Disruption of cortical network activity by the general anaesthetic isoflurane

Background

Actions of general anaesthetics on activity in the cortico-thalamic network likely contribute to loss of consciousness and disconnection from the environment. Previously, we showed that the general anaesthetic isoflurane preferentially suppresses cortically evoked synaptic responses compared with thalamically evoked synaptic responses, but how this differential sensitivity translates into changes in network activity is unclear.

Methods

We investigated isoflurane disruption of spontaneous and stimulus-induced cortical network activity using multichannel recordings in murine auditory thalamo-cortical brain slices.

Results

Under control conditions, afferent stimulation elicited short latency, presumably monosynaptically driven, spiking responses, as well as long latency network bursts that propagated horizontally through the cortex. Isoflurane (0.05-0.6 mM) suppressed spiking activity overall, but had a far greater effect on network bursts than on early spiking responses. At isoflurane concentrations >0.3 mM, network bursts were almost entirely blocked, even with increased stimulation intensity and in response to paired (thalamo-cortical + cortical layer 1) stimulation, while early spiking responses were <50% blocked. Isoflurane increased the threshold for eliciting bursts, decreased their propagation speed and prevented layer 1 afferents from facilitating burst induction by thalamo-cortical afferents.

Conclusions

Disruption of horizontal activity spread and of layer 1 facilitation of thalamo-cortical responses likely contribute to the mechanism by which suppression of cortical feedback connections disrupts sensory awareness under anaesthesia.

Propofol-induced unresponsiveness is associated with impaired feedforward connectivity in cortical hierarchy

BACKGROUND

Impaired consciousness has been associated with impaired cortical signal propagation after transcranial magnetic stimulation (TMS). We hypothesised that the reduced current propagation under propofol-induced unresponsiveness is associated with changes in both feedforward and feedback connectivity across the cortical hierarchy.

METHODS

Eight subjects underwent left occipital TMS coupled with high-density EEG recordings during wakefulness and propofol-induced unconsciousness. Spectral analysis was applied to responses recorded from sensors overlying six hierarchical cortical sources involved in visual processing. Dynamic causal modelling (DCM) of induced time-frequency responses and evoked response potentials were used to investigate propofol's effects on connectivity between regions.

RESULTS

Sensor space analysis demonstrated that propofol reduced both induced and evoked power after TMS in occipital, parietal, and frontal electrodes. Bayesian model selection supported a DCM with hierarchical feedforward and feedback connections. DCM of induced EEG responses revealed that the primary effect of propofol was impaired feedforward responses in cross-frequency theta/alpha-gamma coupling and within frequency theta coupling (F contrast, family-wise error corrected P<0.05). An exploratory analysis (thresholded at uncorrected P<0.001) also suggested that propofol impaired feedforward and feedback beta band coupling. Post hoc analyses showed impairments in all feedforward connections and one feedback connection from parietal to occipital cortex. DCM of the evoked response potential showed impaired feedforward connectivity between left-sided occipital and parietal cortex (T contrast P=0.004, Bonferroni corrected).

CONCLUSIONS

Propofol-induced loss of consciousness is associated with impaired hierarchical feedforward connectivity assessed by EEG after occipital TMS.

Mepacrine Blockade of Arachidonate-lnduced Washed Platelet Aggregation: Relationship to Mepacrine Inhibition of Platelet Cyclooxygenase

Mepacrine, in addition to its established antilipolytic activity, was also found to inhibit the conversion of 14C-arachidonic acid to 14C-thromboxane B2 in human washed platelets. In the concentration range of 3.33-33 μM, mepacrine exerted a dose dependent inhibition of arachidonate conversion to thromboxane B2 in parallel to inhibition of arachidonate-induced platelet aggregation. Mepacrine inhibition of thromboxane formation was not accompanied by a concomitant increase in other cyclooxygenase products. Furthermore, mepacrine did not affect platelet transformation of added prostaglandin H2 to thromboxane A2 and other products. These results indicate that mepacrine inhibits the cyclooxygenase enzyme and not thromboxane synthase. In washed platelets, mepacrine inhibition of arachidonic acid conversion to thromboxane A2 appears to be a major factor in the overall inhibitory effect of the compound on the combined process of arachidonate release from cellular phospholipids and its conversion to proaggregatory products.

Testosterone Potentiation of Ionophore and ADP Induced Platelet Aggregation : Relationship to Arachidonic Acid Metabolism

The role of arachidonic acid oxygenated products in human platelet aggregation induced by the ionophore A23187 was investigated. The ionophore produced an increased release of both saturated and unsaturated fatty acids and a concomitant increased formation of TxA2 and other arachidonate products. TxA2 (and possibly other cyclo oxygenase products) appears to have a significant role in ionophore-induced aggregation only when low concentrations (<1 μM) of the ionophore are employed.

Testosterone added to rat or human platelet-rich plasma (PRP) was shown previously to potentiate platelet aggregation induced by ADP, adrenaline, collagen and arachidonic acid (1, 2). We show that testosterone also potentiates ionophore induced aggregation in washed platelets and in PRP. This potentiation was dose and time dependent and resulted from increased lipolysis and concomitant generation of TxA2 and other prostaglandin products. The testosterone potentiating effect was abolished by preincubation of the platelets with indomethacin.

Morphological and Molecular Characteristic of Megaselia scalaris (Diptera: Phoridae) Larvae as the Cause of Urinary Myiasis

We report a case of urinary myiasis occurring in a 60-yr-old Iranian male patient with urinary tract problems and a history of travel to Thailand who was referred to Shafagh Medical Laboratory in Tehran (Iran). Larvae excreted in the patient's urine were confirmed by morphological identification key and DNA barcoding to belong to the species Megaselia scalaris Loew, which is known as the scuttle fly. Based on the patient's history, he was infected with M. scalaris in Thailand. To the best of our knowledge, this is the first report of urinary myiasis caused by M. scalaris in Thailand.

