Redescription of Lestidiops distans (Ege, 1953) and comments on Lestidiops cadenati (Maul, 1962) from the eastern Atlantic Ocean (Teleostei: Aulopiformes)

The paralepidid species Lestidiops distans (Ege, 1953) is redescribed on the basis of adult specimens collected from the eastern Atlantic Ocean. Observations on the holotype, a detailed description, and full data of the adults are provided. The complete lateral line running to the caudal fin base found in L. distans is a rare condition, with only some species in the family possessing this character. The distribution range of L. distans, from Senegal (14°N) to Namibia (22°S) along the coastline of the eastern Atlantic Ocean, is revised accordingly. Comments on a congener, Lestidiops cadenati (Maul, 1962), that co-occurs in the western Atlantic are provided.

Triggering the Vapochromic Behavior in C60 via the Supramolecular Wrapping of st-PMMA

Understanding the physicochemical modulation of functional molecules is the primary step in exploring novel stimuli-responsive materials, and preventing the π-π stacking configuration of π-conjugated molecules has been an effective strategy of vapochromic material development, such as of nanoporous frameworks. Nevertheless, the more complicated synthetic strategy should in fact be applied in many circumstances. In this study, we explore a facile supramolecular strategy where the commodity plastic, syndiotactic-poly(methyl methacrylate) (st-PMMA), is utilized to wrap C₆₀ to form the inclusion complex. The structural characterization revealed that C₆₀s in the st-PMMA supramolecular helix had a lower coordination number (CN = 2) compared to the face-centered-cubic packing of pure C₆₀s (CN = 12). Since the st-PMMA/C₆₀ helical complex has structural flexibility, the π-π stacking structure of C₆₀ was further interrupted by the intercalation of toluene vapors, and the complete isolation of C₆₀ in the complex induced the desired vapochromic behavior. Furthermore, the aromatic interaction between C₆₀ and aromatic solvent vapors enabled the st-PMMA/C₆₀ inclusion complex to selectively encapsulate chlorobenzene, toluene, etc., and induce the color change. The st-PMMA/C₆₀ inclusion complex exhibited a transparent film of sufficient structural integrity such that it can still induce a reversible color change after several cycles. As a result, a new strategy has been discovered for the development of novel vapochromic materials via host-guest chemistry.

Chiral Silica with Preferred-Handed Helical Structure via Chiral Transfer

A strategy to obtain chiral silica using an achiral stereoregular polymer with polyhedral oligomeric silsesquioxane (POSS) side chains is described herein. The preferred helical conformation of the POSS-containing polymer could be achieved by mixing isotactic polymethacrylate-functionalized POSS (it-PMAPOSS) and a chiral dopant. The array structure of POSS molecules, which are placed along the helical conformation, is memorized even after removing the chiral dopant at high temperatures, leading to a chiral silica compound with exclusive optical activity after calcination.

The COUP-TFs compose a family of functionally related transcription factors

The chicken ovalbumin upstream promoter transcription factors (COUP-TFs) are members of the steroid/thyroid hormone receptor superfamily and function in transcriptional regulation of a wide variety of genes. The COUP-TFs purified from HeLa nuclear extract by COUP-affinity chromatography are composed of multiple M(r) forms. The Low M(r) COUP-TFs (43,000, 44,000, 46,000, and 47,000 M(r)) produce a relatively fast migrating complex (C1) with DNA in electrophoresis mobility shift assays, while the high M(r) forms (66,000, 68,000, 72,000, and 74,000 M(r)) produce a slower migrating (C2) complex. The high M(r) COUP-TFs were purified by gel filtration chromatography and independently formed the C2 DNA complex, probably acting as dimers. The high M(r) forms are indistinguishable from the low M(r) COUP-TFs in DNA binding and in enhancement of in vitro transcription from the ovalbumin promoter. The finding of multiple COUP-TF forms led us to clone a second low M(r) COUP-TF, "COUP-TF2." The COUP-TF2 sequence has very strong homology with COUP-TF1. The N-termini of COUP-TF1 and COUP-TF2 are least similar, but both contain glutamine-rich and proline-rich motifs, putative activation domains.

n-butylidenephthalide protects against dopaminergic neuron degeneration and α-synuclein accumulation in Caenorhabditis elegans models of Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is the second most common degenerative disorder of the central nervous system that impairs motor skills and cognitive function. To date, the disease has no effective therapies. The identification of new drugs that provide benefit in arresting the decline seen in PD patients is the focus of much recent study. However, the lengthy time frame for the progression of neurodegeneration in PD increases both the time and cost of examining potential therapeutic compounds in mammalian models. An alternative is to first evaluate the efficacy of compounds in Caenorhabditis elegans models, which reduces examination time from months to days. n-Butylidenephthalide is the naturally-occurring component derived from the chloroform extract of Angelica sinensis. It has been shown to have anti-tumor and anti-inflammatory properties, but no reports have yet described the effects of n-butylidenephthalide on PD. The aim of this study was to assess the potential for n-butylidenephthalide to improve PD in C. elegans models.

METHODOLOGY/PRINCIPAL FINDINGS

In the current study, we employed a pharmacological strain that expresses green fluorescent protein specifically in dopaminergic neurons (BZ555) and a transgenic strain that expresses human α-synuclein in muscle cells (OW13) to investigate the antiparkinsonian activities of n-butylidenephthalide. Our results demonstrate that in PD animal models, n-butylidenephthalide significantly attenuates dopaminergic neuron degeneration induced by 6-hydroxydopamine; reduces α-synuclein accumulation; recovers lipid content, food-sensing behavior, and dopamine levels; and prolongs life-span of 6-hydroxydopamine treatment, thus revealing its potential as a possible antiparkinsonian drug. n-Butylidenephthalide may exert its effects by blocking egl-1 expression to inhibit apoptosis pathways and by raising rpn-6 expression to enhance the activity of proteasomes.

