Role of polysaccharides in food, digestion, and health

Polysaccharides derived from plant foods are major components of the human diet, with limited contributions of related components from fungal and algal sources. In particular, starch and other storage carbohydrates are the major sources of energy in all diets, while cell wall polysaccharides are the major components of dietary fiber. We review the role of these components in the human diet, including their structure and distribution, their modification during food processing and effects on functional properties, their behavior in the gastrointestinal tract, and their contribution to healthy diets.

Definitions, measurements and prevalence of fear of childbirth: a systematic review

Background

Fear of Childbirth (FOC) is a common problem affecting women’s health and wellbeing, and a common reason for requesting caesarean section. The aims of this review were to summarise published research on prevalence of FOC in childbearing women and how it is defined and measured during pregnancy and postpartum, and to search for useful measures of FOC, for research as well as for clinical settings.

Methods

Five bibliographic databases in March 2015 were searched for published research on FOC, using a protocol agreed a priori. The quality of selected studies was assessed independently by pairs of authors. Prevalence data, definitions and methods of measurement were extracted independently from each included study by pairs of authors. Finally, some of the country rates were combined and compared.

Results

In total, 12,188 citations were identified and screened by title and abstract; 11,698 were excluded and full-text of 490 assessed for analysis. Of these, 466 were excluded leaving 24 papers included in the review, presenting prevalence of FOC from nine countries in Europe, Australia, Canada and the United States. Various definitions and measurements of FOC were used. The most frequently-used scale was the W-DEQ with various cut-off points describing moderate, severe/intense and extreme/phobic fear. Different 3-, 4-, and 5/6 point scales and visual analogue scales were also used. Country rates (as measured by seven studies using W-DEQ with ≥85 cut-off point) varied from 6.3 to 14.8%, a significant difference (chi-square = 104.44, d.f. = 6, p < 0.0001).

Conclusions

Rates of severe FOC, measured in the same way, varied in different countries. Reasons why FOC might differ are unknown, and further research is necessary. Future studies on FOC should use the W-DEQ tool with a cut-off point of ≥85, or a more thoroughly tested version of the FOBS scale, or a three-point scale measurement of FOC using a single question as ‘Are you afraid about the birth?’ In this way, valid comparisons in research can be made. Moreover, validation of a clinical tool that is more focussed on FOC alone, and easier than the longer W-DEQ, for women to fill in and clinicians to administer, is required.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-1659-7) contains supplementary material, which is available to authorized users.

Induction of a cationic shift in IgG anti-DNA autoantibodies. Role of T helper cells with classical and novel phenotypes in three murine models of lupus nephritis

We investigated the underlying mechanisms of systemic autoimmune disease in MRL-+/+, (NZB X NZW)F1, and (NZB X SWR)F1 mice, since these strains develop glomerulonephritis without the superimposition of any secondary lupus-accelerating genes. All three strains manifested a common immunoregulatory defect specific for the production of pathogenic anti-DNA autoantibodies that are of IgG class and cationic in charge. At or just before the age they began to develop lupus nephritis, spleen cells of the mice contained a subpopulation of Th cells that selectively induced their B cells in vitro to produce highly cationic IgG autoantibodies to both single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). By contrast, T cells from younger preautoimmune mice were incapable of providing this help. Moreover, only B cells of the older lupus mice could be induced to secrete cationic anti-DNA antibodies of IgG class. B cells of young lupus mice could not produce the cationic autoantibodies even with the help of T cells from the older mice, nor upon stimulation with mitogens. In the older lupus mice we found two sets of Th cells that spontaneously induced the cationic shift in autoantibodies; one set belonged to the classical Th category with L3T4+,Lyt-2- phenotype, whereas the other surprisingly belonged to a double-negative (L3T4-,Lyt-2-), Lyt-1+ subpopulation. The latter set of unusual Th cells were unexpected in these lupus mice since they lacked the lpr (lympho-proliferation) gene. Thus three apparently different murine models of systemic lupus erythematosus possess a common underlying mechanism specific for the spontaneous production of pathogenic anti-DNA autoantibodies.