Inhibition of malignant thyroid carcinoma cell proliferation by Ras and galectin-3 inhibitors

Anaplastic Thyroid carcinoma is an extremely aggressive solid tumor that resists most treatments and is almost always fatal. Galectin-3 (Gal-3) is an important marker for thyroid carcinomas and a scaffold of the K-Ras protein. S-trans, transfarnesylthiosalicylic acid (FTS; Salirasib) is a Ras inhibitor that inhibits the active forms of Ras proteins. Modified citrus pectin (MCP) is a water-soluble citrus-fruit-derived polysaccharide fiber that specifically inhibits Gal-3. The aim of this study was to develop a novel drug combination designed to treat aggressive anaplastic thyroid carcinoma. Combined treatment with FTS and MCP inhibited anaplastic thyroid cells proliferation in vitro by inducing cell cycle arrest and increasing apoptosis rate. Immunoblot analysis revealed a significant decrease in Pan-Ras, K-Ras, Ras-GTP, p-ERK, p53, and Gal-3 expression levels and significant increase in p21 expression levels. In nude mice, treatment with FTS and MCP inhibited tumor growth. Levels of Gal-3, K-Ras-GTP, and p-ERK were significantly decreased. To conclude, our results suggest K-Ras and Gal-3 as potential targets in anaplastic thyroid tumors and herald a novel treatment for highly aggressive anaplastic thyroid carcinoma.

The Anopheles stephensi odorant binding protein 1 (AsteObp1) gene: a new molecular marker for biological forms diagnosis

Anopheles (Cellia) stephensi Liston 1901 is known as an Asian malaria vector. Three biological forms, namely "mysorensis", "intermediate", and "type" have been earlier reported in this species. Nevertheless, the present morphological and molecular information is insufficient to diagnose these forms. During this investigation, An. stephensi biological forms were morphologically identified and sequenced for odorant-binding protein 1 (Obp1) gene. Also, intron I sequences were used to construct phylogenetic trees. Despite nucleotide sequence variation in exon of AsteObp1, nearly 100% identity was observed at the amino acid level among the three biological forms. In order to overcome difficulties in using egg morphology characters, intron I sequences of An. stephensi Obp1 opens new molecular way to the identification of the main Asian malaria vector biological forms. However, multidisciplinary studies are needed to establish the taxonomic status of An. stephensi.

Alpha linolenic acid in maternal diet halts the lipid disarray due to saturated fatty acids in the liver of mice offspring at weaning

Background

Alpha linolenic acid (ALA, 18:3) in maternal diets has been shown to attenuate obesity associated insulin resistance (IR) in adult offspring in mice. The objective in the present study was to detect the early effects of maternal dietary saturated fatty acids (SFA) and their partial substitution with ω-3 ALA, docosa hexenoic acid (DHA,22:6) and eicosapentenoic acid 20:5 (EPA,20:5) on the HOMA index, liver lipids and fatty acid desaturases in the offspring at weaning.

Methods

3 month old C57Bl6/J female mice were fed diets containing normal amount of calories but rich in SFA alone or partially replaced with ALA, DHA or EPA before mating, during pregnancy and lactation.

Results

Pregnant mice fed SFA produced offspring with the highest HOMA index, liver lipids and desaturase activities. ALA prevented SFA induced lipid increase but DHA and EPA only reduced it by 42% and 31% respectively. ALA, DHA and EPA decreased HOMA index by 84%, 75% and 83% respectively. ALA, DHA and EPA decreased Δ6 and SCD1 desaturase activities about 30%.

Conclusions

SFA feeding to mothers predisposes their offspring to develop IR and liver lipid accumulation already at weaning. ω3 fatty acids reduce IR, ALA halts lipid accumulation whereas DHA and EPA only blunt it.ALA and DHA restore the increased SCD1 to normal. These studies suggest that ω-3 fatty acids have different potencies to preclude lipid accumulation in the offspring partially by affecting pathways associated to SCD1 modulation.

The significance of galectin-3 as a new basal cell marker in prostate cancer

Prostate cancer may originate from distinct cell types, resulting in the heterogeneity of this disease. Galectin-3 (Gal-3) and androgen receptor (AR) have been reported to play important roles in the progression of prostate cancer, and their heterogeneous expressions might be associated with different cancer subtypes. Our study found that in various prostate cancer cell lines Gal-3 expression was always opposite to AR expression and other luminal cell markers but consistent with basal cell markers including glutathione S-transferase-π and Bcl-2. This expression pattern was confirmed in human prostate cancer tissues. Our results also showed that prostate cancer cells positive with basal cell markers were more aggressive. Downregulation of Gal-3 expression resulted in increased apoptotic potential and decreased metastasis potential of prostate cancer cells. Our findings demonstrate for the first time that Gal-3 may serve as a new marker for basal characteristics of prostate cancer epithelium. This study helps us to better understand the heterogeneity of prostate cancer. The clinical significance of this study lies in the application of Gal-3 to distinguish prostate cancer subtypes and improve treatment efficacy with designed personalized therapy.

Psychosocial factors and chronic spontaneous urticaria: a systematic review

BACKGROUND

Chronic spontaneous urticaria (CSU) is one of the most costly allergic conditions challenging physicians as well as patients and their families. Despite evident lacunae in the understanding of the pathogenesis, at least some findings suggest that psychosocial factors likely contribute to the development and exacerbation of CSU. We aim to assess the contribution of psychological factors to CSU.

METHODS

Systematic search of PubMed and OVID/Medline databases was conducted from 1 January 1935 to 1 January 2012. Studies selected include original research in English, Spanish and French exploring the association between CSU and psychosocial factors. Two investigators independently reviewed all titles and abstracts to identify potentially relevant articles and resolved discrepancies by repeated review and discussion and arbitration of a third reviewer. Quality of systematic reviews and meta-analyses was assessed using a measure based on the Newcastle-Ottawa Scale and psychological conditions of CSU patients.

RESULTS

We identified 114 eligible studies spanning 77 years and featuring 17 reviews, 67 studies related to neither CSU nor psychosocial factors, and eight studies that provided either no prevalence estimates or insufficient sample size. Pooling effect sizes using random effects, analyses revealed that, despite large heterogeneity (I(2) of 97.60%), psychosocial factors had a prevalence of 46.09% (95% confidence interval, 44.01%, 48.08%).

CONCLUSION

Future research needs to better establish the contribution of psychosocial factors to the pathogenesis and exacerbation of CSU, and explore the possible benefit of behavioural interventions to the development of new management strategies.