CONCLUSIONS/SIGNIFICANCE

n-Butylidenephthalide may be one of the effective neuroprotective agents for PD.

Dose point kernel simulation for monoenergetic electrons and radionuclides using Monte Carlo techniques

Monte Carlo (MC) simulation has been commonly used in the dose evaluation of radiation accidents and for medical purposes. The accuracy of simulated results is affected by the particle-tracking algorithm, cross-sectional database, random number generator and statistical error. The differences among MC simulation software packages must be validated. This study simulated the dose point kernel (DPK) and the cellular S-values of monoenergetic electrons ranging from 0.01 to 2 MeV and the radionuclides of (90)Y, (177)Lu and (103 m)Rh, using Fluktuierende Kaskade (FLUKA) and MC N-Particle Transport Code Version 5 (MCNP5). A 6-μm-radius cell model consisting of the cell surface, cytoplasm and cell nucleus was constructed for cellular S-value calculation. The mean absolute percentage errors (MAPEs) of the scaled DPKs, simulated using FLUKA and MCNP5, were 7.92, 9.64, 4.62, 3.71 and 3.84 % for 0.01, 0.1, 0.5, 1 and 2 MeV, respectively. For the three radionuclides, the MAPEs of the scaled DPKs were within 5 %. The maximum deviations of S(N←N), S(N←Cy) and S(N←CS) for the electron energy larger than 10 keV were 6.63, 6.77 and 5.24 %, respectively. The deviations for the self-absorbed S-values and cross-dose S-values of the three radionuclides were within 4 %. On the basis of the results of this study, it was concluded that the simulation results are consistent between FLUKA and MCNP5. However, there is a minor inconsistency for low energy range. The DPK and the cellular S-value should be used as the quality assurance tools before the MC simulation results are adopted as the gold standard.

Dendritic spine alterations in neocortical pyramidal neurons following postnatal neuronal Nogo-A knockdown

The myelin-associated protein Nogo-A is a well-known inhibitor of axonal regeneration and compensatory plasticity, yet functions of neuronal Nogo-A are not as clear. The present study examined the effects of decreased levels of neuronal Nogo-A on dendritic spines of developing neocortical neurons. Decreased Nogo-A levels in these neurons resulted in lowered spine density and an increase in filopodial type protrusions. These results suggest a role for neuronal Nogo-A in maintaining a spine phenotype in neocortical pyramidal cells.

Definitive chemoirradiation for resectable head and neck cancer: treatment outcome and prognostic significance of MRI findings

The aim of this study was to evaluate the outcome and prognosticators for patients with resectable head and neck cancer (RHNC) undergoing definitive concurrent chemotherapy and radiotherapy (CCRT). In total, 110 RHNC patients receiving definitive CCRT to defer radical surgery were enrolled. Radiotherapy was given as either 2 Gy once daily with 70 Gy, or 1.2 Gy twice daily with 74.4 Gy. Chemotherapy involved the administration of 5-fluorouracil and cisplatin in two concomitant and two post-radiotherapy adjuvant cycles. 3 months after CCRT, MRI was performed to evaluate the response and determine further treatment plans. Survival outcome was calculated by the Kaplan-Meier method. Log-rank test and Cox regression analyses were used to estimate the significance of prognosticators. 4-year local-regional control, distant metastasis-free survival, disease-free survival and overall survival rates were 76.1%, 85.6%, 67.5% and 53.2%, respectively. Local recurrence (odds ratio = 4.09; p < 0.0001) and T3/T4 stage (odds ratio = 2.34; p = 0.01) were the independent factors associated with poor survival. T stage (odds ratio = 3.29; p = 0.03) and/or remission status on post-CCRT MRI (odds ratio = 7.22; p < 0.0001) were significantly associated with local control, distant metastasis-free survival and disease-free survival. 13 of 20 patients with imaging residuum had local recurrence, compared with 12 of 89 with complete remission (4-year local control rate of 27% vs 86%; p < 0.0001). Post-CCRT MRI may thus be used to predict the chance of a successful non-surgical approach.

Marked decrease of cyclosporin bioavailability caused by coadministration of ginkgo and onion in rats

Quercetin was reported to modulate CYP isoenzymes and P-glycoprotein (Pgp), a drug efflux transporter. Our previous study reported that quercetin significantly decreased the bioavailability of cyclosporin, a substrate for CYP3A4 and Pgp, in rats and pigs. Ginkgo and onion contain quercetin and its glycosides as St. John's Wort. The coadministration of cyclosporin with ginkgo or onion may be subject to clinically relevant interactions as St. John's Wort. Therefore, this study aimed to investigate the influences of ginkgo and onion on the absorption and disposition of cyclosporin in rats. Cyclosporin was administered orally and intravenously to rats with and without an oral dose of ginkgo or onion in crossover designs. Blood samples were collected via cardiopuncture and blood cyclosporin concentration was assayed by a specific monoclonal fluorescence polarization immunoassay. Everted gut sac was used to investigate the effects of ginkgo and onion on the function of intestinal Pgp. Oral coadministration of ginkgo and onion significantly decreased the Cmax of cyclosporin by 62% and 60%, and reduced the AUC0-t by 51% and 68%, respectively, whereas no influence was observed when cyclosporin was given intravenously. This indicates that the interactions between cyclosporin and ginkgo or onion occurred mainly at the absorption site. In conclusion, ginkgo and onion markedly decreased the oral bioavailability of cyclosporin. We suggest that concurrent intake of quercetin-rich herbs or foods with cyclosporin are better avoided in order to ensure the efficacy of cyclosporin.