Prostate Specific Antigen Levels After Radical Prostatectomy in Patients with Organ Confined and Locally Extensive Prostate Cancer

A total of 230 patients with localized prostate cancer underwent radical retropubic prostatectomy at UCLA (pathological stage T1-3 N0, M0). Classification into groups included 115 patients with organ confined disease (group 1), 82 with invasion into or through the capsule (group 2) and 33 with seminal vesicle involvement (group 3). Median followup was 48 months. The 10-year, cause-specific survival was 96%, 90% and 63%, and 5-year, clinical, disease-free survival was 91%, 79% and 58% for the 3 groups, respectively. Recent prostate specific antigen (PSA) levels were measured in most patients, even those operated upon many years ago. Of the patients 41 had detectable (0.4 ng./ml. or greater) PSA levels without any other clinical evidence of progression and 15 with clinical evidence of progression had PSA levels in the detectable range at the time of clinical progression. When isolated detectable PSA was also considered an indicator of progression the 5-year and 10-year, disease-free rates were 61% and 41%, respectively. These data show that radical prostatectomy performed in patients with even microscopic invasion into the capsule, positive margins and seminal vesicle involvement is associated with a higher clinical progression rate than organ confined disease. If isolated detectable PSA is also considered an indicator of recurrence the disease-free survival after radical prostatectomy might be less than indicated by previous studies. The relationship among survival, local tumor extension and PSA must be carefully examined.

Brazilian pemphigus foliaceus autoantibodies are pathogenic to BALB/c mice by passive transfer

Brazilian pemphigus foliaceus (fogo selvagem) is a cutaneous blistering disease endemic to certain areas of South America that has distinctive epidemiologic features suggestive of an infectious disease transmitted by an insect vector. Patients with the disease have antiepithelial autoantibodies, both circulating in the serum and bound to lesional epidermis. In order to examine the possible pathogenic role of these autoantibodies, IgG from the sera of these patients was purified and injected into the peritoneum of neonatal BALB/c mice. Thirty-four of 46 mice (74%) receiving parenteral IgG fractions from these patients developed cutaneous lesions that were identical to the human disease by clinical, histologic, immunologic, and ultrastructural criteria. High-titer Brazilian pemphigus foliaceus sera produced lesions more consistently and rapidly than low-titer sera. When injections were discontinued, new lesions ceased to appear and old lesions resolved. The extent of disease correlated with the titer of human antiepithelial antibodies detected in the mouse serum (z less than 0.01). Similar concentrations of IgG fractions obtained from sera of unaffected Brazilians living in endemic areas and from American donors did not induce disease when injected into littermates. These results establish that the antiepithelial autoantibodies play an important role in the pathogenesis of the cutaneous lesions in Brazilian pemphigus foliaceus.

Glucose-induced protein kinase C activation regulates vascular permeability factor mRNA expression and peptide production by human vascular smooth muscle cells in vitro

Hyperglycemia is an independent risk factor for the development of diabetic microvascular disease. Vascular permeability factor (VPF)/vascular endothelial growth factor (VEGF) is a potent cytokine family that induces angiogenesis and markedly increases endothelial permeability. VPF is produced by many cell types, including vascular smooth muscle (VSM) cells, and has been implicated in the pathogenesis of neovascularization and endothelial dysfunction in diabetes. This study used cultured human VSM cells to study the regulation of VPF production and determine whether elevated glucose concentrations, per se, are a sufficient stimulus for increased VPF production by human cells. In human VSM cells, high extracellular glucose concentrations (20 mmol/l) increased VPF mRNA expression within 3 h (3-fold vs. glucose 5 mmol/l) and significantly increased VPF peptide production within 24 h (1.5-fold) in a time- and glucose concentration-dependent manner. The high glucose-induced increase in VPF mRNA expression was rapidly reversed after normalizing the extracellular glucose concentration and was specific for a high D-glucose concentration, as these effects were not reproduced by osmotic control media containing elevated concentrations of mannitol or L-glucose. High glucose concentrations activate protein kinase C (PKC) in human VSM cells, and PKC inhibitors (H-7 or chelerythrine chloride) or PKC downregulation each prevented the glucose-induced increases in VPF mRNA expression by human VSM cells. In conclusion, high glucose concentrations directly increase VPF mRNA expression and peptide production by human VSM cells via a PKC-dependent mechanism. These results demonstrate a cellular mechanism, whereby hyperglycemia could directly contribute to the development of endothelial dysfunction and neovascularization in diabetes.

