A ventral striatal prediction error signal in human fear extinction learning.

Animal studies have shown that the prediction error (PE) signal that drives fear extinction learning is encoded by phasic activity of midbrain dopamine (DA) neurons. Thus, the extinction PE resembles the appetitive PE that drives reward learning. In humans, fear extinction learning is less well understood. Using computational neuroimaging, a previous study from our group reported hemodynamic activity in the left ventral putamen, a subregion of the ventral striatum (VS), to correlate with a PE function derived from a formal associative learning model. The activity was modulated by genetic variation in a DA-related gene. To conceptually replicate and extend this finding, we here asked whether an extinction PE (EPE) signal in the left ventral putamen can also be observed when genotype information is not taken into account. Using an optimized experimental design for model estimation, we again observed EPE-related activity in the same striatal region, indicating that activation of this region is a feature of human extinction learning. We further observed significant EPE signals across wider parts of the VS as well as in frontal cortical areas. These results may suggest that the prediction errors during extinction learning are available to larger parts of the brain, as has also been observed in human neuroimaging studies of reward PE signaling. Conclusive evidence that the human EPE signal is of DAergic nature is still outstanding.

Anti-CD4 treatment inhibits autoimmunity in scurfy mice through the attenuation of co-stimulatory signals.

A major concept in autoimmunity is that disruption of Foxp3(+) regulatory T cells (Tregs) predisposes to breach of tolerance. This is exemplified by the Foxp3-linked disorder termed IPEX (immunodysregulation, polyendocrinopathy, enteropathy, X-linked) which affects newborn children. There has been considerable clinical interest in the role of non-depleting anti-CD4 antibodies as a means of upregulating the function of Foxp3(+) Tregs in order to control detrimental inflammatory responses such as transplant rejection. However, according to the paradigm of a Treg-dependent mechanism of action, the effectiveness of anti-CD4 antibodies as a therapy for human autoimmune diseases is unclear considering that Treg function might be intrinsically impaired. Specifically, anti-CD4 therapy is expected to fail in patients suffering from the IPEX syndrome due to the lack of functional Foxp3(+) Tregs. Taking advantage of natural Foxp3 mutant scurfy (sf) mice closely resembling the IPEX syndrome, and genetically engineered mice depleted of Foxp3(+) Tregs, we report here that anti-CD4 treatment induces tolerance independent of Foxp3(+) Tregs. This so far undefined mechanism is dependent on the recessive non-infectious tolerization of autoreactive T cells. Treg-independent tolerance alone is powerful enough to suppress both the onset and severity of autoimmunity and reduces clinically relevant autoantibody levels and liver fibrosis. Mechanistically, tolerance induction requires the concomitant activation of autoreactive T cells and is associated with the down-regulation of the co-stimulatory TNF-receptor superfamily members OX40 and CD30 sustaining CD4(+) T cell survival. In the light of ongoing clinical trials, our results highlight an unexpected potency of anti-CD4 antibodies for the treatment of autoimmune diseases. Particularly, CD4 blockade might represent a novel therapeutic option for the human IPEX syndrome.

The continuous reaction times method for diagnosing, grading, and monitoring minimal/covert hepatic encephalopathy.

Existing tests for minimal/covert hepatic encephalopathy (m/cHE) are time- and expertise consuming and primarily useable for research purposes. An easy-to-use, fast and reliable diagnostic and grading tool is needed. We here report on the background, experience, and ongoing research regarding the continuous reaction times (CRT) method. The method has been in clinical use for decades in Denmark for the stated purpose. The method is a 10-minutes, computerised registration of a series of motor reaction times to an auditory stimulus, with results reported as the CRTindex (50 percentile/(90-10) percentile) as a parameter of reaction time variability. The index is a measure of alertness stability and is used to assess attention and cognition deficits. The CRTindex identifies half of patients in a Danish cohort with chronic liver disease, as having m/cHE, a normal value safely precludes HE, it has a broad outcome span reflecting the degree of brain impairment, it shows no learning effect, and it is independent on age and gender. The CRTindex is, therefore, a candidate tool for routine screening, detecting, grading, and monitoring m/cHE. Still, however, further methodological and clinical validation trials are required and are currently being conducted.

