factor 1 (SREBF1) and sterol regulatory element binding transcription factor 2 (SREBF2) genes. Considering the importance of these factors in the lipid biosynthesis and their possible involvement in antipsychotic drug effects, we hypothesized that genetic variants of SREBF1 and/or SREBF2 could affect schizophrenia susceptibility. We therefore conducted a HapMap-based association study in a large German sample, and identified association between schizophrenia and five markers in SREBF1 and five markers in SREBF2. Follow-up studies in two independent samples of Danish and Norwegian origin (part of the Scandinavian collaboration of psychiatric etiology study, SCOPE) replicated the association for the five SREBF1 markers and for two markers in SREBF2. A combined analysis of all samples resulted in highly significant genotypic P-values of 9 x 10(-4) for SREBF1 (rs11868035, odd ration (OR)=1.26, 95% confidence interval (CI) (1.09-1.45)) and 4 x 10(-5) for SREBF2 (rs1057217, OR=1.39, 95% CI (1.19-1.63)). This finding strengthens the hypothesis that SREBP-controlled cholesterol biosynthesis is involved in the etiology of schizophrenia.

Assessment of body composition of male patients with type 2 diabetes by bioelectrical impedance analysis.

INTRODUCTION: Type 2 diabetes is a metabolic disorder and as such should affect the components of body composition of diabetics. The changes it induces in patients complement the anthropological characteristics of this disease. The AIM of the present study was to assess the effect type 2 diabetes has on some of the body composition components in male diabetics. MATERIAL AND METHODS: The study included 169 male patients with type 2 diabetes. All patients (ethnical Bulgarian) were allocated into two age groups: group 1--patients aged 40-60 years and group 2--patients aged 61-80 years. Direct measurements of parameters were performed with a Tanita body composition analyser. The bioimpedance parameters we measured were body fat percentage (%BF), total body water percentage (%TBW), muscle mass (MM), bone mass (BM), and visceral fat (VF). The derived parameters were total body fat (TBF) (kg), active body mass (ABM) (kg), active body mass percentage. RESULTS: Body composition of male diabetics aged 40-60 years: %BF, VF and TBF were statistically significantly higher in diabetics than in healthy controls. Body composition of male diabetic patients aged 61-80 years: BM and VF were significantly higher in diabetic patients than in controls. %BF and MM did not have a high statistical significance. Inter-age comparison of body composition in male diabetics: we found that %BF, %TBW, MM and BM tend to be higher in 40-60-year-olds. Visceral fat was increased in the 61-80-year-olds, the difference reaching high statistical significance. CONCLUSION: Bioimpedance analysis (BIA) of body composition showed the total body fat in male diabetics of both age groups to be greater than that in controls. TBF was greater in the younger age group at the expense of the subcutaneous fat, while in the more elderly patients it was the visceral fat that was increased, which makes their body composition correlate rather adversely with the prognosis, course and outcome of the disease. The relative percentage of active body mass was greater in the healthy individuals than in diabetic patients. This parameter was higher in the younger age group of diabetic patients than in the more elderly patients; this finding is probably due to the longer duration of the disease and also to aging changes such as osteoporosis, muscle atrophy and decreased quantities of body water.

Serotonin-producing cells in human gastric mucosa--immunohistochemical and electron microscopic study.

UNLABELLED: The great many hormones released by the endocrine cells of the glands and lining epithelium of gastric mucosa determine its significance for the processes in the gastrointestinal tract. One of these hormones, serotonin, plays an important role in the regulation of the motility, secretion and sensation in the gastrointestinal tract. The aim of the present study was to conduct immunohistochemical and electron microscopic studies of serotonin-producing EC cell of gastric mucosa. MATERIAL AND METHODS: Gastric mucosa biopsies were obtained and studied immunihistochemically for serotonin expression in the mucosa endocrine cells. Electron microscopic study was performed to specify the processes of synthesis, accumulation and release of secretory product by those cells. RESULTS: The immunohistochemical study revealed a considerable number of serotonin-containing EC cells scattered in the lining epithelium and between the glands in the corpus and pyloric region of the stomach. The electron microscopic study followed the stages of formation of the secretory granules from the initial accumulation of granular substance, its membrane packing and formation of mature granules to their disintegration in the secretory process. CONCLUSIONS: Serotonin as a neurotransmitter and gastrointestinal hormone appears to be a key to understanding a number of symptoms of gastrointestinal disorders like nausea, vomiting, pain, diarrhea and constipation. A detailed study of serotonin functions in the gastrointestinal tract realised through different types of receptors, and of the development of specific antagonists and agonists to these receptors would open up new opportunities for a more efficient treatment of gastrointestinal disorders.