Effects of glucose, fructose and 5-hydroxymethyl-2-furaldehyde on the presystemic metabolism and absorption of glycyrrhizin in rabbits

Our previous study reported that co-administration of honey significantly increased the serum levels of glycyrrhetic acid (GA) after oral administration of glycyrrhizin (GZ) in rabbits. The components of honey are sucrose, glucose, fructose and 5-hydroxymethyl-furaldehyde (HMF). To clarify the causative component(s) in honey that altered the metabolic pharmacokinetics of GZ, rabbits were given GZ (150 mg kg(-1)) with and without glucose (5 g/rabbit), fructose (5 g/rabbit) and HMF (1 mg kg(-1)), respectively, in crossover designs. An HPLC method was used to determine concentrations of GZ and GA in serum as well as GA and 3-dehydroglycyrrhetic acid (3-dehydroGA) in faeces suspension. A noncompartment model was used to calculate the pharmacokinetic parameters and analysis of variance was used for statistical comparison. Our results indicated that the area under curve (AUC) of GA was significantly increased by 29% when HMF was coadministered, whereas the pharmacokinetics of GZ and GA were not significantly altered by coadministration of glucose or fructose. An in-vitro study, using faeces to incubate GZ and GA individually, indicated that HMF significantly inhibited the oxidation of GA to 3-dehydroGA and this may explain the enhanced GA absorption in-vivo. It was concluded that HMF is the causative component in honey that affects the presystemic metabolism and pharmacokinetics of GZ in-vivo.

The Impact of Visual Impairment and Use of Eye Services on Health-Related Quality of Life among the Elderly in Taiwan: The Shihpai Eye Study

To evaluate the effect of impaired vision on health-related quality of life (HRQoL), the authors administered the Medical Outcomes Survey Short-Form 36 (SF-36) to the elderly in a metropolitan Taiwanese community and assessed their visual impairment status. A structured questionnaire was used for door-to-door data collection. Interviewers also collected information on demographics, medical history, and HRQoL. Those who were interviewed were invited to the study hospital for a detailed eye examination. An eye examination, including presenting visual acuity and best-corrected visual acuity, was conducted by ophthalmologists. Presenting visual acuity and best-corrected visual acuity were measured in the better eye. Impaired vision was defined as presenting visual acuity in the better-seeing eye worse than 6/12 (or 20/40) and was used to evaluate the correlation to HRQoL. A total of 1361 subjects at least 65 years of age participated in both the interview and eye examination. Internal-consistency and test-retest reliability of the eight scales were high. Based on the separate multiple regression model, after controlling for all other covariates, subjects in contact with vision services offered by an ophthalmologist had more positive scores on general health perceptions (beta = 4.29; p < 0.001), vitality/energy (beta = 2.73; p < 0.001), and mental health (beta = 2.06; p = 0.01). Impaired vision was associated with significantly lower scores in physical functioning (beta = -3.62; p < 0.001) and social functioning scales (beta = -3.25; p = 0.015). The findings suggest that visual impairment is associated with lower quality of life and use of eye care services is associated with higher quality of life.

Effect of mCOUP-TF1 deficiency on the glossopharyngeal and vagal sensory ganglia

Immunohistochemistry for calcitonin gene-related peptide (CGRP), tyrosine hydroxylase and calbindin D-28k was performed on the glossopharyngeal and vagal ganglia in mCOUP-TFI knockout mice to know the effect of its deficiency on different types of primary sensory neurons. In wild type and heterozygous mice, the glossopharyngeal and vagal ganglia contained abundant CGRP-, tyrosine hydroxylase- and calbindin D-28k-immunoreactive (IR) neurons. In the ganglia of mCOUP-TFI knockout mice, a 38% decrease of CGRP-IR neurons was detected. However, the number of tyrosine hydroxylase- or calbindin D-28k-neurons was not altered by the mCOUP-TFI deficiency. In the tongue of knockout mice, the number of CGRP-IR nerve fibers decreased compared to wild-type and heterozygous mice. The development of CGRP-IR petrosal neurons, which supply innervation of the tongue, may depend on mCOUP-TFI.

Genetically engineered mouse models for lung cancer

The lung is a complex organ consisting of numerous cell types that function to ensure sufficient gas exchange to oxygenate the blood. In order to accomplish this function, the lung must be exposed to the external environment and at the same time maintain a homeostatic balance between its function in gas exchange and the maintenance of inflammatory balance. During the past two decades, as molecular methodologies have evolved with the sequencing of entire genomes, the use of in vivo models to elucidate the molecular mechanisms involved in pulmonary physiology and disease have increased. The mouse has emerged as a potent model to investigate pulmonary physiology due to the explosion in molecular methods that now allow for the developmental and tissue-specific regulation of gene transcription. Initial efforts to manipulate gene expression in the mouse genome resulted in the generation of transgenic mice characterized by the constitutive expression of a specific gene and knockout mice characterized by the ablation of a specific gene. The utility of these original mouse models was limited, in many cases, by phenotypes resulting in embryonic or neonatal lethality that prevented analysis of the impact of the genetic manipulation on pulmonary biology. Second-generation transgenic mouse models employ multiple strategies that can either activate or silence gene expression thereby providing extensive temporal and spatial control of the experimental parameters of gene expression. These highly regulated mouse models are intended to serve as a foundation for further investigation of the molecular basis of human disease such as tumorigenesis. This review describes the principles, progress, and application of systems that are currently employed in the conditional regulation of gene expression in the investigation of lung cancer.