Autocrine motility factor and its receptor expressions in human oral squamous cell carcinoma (SCC) cells

Autocrine motility factor (AMF) a tumor-secreted 55 kDa cytokine induces tumor cell motility by a signal transduction pathway mediated by interaction with its receptor (AMFR) a cell surface glycoprotein of 78 kDa (gp78). Here, AMF secreted by the metastatic LMF4 human oral squamous-cell carcinoma (SCC) cells, induced dose- and time-dependent morphological changes and chemotaxis of the producing cells. Expression of AMFR mRNA was associated with the metastatic ability of SCC cell variants. The data presented show for the first time that SCC cells produce AMF and express AMFR and the expression is related to their invasiveness and metastatic potentials.

Induction of tumorigenicity by galectin-3 in a nontumorigenic human breast-carcinoma cell-line

The human galectin-3 is a galactoside-binding protein of 31 kDa which functions as a receptor for glycoproteins containing poly N-acetyllactosamine side chains and as a substrate for matrix metalloproteinases-2 and -9. We studied its expression by flow cytoflourimetry, Western, Northern and Southern analyses, in five cultured human breast carcinoma cell lines previously characterized as nontumorigenic, poorly metastatic or metastatic in nude mice. The expression of galectin-3 correlated with the reported tumorigenicity of the cells. The introduction of recombinant galectin-3 into the null expressing non-tumorigenic BT-549 cells resulted in the acquisition of anchorage-independent growth properties in all and tumorigenicity in 3/4 sense transfected cell clones. The data indicate a relationship between galectin-3 expression and malignancy of human breast carcinoma cell lines.

Calpain activation through galectin-3 inhibition sensitizes prostate cancer cells to cisplatin treatment

Prostate cancer will develop chemoresistance following a period of chemotherapy. This is due, in part, to the acquisition of antiapoptotic properties by the cancer cells and, therefore, development of novel strategies for treatment is of critical need. Here, we attempt to clarify the role of the antiapoptotic molecule galectin-3 in prostate cancer cells using siRNA and antagonist approaches. The data showed that Gal-3 inhibition by siRNA or its antagonist GCS-100/modified citrus pectin (MCP) increased cisplatin-induced apoptosis of PC3 cells. Recent studies have indicated that cisplatin-induced apoptosis may be mediated by calpain, a calcium-dependent protease, as its activation leads to cleavage of androgen receptor into an androgen-independent isoform in prostate cancer cells. Thus, we examined whether calpain activation is associated with the Gal-3 function of regulating apoptosis. Here, we report that Gal-3 inhibition by siRNA or GCS-100/MCP enhances calpain activation, whereas Gal-3 overexpression inhibits it. Inhibition of calpain using its inhibitor and/or siRNA attenuated the proapoptotic effect of Gal-3 inhibition, suggesting that calpain activation may be a novel mechanism for the proapoptotic effect of Gal-3 inhibition. Thus, a paradigm shift for treating prostate cancer is suggested whereby a combination of a non-toxic anti-Gal-3 drug together with a toxic chemotherapeutic agent could serve as a novel therapeutic modality for chemoresistant prostate cancers.

Short stature, celiac disease and growth hormone deficiency

Celiac disease (CD) is a prevalent, genetically determined, autoimmune, chronic inflammatory state caused by intolerance to gluten that results mainly in gastrointestinal manifestations. One of the most common extra-intestinal manifestations of CD is short stature, and in some patients, short stature may be the presenting and only symptom of the disease, making the diagnosis of CD challenging. Impaired growth in children with CD results mainly from nutritional deficits, and withdrawal of gluten from the diet is frequently associated with a marked improvement of linear growth. In some patients, CD may be characterized by growth hormone (GH) resistance, as suggested by normal or elevated GH levels and low insulin-like growth factor-I (IGF-I) levels. Rarely, it has been shown that poor catch-up growth and/or IGF-I response to gluten-free diet may be due to the coexistence of celiac disease and GH deficiency. We present two children with coexisting CD and GH deficiency. One patient had MRI findings suggesting congenital isolated GH deficiency, and a possibility of developing multiple pituitary hormone deficiencies later in life.

Perioperative use of beta-blockers and COX-2 inhibitors may improve immune competence and reduce the risk of tumor metastasis

BACKGROUND

COX inhibitors and beta-blockers were recently suggested to reduce cancer progression through inhibition of tumor proliferation and growth factor secretion, induction of tumor apoptosis, and prevention of cellular immune suppression during the critical perioperative period. Here we evaluated the perioperative impact of clinically applicable drugs from these categories in the context of surgery, studying natural killer (NK) cell activity and resistance to experimental metastases.

METHODS

F344 rats were treated with COX-1 inhibitors (SC560), COX-2 inhibitors (indomethacin, etodolac, or celecoxib), a beta-blocker (propranolol), or a combination of a COX-2 inhibitor and a beta-blocker (etodolac and propranolol). Rats underwent laparotomy, and were inoculated intravenously with syngeneic MADB106 tumor cells for the assessment of lung tumor retention (LTR). Additionally, the impact of these drug regimens on postoperative levels of NK cytotoxicity was studied in peripheral blood and marginating-pulmonary leukocytes.

RESULTS

Surgery increased MADB106 LTR. COX-2 inhibition, but not COX-1 inhibition, reduced postoperative LTR. Etodolac and propranolol both attenuated the deleterious impact of surgery, and their combined use abolished it. Surgery decreased NK cytotoxicity per NK cell in both immune compartments, and only the combination of etodolac and propranolol significantly attenuated these effects. Lastly, the initiation of drug treatment three days prior to surgery yielded the same beneficial effects as a single pre-operative administration, but, as discussed, prolonged treatment may be more advantageous clinically.

CONCLUSIONS

Excess prostaglandin and catecholamine release contributes to postoperative immune-suppression. Treatment combining perioperative COX-2 inhibition and beta-blockade is practical in operated cancer patients, and our study suggests potential immunological and clinical benefits.