The Pleistocene-Holocene aquatic molluscs as indicators of the past ecosystem changes in Transbaikalia (Eastern Siberia, Russia).

Data on the historical change of the Transbaikalian malacofauna in the Neopleistocene and Holocene is presented. Aquatic mollusc shells from archaeological excavations of the ancient settlements dating from the Neolithic period to Medieval and also from a drill hole of the Neopleistocene alluvial deposits were collected. In total eight species of bivalve molluscs from the families Margaritiferidae, Unionidae, Lymnocardiidae, Glycymerididae [marine], and two gastropod species from families Viviparidae and Planorbidae were identified. These species were aged using radiocarbon dating. It was found that the species ranged in age from more than 50.000 to 2.080-1.210 years BP. Five species inhabited the Transbaikal region which are locally extirpated today. Their disjunctive ranges in the past included southern Europe and Western and Eastern Siberia to Transbaikalia and in the east to Far East and Primorye Territory of Russia. A remarkable finding is that of the bivalve genus Monodacna, which was found very far from its native range, the Ponto-Caspian region. The time of existence and extirpation of the thermophilic species of genera Monodacna, Planorbis, Lanceolaria and Amuropaludina corresponds to cycles of the warming and cooling in Pleistocene and Holocene according to regional climate chronological scales. These species can be used as palaeoclimate indicators. Change of the regional malacofaunal species composition is connected with the natural climatochron cycles in the Pleistocene and Holocene resulting in evidence for succession. In the course of this succession, these stenothermal species became extirpated on a regional level, decreasing their global ranges.

Neutrophil to lymphocyte ratio as a potential predictive marker for treatment with pembrolizumab as a second line treatment in patients with non-small cell lung cancer.

The aim of this multicentric retrospective study is to evaluate the predictive and prognostic performance of neutrophil to lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and their dynamics in patients with non-small cell lung cancer (NSCLC) treated with pembrolizumab as a second line. Patients with metastatic NSCLC (n = 119), whose tumors expressed programmed death-ligand 1 (PD-L1) ≥ 1%, were retrospectively analyzed between Apr 2017 and Apr 2019. All patients received platinum-containing chemotherapy as a first line treatment. Pre-treatment NLR was calculated by dividing the number of neutrophils by the number of lymphocytes in peripheral blood before the first pembrolizumab infusion. Progression free survival (PFS) and overall survival (OS) was compared by Kaplan-Meier method and Cox Proportional Hazard model. Patients with NLR > 5 before immunotherapy showed significantly shorter mean PFS of 6.86 months (95% CI: 5.81-7.90) as compared to those with NLR ≤ 5 of 18.82 months (95% CI: 15.87-21.78) (long rank test p < 0.001). Furthermore in the multivariate analysis, only NLR > 5 was an independent predictive factor for shorter PFS (HR: 4.47, 95% CI: 2.20-9.07, p < 0.001). In multivariate analysis, presence of bone metastases (HR: 2.08, 95% CI: 1.10-4.94, p = 0.030), NLR > 5 before chemotherapy (HR: 8.09, 95% CI: 2.35-27.81, p = 0.001) and high PLR before chemotherapy (HR: 2.81, 95% CI: 1.13-6.97, p = 0.025) were found to be independent negative prognostic factors for poor OS. Our data suggests that NLR ≤ 5 is a potential predictive marker, which may identify patients appropriate for immunotherapy as a second line treatment.

Genetic variation of the FAT gene at 4q35 is associated with bipolar affective disorder.