Macrophage migration inhibitory factor (MIF) promotes cell survival by activation of the Akt pathway and role for CSN5/JAB1 in the control of autocrine MIF activity.

The phosphoinositide-3-kinase (PI3K)/Akt signaling pathway plays an important role in cell survival and the development of cancer. Macrophage migration inhibitory factor (MIF) is a critical inflammatory cytokine that was recently associated with tumorigenesis and that potently inhibits apoptosis. This may involve inhibition of p53-dependent genes, but the initiating molecular mechanism of how MIF controls survival/apoptosis is unknown. Here, we show that MIF prevents apoptosis and promotes tumor cell survival by directly activating the Akt pathway. MIF enhanced Akt activity in primary and immortalized fibroblasts (MEF and NIH/3T3), HeLa cervix carcinoma cells and various breast cancer cell lines. Activation was abolished by kinase inhibitors Ly294002 and PP2 and in Src/Yes/Fyn(SYF)(-/-) and CD74(-/-)(MEFs), while being enhanced in CD74-overexpressing MEFs, demonstrating that the MIF-induced Akt pathway encompasses signaling through the MIF receptor CD74 and the upstream kinases Src and PI3K. Akt was activated by exogenous rMIF and autocrine MIF action, as revealed by experiments in MIF(-/-)MEFs and antibody blockade. siRNA knockdown of CSN5/JAB1, a tumor marker and MIF-binding protein, showed that JAB1 controls autocrine MIF-mediated Akt signaling by inhibition of MIF secretion. Akt activation by MIF led to phosphorylation of the proapoptotic proteins BAD and Foxo3a. Apoptosis inhibition by MIF was functionally associated with Akt activation as it was abolished by overexpression of the Akt pathway inhibitor PTEN and occurred independently of p53. This was shown by studying DNA damage-induced apoptosis in fibroblasts, the Fas death pathway in HeLa cells that do not express functional p53, and etoposide-induced apoptosis in breast carcinoma cells expressing mutant p53. Importantly, dependence of breast cancer cell survival on MIF correlated with Akt activation and the PTEN status of these cells. Thus, MIF can directly promote cell survival through activation of the PI3K/Akt pathway and this effect is critical for tumor cell survival.

Cell-heritable stages of tumor progression in transgenic mice harboring the bovine papillomavirus type 1 genome.

Tumorigenesis of dermal fibroblasts in a line of transgenic mice carrying the BPV-1 genome was found to involve distinct proliferative stages. Cell cultures derived from normal skin, from benign proliferative fibromatoses, and from malignant fibrosarcomas each evidenced distinguishable, cell-heritable characteristics. The latent viral genome was transcriptionally inactive in normal-appearing skin and was activated in the dermal fibromatoses. Fibrosarcoma cells grew continuously in culture, formed domelike foci, and had a more rounded, anaplastic appearance. Independent cultures derived from the fibromatoses varied in their proliferative characteristics, which correlated well with the levels of viral gene expression. In contrast, progression to malignancy was not accompanied by a further increase in transgene activity, which strongly implicated cellular genetic changes in the later stages of tumorigenesis.

A bifunctional chiral [2]catenane based on 1,1'-binaphthyl-phosphates.

A novel [2]catenane was synthesised by ring-closing metathesis from a Ca-bisphosphate template. The resulting interlocked structure features two chiral 1,1'-binaphthyl-phosphates, leading to a bifunctional catenane structure. Initial binding studies point at the applicability of such mechanically interlocked bisphosphates as artificial receptors for dicationic guest molecules.

Maternal serum hCG and SP1 in pregnancies with fetal aneuploidy.

In a retrospective study, maternal serum levels of chorionic gonadotropin (hCG) and pregnancy specific beta 1-glycoprotein (SP1) from 63 pregnancies with aneuploid fetuses were compared to the levels observed in pregnancies with a chromosomally normal fetus. Thirty-eight percent of the abnormal pregnancies had elevated levels (greater than 2.0 multiples of the normal median [MoM]) of hCG and 14% had depressed levels (less than 0.25 MoM). With a false-positive rate of 5%, 44% of the 42 fetuses with trisomy 21 would have been detected by elevated hCG levels. With the same false-positive rate, only 21% had elevated SP1 levels. hCG was significantly depressed in 12 pregnancies affected by fetal trisomy 18.