Synergistic effects of corticosterone and kainic acid on neurite outgrowth in axotomized dorsal root ganglion

Corticosterone is the main adrenal glucocorticoids induced by stress in rats. Therapeutic use of high concentration of synthetic glucocorticoids in clinical treatment of spinal cord injury suggests that pharmacological action of glucocorticoids might be beneficial for nerve repair. In this article we cultured axotomized rat dorsal root ganglion neurons to investigate the effects of corticosterone and a glutamate receptor agonist kainic acid on neurite outgrowth. Our results revealed a synergistic effect of corticosterone and kainic acid in promoting neurite outgrowth when applied as early as one and two days in vitro, but not effective at three and four days in vitro. In addition, applied corticosterone and kainic acid were neurotoxic at three and four days in vitro but not at one and two days in vitro. The minimal concentrations of corticosterone and kainic acid to be effective were 10 microM and 1 mM, respectively. The neurotrophic effect of corticosterone and kainic acid was attenuated by the receptor tyrosine kinase A (TrkA) inhibitor AG-879. Western blot analysis and immunocytochemical studies revealed an increase of expressions of both TrkA and growth-associated protein GAP-43 in dorsal root ganglion neurons with combined treatment of corticosterone and kainic acid. Immunocytochemistry showed that corticosterone+kainic acid increase nerve growth factor immunoreactivity in dorsal root ganglion neurites and enhance GAP-43 immunointensity in dorsal root ganglion neurons. These results suggest that the neurotrophic effect of glucocorticoids on axonal regeneration might require facilitation of excitatory stimulation at an early stage of nerve injury, and nerve growth factor may mediate a growth signaling to accomplish the effect.

Combined effects of onconase and IFN-beta on proliferation, macromolecular syntheses and expression of STAT-1 in JCA-1 cancer cells

Prostate cancer (CaP), the most common malignancy in American men, presents its greatest challenge to clinicians when the cancer progresses to the hormone-refractory state. In the present investigation, we studied the combined effects of interferon (IFN) and onconase, each of which has reported antitumor activity, on growth and specific protein expression in JCA-1 cells. Cells were treated for up to 3 days with 1 and 5 microg/ml onconase, with and without concurrent addition of IFN-beta(ser) (10(3) IU/ml). Cell count and viability, and de novo RNA and protein synthesis were determined. Expression and subcellular distribution of STAT-1 were also assessed by immunoblot analysis. JCA-1 cells treated for 3 days with IFN or onconase showed a 15-30% reduction in cell proliferation, which was increased to 42-51% with both agents. Analysis of [35S]methionine incorporation into cells confirmed a more pronounced inhibitory effect elicited by IFN-beta and onconase; IFN-beta and 1 microg/ml onconase each decreased de novo protein synthesis by 23-25%, while the combination resulted in 59% suppression. Similar studies using incorporation of [3H]uridine into RNA yielded less significant effects. Further investigation using pre-labeled cellular RNA and proteins showed that either agent or their combination did not affect the turnover of macromolecules. To test whether the antiproliferative effects of IFN-beta and onconase were correlated with one or more specific gene changes, expression of an IFN-modulated protein, STAT-1, was determined. Both phosphorylated and unphosphorylated forms of STAT-1 and its subcellular distribution in the nucleus and cytoplasm, were increased 3-fold by IFN-beta. The IFN-elicited elevation of STAT-1 was not additionally augmented by onconase but was reduced 20-25% when onconase was simultaneously present as IFN-beta. These data show that the overall changes in STAT-1 did not correlate with the reduction in cell growth and the suppression of de novo protein/RNA synthesis elicited by these two agents, and imply that other target proteins are likely to be involved in the combined effects of IFN-beta and onconase in JCA-1 cells.

Primary lung fibroblasts from the 129 mouse strain exhibit reduced growth factor responsiveness in vitro

Lung fibroblasts are activated to proliferate and produce connective tissue during the development of lung fibrosis. The 129 mouse strain does not develop asbestos-induced fibrogenesis, whereas several other inbred strains rapidly respond to inhaled fibers. Thus, in the experiments presented here, we have compared the responses of primary lung fibroblasts isolated from 129 and C57BL/6 mice. The 129 and C57BL/6 mouse lung fibroblasts (MLFs) proliferated similarly in 10% fetal bovine serum (FBS), but after quiescence, the 129 MLFs grew more slowly in serum and responded less to the BB isoform of platelet-derived growth factor. This is consistent with our finding that the mRNA for the PDGF-a receptor exhibits reduced expression by the 129 MLFs compared to those from C57BL/6 mice. Fibroblasts from the SJL mouse strain, from a C57BL/6-129 hybrid, and from the 3T3 cell line all proliferated more vigorously than MLFs from the 129 mice. In addition, the 129 MLFs exhibited reduced expression of alpha1 procollagen mRNA consequent to treatment with tumor necrosisfactor alpha. Based on these new findings, we suggest that the reduced fibrogenesis in asbestos-exposed 129 mice is due to an intrinsic difference in the ability of the lung fibroblasts to respond to peptide growth factors.

