Guanosine modulates K+ membrane currents in SH-SY5Y cells: involvement of adenosine receptors

Guanosine (GUO), widely considered a key signaling mediator, is implicated in the regulation of several cellular processes. While its interaction with neural membranes has been described, GUO still is an orphan neuromodulator. It has been postulated that GUO may eventually interact with potassium channels and adenosine (ADO) receptors (ARs), both particularly important for the control of cellular excitability. Accordingly, here, we investigated the effects of GUO on the bioelectric activity of human neuroblastoma SH-SY5Y cells by whole-cell patch-clamp recordings. We first explored the contribution of voltage-dependent K⁺ channels and, besides this, the role of ARs in the regulation of GUO-dependent cellular electrophysiology. Our data support that GUO is able to specifically modulate K⁺-dependent outward currents over cell membranes. Importantly, administering ADO along with GUO potentiates its effects. Overall, these results suggested that K⁺ outward membrane channels may be targeted by GUO with an implication of  ADO receptors in SH-SY5Y cells, but also support the hypothesis of a functional interaction of the two ligands. The present research runs through the leitmotif of the deorphanization of GUO, adding insight on the interplay with adenosinergic signaling and suggesting GUO as a powerful modulator of SH-SY5Y excitability.

Protective, Antioxidant and Antiproliferative Activity of Grapefruit IntegroPectin on SH-SY5Y Cells

Tested in vitro on SH-SY5Y neuroblastoma cells, grapefruit IntegroPectin is a powerful protective, antioxidant and antiproliferative agent. The strong antioxidant properties of this new citrus pectin, and its ability to preserve mitochondrial membrane potential and morphology, severely impaired in neurodegenerative disorders, make it an attractive therapeutic and preventive agent for the treatment of oxidative stress-associated brain disorders. Similarly, the ability of this pectic polymer rich in RG-I regions, as well as in naringin, linalool, linalool oxide and limonene adsorbed at the outer surface, to inhibit cell proliferation or even kill, at high doses, neoplastic cells may have opened up new therapeutic strategies in cancer research. In order to take full advantage of its vast therapeutic and preventive potential, detailed studies of the molecular mechanism involved in the antiproliferative and neuroprotective of this IntegroPectin are urgently needed.

New Neuroprotective Effect of Lemon IntegroPectin on Neuronal Cellular Model

Lemon IntegroPectin obtained via hydrodynamic cavitation of organic lemon processing waste in water shows significant neuroprotective activity in vitro, as first reported in this study investigating the effects of both lemon IntegroPectin and commercial citrus pectin on cell viability, cell morphology, reactive oxygen species (ROS) production, and mitochondria perturbation induced by treatment of neuronal SH-SY5Y human cells with H2O2. Mediated by ROS, including H2O2 and its derivatives, oxidative stress alters numerous cellular processes, such as mitochondrial regulation and cell signaling, propagating cellular injury that leads to incurable neurodegenerative diseases. These results, and the absence of toxicity of this new pectic substance rich in adsorbed flavonoids and terpenes, suggest further studies to investigate its activity in preventing, retarding, or even curing neurological diseases.

Interobserver Reproducibility in Diagnosis of Breast Lesions. A Panel in Puglia (Italy)

Background

Given the incidence of breast cancer, histologic agreement is necessary to select the proper treatment.

Methods & study design

Twelve pathologists working in Puglia (Italy) independently evaluated a set of 88 slides of breast lesions. The set included 31 cases which presented difficulties at the moment of first diagnosis (problem cases) and 57 cases without problems (routine cases). Each pathologist was requested to classify lesions according to four categories: A, benign; B, atypical proliferation; C, in situ carcinoma; D, invasive carcinoma. For each case, the definite diagnosis was considered that provided by most of the pathologists (prevalent diagnosis). For the evaluation of degree of agreement, kappa statistics were utilized.

Results

Among routine cases, agreement was observed in 68.4% of cases (38/57) and in 29% of problem cases (9/31). The pair-wise comparison between all participating pathologists showed a good overall agreement, (kappa mean, 0.66; range, 0.57-0.76). The agreement of each pathologist with the prevalent diagnosis was high for invasive (mean kappa, 0.88) and benign lesions (mean kappa, 0.83) followed by in situ carcinoma (mean kappa, 0.64). The lowest value observed was for atypical lesions (mean kappa, 0.25).

Conclusions

The results showed a good overall degree of diagnostic concordance among participating pathologists, all working in the Italian region of Puglia. The findings emerging from the study are comparable to those of other studies performed with selected pathologists specifically specialized in breast pathology. Moreover, the study confirmed the diagnostic difficulties for borderline lesions and the necessity of further investigation for sclerosing lesions with discordant diagnoses.

Relation between Primary Tumor Shape and Biological Behavior in Breast Cancer

The aim of this study was to investigate the biological significance of tumor shape in breast cancer by considering the shape not as a casual event but as an expression of the behavior and natural history of the tumor. The shape was studied by an analytical morphometry procedure and was related to axillary metastases, which up to now are the most meaningful prognostic factors in this disease. Fifty cases of infiltrating breast carcinoma (25 N+ and 25 N-) were investigated. The shape, studied on subgross sections of the tumor, was considered as the result of two components: the subtle contour irregularities and the main distortions of the figure. The procedures used allowed us to distinguish and to parametrize these two components in order to submit them to univariate analysis (Student's t test), a principal components analysis and, finally, a multivariate discriminant analysis (Hotelling test). The utilized analytical procedures by work-station S.A.M. (S.A.M. work station is a product of « Metamorphosis ») consisted of three steps: 1) Extraction of tumor function curve obtained by Kth order polynomials which gives a smoothing effect to the original curve; 2) Evaluation of contour irregularities by Fourier harmonic analysis; 3) Evaluation of shape asymmetry by SAE (shape asymmetry evaluator). We considered also the roundness factors of the original and function curves and finally the maximum tumor diameter. Three parameters relating to contour irregularities (sum and mean value of Fourier harmonic amplitude and percentage of superimposed points) and parameters relating to main distortions of the figure (mean value of SAE) were highly significant (p < 0.001). The roundness factor of the original curve was more significant (p < 0.001) than that of the function curve (p < 0.01) whereas maximum tumor diameter was not significant when tested by Student's t test. Multivariate discriminant analysis allowed 20 % of error to be reached by using 3 parameters relating to the shape analysis and the two roundness factors. By using 8 parameters, including maximum tumor diameter, the percentage error was 16 %. The results obtained, while they stress the usefulness of the employed procedure, reveal that shape of the tumor, together with its dimensions, is an important expression of the biological behavior relating to metastatic spread.