Structural study on the carbohydrate moiety of calf intestinal alkaline phosphatase.

Surprisingly alkaline phosphatase (AP) (EC 3.1.3.1) of calf intestine is found in large amounts, e.g. 80%, within chyme. Most of the enzyme is present as a mixture of four differently hydrophobic anchor-bearing forms and only the minor part is present as an anchorless enzyme. To investigate whether changes in the N-glycosylation pattern are signals responsible for large-scale liberation from mucosa into chyme, the glycans of the two potential glycosylation sites predicted from cDNA were investigated by matrix-assisted laser desorption/ionization and electrospray ionization mass spectrometry in combination with exoglycosidase treatment after tryptic digestion and reversed-phase chromatography. The glycans linked to Asn249 are at least eight different, mainly non-fucosylated, biantennary or triantennary structures with a bisecting N-acetylglucosamine. For the most abundant glycopeptide (40%) the following glycan structure is proposed: [carbostructure: see text]. The glycans linked to Asn410 are a mixture of at least nine, mainly tetraantennary, fucosylated structures with a bisecting N-acetylglucosamine. For the most abundant glycopeptide (35%) the following glycan structure is proposed: [carbostructure: see text]. For the structures the linkage data were deduced from the reported specificities of the exoglycosidases used and the specificities of the transglycosidases active in biosynthesis. The majority of glycans are capped by alpha-galactose residues at their non-reducing termini. In contrast to the glycans linked to other AP isoenzymes, no sialylation was observed. Glycopeptide 'mass fingerprints' of both glycosylation sites and glycan contents do not differ between AP from mucosa and chyme. These results suggest that the observed large-scale liberation of vesicle-bound glycosylphosphatidylinositol (GPI)-anchored AP from mucosa into chyme is unlikely to be mediated by alteration of glycan structures of the AP investigated. Rather, the exocytotic vesicle formation seems to be mediated by the controlled organization of the raft structures embedding GPI-AP. (c) 2001 John Wiley & Sons, Ltd.

Health of infant is the main reason for breast-feeding in a WIC population in Hawaii.

OBJECTIVE: To determine factors influencing infant feeding method choices among women who received services from the Special Supplemental Food Program for Women, Infants, and Children (WIC) during pregnancy in Hawaii. DESIGN: A retrospective survey mailed to all resident mothers who had live births in Hawaii between January 1, 1989, and March 31, 1989, and who received WIC services during pregnancy. SETTING: The state of Hawaii. SUBJECTS: The subjects were 322 mothers who received WIC services during pregnancy for whom data were complete, taken from a sample of 2,013 women who had live births in the state of Hawaii (51% response rate) between January 1, 1989, and March 31, 1989, of whom 324 participated in WIC during pregnancy. MAIN OUTCOME MEASURES: Infant feeding method (exclusive breast, exclusive formula or mixed) at hospital discharge. STATISTICAL ANALYSES PERFORMED: The chi 2 analysis for differences among feeding method groups and multiple logistic regression to calculate odds ratios for independent effects of maternal characteristics and other influences on feeding method choice. RESULTS: Reasons for infant feeding choice, timing of the choice, maternal age, parity, and place of residence were the main factor influencing infant method choice. Health of the infant was the primary reason for choice of feeding method and was the strongest determinant of exclusive breast-feeding (odds ratio = 23.99; confidence interval = 9.75-59.02; P < .0001) and was negatively related to the choice to formula-feed (odds ratio = 0.03; confidence interval = 0.01-0.08; P < .0001). APPLICATIONS: Relationship between WIC and hospital lactation consultants could enhance follow up in the hospital and after returning home with WIC mothers who prenatally state an intention to breast-feed. Convenience and bonding are aspects of breast-feeding enjoyed by WIC mothers in Hawaii that could be used in breast-feeding promotion efforts.