Cdc25B functions as a novel coactivator for the steroid receptors

We have previously demonstrated that overexpression of Cdc25B in transgenic mice resulted in mammary gland hyperplasia and increased steroid hormone responsiveness. To address how Cdc25B enhances the hormone responsiveness in mammary glands, we showed that Cdc25B stimulates steroid receptor-dependent transcription in transient transfection assays and in a cell-free assay with chromatin templates. Surprisingly, the effect of Cdc25B on steroid receptors is independent of its protein phosphatase activity in vitro. The direct interactions of Cdc25B with steroid receptors, on the other hand, were evidenced in in vivo and in vitro assays, suggesting the potential direct contribution of Cdc25B on the steroid receptor-mediated transcription. In addition, p300/CBP-associated factor and CREB binding protein were shown to interact and synergize with Cdc25B and further enhance its coactivation activity. Thus, we have uncovered a novel function of Cdc25B that serves as a steroid receptor coactivator in addition to its role as a regulator for cell cycle progression. This dual function might likely contribute to its oncogenic action in breast cancer.

Sequential recruitment of steroid receptor coactivator-1 (SRC-1) and p300 enhances progesterone receptor-dependent initiation and reinitiation of transcription from chromatin

Employing a cell-free chromatin transcription system that recapitulates progesterone receptor (PR)-mediated transcription in vivo, we have investigated further the coactivator functions of steroid receptor coactivator-1 (SRC-1) in terms of its functional domains as well as cooperation with other coactivators in PR transactivation. By analyzing wild-type and mutant SRC-1 with liganded PR in the chromatin transcription system in vitro, the basic helix-loop-helix/Per-Arnt-Sim domain, the p300-binding domain, and the carboxyl-terminal region (containing the PR-binding site) of SRC-1 were shown to be important for PR transactivation. Although in context of a synthetic promoter its histone acetyltransferase activity was nonessential for PR-mediated transcription, SRC-1 was observed to act synergistically with p300 to enhance PR transactivation from chromatin. Moreover, SRC-1 and p300 were found to function cooperatively to increase the efficiency of productive transcription initiation and reinitiation. Further analysis of synergism between SRC-1 and p300 revealed an obligatory "sequential" recruitment of SRC-1 and p300 to liganded PR. Efficient recruitment of p300 required the presence of SRC-1. In addition, functional analysis of SRC-2 and SRC-3 coactivators indicated that the SRC family modulated PR transactivation from chromatin by a similar mechanism.

TGF-beta1 and IL-6 expression in rat pineal gland is regulated by norepinephrine and interleukin-1beta

The pineal gland is part of the neuroendocrine system that modulates immune functions. Because the gland is outside the blood-brain barrier, it is accessible to direct feedback from circulating cytokines that affect the synthesis and secretion of melatonin. Recent studies have suggested that intrinsic immunoregulatory cytokines mediate these neuro-immune interactions under the control of sympathetic innervation to the pineal. This study focused on the expression of transforming growth factor-beta1 (TGF-beta1) and interleukin-6 (IL-6), two cytokines that have important regulatory functions on both neurons and immune cells. Northern blot RNA analysis showed that TGF-beta1, but not IL-6, was expressed in freshly dissected rat pineal glands from neonatal age (1-day-old) into adults. Immunocytochemistry for TGF-beta1 in adult glands revealed localization of this protein in astrocyte-like cells. The sympathetic neurotransmitter norepinephrine (NE) increased transcript levels for both TGF-beta1 and IL-6 in adult pineal organ cultures. The effect of NE on IL-6 expression was not found in dispersed cell cultures established from neonatal pineal glands. The immunoregulatory molecule interleukin-1beta (IL-1beta) up-regulated the expression of both IL-6 and TGF-beta1 in adult pineal organ cultures, but not in neonate pineal organ cultures. These findings suggest that TGF-beta1 and IL-6 have intrinsic regulatory roles in the pineal gland and that both neural and immune factors are important mechanisms of regulation.

Targeted gene regulation and gene ablation

Investigations of the mechanisms involved in appropriate, developmentally regulated tissue-specific gene transcription have laid the foundations for transgenic and gene-therapy technologies directing specific induction or ablation of genes of interest in a tissue-restricted manner. This technology has further evolved to allow for temporal control of gene expression and ablation. Genes can now be switched on and off or be ablated by administering exogenous compounds. These technologies are based on the development of ligand-inducible transcription factors or recombinases that regulate gene expression or ablation by the administration of specific ligands and should lead to animal models that are better suited for investigating the molecular basis of human disease. This review describes the evolution, components and applications of systems that are currently being employed in transgenic and mutant-mouse technology for the conditional regulation of gene expression and ablation.

Seizure frequency affects event-related potentials (P300) in epilepsy

To analyse the effect of epilepsy an P300 event-related potentials we studied 27 patients with idiopathic generalized epilepsy (IGE), 13 patients with temporal lobe epilepsy (TLE) and 60 normal controls. The prolongation of P300 latencies was highly cor related with increasing age in controls but not epileptic patients. The age-corrected P300 latency used in this study was actual P300 latency-predicted P300 latency (predicted P300 (msec)=306.20+0.79 age, P=0.001, R2=0.32). By using ANOVA analysis, the age-corrected latencies of P300 were significantly longer in TLE patients (19.72+/-47.82 msec, mean+/-SD) than in IGE patients (10.97+/-36.97 msec) and controls (0.23+/-20.28 msec). Likewise, significantly prolonged P300 latencies were seen in the epileptic patients with a seizure frequency more than 400 times (37.21+/-47.50 msec). The multivariate-adjusted odds ratio for those who had TLE was 10.97 (95% CI=3.99 - 30.14 ) in the prolonged latencies of P300 compared with that of IGE patients. The odds ratio of longer latencies of P300 was 7.43 (95% CI=2.75 - 20.08) among those who had a high seizure frequency (> or =400 times) compared with those who had a low seizure frequency. No interaction between TLE and high frequency of attacks was found. The age at onset of seizure and duration of illness was not associated with P300 latency prolongation. From the above results, we might infer that the seizure type of TLE and a high frequency of seizure are two major independent precipitate factors for abnormal latencies of P300 in the epileptic patients.