Allopurinol-induced Sweet's syndrome

Sweet's syndrome, or acute febrile neutrophilic dermatosis, is an uncommon severe cutaneous condition, not previously associated with allopurinol therapy. We describe the case of an 87-year-old woman with hyperuricemia who developed classic Sweet's syndrome manifestations 8 days after being treated with allopurinol. Patient's symptoms included fever, painful edema in the hands and lower limbs with non-pruritic erythematous plaques topped by pus-filled skin blisters, right eye conjunctivitis, splenomegaly and joint pain. At the emergency department, blood tests showed neutrophilic leukocytosis, inflammatory state and altered liver function. During hospitalization, she received unsuccessful treatments with two different antibiotics (namely ceftriaxone and levofloxacin), while treatment with intravenous methylprednisolone produced a rapid clinical remission of symptoms, cutaneous lesion pain improvement, normalization of her body temperature and her blood values returned to normal. Use of the Naranjo adverse drug reaction probability scale indicated a probable relationship between the patient's development of Sweet's syndrome and allopurinol therapy. Because the signs and symptoms of Sweet's syndrome resemble an infectious process, the correct diagnosis may be delayed and inappropriate treatment regimen with antibiotics may often precede glucocorticoid therapy.

Central review of discordant samples for microarray-based ER, PR, and HER2 and local IHC/FISH assessment worldwide from 827 patients

11

Background: Differences in fixation and IHC and subjective interpretation can substantially affect the accuracy and reproducibility of estrogen receptor (ER), progesterone receptor (PR) and HER2 expression. The commercially available TargetPrint test measures the mRNA expression level of ER, PR and HER2 and is 98% concordant with centrally assessed ER as presented by Viale et al, SABCS 2011. This study compares results from the microarray-based TargetPrint with IHC and FISH (for HER2 IHC2+) generated by local standard procedures. Methods: Fresh tumor samples (core needle biopsies or surgical) were collected for 831 patients diagnosed with breast cancer stage I to IV (Feb 2008 - Jan 2011) from 22 hospitals from Europe, New Zealand, Japan and US. The results of the IHC/FISH assessments performed according to the local standards at the hospitals were compared to the quantitative gene expression readouts with TargetPrint. Discordant cases were centrally reviewed for IHC/FISH assessment. Results: Of the 831 samples, IHC assessment was unknown for 4 ER/ PR samples; HER2 was unknown for 12 samples. Comparison of IHC and gene expression read out by TargetPrint showed a concordance of 95% for ER; 83% for PR and 94% for HER2. In this study, 3% of all IHC ER positive samples were classified negative by microarray, and 11% of IHC PR positive samples were classified negative by microarray. For HER2, 4% of IHC/FISH HER2 positive samples were classified negative by microarray and 2% of IHC/FISH HER2 negative samples were classified positive by microarray. Most notably, all available 5 ER IHC negative/TargetPrint positive samples turned out to be positive with central re-assessment. HER2 IHC2+ samples with discordant classifications for TargetPrint and local assessment are currently being reviewed for FISH/SISH assessment. Conclusions: Microarray based readout of ER, PR and HER2 status using TargetPrint is fairly comparable to local IHC and FISH analysis in 827 analyzed samples in various hospitals worldwide. However, re-assessment of discordant cases–especially IHC ER-/TargetPrint ER+ cases- confirms TargetPrint to be a useful high quality second opinion for local IHC/FISH assessment.

Central review of discordant samples for microarray based on ER, PR, and HER2 and local IHC/FISH assessment worldwide from 827 patients

10554

Background: Differences in fixation and IHC and subjective interpretation can substantially affect the accuracy and reproducibility of estrogen receptor (ER), progesterone receptor (PR) and HER2 expression. The commercially available TargetPrint test measures the mRNA expression level of ER, PR and HER2 and is 98% concordant with centrally assessed ER as presented by Viale et al, SABCS 2011. This study compares results from the microarray-based TargetPrint with IHC and FISH (for HER2 IHC2+) generated by local standard procedures. Methods: Fresh tumor samples (core needle biopsies or surgical) were collected for 831 patients diagnosed with breast cancer stage I to IV (Feb 2008 - Jan 2011) from 22 hospitals from Europe, New Zealand, Japan and US. The results of the IHC/FISH assessments performed according to the local standards at the hospitals were compared to the quantitative gene expression readouts with TargetPrint. Discordant cases were centrally reviewed for IHC/FISH assessment. Results: Of the 831 samples, IHC assessment was unknown for 4 ER/ PR samples; HER2 was unknown for 12 samples. Comparison of IHC and gene expression read out by TargetPrint showed a concordance of 95% for ER; 83% for PR and 94% for HER2. In this study, 3% of all IHC ER positive samples were classified negative by microarray, and 11% of IHC PR positive samples were classified negative by microarray. For HER2, 4% of IHC/FISH HER2 positive samples were classified negative by microarray and 2% of IHC/FISH HER2 negative samples were classified positive by microarray. Most notably, all available 5 ER IHC negative/TargetPrint positive samples turned out to be positive with central re-assessment. HER2 IHC2+ samples with discordant classifications for TargetPrint and local assessment are currently being reviewed for FISH/SISH assessment. Conclusions: Microarray based readout of ER, PR and HER2 status using TargetPrint is fairly comparable to local IHC and FISH analysis in 827 analyzed samples in various hospitals worldwide. However, re-assessment of discordant cases –especially IHC ER-/TargetPrint ER+ cases- confirms TargetPrint to be a useful high quality second opinion for local IHC/FISH assessment.

P5-11-09: High Concordance for Microarray Based Determination of ER, PR and HER2 Receptor Status and Local IHC/FISH Assessment Worldwide in 749 Patients

Background The level of estrogen receptor (ER), progesterone receptor (PR) and HER2 expression is predictive for prognosis and/or treatment response in breast cancer patients. However, differences in fixation and IHC and subjective interpretation can substantially affect the accuracy and reproducibility of the results. The commercially available TargetPrint test measures the mRNA expression level of ER, PR and HER2 and provides high quality second opinion for local IHC/FISH assessment. This study compares results from the microarray-based TargetPrint with IHC and FISH (for HER2 IHC2+) generated by local standard procedures.

Methods Prospective tumor samples were collected for 749 patients diagnosed with breast cancer stage I to IV between February 2008 and January 2011. The mRNA level of ER, PR and HER2 (TargetPrint) was assessed in the Agendia laboratories (Agendia Inc, Irvine, CA; Agendia BV, Amsterdam, the Netherlands) in fresh tumor samples submitted from 22 hospitals from Europe, New Zealand, Japan and US. The results of the IHC/FISH assessments performed according to the local standards at the hospitals were compared to the quantitative gene expression readouts.

Results Of the 749 samples, IHC assessment was unknown for 5 ER samples and 4 PR samples; FISH was unknown for 24 samples. TargetPrint read out was not assessed for HER2 for 11 samples.

Median age of these patients was 61 years. Comparison of IHC and gene expression read out by TargetPrint showed a concordance of 95% for ER; 82% for PR and 91% for HER2.

In this study, only 4% of all IHC ER positive samples were classified negative by microarray. In contrast, 14% of IHC ER negative samples were classified positive by microarray. However for HER2, 28% of IHC/FISH HER2 positive samples were classified negative by microarray and 5% of IHC/FISH HER2 negative samples were classified positive by microarray.