Dietary change and obesity associated with glucose intolerance in Alaska Natives.

OBJECTIVE: To investigate frequency of food intake, body weight, and glucose intolerance in Alaska Natives. DESIGN: Height, weight, and random blood glucose levels were measured and a frequency-of-food-intake questionnaire was obtained. This questionnaire classified persons as consumers of indigenous foods or nonindigenous foods within three food groups. Those with a random blood glucose measurement > or = 6.72 mmol/L received an oral glucose tolerance test. SETTING: Community screening in 15 villages in Alaska. SUBJECTS: Nutrition screenings were done for 1,124 Alaska Native residents aged 20 years or older. An oral glucose tolerance test was done for 202 subjects. OUTCOMES MEASURED: Subjects were classified as consumers of indigenous or nonindigenous foods within three food groups. A diagnosis of non-insulin-dependent diabetes mellitus (NIDDM) was made on the basis of World Health Organization criteria. A determination of overweight was made on the basis of National Center for Health Statistics criteria. STATISTICAL ANALYSIS: A chi 2 test with Yates correction, t test, and linear regression, with two-sided P values. RESULTS: Athabascan Indians had twice the rate of NIDDM as Yup'ik Eskimos with significantly higher frequency of nonindigenous food intake, plus lower frequency of indigenous carbohydrate and fat intake. Subjects < or = 30 years old consumed significantly more nonindigenous protein and fat and low-nutrient-density carbohydrates than those > or = 60 years old. Persons who had glucose intolerance reported significantly greater consumption of nonindigenous protein and less seal oil. Incidence of overweight was significantly higher than was found 25 years ago. Participants with glucose intolerance were significantly more overweight than others. CONCLUSION: A pattern of increased frequency of nonindigenous protein, low-nutrient-density carbohydrate, and fat intake with less indigenous carbohydrate and fat consumption was found in subjects < or = 30 years old and in association with the higher rate of NIDDM found in the Athabascan Indians. Persons with glucose intolerance were significantly more overweight than others. APPLICATIONS: Although the nutritional value of indigenous foods for reducing disease risk should be promoted, nutrition education, especially among young adults, should also include building skills to select and prepare nonindigenous foods to attain a healthful diet. Although snacking is a concern, dietary fat was the most significant factor in obesity and NIDDM.

Detection of tumor cells in peritoneal lavages from patients with gastrointestinal cancer by multiplex reverse transcriptase PCR.

BACKGROUND/AIMS: Cytological examination of peritoneal lavages is a useful predictor of peritoneal recurrence in gastrointestinal carcinoma patients. Nevertheless, it may be inadequate for those patients with lavages containing only few cancer cells. In the present study, sensitive detection of free cancer cells could be achieved through amplification of cytokeratin 19, carcinoembryonic antigen, alpha-fetoprotein mRNAs by means of multiplex reverse transcriptase polymerase chain reaction and nested polymerase chain reaction. METHODOLOGY: The multiplex reverse transcriptase polymerase chain reaction assay was used to examine lavage samples from 64 patients with various gastrointestinal malignant lesions (colorectal n = 27; duodenal carcinoma n = 1; gastric n = 7; pancreatic n = 4; hepatocellular carcinoma n = 2; gallbladder n = 1; cholangiocellular carcinoma n = 2 and 20 colorectal liver metastases. Specificity was assessed by examination of 15 donors without malignancies. In addition, nested polymerase chain reaction was used to improve the sensitivity of the assay for the detection of alpha-fetoprotein transcripts. RESULTS: Peritoneal lavages from 12 of 64 gastrointestinal carcinoma patients were positive for carcinoembryonic antigen mRNA. Carcinoembryonic antigen proved a specific marker, as no false-positives were detected in any patients without gastrointestinal cancer. alpha-fetoprotein mRNA was detected exclusively in peritoneal lavages from tumor patients, i.e., in 16 of 27 colon cancer patients, 14 of 20 patients with colorectal liver metastasis, 2 of 7 patients with gastric cancer, two patients with hepatocellular carcinoma and 2 of 4 patients with pancreatic cancer. Cytokeratin 19 mRNA was not found a useful marker, since control patients without malignancies were also positive. CONCLUSIONS: Our data suggest that carcinoembryonic antigen- and alpha-fetoprotein mRNA in peritoneal lavage are potentially useful specific markers for early diagnosis of metastasis of gastrointestinal cancer. It has been shown that alpha-fetoprotein-specific nested reverse transcriptase polymerase chain reaction can detect not only hepatocellular carcinoma cells, but also malignant cells from other gastrointestinal carcinomas. In contrast, cytokeratin 19 mRNA lacks specificity for gastrointestinal cancer.