Effects of propofol on mitochondrial function and intracellular calcium shift in bovine aortic endothelial model

BACKGROUND

Hypotension was commonly encountered in clinical practice during induction of anesthesia with propofol. The purpose of this study is to investigate the effect of propofol on mitochondrial membrane potential and morphology so as to infer its relation with intracellular calcium mobilization in bovine aortic endothelium.

METHODS

In this study, we used the cultured bovine aortic endothelial cells (Gm 7372a) to elucidate the impact of propofol upon the membrane potential and morphology of mitochondria in correlation with its effect on intracellular calcium shift. The intracellular calcium mobilization within the cells preincubated with or without propofol was evaluated using a fluorescent spectrophotometer (confocal microscope) after being treated with Fluo-3. The mobilization of intracellular calcium was demonstrated by the appearance of "hot spots" released from intracellular stores after the addition of an ionophore, ionomycin, to the incubation system. The membrane potential of mitochondria was measured by DiOC6 and the morphology of the mitochondria was evaluated by the treatment of TM Ros and compared with that by the treatment of the uncoupler, FCCP, as control.

RESULTS

The release of calcium "hot spots" from the intracellular stores (e.g. mitochondria) after the addition of ionomycin was visualized to decrease dramatically within the endothelial cells after preincubation with propofol. The membrane potential of mitochondria was significantly inhibited by pretreatment of propofol at 0.01 mM, 37 degrees C for 30 min. Morphologically, the integrity of mitochondria was distorted and fragmented in the presence of propofol as compared with that of control.

CONCLUSIONS

Our data showed that propofol in clinical concentration, 0.01 mM, could inhibit intracellular calcium shift from the intracellular stores and decrease the membrane potential and distort the morphology of mitochondria in bovine aortic endothelial cells. These inhibitions of the function and disfiguration of the morphology of mitochondria signify that the clinical hypotension induced by propofol might be of a potential mechanism.

An in vitro model for evaluation of vaporous toxicity of trichloroethylene and tetrachloroethylene to CHO-K1 cells

Toxicokinetics of trichloroethylene (TCE) and tetrachloroethylene (PER) in culture medium and their toxicity to CHO-K1 cells were investigated by employing an in vitro vapor exposure system. Cells were cultured in a 60 mm petri dish with a 25 mm glass dish glued in the central area. TCE or PER was added to the central glass dish so that it would evaporate and dissolve in the surrounding medium in which cells were growing. The results showed that the concentration of TCE or PER in medium increased significantly within 20 min and then decreased very rapidly with time. After a 24 h incubation, the residual of TCE or PER in the medium was very low, but was displayed in a dose-dependent manner. Treatment of cells with either TCE or PER resulted in a dose- and time-dependent inhibition of cell growth. A significantly increase in the frequency of micronuclei (MN) was also observed with either TCE or PER treatment. Low doses of TCE (5-20 microl) or PER (1-5 microl) significantly enhanced the intracellular glutathione (GSH) level. However, the level of GSH rapidly decreased with higher doses of TCE (40-80 microl) or PER (10-20 microl). Depletion of cellular GSH showed no effect on the sensitivity of cells to TCE or PER treatment. GSH-conjugation has been proposed as an activation mechanism to account for the nephrotoxicity of TCE and PER, however the toxicity of TCE and PER to CHO-K1 cells is probably mediated through a distinct mechanism.

COUP-TFI: an intrinsic factor for early regionalization of the neocortex

Regionalization of the cerebral cortex is thought to involve two phases: an early regionalization phase and a later refinement phase. It has been shown that early regionalization of the neocortex does not require thalamic inputs and is regulated by intrinsic factors. Recently, two such intrinsic factors, Pax6 and Emx2, have been identified. In this study, we identified COUP-TFI as a regulatory factor for early neocortical regionalization. The spatial and temporal expression pattern of COUP-TFI suggested a role in specification of the neocortex and in maintaining cortical identity. Altered region-specific expression of marker genes in the cortex as well as miswired area-specific connections between the cortex and the thalamus in COUP-TFI null mice indicate COUP-TFI plays a critical role in regulating early regionalization. Our results substantiate that COUP-TFI, an intrinsic factor, may work in concert with Pax6 and Emx2 to specify neocortical identity.

Physiological function of the orphans GCNF and COUP-TF

Orphan nuclear receptors are members of the nuclear receptor superfamily of ligand-activated transcription factors for which ligands and functions have not been identified. Since the cloning of the original orphans, ligands have been identified for several orphan receptors that heterodimerize with the retinoid X receptor and are no longer classified as orphan receptors. Considering the central role that nuclear receptors play in differentiation, development, metabolic regulation, homeostasis and disease, it is crucial that we understand the roles of the remaining orphans. However, the identification of ligands for those orphans that form homodimers has proven more difficult. Thus, to gain greater insight into the functions of orphan receptors, gene targeting has been used to knock out these factors and study mouse development in their absence. Here we will review the progress made in understanding the roles of the orphans GCNF and the COUP-TFs with the use of gene knockouts.