Samples with discordant classifications for TargetPrint and local assessment are being reviewed in greater detail by a central pathologist.

Conclusions Microarray based readout of ER, PR and HER2 status using TargetPrint is highly comparable to local IHC and FISH analysis in 749 analyzed samples in various hospitals worldwide. The results indicate mRNA expression read out for ER, PR and HER2 by TargetPrint provides high quality second opinion for local IHC/FISH assessment.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-11-09.

[Subareolar injection for sentinel lymph node biopsy in multiple breast cancer]

In this study we performed subdermal injection of 99mTc-labeled albumin combined with subareolar (SA) injection of blue dye to axillary lymphatic mapping and sentinel lymph node biopsy (SNLB) in patients with multifocal and multicentric breast cancer (MC) to evaluate the feasibility and accuracy of this technique. We compared the results with a group of patients with unifocal breast cancer. From January 1999 to March 2006 axillary lymph node mapping and SLNB was performed on 250 patients followed by a complete axillary lymph node dissection. Retrospective analysis showed that 32 (12.8%) of these patients have MC on final histopathologic examination and 218 (87.2%) have unifocal cancer. In statistical analysis tumor size shows a significant difference (p=.01) with largest lesions in MC. In MC often histological type is invasive lobular with or without in situ cancer (p= .001). Metastatic lymph node involvement was significantly higher in the MC group compared to unifocal cancer group (p=.001). False negative (FN) rate was 5.8% in MC and 9.6% in unifocal cancers. The overall accuracy of lymphatic mapping was 96.8% in MC and 97.6% in unifocal cancers. Sensitivity was 94.4% in MC and 91.2% in unifocal cancers. In this study we provide further evidence that lymphatic mapping may be reliable even in patients with MC. SA injection technique demonstrates a high sentinel lymph node identification rate and low FN rate; therefore this technique should been recommended to SLNB in patients with MC of the breast.

Airways humidification during mechanical ventilation. Effects on tracheobronchial ciliated cells morphology

AIM

Airways humidification during mechanical ventilation (MV) can be performed by means of heat and moisture exchangers (HME). Good performance of selected hygroscopic HME was shown in terms of tracheal temperature and humidity control and low tube obstruction rates. However, few data are available on their effects on tracheobronchial ciliated cells. The purpose of this study was to evaluate the effects of 2 different HME on ciliated cell during MV.

METHODS

Twenty consecutive patients undergoing elective surgery lasting <4 h were randomly assigned to be treated with Rusch (Group 1) or Mediflux (Group 2) hygroscopic HME. The morphology of tracheobronchial ciliated cells was evaluated from cytologic smears of endotracheal aspirate. Smears were prepared by using the thin-prep processor, stained using the Papanicolau method and examined in triplicate: recognizable respiratory cells were graded on a six-point scale, according to the normal appearance of cilia, cytoplasm and nucleus.

RESULTS

In Group 1, 178.3+37 cells were retrieved from aspirates and , 155.6+58 in Group 2 (NS). The score was 739+241 in Group 1 and 617+329 in Group 2 (NS). Cilia and end plate were undamaged in 80+17% and 81+20% cells respectively in Group 1 and in 56+23% and 62+22% cells respectively in Group 2 (P<0.01 and <0.05).

CONCLUSIONS

During MV epithelial tracheobronchial cells can be affected by the humidification device used. Our findings suggest that the 2 HME tested in the present study have a different impact on ciliated cells structure.

Oral squamous cell carcinoma during long-term treatment with hydroxyurea

Hydroxyurea (HU) is commonly used for the treatment of chronic myelogenous leukaemia, polycythemia vera and essential thrombocythaemia. Patients receiving HU present a number of side-effects including skin/mucosa changes and tumours. Mucocutaneous abnormalities include xerosis, ichthyosiform lesions, dark brown pigmentation of skin folds and nails, malleolar ulcers, oral mucositis and oral ulcers. Cutaneous squamous/basal cell carcinomas have also often been reported following long-term administration of HU. HU-induced carcinogenesis is due to both the mutagenic potential of this agent and to an impairment of DNA repair mechanisms after damage by external factors such as ultraviolet radiation. Oral cancer following long-term treatment with HU has been reported only once, in a patient with concomitant multiple skin tumours. We present the unique case of a patient with polycythemia vera who developed oral cancer after 15 years of HU therapy.

Silica-induced caspase activation in mouse alveolar macrophages is dependent upon mitochondrial integrity and aspartic proteolysis

Although silica has been documented to cause apoptotic cell death, the cellular pathways leading to caspase activation have not been extensively investigated. Here we demonstrate in a mouse macrophage cell line (MH-S cells) that alpha-quartz silica exposure (12.5 mug/cm2 to 50 mug/cm2) elicited activation of both caspase 3 and caspase 9, whereas anatase titanium dioxide (TiO2), a non-fibrogenic particle, did not. Silica exposure in vitro also induced apoptosis after 6 h, as measured by the appearance of subdiploid cell fragments in a flow cytometric analysis. Exposure to TiO 2 did not elicit significant apoptosis. Silica-induced apoptosis and caspase 3 activation were, in part, caspase 9 dependent, as determined by their sensitivity to either a general caspase inhibitor (Z-VAD-FMK) or a specific caspase 9 inhibitor (Z-LEHD-FMK). Silica exposure in vitro also elicited significant mitochondrial depolarization after 2 and 6 h of exposure. Cyclosporin A, an inhibitor of the mitochondrial permeability pore, partially decreased mitochondrial depolarization, caspase 3 activation, and caspase 9 activation, suggesting a role for mitochondrial dysfunction in these events. Pepstatin A, an inhibitor of cathepsin D, also decreased mitochondrial depolarization, caspase 3 activation, and caspase 9 activation, whereas leupeptin, an inhibitor of cathepsin B, had no effect. These data suggest that short-term silica exposure in vitro induces both caspase 3 and caspase 9 activity, which appears to participate in apoptosis. Activation of these caspases seems to be dependent, in part, on aspartic proteolysis and loss of mitochondrial integrity.