A tale of switched functions: from cyclooxygenase inhibition to M-channel modulation in new diphenylamine derivatives

Cyclooxygenase (COX) enzymes are molecular targets of nonsteroidal anti-inflammatory drugs (NSAIDs), the most used medication worldwide. However, the COX enzymes are not the sole molecular targets of NSAIDs. Recently, we showed that two NSAIDs, diclofenac and meclofenamate, also act as openers of Kv7.2/3 K(+) channels underlying the neuronal M-current. Here we designed new derivatives of diphenylamine carboxylate to dissociate the M-channel opener property from COX inhibition. The carboxylate moiety was derivatized into amides or esters and linked to various alkyl and ether chains. Powerful M-channel openers were generated, provided that the diphenylamine moiety and a terminal hydroxyl group are preserved. In transfected CHO cells, they activated recombinant Kv7.2/3 K(+) channels, causing a hyperpolarizing shift of current activation as measured by whole-cell patch-clamp recording. In sensory dorsal root ganglion and hippocampal neurons, the openers hyperpolarized the membrane potential and robustly depressed evoked spike discharges. They also decreased hippocampal glutamate and GABA release by reducing the frequency of spontaneous excitatory and inhibitory post-synaptic currents. In vivo, the openers exhibited anti-convulsant activity, as measured in mice by the maximal electroshock seizure model. Conversion of the carboxylate function into amide abolished COX inhibition but preserved M-channel modulation. Remarkably, the very same template let us generating potent M-channel blockers. Our results reveal a new and crucial determinant of NSAID-mediated COX inhibition. They also provide a structural framework for designing novel M-channel modulators, including openers and blockers.

Adhesive properties of metastasizing tumour cells

Cancer metastasis depends on a functional property which enables tumour cells to depart from the primary site of growth, to disseminate to distant organs and to establish secondary growth. The acquisition of a metastatic phenotype by neoplastic cells most probably involves alterations in their adhesive properties as the migrating cells continuously break and establish cellular contacts throughout the process. In vitro, normal cells of either mesenchymal or epithelial origin usually depend on adhesion to and spreading on a solid substratum (anchoring) for cell division. Neoplastic cells, however, are free of dependence on the support of solid substrata for cell proliferation (anchorage independent). The search for the characteristic alterations in cell adhesion, spreading and morphology which may accompany neoplastic transformation in general and cancer metastasis in particular has engendered a wide range of research activities. These studies have led to the identification of various membrane receptors that mediate cell-cell and cell-extracellular matrix recognition and adhesion on normal and tumour cells. Central to this is the effect of cell adhesion on cell shape and cytoskeleton organization in relation to metastasis. The use of specific antibodies, ligands, drugs and culture conditions permits exploration and identification of some of the macromolecules involved in tumour cell adhesion in vitro and metastasis in vivo. Nevertheless the specificity of the interactions which might determine organ-specific metastasis remains to be elucidated. This paper discusses the interrelation between cell adhesion, cell shape, cytoskeleton and metastasis.

Individual differences and attentional varieties

With its own functional anatomy, circuitry and cellular structure, attention can be viewed as an organ system. This conceptualization reframes many problems in cognitive science and permits important insights into neurological and psychiatric disorders of both children and adults. Specifically, construing attention as an organ system helps to describe the evolutionary and developmental aspects of volitional control, thus paving the road towards a better appreciation of how such factors as genetics and culture influence control systems. The efficiency of the attention networks differs between people. However, these individual differences may elucidate variation in intelligence as well as the ability to regulate affect.

On the role of galectin-3 in cancer apoptosis

Galectin-3, a member of the beta-galactoside-binding gene family, is a multifunctional protein implicated in a variety of biological functions, including tumor cell adhesion, proliferation, differentiation, angiogenesis, cancer progression and metastasis. Recent studies revealed that intracellular galectin-3 exhibits the activity to suppress drug induced apoptosis and anoikis (apoptosis induced by the loss of cell anchorage) that contribute to cell survival. Resistance to apoptosis is essential for cancer cell survival and plays a role in tumor progression. Conversely, it was recently shown that tumor cells' secreted galectin-3 induces T-cells' apoptosis, thus playing a role in the immune escape mechanism during tumor progression through induction of apoptosis of cancer-infiltrating T-cells. This review summarizes recent evidences on the role of galectin-3 as an anti-apoptotic and/or pro-apoptotic factor in various cell types and discusses the recent understanding of the molecular mechanisms of galectin-3 role in apoptosis. We also suggest potential directions for further analyses of this multifunctional protein.

Autocrine motility factor receptor expression implies an unfavourable prognosis in resected stage I pulmonary adenocarcinomas

BACKGROUND

Pulmonary adenocarcinomas constitute a different histological subtype among the histological subtypes of non small cell lung carcinomas by showing comparably unfavourable rates of prognosis and different immunobiological features. Autonomous motility of tumour cells plays an important role in the regulation of local invasion and distant metastasis of tumour lesions which have great impact on overall survival. AMF (Autocrine motility factor) is a tumour secreted cytokine that stimulates motility during invasion and metastasis via its receptor, AMFR. We conducted an immunohistochemical study to investigate AMFR expression in pulmonary adenocarcinomas and its effect on survival.

MATERIAL AND METHODS

We assessed AMFR expression using a monoclonal antibody (3F3A) in a total of 32 surgical specimens with stage I pulmonary adenocarcinomas that underwent curative resection. We analyzed AMFR expression as a possible prognostic factor on survival and its correlations with clinicopathological features.

RESULTS

A total of 19 (59.3%) specimens showed AMFR expression. The 3-year survival rates of AMFR positive and AMFR negative patients were 47.3% and 84.6%, respectively, which was a significant difference (P = 0.0197). The univariate predictors of surgical outcome were AMFR expression (P = 0.032) and perineural invasion (P = 0.038). However, multivariate analysis revealed AMFR expression (P = 0.045) as the only independent prognostic factor.

CONCLUSIONS

AMFR expression predicts an unfavourable surgical outcome in patients with stage I pulmonary adenocarcinomas.