Effect of honey and sugars on the metabolism and disposition of naringin in rabbits

To investigate the effect of honey and sugars on the metabolism and disposition of naringin, rabbits were administered naringin alone and naringin with honey or its component sugars - fructose, glucose and sucrose in crossover designs. An HPLC method was developed to determine naringenin in serum after enzymatic hydrolysis. Our results indicate that honey, fructose and sucrose significantly reduced AUC(0-t) of naringenin by 41 %, 61 % and 45 %, respectively. In vitro studies using a rabbit feces suspension to incubate naringin without or with honey or the respective sugars were employed to investigate the mechanism of this interaction. The results indicated that honey and its component sugars did not affect the rate and extent of naringin hydrolysis, whereas the degradation of naringenin was significantly enhanced in the presence of honey and fructose. It could be concluded that concomitant intake of honey, fructose and sucrose resulted in the reduction of naringin absorption which could be attributable in part to the enhanced preabsorption degradation of absorbable naringenin in the large intestine.

Examining prognostic factors and patterns of failure in nasopharyngeal carcinoma following concomitant radiotherapy and chemotherapy: impact on future clinical trials

PURPOSE

Concomitant chemotherapy and radiotherapy (CCRT), followed by adjuvant chemotherapy, has improved the outcome of nasopharyngeal carcinoma (NPC). However, the prognosis and patterns of failure after this combined-modality treatment are not yet clear. In this report, the prognostic factors and failure patterns we observed with CCRT may shed new light in the design of future trials.

METHODS AND PATIENTS

One hundred forty-nine (149) patients with newly diagnosed and histologically proven NPC were prospectively treated with CCRT followed by adjuvant chemotherapy between April 1990 and December 1997. One hundred and thirty-three (89.3%) patients had MRI of head and neck for primary evaluation before treatment. Radiotherapy was delivered either at 2 Gy per fraction per day up to 70 Gy or 1.2 Gy per fraction, 2 fractions per day, up to 74.4 Gy. Chemotherapy consisted of cisplatin and 5-fluorouracil. According to the AJCC 1997 staging system, 32 patients were in Stage II, 53 in Stage III, and 64 in Stage IV (M0).

RESULTS

Univariate analysis revealed that WHO (World Health Organization) Type II histology, T4 classification, and parapharyngeal extension were poor prognostic factors for locoregional control. Multivariate analysis revealed that T4 disease was the most important adverse factor that affects locoregional control, the risk ratio being 5.965 (p = 0.02). Univariate analysis for distant metastasis revealed that T4 and N3 classifications, serum LDH level > 410 U/L (normal range, 180-460), parapharyngeal extension, and infiltration of the clivus were significantly associated with poor prognosis. Multivariate analysis, however, revealed that T4 classification and N3 category were the only two factors that predicted distant metastasis; the risk ratios were 3.994 (p = 0.02) and 3.390 (p = 0.01), respectively. Therefore, based on the risk factor analysis, we were able to identify low-, intermediate-, and high-risk patients. Low-risk patients were those without the risk factors mentioned above. They consisted of Stage II patients with T2aN0, T1N1, and T2aN1 categories and of Stage III patients with T1N2 and T2aN2 categories. Their risk of recurrence is low (4%). Intermediate-risk patients were those with at least one univariate risk factor. They are Stage II patients with T2bN0 and T2bN1 categories and Stage III patients with T2bN2 and T3N0-2 categories. The risk of recurrence is modest (18%). High-risk patients have risk factors by multivariate analysis. They are stage T4 or N3 patients. Their risk of recurrence is high (36%).

CONCLUSION

Low-risk patients have an excellent outcome. Future trials should focus on reducing treatment-associated toxicities and complications and reevaluate the benefit of sequential adjuvant chemotherapy. The recurrence in treatment of intermediate-risk patients is modest; CCRT and adjuvant chemotherapy may be the best standard for them. Patients with T4 and N3 disease have poorer prognosis. Hyperfractionated radiotherapy may be considered for the T4 patients. Future study in these high-risk patients should also address the problem of distant spread of the disease.

Transforming growth factor-beta(1) overexpression in tumor necrosis factor-alpha receptor knockout mice induces fibroproliferative lung disease

Tumor necrosis factor-alpha receptor knockout (TNF-alphaRKO) mice have homozygous deletions of the genes that code for both the 55- and 75-kD receptors. The mice are protected from the fibrogenic effects of bleomycin, silica, and inhaled asbestos. The asbestos-exposed animals exhibit reduced expression of other peptide growth factors such as transforming growth factor (TGF)-alpha, platelet-derived growth factors, and TGF-beta. In normal animals, these and other cytokines are elaborated at high levels during the development of fibroproliferative lung disease, but there is little information available that has allowed investigators to establish the role of the individual growth factors in disease pathogenesis. Here, we show that overexpression of TGF-beta(1) by means of a replication-deficient adenovirus vector induces fibrogenesis in the lungs of the fibrogenic-resistant TNF-alphaRKO mice. The fibrogenic lesions developed in both the KO and background controls within 7 d, and both types of animals exhibited similar incorporation of bromodeoxyuridine. Interestingly, airway epithelial cell proliferation appeared to be suppressed, perhaps due to the presence of the TGF-beta(1), a well-known inhibitor of epithelial mitogenesis. Before these experiments, there was no information available that would provide a basis for predicting whether or not TGF-beta(1) expression induces fibroproliferative lung disease in fibrogenic-resistant TNF-alphaRKO mice, an increasingly popular animal model.