Soft drink consumption among Yup'ik Eskimo teenagers.

Soft drink intake among Yup'ik Eskimo teenagers was assessed as part of a monitoring system for a nutrition education intervention project. Soft drink intakes were found to be three to four times greater than in the general US teenage population. Over half of the soft drinks consumed were in the form of sweetened non-carbonated beverages, e.g., Tang, Koolaid. At the end of two years of intervention, soft drink consumption decreased by 10% in the 10 intervention villages as a whole, while intakes decreased by 4% in the 4 control villages. Soda pop consumption alone decreased by 18% in the intervention villages and increased by 20% in control villages.

In serum veritas-in serum sanitas? Cell non-autonomous aging compromises differentiation and survival of mesenchymal stromal cells via the oxidative stress pathway.

Even tissues capable of complete regeneration, such as bone, show an age-related reduction in their healing capacity. Here, we hypothesized that this decline is primarily due to cell non-autonomous (extrinsic) aging mediated by the systemic environment. We demonstrate that culture of mesenchymal stromal cells (MSCs) in serum from aged Sprague-Dawley rats negatively affects their survival and differentiation ability. Proteome analysis and further cellular investigations strongly suggest that serum from aged animals not only changes expression of proteins related to mitochondria, unfolded protein binding or involved in stress responses, it also significantly enhances intracellular reactive oxygen species production and leads to the accumulation of oxidatively damaged proteins. Conversely, reduction of oxidative stress levels in vitro markedly improved MSC function. These results were validated in an in vivo model of compromised bone healing, which demonstrated significant increase regeneration in aged animals following oral antioxidant administration. These observations indicate the high impact of extrinsic aging on cellular functions and the process of endogenous (bone) regeneration. Thus, addressing the cell environment by, for example, systemic antioxidant treatment is a promising approach to enhance tissue regeneration and to regain cellular function especially in elderly patients.

Meta-analysis: banding ligation and medical interventions for the prevention of rebleeding from oesophageal varices.

BACKGROUND: In patients with oesophageal varices, the combination of endoscopic variceal ligation (EVL) and medical therapy is recommended as standard of care for prevention of rebleeding. The results of previous meta-analyses on this topic are equivocal. AIM: To assess the effects of EVL plus medical therapy vs. monotherapy (EVL or medical therapy alone) for secondary prevention in oesophageal varices. METHODS: Electronic and manual searches were combined. The primary outcome measures were overall rebleeding (variceal and nonvariceal) and mortality. Random-effects meta-analyses were performed with subgroup, sensitivity, regression and sequential analyses to identify sources of intertrial heterogeneity and the robustness of the results. RESULTS: Nine randomised trials were included. In total, 442 patients were randomised to combination therapy and 513 to monotherapy. Combination therapy reduced rebleeding (RR = 0.68; 95% CI = 0.54-0.85; number needed to treat eight patients). The result was confirmed in sequential and regression analyses, but not when limiting the analysis to trials with adequate selection bias control. No effect on overall mortality was identified (RR = 0.89; 95% CI = 0.65-1.21). Combination therapy reduced bleeding-related mortality (RR = 0.52; 95% CI 0.27-0.99; number needed to treat 33 patients) and the risk of rebleeding from oesophageal varices. Combination therapy increased the risk of serious adverse events in fixed, but not in random-effects meta-analyses. CONCLUSIONS: The combination of endoscopic variceal ligation and medical therapy reduce the risk of rebleeding, but not overall mortality. Additional research is needed to determine why reduced rebleeding rates do not lead to reduced mortality.