Novel roles of the autocrine motility factor/phosphoglucose isomerase in tumor malignancy

Autocrine motility factor (AMF) stimulates cell motility in an autocrine manner and is related to tumor malignancy. AMF is a multifunctional molecule, also known as phosphoglucose isomerase and neuroleukin. Signal cascades of the AMF-stimulated motility and novel functions of this protein contributing to tumor malignancy have been presented recently. AMF stimulation activated small Rho-like GTPases and subsequently induced actin fiber rearrangement, which was removed by the C3 exoenzyme, a specific inhibitor of Rho. The expression of Jun N-terminal kinase (JNK)1, JNK2 and the Rho GDP dissociation inhibitor-beta was upregulated by AMF. The addition of AMF to culture medium stimulated the motility of the endothelial cells and the formation of tube-like structures in collagen gels. Highly AMF-expressing HT1080 cells induced aggressive angiogenesis in vivo. The expression of fms-like tyrosine kinase (Flt)-1, a vascular endothelial growth factor (VEGF) receptor, was enhanced in AMF-expressing tumors dependent on protein kinase C and phosphatidylinositol 3 kinase (PI3K) activation; meanwhile kinase insert domain-containing receptor, another receptor of VEGF, was not. Permeability of mesothelial and endothelial cell monolayers was increased by AMF, and numerous gaps were observed in the monolayers after treatment with AMF. AMF gene transfection transformed NIH3T3 cells to proliferate quickly and acquire anti-apoptosis ability induced by serum deprivation in a PI3K-dependent manner. The anti-apoptotic effect of AMF has been described by other authors who have shown that the AMF over-expressing cells were resistant to mitomycin-C-induced apoptosis showing regression of Apaf-1 and caspase-9 dependent on PI3K and MAP kinase. These novel functions of AMF makes it a likely target for cancer therapy.

Nutritional-pharmacological combinations--a novel approach to reducing colon cancer incidence

BACKGROUND

Recent studies have suggested that n-9 fatty acids in olive oil prevent colon carcinogenesis while n-6 PUFA seems to activate this process.

AIMS

To evaluate the effects of nutritional-pharmacological combinations made up of olive or soy oil-based diets and the drug sulindac, on colon cancer incidence in a chemically induced (1,2-dimethylhydrazine, DMH) rat cancer model.

METHODS

Male rats were assigned to two different dietary regimes based on a standard murine defined diet (AIN-76A) containing either a low (4%) or high (15 %) concentration of olive or soy oil. Some groups also received sulindac in their food (80 mg/kg food) starting from the ninth week following the first DMH or vehicle administration.

RESULTS

Oleic and linoleic acid reached higher levels in plasma and liver lipids when rats were fed high concentrations of olive or soy oil, respectively. Rats fed a low or high soy oil-based diet showed no significant difference in the number of aberrant crypt foci (ACF) in proximal or distal colon specimens. In contrast, rats fed a higher olive oil-based diet developed a significantly lower number of ACF than rats fed a low concentration of olive oil. Addition of sulindac reduced the number of ACF in rats fed the 4%, but not the 15%, soy oil diet. In contrast, the effect of sulindac was significant when combined with both the low and high concentrations of olive oil. High soy oil-based diet or DMH treatment upregulated colon expression of Bcl-2, but not that of cyclooxygenase-2 (COX-2). In contrast, olive oil dose-dependently downregulated the expression of both Bcl-2 and COX-2 in colonic mucosa and also abrogated the upregulation of Bcl-2 by DMH. Olive oil/sulindac combinations were effective in downregulating colonic mucosa Bcl-2 expression (with the 4% oil diet) and COX-2 expression (with the 15% oil diet). These effects were not observed in rats fed the soy oil/sulindac combinations. Caspase-3 activity in colonic mucosa was unaffected by soy oil or soy oil/sulindac combinations. The addition of olive oil, on the other hand, significantly enhanced colonic caspase-3 activity.

CONCLUSIONS

Diets containing high levels of olive oil exert a significant protective effect from tumor development that is additive with the inhibitory effect of sulindac. These inhibitory effects are mediated by regulating the expression and activity of key proteins involved in prostaglandin-biosynthesis and apoptosis-induction pathways. It may be concluded that appropriate dietary-pharmacological combination can improve anti-tumor efficacy over either dietary or pharmacological intervention alone.

Detection of onset of neuronal activity by allowing for heterogeneity in the change points

We consider situations in which there is a change point in the activity of a cell, that is, some time after an external event the firing rate of the cell changes. The change can occur after a random delay. The distribution of the time to change is considered unknown. Formally we deal with n random point processes, each of these is an inhomogeneous Poisson process, with one intensity until a random time, and a different intensity thereafter. Thus, the change point is not explicitly observed. We present both a simple estimator and the non-parametric maximum likelihood estimator (NPMLE) of the change point distribution, both having the same rate of convergence. This rate is proved to be the best possible. The extension of the basic model to multiple processes per trial with different intensities and joint multiple change points is demonstrated using both simulated and neural data. We show that for realistic spike train data, trial by trial estimation of a change point may be misleading, while the distribution of the change point distribution can be well estimated.

On the role of cell surface carbohydrates and their binding proteins (lectins) in tumor metastasis

This review focuses on the recent advances in investigations of the role of cell surface carbohydrates in tumor metastasis. It also summarizes the results of extensive studies of endogenous lectins, their structure, carbohydrate specificity and biological functions with the major emphasis on the significance of lectin-cell surface carbohydrate interactions in a metastatic process. Numerous data demonstrate that malignant transformation is associated with various and complex alterations in the glycosylation process. Some of these changes might provide a selective advantage for tumor cells during their progression to more invasive and metastatic phenotype. Cell glycosylation depends on the expression and function of various glycosyltransferases and glycosidases. Recently, transfection of genes encoding various glysosyltransferases gene in sense and antisense orientation helped to bring direct evidence that changes in cell surface carbohydrates are important for the metastatic behavior of tumor cells. Cell surface carbohydrates affect tumor cell interactions with normal cells or with the extracellular matrix during metastatic spread and growth. These interactions can be mediated via tumor cell carbohydrates and their binding proteins known as endogenous lectins. The family of the discovered endogenous lectins is rapidly expanding. The number of C-type lectins has reached 50 and at least 10 galectins have been identified. The biological significance of the endogenous lectins and their possible role in tumor growth and metastasis formation has started to unravel. Some lectins recognize the 'foreign' patterns of cell surface carbohydrates expressed by microorganisms and tumor cells, and play a role in innate and adaptive immunity. It was shown that lectins affect tumor cell survival, adhesion to the endothelium or extracellular matrix, as well as tumor vascularization and other processes that are crucial for metastatic spread and growth.