Pure ductal carcinoma in situ and in situ component of ductal invasive carcinoma of the breast. A preliminary morphometric study

Nuclear pleomorphism is a fundamental feature in evaluating the aggressiveness of ductal carcinoma in situ (DCIS) of the breast. In this study, pure DCIS and the in situ component (IS-comp) of invasive duct carcinoma (IDC) are compared in order to verify if these are two different entities or the same process observed at different times during its evolution. Five cases of pure DCIS and nine of IDC with extensive in situ component were selected. They were moderately and poorly differentiated. 30 nuclei for each DCIS, and 30 nuclei for both the in situ and invasive component of each IDC were studied; thus, a total of 720 nuclei were submitted to the SAM (Shape Analytical Morphometry) analysis, which enables a numerical expression not only of dimensions (area, perimeter, diameter) but also of nuclear contour irregularities and nuclear shape distortions. Univariate statistical comparisons were carried out between the nuclei of: (1) DCIS and in situ component of invasive duct carcinoma, (2) DCIS and the invasive component of infiltrating carcinoma and (3) between the in situ and invasive component of infiltrating carcinoma. Multivariate analysis was utilized to compare nuclei of DCIS with the in situ component of IDC. The in situ features of each tumor were also evaluated with the mitotic index (MI). Nuclei of pure DCIS resulted significantly larger (p < 0.001) and with a more regular shape (p < 0.001) than those of the in situ component of IDC. No differences were observed between the nuclei of the in situ and the invasive component of infiltrating carcinomas. Multivariate statistical analysis discriminated 77% of nuclei of in situ proliferation when both G2 and G3 tumors were considered, and 80% when only G3 tumors were considered. In conclusions morphological differences exist between pure DCIS and the in situ component of IDC, which may be an expression of their biological behavior; moreover, these morphological differences seem to have a better discriminating power within the same histological grade.

Interspecific hybridization induced amplification of Mdm2 on double minutes in a Mus hybrid

We report a case of interspecific hybridization induced amplification of Chromosome 10 on double minutes (dm) in the karyotype of a hybrid Mus embryo. Stable, non-mosaic dm were previously found in tissues of a 16.5-day Mus Musculus x Mus Caroli hybrid (Graves, 1984). Dm in tissues of the hybrid was of interest to us because of previous reports of genomic instability in interspecific hybrids (O'Neill et al., 1998) and thus we decided to characterize the dm in the hybrid karyotypes. Whole chromosome painting of the hybrid cell lines showed amplification of Chromosome 10 sequences. Southern analysis with a probe for the candidate gene Mdm2 showed amplification of the paternal allele of this oncogene. Overexpression of Mdm2 was confirmed by a western analysis that also showed an associated inactivation of the tumor suppressor, Trp53. Evidence indicates that the event leading to the instability observed was an early adaptive response to stress on the genome, i.e. interspecific hybridization.

[The Ljubljana classification of epithelial hyperplastic laryngeal lesions: a morphometric evaluation of nuclear pleomorphism]

Epithelial hyperplastic laryngeal lesions (EHLL) are associated, with a varying degree of "epithelial risk"- to develop invasive carcinoma. Several classifications have been proposed but none has received a total agreement. The 1999 Ljubljana classification distinguished four grades: simple, abnormal and atypical hyperplasia and in situ carcinoma (ISC). The first two grades are considered benign lesions; the ISC is the malignant lesion, while the atypical hyperplasia is considered a "risky lesion". This is characterized by alterations of epithelial cells towards malignancy, but not to the extent to be found in carcinoma cells. Such characteristics refer to cytomorphological (e.g., nuclear hyperchromatism, nucleoli, increased nuclear/cytoplasmic ratio) and architectural (e.g. stratification, orientation, maturation) features. In the Ljubljana scheme, nuclear pleomorphism is one of the most important features. We wanted to improve the importance of nuclear pleomorphism in the basal cells layer in different classes of EHLL using morphometrical analysis. We studied 8 cases of simple hyperplasia, 10 of abnormal hyperplasia, 10 of atypical hyperplasia and 8 of ISC using the software SAM (Shape Analytical Morphometry). The results were submitted to univariate statistical analysis. Nuclear dimensions (maximum diameter, perimeter and area) showed a progressive increase from simple to atypical hyperplasias to ISC, while abnormal hyperplasia showed the lowest values. On the contrary, analytical parameters related to nuclear contour irregularities and asymmetries showed their highest values in abnormal hyperplasia nuclei. There were no significant differences between atypical hyperplasia and ISC, while it was possible to differentiate abnormal hyperplasia from the others. In conclusion basal nuclei of atypical hyperplasia and ISC are similar so that other cytological and morphological architectural parameters are necessary to distinguish the two lesions. Abnormal hyperplasia seems to be the biological category of 'proliferative " benign laryngeal epithelium; simple hyperplasia refers to "stable" - irritative epithelium.

Quantitative morphometrical investigation of basal cell layer in laryngeal premalignant lesions

Histological diagnosis of laryngeal dysplasia is quite subjective. Since morphometry is highly reproducible, this method was applied to compare shape and size variations of the basal nuclei of the laryngeal epithelium in normal, laryngeal intraepithelium neoplasia (LIN) and invasive carcinoma to assess the reliability of light microscopic criteria used in grading dysplasia according to Friedman classification. Morphometrical analysis was carried out by Shape Analytical Morphometry (S.A.M) system. The logical architecture assumes that each irregular shape contains elements of two distinct logical domains: gross distortions that interest the contour and its local perturbations. These features were investigated separately by analytical procedures to acquire independent parameters both on the logical level and the numerical one. The nuclear area significantly increased from normal to carcinoma (p<.001). The increasing of the nuclear area was evident also in LIN I. Nuclear distortions were present in LIN II and LIN III. The highest nuclear contour irregularities were found in LIN III. Multivariate analysis showed a difficulty in discriminating various grades of dysplasia, especially between LIN I and LIN II (31% of error). In conclusion, our results indicate that nuclear pleomorphism of the basal cells layer, using a unique evaluator, is an unsatisfying criterion to distinguish moderate dysplasia.

Sentinel lymph node biopsy for sparing axillary dissection in selected patients with breast cancer

Axillary lymph nodal status in breast cancer remains one of the more important prognostic factors. In early breast cancer axillary lymph node metastasis are found only in 10-18%. It can be deduced that in all these patients a complete axillary dissection is an overtreatment. The concept of sentinel lymph node (SN) was applied to breast cancer. Of course if SN examination gives negative findings, the patient will avoid axillary lymphadenectomy. 134 patients with localized breast cancer were evaluated for enrollment into the study. In 40 (29.8%) patients lymphoscintigraphy was performed together with an injection of vital dye to identify the SN, in 94 (70.1%) only vital dye was utilized. The mapping procedure was successful in 129 cases (96.2%). In our study there was concordance between SNs and axillary nodes in 120 out off 124 cases (96.7%). The false-negative rate was 4.8% (4/83). The overall sensitivity of the SN biopsy was 91.1% (41/45), with a negative predictive value of 95.1% (79/83). Five patients had SN negative and they decided do not undergo axillary lymphadenectomy. This study demonstrates that accurate SN identification was obtained combining lymphoscintigraphy and blue dye. Moreover, each method requires a suitable learning curve. After an accurate training, complete axillary lymphadenectomy can be avoided in selected patients.