A recent study suggested that the cadherin gene FAT exerts an influence on susceptibility to bipolar affective disorder (BPAD). We aimed to replicate this finding in a German sample (425 BPAD I and 419 controls). In addition, we performed a comprehensive linkage disequilibrium mapping of the whole genomic region of FAT and the neighboring circadian gene MTNR1A (48 single nucleotide polymorphisms (SNPs) covering 191 kb). No significant association was observed for SNPs located in the MTNR1A gene. In FAT, however, nine SNPs showed association, eight of them being located in the same haplotype block found to be associated with BPAD by Blair et al. The smallest P-value of 0.00028 (OR 1.71) was seen for non-synonymous SNP rs2637777. A combination of five markers including this marker showed a haplotype distribution with a nominal P-value of 1.8 x 10(-5) that withstands correction for multiple testing. While the control allele frequencies between our sample and the samples of the original study are comparable, tendencies of risk allele frequencies are opposite. Possible explanations for this include potential differences in linkage disequilibrium structure between the German, Australian, UK, and Bulgarian populations sampling variation, multilocus effects and/or the occurrence of independent mutational events. We conclude that our results support an involvement of variation at the FAT gene in the etiology of BPAD, but that further work is needed both to clarify possible reasons for the observed risk allele differences and to ultimately identify the functionally relevant variant(s).

Cryptococcus gattii meningoencephalitis in an immunocompetent person 13 months after exposure.

A 53-year old immunocompetent Swiss female is described who developed severe meningoencephalitis due to infection with Cryptococcus gattii 13 months following exposure on Vancouver Island, Canada. Diagnosis was based on cerebrospinal fluid (CSF) examination, i.e., positive India-ink staining, positive latex particle agglutination, and positive culture. Species identification was performed by growth on L-canavanine-glycine-bromthymol blue medium and by sequencing of the intergenic and internal transcribed spacer regions of the rRNA genes. After initial therapy with fluconazole by which the patient did not improve, therapy was changed to amphotericin B and flucytosine and later to high-dose fluconazole and amphotericin B. Despite long-term treatment and external drainage of the CSF, the patient's condition improved only slowly. The patient was discharged after 132 days of hospitalization.

Isotope fractionation of benzene during partitioning - Revisited.

Isotope fractionation between benzene-D0 and benzene-D6 caused by multi-step partitioning of the benzenes between water and two organic solvents, n-octane and 1-octanol, as well as between water and the gas phase, was measured. The obtained fractionation factors αH = KH/KD are αH = 1.080 ± 0.015 and αH = 1.074 ± 0.015 for extraction into n-octane and 1-octanol, respectively, and αH = 1.049 ± 0.010 for evaporation from aqueous solution. The comparison of solvent- and gas-phase partitioning reveals that about 2/3 of the driving force of fractionation is due to different interactions in the aqueous phase, whereas 1/3 is due to different interactions in the organic phase. The heavy benzene isotopologue behaves more 'hydrophilically' and the light one more 'hydrophobically'. This synergistic alignment gives rise to relatively large fractionation effects in partitioning between water and non-polar organic matter. In contrast to a previous study, there is no indication of strong fractionation by specific interactions between benzene and octanol. Partitioning under non-equilibrium conditions yields smaller apparent fractionation effects due to opposite trends of thermodynamic and kinetic fractionation parameters, i.e. partition and diffusion coefficients of the isotopologues. This may have consequences which should be taken into account when considering isotope fractionation due to sorption in environmental compartments.

Increased Circulating CD4+CD25+CD127low/neg Regulatory T-cells as a Prognostic Biomarker in Acute Pancreatitis.

OBJECTIVE: Early detection of severe forms with unfavorable outcome is the cornerstone that could provide reduction of morbidity and mortality in acute pancreatitis (AP). METHODS: The percentage of circulating CD4CD25CD127 regulatory T-cells (Tregs) was determined at admission, on the 48th hour, and on the fifth day in 72 patients with AP. We divided patients in 2 groups-Sev1, which includes 19 patients (26.4%) with moderate AP and 39 patients (54.2%) with mild disease, and Sev2, which includes 14 patients (19.4%) with severe AP. Seven patients (9.7%) developed septic complications. The mortality in our group was 9.7%. RESULTS: The patients in Sev2 had higher percentage of Tregs at admission and on the fifth day compared with patients in Sev1 (P = 0.007 and P = 0.033, respectively). There was no significant difference in percentage of Tregs at admission, on the 48th hour, and on the fifth day in patients who developed and did not develop infected necrosis (P = 0.50, P = 0.72, and P = 0.92, respectively). Patients with poor outcome had elevated percentage of Tregs on the fifth day (P = 0.045). CONCLUSIONS: The percentage of circulating Tregs may be implicated in the development of early immune suppression in AP. Elevated percentage of circulating Tregs at admission in AP is an independent prognostic biomarker for severe disease.

TFOS DEWS II Tear Film Report.