Quantitative structure-permeability relationships (QSPRs) for percutaneous absorption

Quantitative structure-permeability relationships (QSPRs) have been derived by many researchers to model the passive, diffusion-controlled, percutaneous penetration of exogenous chemicals. Most of these relationships are based on experimental data from the published literature. They indicate that molecular size (as molecular weight) and hydrophobicity (as the logarithm of the octanol-water partition coefficient; log k(ow)) are the main determinants of transdermal penetration. This article reviews the current state of the art in QSPRs for absorption of chemicals through the skin, and where this technology can be exploited in future research. The main shortfalls in QSPR models result from inconsistency and error of the experimental values used to derive them. This is probably caused by the manner in which they employ data from a variety of sources and, in some cases, slightly different experimental protocols. Further, most current models are based on data generated from either aqueous or ethanolic solution, where each penetrant is present at its saturated solubility or a fraction of its saturated solubility. No models currently account for the influences of formulation upon percutaneous penetration. Current QSPR models provide a significant tool for assessing the percutaneous penetration of chemicals. They may be important in determining the bioavailability of a range of topically applied exogenous chemicals, and in issues of dermal toxicology and risk assessment. However, their current use may be limited by their lack of applicability across different formulation types. As a consequence, their true value may be to make predictions within specific formulation types, as opposed to a general model based on a range of formulation types. In addition, the endpoint of models may be inappropriate for specific applications other than the systemic delivery of topically applied chemicals.

Bifrontal decompressive craniectomy in the management of posttraumatic intracranial hypertension

Bifrontal decompressive craniectomy has been used on an ad hoc basis for the treatment of post-traumatic intracranial hypertension for more than thirty years. In this observational study we report the clinical outcome and physiological effects of the procedure in a series of 26 patients with refractory intracranial hypertension treated on a protocol driven basis. Bifrontal decompressive craniectomy was associated with significant reductions in mean ICP from 37.5 to 18.1 mmHg (p = 0.003). In addition, craniectomy reduced the amplitude of ICP waves (p < 0.02) and increased compensatory reserve (p < 0.05). A favourable outcome was achieved in 69% of patients; 8% were severely disabled and 23% died. We conclude that this study provides pathophysiological evidence that bifrontal decompressive craniectomy significantly reduces posttraumatic intracranial hypertension and improves pressure dynamics. Our results support the continued use of bifrontal decompressive craniectomy in selected patients after head injury.

Measurement of MAP kinase activation by flow cytometry using phospho-specific antibodies to MEK and ERK: potential for pharmacodynamic monitoring of signal transduction inhibitors

Cancer cells frequently show abnormal signaling via the mitogen activated protein kinase (MAP kinase) pathway due to increased activity of surface receptors for growth factors, or as a result of ras mutations. The development of potent anti-cancer agents that target this pathway prompts the need for analytical methods that allow pharmacodynamic monitoring of drug effects in patients during early phase clinical trial. We describe such a method, based on the activation of T-lymphocytes in undiluted peripheral blood using phorbol myristate acetate (PMA). Following rapid hypotonic lysis and formaldehyde fixation, activation of the MAP kinase pathway can then be demonstrated using phospho-specific antibodies that recognize the activated mediators MEK or ERK, followed by surface labeling with anti-CD3 to identify T-lymphocytes. This method was used to investigate the effects of a MEK inhibitor, U0126, and a new raf kinase inhibitor BAY 37-9751 in blood samples from normal donors. Dose-dependent inhibition of pERK activation was demonstrated for both agents. Furthermore, differential effects on pMEK activation allowed the molecular targets of the two inhibitors to be distinguished. In addition to monitoring drug effects in patients during treatment with inhibitors of the MAP kinase pathway, the general methodology described in this paper has the potential for wide application to the study of signal transduction at the single cell level using flow cytometry.

Human serum amyloid A has cytokine-like properties

Human serum amyloid A (SAA) proteins are a group of 12-14 kDa apolipoproteins found predominantly in the high-density lipoprotein (HDL) fraction of plasma. Several functions have been proposed for SAA, but its primary physiological function remains elusive. In this report, we used the monocytic cell line THP-1 to investigate whether recombinant SAA1 (rSAA) or the HDL-rSAA protein complex can affect the capacity of these cells to produce inflammatory cytokines in vitro. Incubation of rSAA, plasma HDL (which contains < or = 30 microg/ml of SAA) or HDL-rSAA complex with THP-1 cells induced synthesis of IL-1beta, IL-1ra and sTNFR-II protein and mRNA. The induction of cytokine synthesis was not due to endotoxin contamination since the effect was abrogated by protein denaturation. The rSAA and HDL-rSAA complex did not induce detectable levels of IL-6 or TNFalpha protein or mRNA. In contrast 10 microg/ml LPS stimulated secretion of the inflammatory cytokines, IL-1beta, IL-6 and TNFalpha, as well as IL-1ra and sTNFR-II from THP-1 cells. We confirmed that rSAA has chemoattractant properties in vivo, by subcutaneous injections into mice and examined the histology of the injection site at 72 h, however, the HDL-rSAA complex has a substantially reduced effect.