[The stereotaxic core breast biopsy using the Mammotome: an alternative to intraoperative examination]

The aim of this work was to evaluate the accuracy of vacuum-assisted biopsy by comparing it with frozen biopsy. 141 stereotaxic biopsies were performed by Mammotome (Ethicon Endo-Surgery, Hamburg) from January 2000 to March 2001. Biopsies were performed for microcalcifications (n = 105, 74.5%), irregular opacities (n = 20, 14.2%), regular opacities (n = 6, 4.2%), stellate lesions (n = 10, 7.1%). Histological analysis showed 85 (60.3%) benign lesions, 46 (32.6%) malignant lesions including (21 cases of carcinoma in situ and 25 invasive carcinomas) and 10 (7.1%) atypical lesions. All malignant lesions were subjected to surgery. In three cases (1 in situ and 2 invasive), core biopsy was excisional and no residual lesion was observed. Two of the carcinomas in situ revealed invasive features on the surgical biopsy. One of the atypical lesions was underestimated and the final diagnosis was "well differentiated carcinoma in situ." Only three of benign lesions underwent surgery after Mammotome biopsy. Among the 55 frozen-section biopsies of mammographically detected breast lesions performed in the same period, were one false-positive and 3 false-negative cases, while in 4 cases the diagnosis was deferred after paraffin embedding. Our results confirmed Mammotome biopsy as an effective alternative and a more reliable method than frozen-section examination.

Malignant fibrous histiocytoma arising on chronic osteomyelitis

We present a case of a primary malignant fibrous histiocytoma of the skin (MFH) arising on chronic osteomyelitis in a 67-year-old woman. Although this condition seems to be a predisposing factor for the onset of the malignancy, MFH complicating chronic osteomyelitis is generally localized at the level of the bone tissue. In the case we report the neoplasm was primitively localized at the dermal and subcutaneous level and presented as a rapidly growing mass.

Malignant deciduoid mesothelioma of the pleura: report of two cases with long survival

AIMS

To present two rare cases of malignant mesotheliomas with deciduoid features arising in the pleura, both with long survival.

METHODS AND RESULTS

These two cases of deciduoid mesotheliomas were observed in adult patients (one 73-year-old male and one 23-year-old female). Only the male had a history of occupational asbestos exposure, whereas the woman had a history of familial mesothelioma. A deciduoid morphology was predominant and focal areas with tubular-papillary features were noted. The tumour cells were positive for cytokeratins, HMBE-1, calretinin, EMA and mitochondrion antibodies. The follow-up data did not suggest a particularly poor prognosis; the mean survival observed was 23 months (17 and 39 months, respectively).

CONCLUSIONS

This deciduoid mesothelioma histological subtype does not appear to represent an unfavourable prognostic category.

Initial experience with sentinel lymph node mapping and biopsy in breast cancer. Preliminary results on 80 consecutive patients

Sentinel node biopsy, in breast cancer, is a promising surgical technique for predicting histological findings in the remaining axillary lymph nodes, especially in patients with clinically node-negative breast cancer. 80 patients with breast cancer were evaluated for enrollment in this study. For mapping procedure 32 patients underwent lymphoscintigraphy in combination with an injection of vital blue dye, while 48 utilized only vital dye. In all patients, after sentinel node (SLN) biopsy, a complete axillary dissection was performed. The mapping procedure was possible in 79 cases (98.7%). The SLNs were positive in 27 (34.1%), in 52 patients SLNs were negative and in 50 of these all axillary nodes were negative. There was concordance in 77/79 cases (97.4%). The false negative rate was 3.8% (2/52). The overall sensitivity of the SNL biopsy was 93.1% (27/29), with a negative predictive value of 96.1% (50/52). This study demonstrates that accurate SLN identification was obtained combining lymphoscintigraphy and blue dye. Moreover, each method requires a suitable learning curve. Further studies are needed to define an accurate patient selection and the most speedy and precise method for intraoperative histological examination of SLNs.

Butyrate suppression of colonocyte NF-kappa B activation and cellular proteasome activity

Butyrate is derived from the microbial metabolism of dietary fiber in the colon where it plays an important role in linking colonocyte turnover and differentiation to luminal content. In addition, butyrate appears to have both anti-inflammatory and cancer chemopreventive activities. Using confocal microscopy and cell fractionation studies, butyrate pretreatment of a human colon cell line (HT-29 cells) inhibited the tumor necrosis factor-alpha (TNF-alpha)-induced nuclear translocation of the proinflammatory transcription factor NF-kappaB. Butyrate inhibited NF-kappaB DNA binding within 30 min of TNF-alpha stimulation, consistent with an inhibition of nuclear translocation. IkappaB.NF-kappaB complexes extracted from butyrate-treated cells were relatively resistant to in vitro dissociation by deoxycholate, suggesting a change in cellular IkappaB composition. Butyrate treatment increased p100 expression, an IkappaB that was not degraded upon TNF-alpha treatment. Butyrate also reduced the extent of TNF-alpha-induced IkappaB-alpha degradation and enhanced the presence of ubiquitin-conjugated IkappaB-alpha. The suppression of IkappaB-alpha degradation corresponded with a reduction in cellular proteasome activity as determined by in vitro proteasome assays and the increased presence of ubiquitin-conjugated proteins. The butyrate suppression of IkappaB-alpha degradation and proteasome activity may derive from its ability to inhibit histone deacetylases since the specific deacetylase inhibitor trichostatin A had similar effects. These results suggest a potential mechanism for the anti-inflammatory activity of butyrate and demonstrate the interplay between short chain fatty acids and cellular proteasome activity.

Cellular and molecular mechanisms regulating silica-induced adhesion molecule expression in mice

Exposure of mice to silica particles generates an intense inflammatory response characterized by the influx of neutrophils and monocytes into the alveoli with resulting cell activation. These cell trafficking and effector functions are, in part, mediated by different families of adhesion molecules. One such adhesion protein, intercellular adhesion molecule-1 (ICAM-1), is expressed on a variety of cells including vascular endothelial cells, fibroblasts, types I and II alveolar epithelial cells, some lymphocytes, and monocytes/macrophages. Over the last several years, our laboratory has focused on silica-induced ICAM-1 expression in exposed mice (in vivo) and cells (in vitro) by examining the role and regulation of this adhesion protein on pulmonary cells. We have determined that intratracheal exposure of mice to silica (2 mg per mouse) elicits increased expression of ICAM-1 on pulmonary macrophages and type II epithelial cells within the lung parenchyma, on bronchoalveolar lavage macrophages, and as a soluble protein in lavage fluid. We hypothesize that increased ICAM-1 expression mayparticipate in silica-induced neutrophil influx into the alveoli, as well as in macrophage-derived phlogistic signals responsible for migration of neutrophils. ICAM-1 expression on silica-exposed mouse macrophages is enhanced by reactive oxygen species (ROS) and tumor necrosis factor-alpha (TNF-alpha) and appears to be regulated through specific sequence elements within the ICAM-1 promoter.

Morphometric discrimination between syndromic (Gorlin) and nonsyndromic keratocysts

OBJECTIVE

To search for morphologic nuclear features in the epithelial lining of odontogenic keratocysts to differentiate simple from Gorlin syndrome cysts.