Differential metabolism of dihomo-gamma-linolenic acid and arachidonic acid by cyclo-oxygenase-1 and cyclo-oxygenase-2: implications for cellular synthesis of prostaglandin E1 and prostaglandin E2

Prostaglandin (PG) E(1) has been shown to possess anti-inflammatory properties and to modulate vascular reactivity. These activities are sometimes distinct from those of PGE(2), suggesting that endogenously produced PGE(1) may have some beneficial therapeutic effects compared with PGE(2). Increasing the endogenous formation of PGE(1) requires optimization of two separate processes, namely, enrichment of cellular lipids with dihomo-gamma-linolenic acid (20:3 n-6; DGLA) and effective cyclo-oxygenase-dependent oxygenation of substrate DGLA relative to arachidonic acid (AA; 20:4 n-6). DGLA and AA had similar affinities (K(m) values) and maximal reaction rates (V(max)) for cyclo-oxygenase-2 (COX-2), whereas AA was metabolized preferentially by cyclo-oxygenase-1 (COX-1). To overcome the kinetic preference of COX-1 for AA, CP-24879, a mixed Delta(5)/Delta(6) desaturase inhibitor, was used to enhance preferential accumulation of DGLA over AA in cells cultured in the presence of precursor gamma-linolenic acid (18:3 n-6). This protocol was tested in two cell lines and both yielded a DGLA/AA ratio of approx. 2.8 in the total cellular lipids. From the enzyme kinetic data, it was calculated that this ratio should offset the preference of COX-1 for AA over DGLA. PGE(1) synthesis in the DGLA-enriched cells was increased concurrent with a decline in PGE(2) formation. Nevertheless, PGE(1) synthesis was still substantially lower than that of PGE(2). It appears that employing a dietary or a combined dietary/pharmacological paradigm to augment the cellular ratio of DGLA/AA is not an effective route to enhance endogenous synthesis of PGE(1) over PGE(2), at least in cells/tissues where COX-1 predominates over COX-2.

Expression and function of the AMF receptor by human melanoma in experimental and clinical systems

Motility of tumor cells is the rate limiting potential of metastatic cells and is regulated by autocrine and paracrine factors. Autocrine motility factor/neuroleukin/phosphohexose isomerase (AMF) is one of the best characterized autocrine motogenic cytokines. Here we have studied its in vitro effects on several human melanoma cell lines and found that neither cell line exhibited mitogenic response to AMF at a concentration where motogenic response could be initiated. Similar to previous studies on murine melanoma, activation of the AMF receptor upregulated beta3 while it downregulated beta1 integrins at the cell surface, inducing an integrin phenotype characteristic for invasive/metastatic melanoma. The gp78/AMF receptor protein expression in human melanoma cell lines correlated to their in vivo spontaneous metastatic potential. Furthermore, in two out of three human melanoma lines the expression significantly increased in the primary tumor when spontaneous metastases developed (immunosuppressed newborn rat model versus SCID mice). In a prospective study we have also analyzed AMF receptor protein expression in primary tumors of 54 skin melanoma patients using IHC. These studies revealed three types of AMF receptor phenotype: weak, heterogenous and strong expression profile. While in thin tumors weak/heterogenous AMFR expression predominated, in thick tumors the strong expression profile was predominant. The connection between AMFR expression and the invasive/metastatic potential of melanoma was further supported by our observation that SSM melanoma in the vertical growth phase expressed this motility receptor more strongly than tumors in the radial growth phase.

Hypoxia enhances the expression of autocrine motility factor and the motility of human pancreatic cancer cells

The incidence of distant metastases is higher in the tumours with low oxygen pressure than in those with high oxygen pressure. It is well known that hypoxia induces the transcription of various genes involved in angiogenesis and anaerobic metabolism necessary for the growth of tumour cells in vivo, suggesting that hypoxia may also induce the transcription of metastasis-associated genes. We sought to identify the metastasis-associated genes differentially expressed in tumour cells under hypoxic conditions with the use of a DNA microarray system. We found that hypoxia enhanced the expression of autocrine motility factor mRNA in various cancer cells and also enhanced the random motility of pancreatic cancer cells. Autocrine motility factor inhibitors abrogated the increase of motility under hypoxic conditions. In order to explore the roles of hypoxia-inducible factor-1alpha, we established hypoxia-inducible factor-1alpha-transfectants and dominant negative hypoxia-inducible factor-1alpha-transfectants. Transfection with hypoxia-inducible factor-1alpha and dominant-negative hypoxia-inducible factor-1alpha enhanced and suppressed the expression of autocrine motility factor/phosphohexase isomerase/neuroleukin mRNA and the random motility, respectively. These results suggest that hypoxia may promote the metastatic potential of cancer cells through the enhanced autocrine motility factor/phosphohexase isomerase/neuroleukin mRNA expression and that the disruption of the hypoxia-inducible factor-1 pathway may be an effective treatment for metastasis.

Tumor cell motility as a novel target in cancer--experimental and clinical results

BACKGROUND

Surgery, chemotherapy and radiotherapy are the mainstay of tumor management. However, in systemic disease cure can be achieved in yet a few tumor entities. Based on cell biological research we have characterized the process of tumor progression and metastasis and disclosed that the loss of cell-cell adhesion in association with an increased tumor cell motility is an essential feature of the malignant potential of a tumor.

METHODS

According to this principle we derived therapeutical methods differing from hitherto existing treatments by being exclusively focused on tumor cell motility. Characterization of so-called anti-motility factors was performed biochemically as well as with motility assays by in vitro studies in established bladder carcinoma cell lines.

RESULTS

We evaluated the potential therapeutic benefit in a model of chemically induced bladder carcinoma followed by a phase I/II trial applying antimotility factors in patients with advanced bladder cancer.

CONCLUSION

Both basic research as well as the results of first clinical trials confirm, that advanced carcinomas can be influenced by inhibition of tumor cell motility.

Speech sounds learned by sleeping newborns

It is not yet clear whether humans are able to learn while they are sleeping. Here we show that full-term human newborns can be taught to discriminate between similar vowel sounds when they are fast asleep. It is possible that such sleep training soon after birth could find application in clinical or educational situations.