SETD2 loss-of-function promotes renal cancer branched evolution through replication stress and impaired DNA repair

Defining mechanisms that generate intratumour heterogeneity and branched evolution may inspire novel therapeutic approaches to limit tumour diversity and adaptation. SETD2 (Su(var), Enhancer of zeste, Trithorax-domain containing 2) trimethylates histone-3 lysine-36 (H3K36me3) at sites of active transcription and is mutated in diverse tumour types, including clear cell renal carcinomas (ccRCCs). Distinct SETD2 mutations have been identified in spatially separated regions in ccRCC, indicative of intratumour heterogeneity. In this study, we have addressed the consequences of SETD2 loss-of-function through an integrated bioinformatics and functional genomics approach. We find that bi-allelic SETD2 aberrations are not associated with microsatellite instability in ccRCC. SETD2 depletion in ccRCC cells revealed aberrant and reduced nucleosome compaction and chromatin association of the key replication proteins minichromosome maintenance complex component (MCM7) and DNA polymerase δ hindering replication fork progression, and failure to load lens epithelium-derived growth factor and the Rad51 homologous recombination repair factor at DNA breaks. Consistent with these data, we observe chromosomal breakpoint locations are biased away from H3K36me3 sites in SETD2 wild-type ccRCCs relative to tumours with bi-allelic SETD2 aberrations and that H3K36me3-negative ccRCCs display elevated DNA damage in vivo. These data suggest a role for SETD2 in maintaining genome integrity through nucleosome stabilization, suppression of replication stress and the coordination of DNA repair.

Multi-polygenic score approach to trait prediction

A primary goal of polygenic scores, which aggregate the effects of thousands of trait-associated DNA variants discovered in genome-wide association studies (GWASs), is to estimate individual-specific genetic propensities and predict outcomes. This is typically achieved using a single polygenic score, but here we use a multi-polygenic score (MPS) approach to increase predictive power by exploiting the joint power of multiple discovery GWASs, without assumptions about the relationships among predictors. We used summary statistics of 81 well-powered GWASs of cognitive, medical and anthropometric traits to predict three core developmental outcomes in our independent target sample: educational achievement, body mass index (BMI) and general cognitive ability. We used regularized regression with repeated cross-validation to select from and estimate contributions of 81 polygenic scores in a UK representative sample of 6710 unrelated adolescents. The MPS approach predicted 10.9% variance in educational achievement, 4.8% in general cognitive ability and 5.4% in BMI in an independent test set, predicting 1.1%, 1.1%, and 1.6% more variance than the best single-score predictions. As other relevant GWA analyses are reported, they can be incorporated in MPS models to maximize phenotype prediction. The MPS approach should be useful in research with modest sample sizes to investigate developmental, multivariate and gene-environment interplay issues and, eventually, in clinical settings to predict and prevent problems using personalized interventions.

Thioredoxin 2 is involved in the oxidative stress response in Escherichia coli

Two genes encoding thioredoxin are found on the Escherichia coli genome. Both of them are capable of reducing protein disulfide bonds in vivo and in vitro. The catalytic site contains a Cys-X(1)-X(2)-Cys motif in a so-called thioredoxin fold. Thioredoxin 2 has two additional pairs of cysteines in a non-conserved N-terminal domain. This domain does not appear to be important for the function of thioredoxin 2 in donating electrons to ribonucleotide reductase, 3'-phosphoadenylsulfate-reductase, or the periplasmic disulfide isomerase DsbC. Our results suggests that the two thioredoxins are equivalent for most of the in vivo functions that were tested. On the other hand, transcriptional regulation is different. The expression of trxC is regulated by the transcriptional activator OxyR in response to oxidative stress. Oxidized OxyR binds directly to the trxC promoter and induces its expression in response to elevated hydrogen peroxide levels or the disruption of one or several of the cytoplasmic redox pathways. Mutants lacking thioredoxins 1 and 2 are more resistant to high levels of hydrogen peroxide, whereas they are more sensitive to diamide, a disulfide bond-inducing agent.