STUDY DESIGN

Five cases of syndrome-associated keratocysts and five of simple ones were studied. Thirty nuclei from the epithelial basal layer for each case were analyzed by the shape analytical morphometry (SAM) software system to quantitatively evaluate nuclear dimensions (area, perimeter, diameter), contour irregularities and nuclear shape asymmetries. Results were subjected to Student's t test and cluster analysis.

RESULTS

Values of nuclear dimensions were very close in both groups of keratocysts, without any significant statistical differences. The variables related to nuclear profile irregularities, as well as those describing nuclear asymmetry, showed significantly higher values (P < .001) in syndromic cysts. Cluster analysis produced two different clusters by using variables related to nuclear contour irregularities.

CONCLUSION

Preliminary results indicate the existence of nuclear morphologic differences between simple and syndromic cysts.

[Polycystic mesothelioma of the peritoneum. Description of 4 cases]

Cystic mesothelioma is a rare tumor of the peritoneal cavity arising from mesothelial cells. About 130 cases have been reported in the literature. The tumor is more frequent (85%) in adult women and rarely occurs in children. It is benign but recurrences are often described. The differential diagnosis with adenomatoid tumors, lymphangiomas, cystic malignant mesotheliomas and metastatic serous cystic tumors of the ovary is supported by immunohistochemistry. We describe four cases of cystic mesothelioma of the peritoneum; two of the cases occurred in pregnant women, one in a 45-year-old man and one in a 5-year-old boy. Asbestos exposure was not documented. The mesothelial origin of the neoplasms was supported by immunohistochemical analysis. Furthermore, tests for simian virus 40 (SV40 T antigen), to determine whether this virus was also present in the lesions, were negative.

Aberrant transforming growth factor-beta signaling in azoxymethane-induced mouse colon tumors

Alterations in the transforming growth factor-beta (TGF-beta) pathway are implicated in the pathogenesis of colorectal cancer. We hypothesize that alterations in the TGF-beta pathway contribute to differential sensitivity of mice to the colon carcinogen azoxymethane (AOM). A/J (sensitive) and AKR/J (resistant) mice were injected intraperitoneally with AOM (10 mg/kg of body weight once a week for 6 wk). Twenty-four weeks after AOM exposure, mutational analysis of TGF-beta type II receptor (TbetaR-II) from normal colons and from tumors showed no AOM-induced alterations. A significant decrease (1.5-fold, P < 0.05) in TbetaR-II mRNA levels, however, was found in A/J tumors with the RNase protection assay. Immunofluorescence of TbetaR-II showed marked loss of staining in A/J tumors. The RNase protection assay and sequence analysis of the downstream signaling molecule Smad3 revealed no carcinogen-induced alterations in either strain. To gain further insight into the functionality of the pathway, expression of TGF-beta, TGF-beta type I receptor (TbetaR-I), and several downstream targets of TGF-beta signaling, including Smad7, c-myc, and p15, was examined. Although no alterations in TGF-beta, TbetaR-I, or Smad7 were found in tumors, a significant increase in c-myc expression (2.5-fold, P < 0.05 ) and a significant decrease in p15 expression (4.5-fold, P < 0.05 ) were noted. Concomitant repression of TbetaR-II and overexpression of c-myc may render epithelial cells insensitive to TGF-beta-mediated growth arrest, a possibility that also is suggested by this model. The significant decrease in p15 expression in tumors provides additional evidence that TGF-beta signaling may be markedly attenuated during colon tumorigenesis.

Cytokine-induced stabilization of newly synthesized I(kappa)B-alpha

NF-kappaB activation is triggered by the degradation of inhibitory proteins, such as I(kappa)B-alpha. I(kappa)B-alpha levels are only transiently lowered since one gene activated by NF-kappaB is I(kappa)B-alpha. We found that I(kappa)B-alpha was replenished rapidly in a human colon cell line (HT-29), even in the presence of degradation-inducing phosphorylation (at serine-32). This finding lead us to hypothesize that posttranscriptional mechanisms were also in place to facilitate I(kappa)B-alpha replenishment. Expression of I(kappa)B-alpha from the constitutive, non-NF-kappaB regulated cytomegalovirus promoter in HT-29 cells showed that TNF-alpha or IL-1beta treatment increased I(kappa)B-alpha levels in the absence of transcriptional activation. The TNF-alpha-induced increase in transgenic I(kappa)B-alpha appeared to result from the stabilization of newly synthesized I(kappa)B-alpha, since this increase was effectively preempted by a proteasome inhibitor (MG132) or by I(kappa)B-alpha stabilization through the deletion C-terminal destabilizing elements (without additive or synergistic effects). Analysis of a hepatoma cell line (Hepa 1-4C7) indicated that the I(kappa)B-alpha stabilization may be constitutive in these cells. NF-kappaB stimuli therefore appear to trigger negative feedback pathways in some cells that terminate a NF-kappaB response by increasing the stability of newly synthesized I(kappa)B-alpha.

Prognostic factors in breast cancer: the predictive value of the Nottingham Prognostic Index in patients with a long-term follow-up that were treated in a single institution

The Nottingham Prognostic Index (NPI) is an index, derived from a retrospective multivariate study, that is able to predict survival in patients with breast cancer. The index is based on tumour size, lymph node stage and histological grade and allows the stratification of patients into three different prognostic groups. The aim of this study was to verify, according to our experience with a long-term follow-up, the effect of some prognostic variables on survival and to establish the independent influence of each of them by means of a survival regression analysis. Then we applied the NPI to the same group of patients in order to assess the predictive power and reproducibility of the index. 402 patients treated from January 1979 to December 1987 were evaluated. In multivariate analysis (Cox proportional hazard model), only size, lymph node involvement and histological grade remained independent prognostic factors. The survival curves obtained after applying the NPI are similar to those for the factors with independent prognostic significance derived from our multivariate analysis. Our improved survival rates may be attributed to the administration of adjuvant therapies to a larger number of patients. The NPI allow us to accurately predict prognosis and we advocate its more common use.

NF-kappaB is involved in the survival of cerebellar granule neurons: association of IkappaBbeta [correction of Ikappabeta] phosphorylation with cell survival