Is inhibition of cyclooxygenase required for the anti-tumorigenic effects of nonsteroidal, anti-inflammatory drugs (NSAIDs)? In vitro versus in vivo results and the relevance for the prevention and treatment of cancer

Active research is being conducted to unravel the cellular mechanisms mediating the anti-tumorigenic effects of nonsteroidal anti-inflammatory drugs (NSAIDs) and their association with cyclooxygenase (COX) inhibition. The majority of NSAIDs inhibit either COX-1, COX-2, or both and exert their anti-COX, anti-inflammatory, and anti-tumorigenic effects in vivo in a parallel dose-dependent manner. The effects are seen at NSAID blood plasma concentrations of 0.1-5 microM. Significantly, the same compounds tested at the same concentrations in incubations with cultured tumor cells in vitro similarly inhibit COX activities but are devoid of anti-proliferative activity. Yet, at much higher concentrations (100-20,000 microM), these same NSAIDs do exert anti-proliferative effects in vitro due to apparent non-specific toxic effects, as evidenced by disruption of ion transport and mitochondrial oxidation in some cells. A small group of NSAIDs (e.g. sulindac) do not inhibit COX enzymes significantly but can reduce the synthesis of prostanoids by alternate mechanisms. One such mechanism is inhibition of agonist-stimulated phospholipase-mediated release of arachidonic acid from phospholipids leading to depressed synthesis of prostanoids, especially prostaglandin E(2) (PGE(2)). Another group of non-COX inhibitors are the R-isomers of NSAIDs, based on the structure of 2-arylpropionic acid. These compounds exert anti-proliferative effects in vivo, acting by an as yet undetermined mechanism. A possible caveat in these data is an R to S chiral transformation in vivo that would render the R-isomer effect as being due to the S-isomer generated in vivo from it. Demonstration of minimal or no R to S inversion under the experimental in vivo conditions employed is, therefore, a necessary control in these studies. The overall body of data supports the conclusion that, for COX-inhibiting NSAIDs, their anti-tumorigenic effect in vivo is due to, and depends upon, inhibition of tumor COX enzymes, primarily COX-2. The cellular effects seen when adding high concentrations of NSAIDs to tumor cells cultured in vitro and the mechanisms proposed to mediate these effects may not have substantial relevance to the mechanisms that mediate the effects of NSAIDs in vivo.

Regulation of cell motility via high and low affinity autocrine motility factor (AMF) receptor in human oral squamous carcinoma cells

A tumour-secreted cytokine autocrine motility factor (AMF) induces in vivo invasion and metastasis, and in vitro tumour cell motility by a signal transduction through interaction with its cell surface receptor gp78. In this report, we investigated the characterization of a high-metastatic human oral squamous cell carcinoma (SCC) cell line LMF4 and low-metastatic HSC-3 in comparison with non-metastatic HSC-2 and HSC-4. Morphological and motility analyses revealed LMF4 cells to have the highest motile activity among those cells. However, LMF4 cells shared the similar features with HSC-3: high level secretion of AMF, enhancement of gp78 expression, co-expression of vimentin and cytokeratin, although LMF4 cells showed twice as high motile reactivity as HSC-3. The only difference was that LMF4 had twice as high amount of low-affinity receptor(s) as HSC-3, shown by Scatchard analysis.

Significance of autocrine motility factor receptor gene expression as a prognostic factor in non-small-cell lung cancer

Autocrine motility factor receptor (AMF-R) has been shown to play an important role in tumor cell migration, invasion and metastasis. We have detected AMF-R expression in tissue specimens from patients with non-small-cell lung cancer (NSCLC) and have assessed their clinical characteristics. Using RT-PCR and immunohistochemistry, we quantified the expression of AMF-R in 47 patients with NSCLC who underwent curative tumor resection, to investigate the relationship between AMF-R expression and clinicopathologic factors and prognosis. RT-PCR results agreed well with the immunohistochemic results (p < 0.0001). In 47 NSCLC patients, 34 (72.3%) samples were evaluated as having high AMF-R gene expression. AMF-R gene expression was significantly associated with lymph node metastasis and stage (p = 0.0295 for lymph node metastasis, p = 0.0152 for stage). The overall survival rate for patients with high AMF-R gene-expressing tumors was significantly worse than for those whose tumors had low AMF-R expression (p = 0.0029). Multivariate analysis also showed that AMF-R gene expression was significantly related to survival (p = 0.0165). These data indicate that AMF-R may contribute to tumor progression and that AMF-R gene expression can serve as a useful prognostic marker in NSCLC.

Lipid remodeling in mouse liver and plasma resulting from delta6 fatty acid desaturase inhibition

Electrospray/tandem mass spectrometry was used to quantify lipid remodeling in mouse liver and plasma during inhibition of polyunsaturated fatty acid synthesis by the delta6 fatty acid desaturase inhibitor, SC-26196. SC-26196 caused increases in linoleic acid and corresponding decreases in arachidonic acid and docosahexaenoic acid in select molecular species of phosphatidylcholine, phosphatidylethanolamine, and cholesterol esters but not in phosphatidylserine, phosphatidylinositol, or triglycerides. For linoleic acid-, arachidonic acid-, and docosahexaenoic acid-containing phospholipid species, this difference was, in part, determined by the fatty acid at the sn-1 position, namely, palmitic or stearic acid. An understanding of phospholipid remodeling mediated by delta6 desaturase inhibition should aid in clarifying the contribution of arachidonic acid derived via de novo synthesis or obtained directly in the diet during inflammatory responses.

Congenital short-bowel and malrotation: clinical presentation and outcome of six affected offspring in three related families

Newborns with congenital short small bowel associated with malrotation and intestinal dysmotility have a uniformly bad prognosis. However, few long-term survivors have been reported, suggesting that the disorder is not invariably fatal. The majority of cases previously reported were familial. We report on six affected siblings in three related families. The aim of this report is to assess the mode of inheritance, the expression of this disorder, and to point to the correlation between the onset of gastrointestinal symptoms and the outcome.

Is pre-attentive processing compromised by prolonged wakefulness? Effects of total sleep deprivation on the mismatch negativity

We investigated the potential influence of sustained wakefulness on pre-attentive capacities by recording the mismatch negativity (MMN), an electrophysiological manifestation associated with nonintentional detection of auditory oddball stimuli. The MMN was elicited by pitch deviants presented to both ears via earphones, at the beginning of a total sleep deprivation session (baseline), after 24 hr, and after 36 hr of continuous controlled wakefulness. A conspicuous MMN response was elicited at all three sessions. With time, however, a small yet significant gradual reduction in the MMN amplitude was evident. Whereas previous research suggested that controlled attention-demanding tasks are hampered by sleep deprivation, the balance of the present results suggests that passive (total) sleep deprivation may also bring about some degradation in the pre-attentive detection of environmental irregularities and as a consequence may disrupt the reflexive shift of attention induced by such events.