Evaluation of a unique oral contraceptive in the treatment of premenstrual dysphoric disorder

Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome (PMS). This is the first trial of a unique oral contraceptive containing a combination of drospirenone (DRSP, 3 mg) and ethinyl estradiol (EE, 30 microg) for the treatment of PMDD. DRSP is a spironolactone-like progestin with antiandrogenic and antimineralocorticoid activity. Spironolactone has been shown to be beneficial in PMS, whereas oral contraceptives have shown conflicting results. In this double-blind, placebo-controlled trial, 82 women with PMDD (Diagnostic and Statistical Manual of Mental Disorders, 4th ed. [DSM IV]) were randomized to receive DRSP/EE or placebo for three treatment cycles. The primary end point was change from baseline in luteal phase symptom scores as assessed on the Calendar of Premenstrual Experiences (COPE) scale. Patients treated with DRSP/EE showed a numerically greater change from baseline compared with those treated with placebo on each of the 22 COPE items and each of the 4 symptom factors. Between-group differences in symptom improvement reached statistical significance in factor 3 only (appetite, acne, and food cravings, p = 0.027). The secondary end points, Beck Depression Inventory (BDI) and Profile of Mood States (PMS), were consistent with the primary end point in that patients treated with the oral contraceptive showed a numerically greater improvement from baseline compared with those treated with placebo. The results of this study show a consistent trend in the reduction of symptoms that suggested a beneficial effect of DRSP/EE for the treatment of PMDD, despite limitations of the study design.

Ligation of the T cell receptor complex results in activation of the Ras/Raf-1/MEK/MAPK cascade in human T lymphocytes

Stimulation of T cells with antibodies directed towards the T cell receptor complex results in the activation of mitogen-associated protein kinase (MAPK). Two pathways have been described in other cell types that can lead to MAPK activation. One of these pathways involves the activation of Ras, leading to the activation of Raf-1, and the subsequent activation of MEK (MAPK or ERK kinase). The contribution of this pathway in T cells for anti-CD3 or phorbol myristate acetate (PMA)-mediated MAPK activation was examined. We detected the kinase activities of Raf-1 and MEK towards their substrates (MEK for Raf-1 and MAPK for MEK) in this pathway leading to the activation of MAPK. Stimulation of the T cells with either anti-CD3 antibody or PMA resulted in a rapid activation of both Ras and Raf-1. MEK activity towards kinase-active or -inactive recombinant MAPK also increased upon stimulation. In addition, both MAPK and p90rsk were activated in these cells. We suggest that activation of MAPK and the subsequent activation of ribosomal S6 kinase (p90rsk) occurs by the Ras/Raf-1/MEK cascade in T lymphocytes stimulated by ligation of the T cell receptor complex.

Procarbazine, lomustine, and vincristine (PCV) chemotherapy for grade III and grade IV oligoastrocytomas

The authors provided procarbazine, lomustine (CCNU), and vincristine (PCV) chemotherapy to 32 patients whose tumors contained varying mixtures of oligodendroglial and astrocytic cells. Twenty-five patients had oligodendroglioma-astrocytoma (oligoastrocytoma) with a histological Grade of III (19 patients) or IV (six patients); seven had anaplastic oligodendroglioma. The PCV therapy was administered every 6 weeks for a total of at least 124 cycles. The median duration of follow-up review from the start of chemotherapy was 19.3 months. Nineteen patients were treated before receiving radiation therapy and 12 after receiving it (one patient received concurrent radiotherapy and chemotherapy). Grade 3 or 4 hematological toxicity was experienced by nine (31%) of 29 patients. Ten patients had delayed treatment due to treatment-related toxicities (34.5%). Ninety-one percent of the 32 patients responded to the therapy. These included 10 patients with a complete response and 19 with a partial response. The median time to progression was 15.4 months for all patients and 23.2 months for those with Grade III tumors. The median time to progression for patients with Grade III oligoastrocytomas was 13.8 months; for those with Grade IV oligoastrocytoma it was 12.4 months and for those with anaplastic oligodendrogliomas it was 63.4 months (p = 0.0348). These patients survived a median of 49.8 months, 16 months, and 76 or more months, respectively, from the start of chemotherapy (p = 0.0154). The PCV therapy provides durable responses in patients with Grade III or IV oligoastrocytomas.

Racial or ethnic differences in allele frequencies of single-nucleotide polymorphisms in the methylenetetrahydrofolate reductase gene and their influence on response to methotrexate in rheumatoid arthritis

BACKGROUND

The anti-folate drug methotrexate (MTX) is commonly used to treat rheumatoid arthritis.

OBJECTIVE

To determine the allele frequencies of five common coding single-nucleotide polymorphisms (SNPs) in the methylenetetrahydrofolate reductase (MTHFR) gene in African-Americans and Caucasians with rheumatoid arthritis and controls to assess whether there are differences in allele frequencies among these ethnic or racial groups and whether these SNPs differentially affect the efficacy or toxicity of MTX.