The NF-kappaB transcription factor consists of dimeric complexes belonging to the Rel family, which include p50, p52, p65 (RelA), RelB and c-Rel. NF-kappaB activity is tightly controlled by IkappaB proteins which bind to NF-kappaB preventing its translocation to the nucleus. Activation of NF-kappaB is most often mediated by IkappaB degradation, which permits NF-kappaB to enter the nucleus. We investigated the role of NF-kappaB in the survival of cerebellar granule neurons. We found that survival of these neurons in high potassium medium is blocked by three separate inhibitors of NF-kappaB activity: SN-50, N-tosyl-L-phenylalanine chloromethyl ketone and pyrrolidinedithiocarbamate, indicating that NF-kappaB is required for neuronal survival. Gel-shift assays reveal three complexes that bind to the NF-kappaB binding site in high potassium medium. Switching these cultures to low potassium medium, a stimulus that leads to apoptotic death, causes a reduction in the level of the largest complex, which contains p65. Overexpression of p65 by transfection inhibits low potassium-induced apoptosis, whereas overexpression of IkappaBalpha promotes apoptosis even in high potassium medium. Surprisingly, however, neither the level of endogenous p65 nor that of IkappaBalpha and IkappaBbeta is altered by low potassium treatment. Similarly, no changes are seen in the nuclear or cytoplasmic levels of p50, p52, RelB and c-Rel. Phosphorylation of p65, which can lead to its activation, is unchanged. Phosphorylation of IkappaBbeta is, however, reduced by low potassium treatment. Besides being necessary for high potassium-mediated neuronal survival, NF-kappaB is also involved in the survival-promoting effects of IGF-1 and cAMP as judged by the ability of SN-50 to inhibit the actions of these survival factors and the ability of these factors to inhibit the low potassium-induced alterations in the DNA-binding activity of NF-kappaB. Taken together, our results show that NF-kappaB may represent a point of convergence in the signaling pathways activated by different survival factors and that uncommon mechanisms might be involved in NF-kappaB-mediated survival of cerebellar granule neurons.

Transcription factor NF-kappaB participates in regulation of epithelial cell turnover in the colon

The transcription factor nuclear factor (NF)-kappaB regulates the expression of genes that can influence cell proliferation and death. Here we analyze the contribution of NF-kappaB to the regulation of epithelial cell turnover in the colon. Immunohistochemical, immunoblot, and DNA binding analyses indicate that NF-kappaB complexes change as colonocytes mature: p65-p50 complexes predominate in proliferating epithelial cells of the colon, whereas the p50-p50 dimer is prevalent in mature epithelial cells. NF-kappaB1 (p50) knockout mice were used to study the role of NF-kappaB in regulating epithelial cell turnover. Knockout animals lacked detectable NF-kappaB DNA binding activity in isolated epithelial cells and had significantly longer crypts with a more extensive proliferative zone than their wild-type counterparts (as determined by proliferating cell nuclear antigen staining and in vivo bromodeoxyuridine labeling). Gene expression profiling reveals that the NF-kappaB1 knockout mice express the potentially growth-enhancing tumor necrosis factor (TNF)-alpha and nerve growth factor-alpha genes at elevated levels, with in situ hybridization localizing some of the TNF-alpha expression to epithelial cells. TNF-alpha is NF-kappaB regulated, and its upregulation in NF-kappaB1 knockouts may result from an alleviation of p50-p50 repression. NF-kappaB complexes may therefore influence cell proliferation in the colon through their ability to selectively activate and/or repress gene expression.

NF-kappa B regulates transcription of the mouse telomerase catalytic subunit

Expression of the telomerase catalytic subunit (TERT) is the rate-limiting determinant of telomerase activity in most cells. Analysis of the mouse TERT promoter revealed a potential NF-kappaB binding site 350 base pairs upstream from the translational start site. An oligonucleotide from this region of the TERT promoter bound to proteins in a nuclear extract prepared from a mouse hepatoma cell line. These proteins were identified as NF-kappaB by a number of criteria: 1) the protein complex formed on the TERT oligonucleotide had an electrophoretic mobility similar to that formed on an NF-kappaB consensus oligonucleotide; 2) protein binding to this site was enhanced by NF-kappaB activators tumor necrosis factor-alpha, phorbol 12-myristate 13-acetate, and interleukin-1beta; and 3) the complex was specific and could be supershifted with antibodies against the p50 or p65 NF-kappaB subunits. The NF-kappaB binding site from the mouse TERT promoter activated transcription when fused to a basal SV40 promoter and enhanced the activity of the native TERT promoter in mouse hepatoma cells stimulated with phorbol 12-myristate 13-acetate. Transcriptional activation by the TERT NF-kappaB site could also be enhanced by co-transfection with an NF-kappaB1 expression vector. NF-kappaB may therefore contribute to the activation of TERT expression observed in mouse tissue.

IkappaBbeta-related proteins in normal and transformed colonic epithelial cells

The transcription factor nuclear factor-kappaB (NF-kappaB) regulates genes that can influence cell proliferation, apoptosis, and inflammatory responses. Since these events can contribute to carcinogenesis, we examined the expression of NF-kappaB inhibitory proteins (IkappaBs) in normal and transformed colonic epithelial cells. Immunohistochemical analysis of the mouse colon revealed a high level of IkappaBbeta expression in epithelial cells relative to the rest of the tissue, whereas IkappaBalpha was found primarily in cells of the lamina propria. Mouse colon tumors showed a similar cell-specific staining pattern. Immunoblot analysis of IkappaBbeta from mouse colonocytes and the human HT-29 colon cancer cell line indicated that most of the IkappaBbeta in these cells was similar to the C-terminal-truncated IkappaBbeta2 isoform. Cell fractionation studies were consistent with IkappaBbeta being a major regulator of p65-p50 NF-kappaB complexes in HT-29 cells. Interestingly, two larger proteins specifically recognized by IkappaBbeta antibodies (p106 and p112) were found in HT-29 cells and in colon tissue of carcinogen-exposed mice. The p106 and p112 proteins bound to NF-kappaB, and their levels changed during the transient interleukin-1beta activation of NF-kappaB in HT-29 cells. Evidence was obtained indicating that p106 and p112 are stably ubiquitinated forms of IkappaBbeta. We propose that deficiencies in the proteasomal degradation of IkappaBbeta lead to p106 and p112 accumulation, which in turn alter NF-kappaB regulation in colon cancer cells.

Augmented humoral immune function in metallothionein-null mice

Stress response proteins can play integral roles as modulators of cellular function and can be involved in mechanisms that are important to immune function. Metallothionein (MT), a cysteine-rich stress response protein, has been shown to play numerous roles in the cell: it serves as a reservoir of essential heavy metals, it scavenges free radicals, and it can sequester heavy metals. These various functions suggest that MT may also participate in modulating immune responses. In previous work, we have shown that exogenous metallothionein can suppress the developing humoral immune response when coinjected with antigen. The present study was designed to evaluate the effects of endogenous MT on the development of humoral immunity. We compared the humoral immune function of animals with a targeted disruption of Mt-1 and -2 genes (MTKO) and their wild-type counterparts. MTKO mice displayed a significantly higher humoral response to challenge with ovalbumin (OVA) compared to wild-type controls. The secondary anti-OVA response in MTKO mice is as much as 58% higher than the response in control mice injected at the same time. Overall circulatory immunoglobulin levels are also substantially higher in MTKO mice (0.039 mg/ml IgM and 0.42 mg/ml IgG) than wild-type controls. MTKO mice displayed increased B cell differentiation following OVA challenge and an enhanced lymphoproliferative response to mitogenic stimulation. These changes in immune functional capacity occur in the context of changes in the makeup of the lymphoid compartments of the blood and spleen. There are substantially fewer T and B cells in the circulation of MTKO mice, but more T cells in the spleen of these mice than in control animals. Finally, we have found that splenocytes from MTKO animals displayed significantly elevated levels of NF-kappaB activity compared to wild-type controls. In conclusion, we have provided evidence that endogenous metallothionein can modulate the immune response in vivo and that intracellular MT may modulate immune function by regulation of transcription factor activity.