Galectin-3 protects human breast carcinoma cells against nitric oxide-induced apoptosis: implication of galectin-3 function during metastasis

Galectin-3 is a beta-galactoside-binding protein which regulates many biological processes including cell adhesion, migration, cell growth, tumor progression, metastasis, and apoptosis. Although the exact function of galectin-3 in cancer development is unclear, galectin-3 expression is associated with neoplastic progression and metastatic potential. Since studies have suggested that tumor cell survival in microcirculation determines the metastatic outcome, we examined the effect of galectin-3 overexpression in human breast carcinoma cell survival using the liver ischemia/reperfusion metastasis model. While the majority of control cells died by hepatic ischemia/reoxygenation, nearly all of galectin-3 overexpressing cells survived. We showed that galectin-3 inhibits nitrogen free radical-mediated apoptosis, one of the major death pathways induced during hepatic ischemia/reperfusion. Galectin-3 inhibition of apoptosis involved protection of mitochondrial integrity, inhibition of cytochrome c release and caspase activation. Taking these results together with the previous observation that galectin-3 inhibits apoptosis induced by loss of cell adhesion, we propose that galectin-3 is a critical determinant for anchorage-independent and free radical-resistant cell survival during metastasis.

Pomegranate juice supplementation to atherosclerotic mice reduces macrophage lipid peroxidation, cellular cholesterol accumulation and development of atherosclerosis

Inhibition of lipid peroxidation contributes to the attenuation of macrophage cholesterol accumulation, foam-cell formation and atherosclerosis. Evidence suggests that nutritional antioxidants such as pomegranate juice (PJ) can contribute to the reduction of oxidative stress and atherogenesis. The goals of the present study were to determine whether such beneficial effects of PJ exist when supplemented to apolipoprotein E-deficient (E(0)) mice with advanced atherosclerosis and to analyze the antiatherosclerotic activity of a tannin-fraction isolated from PJ. Mice (4-mo-old) were supplemented with PJ in their drinking water for 2 mo and compared with age-matched placebo-treated mice, as well as to young (4-mo-old) control mice, for their mouse peritoneal macrophage (MPM) oxidative state, cholesterol flux and mice atherosclerotic lesion size. PJ supplementation reduced each of the proatherogenic variables determined in the present study compared with age-matched placebo-treated mice. It significantly induced serum paraoxonase activity and reduced MPM lipid peroxide content compared with placebo-treated mice and control mice. PJ administration to E(0) mice significantly reduced the oxidized (Ox)-LDL MPM uptake by 31% and MPM cholesterol esterification and increased macrophage cholesterol efflux by 39% compared with age-matched, placebo-treated mice. PJ consumption reduced macrophage Ox-LDL uptake and cholesterol esterification to levels lower than those in 4-mo-old, unsupplemented controls. PJ supplementation to E(0) mice with advanced atherosclerosis reduced the lesion size by 17% compared with placebo-treated mice. In a separate study, supplementation of young (2-mo-old) E(0) mice for 2 mo with a tannin fraction isolated from PJ reduced their atherosclerotic lesion size, paralleled by reduced plasma lipid peroxidation and decreased Ox-LDL MPM uptake. PJ supplementation to mice with advanced atherosclerosis reduced their macrophage oxidative stress, their macrophage cholesterol flux and even attenuated the development of atherosclerosis. Moreover, a tannin-fraction isolated from PJ had a significant antiatherosclerotic activity.

Tumor autocrine motility factor is an angiogenic factor that stimulates endothelial cell motility

Autocrine motility factor (AMF) is a type of tumor-secreted cytokine which primarily stimulates tumor cell motility via receptor-mediated signaling pathways, and is thought to be connected to tumor progression and metastasis. Using in vivo models, we showed that critical neovascularization responded to a biological amount of AMF. This angiogenic activity was fixed by specific inhibitors against AMF. AMF stimulated in vitro motility of human umbilical vein endothelial cells (HUVECs), inducing the expression of cell surface AMF receptor localizing a single predominant perinuclear pattern closely correlated with its motile ability. AMF also elicited the formation of tube-like structures mimicking angiogenesis when HUVECs were grown in three-dimensional type I collagen gels. We further immunohistochemically detected AMF receptors on the surrounding sites of newborn microvessels. These findings suggest that AMF is a possible tumor progressive angiogenic factor which may act in a paracrine manner for the endothelial cells in the clinical neoplasm, and it will be a new target for antiangiogenic treatment.

Tumor autocrine motility factor is an angiogenic factor hat stimulates endothelial cell motility

Autocrine motility factor (AMF) is a type of tumor-secreted cytokine that primarily stimulates tumor cell motility via receptor-mediated signaling pathways and is thought to be connected to tumor progression and metastasis. Using in vivo models, we showed that critical neovascularization responded to a biological amount of AMF. This angiogenic activity was fixed by specific inhibitors against AMF. AMF stimulated in vitro motility of human umbilical vein endothelial cells (HUVECs), inducing the expression of cell surface AMF receptor localizing a single predominant perinuclear pattern closely correlated with its motile ability. AMF also elicited the formation of tube-like structures mimicking angiogenesis when HUVECs were grown in three-dimensional type I collagen gels. We further immunohistochemically detected AMF receptors on the surrounding sites of newborn microvessels. These findings suggest that AMF is a possible tumor progressive angiogenic factor which may act in a paracrine manner for the endothelial cells in the clinical neoplasm, and it will be a new target for anti-angiogenic treatment.

Galectin-3 maintains the transformed phenotype of thyroid papillary carcinoma cells

Galectin-3, a beta-galactoside-binding protein, is highly expressed in thyroid papillary carcinomas, while functional relevance of galectin-3 overexpression to the malignant phenotype remains elusive. In the present study we transfected galectin-3 antisense cDNA into the human thyroid papillary carcinoma cell line NPA which expresses an innately high level of galectin-3, and examined the effect of antisense inhibition of galectin-3 expression on the transformed phenotype. There was no difference in anchorage-dependent growth between the antisense clones and either the control or parental clones. In contrast, anchorage-independent growth and saturation density of the antisense clones were significantly suppressed compared to those of either the control or parental clones. These results demonstrate that overexpression of galectin-3 in thyroid papillary carcinoma cells is necessary for the maintenance of transformed phenotype, and suggest galectin-3 as a potential target for therapeutic interventions in the future.