METHODS

Allele frequencies in the 677, 1298 and 3 additional SNPs in the MTHFR coding region in 223 (193 Caucasians and 30 African-Americans) patients with rheumatoid arthritis who previously participated in one of two prospective clinical trials were characterised, and genotypes were correlated with the efficacy and toxicity of MTX. Another 308 subjects with rheumatoid arthritis who participated in observational studies, one group predominantly Caucasian and the other African-American, as well as 103 normal controls (53 African-Americans and 50 Caucasians) were used to characterise allele frequencies of these SNPs and their associated haplotypes.

RESULTS

Significantly different allele frequencies were seen in three of the five SNPs and haplotype frequencies between Caucasians and African-Americans. Allele frequencies were similar between patients with rheumatoid arthritis and controls of the same racial or ethnic group. Frequencies of the rs4846051C, 677T and 1298C alleles were 0.33, 0.11 and 0.13, respectively, among African-Americans with rheumatoid arthritis. Among Caucasians with rheumatoid arthritis, these allele frequencies were 0.08 (p<0.001 compared with African-Americans with rheumatoid arthritis), 0.30 (p = 0.002) and 0.34 (p<0.001), respectively. There was no association between SNP alleles or haplotypes and response to MTX as measured by the mean change in the 28-joint Disease Activity Score from baseline values. In Caucasians, the 1298 A (major) allele was associated with a significant increase in MTX-related adverse events characteristic of a recessive genetic effect (odds ratio 15.86, 95% confidence interval 1.51 to 167.01; p = 0.021), confirming previous reports. There was an association between scores of MTX toxicity and the rs4846051 C allele, and haplotypes containing this allele, in African-Americans, but not in Caucasians.

CONCLUSIONS

: These results, although preliminary, highlight racial or ethnic differences in frequencies of common MTHFR SNPs. The MTHFR 1298 A and the rs4846051 C alleles were associated with MTX-related adverse events in Caucasians and African-Americans, respectively, but these findings should be replicated in larger studies. The rs4846051 SNP, which is far more common in African-Americans than in Caucasians, can also be proved to be a useful ancestry informative marker in future studies on genetic admixture.

Activin, inhibin, and follistatin in zebrafish ovary: expression and role in oocyte maturation

Activins, inhibins, and follistatins are important regulators of mammalian reproduction. However, their roles in lower vertebrates are poorly understood. In this study, we examined the expression of activin A, inhibin A, and follistatins in the zebrafish ovary and determined their role in final oocyte maturation. Using reverse transcription-polymerase chain reaction with primers specific for activin/inhibin beta(A) subunit and for follistatins, we detected DNA fragments of the expected size, which, upon sequencing, conformed to activin/inhibin beta(A) and follistatin. Western blot analysis using an antibody against activin/inhibin beta(A) subunit revealed two bands with sizes similar to those of activin A and inhibin A. The expression of follistatins was also confirmed by Western blot analysis. These results suggest that activin A, an inhibin A-like molecule, and follistatins are expressed in the zebrafish ovary. In cultured zebrafish follicles, activin A and inhibin A both induced final oocyte maturation in a dose-dependent manner. The effects of activin A and inhibin A were blocked by their binding protein, follistatin-288. Interestingly, follistatin-288 also inhibited final oocyte maturation induced by gonadotropin and by maturation-inducing hormone (MIH), suggesting that activin A and/or inhibin A may be local regulators mediating gonadotropin- and MIH-induced final oocyte maturation. Taken together, these findings suggest that activin A and inhibin A are paracrine regulators of ovarian functions in fish.

A conventional myosin motor drives neurite outgrowth

Neuritic outgrowth is a striking example of directed motility, powered through the actions of molecular motors. Members of the myosin superfamily of actin-associated motors have been implicated in this complex process. Although conventional myosin II is known to be present in neurons, where it is localized at the leading edge of growth cones and in the cell cortex close to the plasma membrane, its functional involvement in growth cone motility has remained unproven. Here, we show that antisense oligodeoxyribonucleotides, complementary to a specific isoform of conventional myosin (myosin IIB), attenuate filopodial extension whereas sense and scrambled control oligodeoxyribonucleotides have no effect. Attenuation is shown to be reversible, neurite outgrowth being restored after cessation of the antisense regimen. Myosin IIB mRNA was present during active neurite extension, but levels were minimal in phenotypically rounded cells before neurite outgrowth and message levels decreased during antisense treatment. By contrast, the myosin IIA isoform is shown to be expressed constitutively both before and during neurite outgrowth and throughout exposure to myosin IIB antisense oligodeoxyribonucleotides. These results provide direct evidence that a conventional two-headed myosin is required for growth cone motility and is responsible, at least in part, for driving neuritic process outgrowth.