Real-time quantification of the proliferative state in astrocytomas

OBJECTIVE

To evaluate proliferative activity in a set of gliomas and to compare the quantitative data obtained by a real-time processor with the labelling index (LI) and mitotic index (MI).

STUDY DESIGN

Ki-67 immunostaining was performed on paraffin-embedded specimens from 42 cases of glioblastomas, 17 cases of anaplastic astrocytomas and 14 cases of low grade astrocytomas. Nuclear positivity was calculated as LI and by a real-time image processor for quantitative evaluation. MI was also calculated at 10 high-power fields. The data obtained from glioblastomas were compared with those from anaplastic and low grade astrocytomas. To all the data was applied the Pearson test to verify the correlation between counting and quantitative values and between proliferative markers and survival.

RESULTS

A positive trend from low grade astrocytomas to glioblastomas was found for Ki-67 (LI and quantitative values) and MI, with highly significant differences between the three grades of gliomas considered. A good correlation between LI and quantitative values of Ki-67 was found. Very little relationship resulted between survival and Ki-67 LI. No relationship was found between survival and quantitative values of Ki-67.

CONCLUSION

Ki-67 allowed effective separation of astrocytic tumors with different grades of malignancy. Quantitative evaluation of color information by means of a real-time processor proved to be a useful, objective and fast way to obtain readings, useful for grading purposes but not for prognostic evaluation.

Acetaminophen inhibits NF-kappaB activation by interfering with the oxidant signal in murine Hepa 1-6 cells

A toxic dose of acetaminophen (APAP) reduces the activity of NF-kappaB in mouse liver. NF-kappaB inactivation may be important for APAP toxicity, as this transcription factor can play a central role in maintaining hepatic viability. We recently reported that APAP likewise inhibits serum growth factor activation of NF-kappaB in a mouse hepatoma cell line (Hepa 1-6 cells). Here we present evidence that APAP's antioxidant activity may be involved in this NF-kappaB inhibition in Hepa 1-6 cells. Like the antioxidants N-acetylcysteine (NAC) and pyrrolidinedithiocarbamate (PDTC), APAP was found to suppress the H(2)O(2)-induced oxidation of an intracellular reactive oxygen species probe (dihydrodichlorofluorescein) in Hepa 1-6 cells. Treatment of Hepa 1-6 cells with H(2)O(2) was sufficient for NF-kappaB activation and IkappaBalpha degradation, and APAP was able to block both of these events. The APAP inhibition of NF-kappaB activation by serum growth factors may also be due to APAP's antioxidant activity, as the antioxidants NAC and PDTC likewise inhibit this activation. The potential role of NF-kappaB and oxidant-based growth factor signal transduction in APAP toxicity is discussed.

The luminal short-chain fatty acid butyrate modulates NF-kappaB activity in a human colonic epithelial cell line

BACKGROUND & AIMS

The transcription factor nuclear factor-kappaB (NF-kappaB) plays a central role in regulating immune and inflammatory responses. Because butyrate deficiency has been associated with inflammatory bowel disease, we examined the effect of butyrate on NF-kappaB activity in the human HT-29 colonic cell line.

METHODS

The influence of butyrate (4 mmol/L) on NF-kappaB activity was determined using the gel mobility shift assay. The effect of butyrate on the expression of NF-kappaB subunits and inhibitory proteins was determined by immunoblotting. NF-kappaB-regulated gene expression was assayed by primer extension of intercellular adhesion molecule 1 and Mn superoxide dismutase messenger RNA, and by analysis of a transfected luciferase reporter.

RESULTS

Exposure of HT-29 cells to butyrate eliminated their constitutive NF-kappaB, p50 dimer activity. This inhibition corresponded with a reduction in p50 nuclear localization, without a reduction in expression. Butyrate also selectively modulated activation of NF-kappaB, suppressing its activation by tumor necrosis factor alpha and phorbol ester more than 10-fold, without affecting the activity induced by interleukin (IL)-1beta. Butyrate did, however, enhance formation of the stronger p65-p50 transcriptional activator in IL-1beta-stimulated cells. The changes in NF-kappaB activation did not correlate with changes in IkappaBalpha levels. Gene expression reflected DNA binding. The influence of butyrate on NF-kappaB may result in part from its ability to inhibit deacetylases because the specific deacetylase inhibitor trichostatin A has a similar effect.

CONCLUSIONS

These findings suggest that the influences of butyrate on colonic inflammatory responses may result in part from its influence on NF-kappaB activation. This activity of butyrate apparently involves its ability to inhibit deacetylases.

Regulation of ICAM-1 expression in mouse macrophages

In a mouse model of silica (SI) induced lung injury, SI exposure increases expression of intercellular adhesion molecule-1 (ICAM-1) on lung (alveolar/interstitial) macrophages and alveolar type II epithelial cells. To investigate the regulation of SI induced ICAM-1 expression on mouse macrophages, freshly isolated macrophages (alveolar, peritoneal) and macrophage cell lines (MH-S, RAW 264.7) were evaluated for ICAM-1 expression elicited by the particle silica (alpha quartz; 20 microg/ml; 6 microg/cm2) or the inflammatory cytokine, TNFalpha (20 ng/ml). TNFalpha significantly increased ICAM-1 expression in all cell types whereas SI elicited an increase in peritoneal macrophages (PM) and the cell line, MH-S. This pattern of increased expression was confirmed by immunocytochemistry. To investigate the regulation of ICAM-1 expression, PM were incubated with SI, TNFalpha or media concomitantly with anti-TNFalpha antibody, the antioxidant, NAC, or the iNOS synthase inhibitor, L-NAME. Both anti-TNFalpha and NAC, but not L-NAME, inhibited elicited (TNFalpha, SI) as well as constitutive (media) ICAM-1 expression. These data demonstrate that both inflammatory cytokines and inorganic particles can increase ICAM-1 expression on mouse macrophages and that this expression is mediated, in part, by TNFalpha and reactive oxygen species.

Discrete spin variables and critical temperature in deterministic models with glassy behavior

The problem of the existence of a glassy phase transition in deterministic spin models is reconsidered, examining an Ising model with general spin s and nontranslationally invariant interaction. The discrete nature of the spin variables is shown to allow the glass state.

Finite thermal conductivity in 1D lattices

We discuss the thermal conductivity of a chain of coupled rotators, showing that it is the first example of a 1D nonlinear lattice exhibiting normal transport properties in the absence of an on-site potential. Numerical estimates obtained by simulating a chain in contact with two thermal baths at different temperatures are found to be consistent with those based on linear response theory. The dynamics of the Fourier modes provides direct evidence of energy diffusion. The finiteness of the conductivity is traced back to the occurrence of phase jumps. Our conclusions are confirmed by the analysis of two variants of this model.