The members of the Tear Film Subcommittee reviewed the role of the tear film in dry eye disease (DED). The Subcommittee reviewed biophysical and biochemical aspects of tears and how these change in DED. Clinically, DED is characterized by loss of tear volume, more rapid breakup of the tear film and increased evaporation of tears from the ocular surface. The tear film is composed of many substances including lipids, proteins, mucins and electrolytes. All of these contribute to the integrity of the tear film but exactly how they interact is still an area of active research. Tear film osmolarity increases in DED. Changes to other components such as proteins and mucins can be used as biomarkers for DED. The Subcommittee recommended areas for future research to advance our understanding of the tear film and how this changes with DED. The final report was written after review by all Subcommittee members and the entire TFOS DEWS II membership.

A field investigation on transport of carbon-supported nanoscale zero-valent iron (nZVI) in groundwater.

The application of nanoscale zero-valent iron (nZVI) for subsurface remediation of groundwater contaminants is a promising new technology, which can be understood as alternative to the permeable reactive barrier technique using granular iron. Dechlorination of organic contaminants by zero-valent iron seems promising. Currently, one limitation to widespread deployment is the fast agglomeration and sedimentation of nZVI in colloidal suspensions, even more so when in soils and sediments, which limits the applicability for the treatment of sources and plumes of contamination. Colloid-supported nZVI shows promising characteristics to overcome these limitations. Mobility of Carbo-Iron Colloids (CIC) - a newly developed composite material based on finely ground activated carbon as a carrier for nZVI - was tested in a field application: In this study, a horizontal dipole flow field was established between two wells separated by 5.3m in a confined, natural aquifer. The injection/extraction rate was 500L/h. Approximately 1.2kg of CIC was suspended with the polyanionic stabilizer carboxymethyl cellulose. The suspension was introduced into the aquifer at the injection well. Breakthrough of CIC was observed visually and based on total particle and iron concentrations detected in samples from the extraction well. Filtration of water samples revealed a particle breakthrough of about 12% of the amount introduced. This demonstrates high mobility of CIC particles and we suggest that nZVI carried on CIC can be used for contaminant plume remediation by in-situ formation of reactive barriers.

Pathophysiological mechanisms of acute pancreatitis define inflammatory markers of clinical prognosis.

Development of acute pancreatitis illustrates the need to understand the basic mechanisms of disease progression to drive the exploration of therapeutic options. Cytokines play a major role in the pathogenesis of acute pancreatitis as underlying systemic inflammatory response, tissue damage, and organ dysfunction. However, little is known about circulating concentrations of these inflammatory markers and their real impact on clinical practice. Experimental studies have suggested that the prognosis for acute pancreatitis depends on the degree of pancreatic necrosis and the intensity of multisystem organ failure generated by the systemic inflammatory response. This suggests an intricate balance between localized tissue damage with proinflammatory cytokine production and a systemic anti-inflammatory response that restricts the inappropriate movement of proinflammatory agents into the circulation. Implication of such mediators suggests that interruption or blunting of an inappropriate immune response has the potential to improve outcome. A detailed understanding of pathophysiological processes and immunological aspects in patients with acute pancreatitis is the basis for the development of therapeutic strategies that will provide significant reductions in morbidity and mortality.

Epithelial cells expressing cytokeratins-19 and bone marrow micrometastases in patients with breast cancer at the time of primary surgery: clinical outcome during long-term follow-up.

PURPOSE: To evaluate the detection of epithelial cells in bone marrow of breast cancer patients as an indicator of metastatic disease. PATIENTS AND METHODS: Between 2001 and 2005, bone marrow biopsies were taken from 79 breast cancer patients during primary surgery. Specimens were stained immunocytochemically for epithelial cells expressing cytokeratins or epithelial membrane antigen. The long-term outcomes of these patients were analyzed. RESULTS: In 51 CK-positive results of 79 patients, epithelial cells were found in the bone marrow (BM) biopsies. These patients were designated CK(+). The rate of tumor recurrence or cancer-related death was significantly higher in CK(+) patients than in CK-negative patients. Multivariate analysis using the Cox regression model revealed BM status as a prognostic parameter independent of axillary lymph node status. CONCLUSION: Disseminated epithelial cells in BM are associated with poor clinical outcome in breast cancer patients. However, the presence of these cells is not a sufficient parameter, suggesting that epithelial cells in the BM of breast cancer patients at the time of surgery have limited metastatic potential. The role of these cells needs to be further evaluated.