Cross-talk between transcription factors NF-kappa B and C/EBP in the transcriptional regulation of genes

The study of the acute phase response has attracted substantial interest, not only for its medical implication, but also its provision as an excellent system with which to elucidate the molecular mechanisms involved in the modulation of gene expression. Our previous data suggest that the synergistic induction of the major acute phase reactant serum amyloid A2 (SAA2) expression by interleukin-1 (IL-1) and interleukin-6 (IL-6) is mediated by two families of transcription factors, namely NF-kappa B and C/EBP. To understand the molecular mechanisms of this synergy, we have undertaken a molecular dissection of the factors involved in the formation of the regulatory complex. Electrophoretic mobility shift analysis indicates that NF-kappa B p65 (RelA) and p50, but not p52 or c-Rel, bind specifically to the NF-kappa B site of the SAA2 promoter in response to IL-1 stimulation. In addition, C/EBP beta and C/EBP delta, but not C/EBP alpha, bind specifically to the C/EBP site of SAA2 in response to IL-6 stimulation. Transient co-transfection analysis indicates that co-operative association of NF-kappa B p65 with C/EBP beta and, in particular, with C/EBP delta, results in synergistic transcriptional activation of the SAA2 promoter. When incubated together, NF-kappa B p65 and C/EBP beta form a ternary complex by direct protein/protein interaction. Mutational analysis demonstrates that the C-terminus region of the Rel homology domain (RHD) and the C-terminus of the activation domain of p65 are important for its interaction with C/EBP beta. These results suggest the NF-kappa B and C/EBP may form a new complex of transcription factors that mediates the synergistic induction of SAA2 by IL-1 and IL-6.

Detection and clinical significance of occult tumour cells in colorectal cancer

BACKGROUND

A variety of techniques have been employed for the detection of occult tumour cells in the blood, bone marrow and lymph nodes of patients with colorectal cancer. This review examines the methods used, results obtained and the clinical significance of studies in this field.

METHODS

A Medline literature search was performed using the terms colorectal cancer, minimal residual disease, micrometastasis, polymerase chain reaction, reverse transcriptase polymerase chain reaction and immunocytochemistry; further references were obtained from key articles.

RESULTS

Immunocytochemical examination of bone marrow is the benchmark for detecting clinically significant occult disease. Larger standardized studies are required to confirm the prognostic significance of molecular assays for the detection of tumour cells in blood and bone marrow. The prognostic significance of lymph node tumour cells detected by either immunohistochemical or molecular methods awaits further affirmation.

CONCLUSION

Standardization of terminology and techniques used, combined with large prospective clinical studies, is required if detection of occult residual disease is to become a prognostic marker for recurrence in colorectal cancer.

Spontaneous spinal epidural hematoma in children

Spontaneous spinal epidural hematoma is rare in children. It is usually confined to the dorsal epidural space. Ventral spontaneous spinal epidural hematoma (SSEH) is rarer, with only two previous reports. The authors present three children, two with dorsal and one with ventral spinal epidural hematoma, and review the literature. No etiology of the hematoma was found in the authors' patients and there was no history of trauma. A review of 24 patients of children younger than 18 years of age reported in the literature and the authors' three patients revealed that the cervicothoracic region was the most common site of SSEH, the mode of onset was frequently subacute, and there was no male preponderance as has been reported in adults. We found that the initial symptoms were often nonspecific, leading to a delay in diagnosis, especially in younger children. Follow-up data revealed that 15 of the 27 patients recovered completely, 11 had residual neurologic deficits, and one patient died. Irritability and neck pain with restricted movements of the cervical spine in an afebrile child may be early signs of SSEH and often precede onset of neurologic deficits by several hours to days. These signs should alert the clinician to consider spinal epidural hematoma and the need for urgent magnetic resonance imaging (MRI) of the spine for early diagnosis and treatment to minimize morbidity.

Glucocorticoids for acute viral bronchiolitis in infants and young children

BACKGROUND

Systemic glucocorticoids have been widely prescribed for use in infants and young children with acute viral bronchiolitis but the actual benefit of this intervention requires clarification.

OBJECTIVES

To systematically review the evidence on the effectiveness of systemic glucocorticoids for the treatment of infants and young children with acute viral bronchiolitis.

SEARCH STRATEGY

Multiple strategies were incorporated to maximize identification of suitable studies. The following databases were searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2003); MEDLINE (January 1966 to September 2003); Current Contents (1998 to 2000); EMBASE (January 1990 to September 2003); and Sci Search. Handsearches through cited references and contacts with experts were also used.

SELECTION CRITERIA

Only randomised controlled trials (RCT) were eligible for inclusion. Studies were included if participants were diagnosed with acute viral bronchiolitis and treated with systemic (oral, intramuscular or intravenous) corticosteroids. Three reviewers independently selected potentially relevant articles. Four reviewers evaluated these studies, determined eligibility and assessed the methodological quality of each RCT.

DATA COLLECTION AND ANALYSIS

The primary outcome of interest was length of hospital stay (LOS). Secondary outcomes were: respiratory rate, haemoglobin oxygen saturation, and hospital admission and revisit rates. Data were extracted independently by the four reviewers and the results compiled and compared. Two reviewers reassessed studies to clarify points of discrepancy in the data extraction and database entry processes. Missing data were requested from the authors or calculated from other data presented in the study report.

MAIN RESULTS

There was complete agreement on the inclusion of 13 trials and the exclusion of five studies. Two main study recruitment groups were identified: a) infants and young children within the first 48 hours of hospitalisation (10 trials), and b) outpatient infants and young children who were randomised from the emergency department and who may nor may not have required hospital admission (three trials).A total of 1,198 children aged 0 to 30 months were treated with the equivalent of 0.5 to 10 mg/kg of systemic prednisone for two to seven days. Outcomes of interest were not measured in each RCT. In the pooled analysis of seven trials, there was a decrease in LOS in treated children of 0.38 days (95% confidence interval (CI) -0.81 to 0.05), indicating no significant difference between treatment groups. In the pooled analysis of eight trials, the day three clinical score measured: a standard mean difference (SMD) of -0.20 (95% CI -0.73 to 0.32), indicating no difference between treatment groups. Subgroup analyses for base LOS and clinical score outcomes were performed on infants who were a) less than 12 months of age, b) all respiratory syncytial virus (RSV) positive, c) treated with less than 6 mg/kg of prednisone equivalent throughout the illness and d) first-time wheezers. These were limited by the small number of studies in each subgroup. Hospital admission rates were examined in three trials and no difference was seen between treatment groups (odds ratio (OR) 1.05 (95% CI 0.23 to 4.87). Readmission rates were reported in six studies; with no significant differences between treatment groups. Hospital revisit rates were reported in three studies, with a significant difference between treatment groups reported in one study only. The respiratory rate and haemoglobin oxygen saturation were reported descriptively in six RCTs; no differences were found between groups. Co-interventions (oxygen, supportive fluids and bronchodilators) were used similarly between treatment groups in all RCTs.

REVIEWERS' CONCLUSIONS

No benefits were found in either LOS or clinical score in infants and young children treated with systemic glucocorticoids as compared to placebo. There were no differences in these outcomes between treatment groups; either in the pooled groups; either in the pooled analysis or in any of the sub analyses. Among the three studies evaluating hospital admission rates following the initial hospital visit there was no difference between treatment groups. There were no differences found in respiratory rate, haemoglobin oxygen saturation, hospital revisit or readmission rates. Subgroup analyses were significantly limited by the low number of studies in each comparison. Marked study heterogeneity and occasionally conflicting direction of benefit between trials suggests that these results should be interpreted with caution. Specific data on the harm of corticosteroid therapy in this patient population are lacking. Available evidence suggests that corticosteroid therapy is not of benefit in this patient group.

Optic nerve hypoplasia with hypopituitarism. Septo-optic dysplasia with hypopituitarism

Four children had optic nerve hypoplasia with hypopituitarism, and their clinical picture varied with age. The newborn had apnea, hypotonia, seizures, hyopglycemia, and prolong jaundice. The young infant had defective vision, behavioral delay, hypotonia, and seizures. Except for a mildly receding lower jaw and a high-arched palate, the appearance of the patients was not unusual. The fasting blood glucose level was mildly depressed. In two cases the liver was palpable and results of liver function tests were abnormal. The older child, who was blind and mentally retarded, had growth failure. The extent of the pituitary hormone deficiencies was variable, including diabetes insipidus. The septum pellucidum was not invariably absent. Clinical and pathological findings indicate that the brain lesion might be more diffuse than hitherto recognized. Early recognition of this syndrome and timely intervention might diminish serious sequels.