Blunted renal responses to angiotensin II infusion in lifetime captopril-treated spontaneously hypertensive rats

Previously, we had found that inhibition of the renin-angiotensin system in the early lifespan of spontaneously hypertensive rat could prevent the development of hypertension in this animal model. In the present study we evaluated the responses of blood pressure and renal function to intracerebroventricular administration of angiotensin II in long-term captopril-treated spontaneously hypertensive rats. Spontaneously hypertensive rats had been mated and their pups were treated with captopril through drinking water after birth. Age-matched Wistar-Kyoto and spontaneously hypertensive rats drinking tap water were used as control groups. At 4 months of age, the basal mean arterial blood pressure of captopril-treated hypertensive rats was the lowest among those of controlled hypertensive and normotensive rats (98+/-5 vs. 160+/-4 and 126+/-4 mmHg, respectively). Intravenous administration of angiotensin II caused similar increments of blood pressure in all rat groups. However, intracerebroventricular administration of angiotensin II to captopril-treated hypertensive rats induced a significantly less increase of arterial blood pressure in comparison with other groups. The sensitivity of baroreflex in captopril-treated hypertensive rats was also the lowest among all rat groups. The basal urine flow, sodium and potassium excretion rates, and osmolar clearance of captopril-treated hypertensive rats were significantly higher than those of controlled hypertensive rats. Intracerebroventricular infusion of angiotensin II caused significant increases in urine flow, electrolytes excretion, osmolar clearance, and free water reabsorption rate of both normotensive and controlled hypertensive rats. However, the same angiotensin II treatment did not change any of the renal excretion indices in captopril-treated hypertensive rats. Our results suggest that lifetime captopril treatment can decrease the activity of the renin-angiotensin system in the brain of hypertensive animals, which caused increases in basal urine flow and excretion of electrolytes and enhanced the sensitivity of baroreflex. It is likely that changes in the renal and baroreflex functions underlie the prevention of hypertension elicited by long-term captopril treatment.

Phenotypic consequences of lung-specific inducible expression of FGF-3

Members of the fibroblast growth factor (FGF) family play a critical role in embryonic lung development and adult lung physiology. The in vivo investigation of the role FGFs play in the adult lung has been hampered because the constitutive pulmonary expression of these factors often has deleterious effects and frequently results in neonatal lethality. To circumvent these shortcomings, we expressed FGF-3 in the lungs under the control of the progesterone antagonist-responsive binary transgenic system. Four binary transgenic lines were obtained that showed ligand-dependent induction of FGF-3 with induced levels of FGF-3 expression dependent on the levels of expression of the GLp65 regulator as well as the dose of the progesterone antagonist, RU486, administered. FGF-3 expression in the adult mouse lung resulted in two phenotypes depending on the levels of induction of FGF-3. Low levels of FGF-3 expression resulted in massive free alveolar macrophage infiltration. High levels of FGF-3 expression resulted in diffuse alveolar type II cell hyperplasia. Both phenotypes were reversible after the withdrawal of RU486. This system will be a valuable means of investigating the diverse roles of FGFs in the adult lung.

Effects of symptomatic severity on elevation of plasma soluble interleukin-2 receptor in bipolar mania

BACKGROUND

Circulating soluble interleukin-2 receptors (sIL-2Rs) and soluble interleukin-6 receptors (sIL-6Rs) are stable immune measures. Elevated plasma sIL-2R levels are present in patients with schizophrenia, major depression, and bipolar mania, but not with minor psychiatric disorders. The increased plasma sIL-2R levels are state-dependent in bipolar mania. However, altered production of plasma sIL-6R and the effects of clinical characteristics on plasma sIL-6R and sIL-2R levels in bipolar disorder remains uncertain.

METHODS

Plasma sIL-2R and sIL-6R levels were measured in 31 Taiwanese bipolar manic (DSM-IV) patients with Young Mania Rating Scale (YMRS) scores of > or =26 as well as during the subsequent remission (YMRS< or =12), and equal numbers of age- and gender-matched healthy controls. The relationships of clinical variables such as age, age of onset, smoking, medication status, coexisting psychotic features, number of prior episodes, duration of illness, presence of depression before or following the manic episode, and manic severity to plasma sIL-2R and sIL-6R levels in acute mania along with remission were examined.

RESULTS

Plasma sIL-2R but not sIL-6R levels were significantly higher in acute mania than in subsequent remission (P<0.05) and controls (P<0.0005). In acute mania, the plasma sIL-2R levels were significantly correlated to YMRS scores (r=0.34, P<0.05). The remaining clinical variables had no effect on plasma sIL-2R and sIL-6R levels in acute mania or remission. There was a significantly positive relationship between the reduction of plasma sIL-2R levels from the acute to follow-up measurements (DeltasIL-2R) and symptomatic improvement of acute mania (DeltaYMRS) (r=0.61, P<0.001).

LIMITATIONS

Our sample included medicated and unmedicated patients in acute mania. The psychotropic medication may have divergent effects on the plasma sIL-2R levels in acute mania and subsequent remission.

CONCLUSIONS

Elevation of plasma sIL-2R but not sIL-6R levels in bipolar mania supports the idea that the immunomodulatory mechanism may vary in different psychotic disorders. In contrast to being a trait marker in schizophrenia and depressive disorder, plasma sIL-2R levels may be considered a biological indicator of manic severity in a group of bipolar affective patients.

Causes of death of patients with substance dependence: a record-linkage study in a psychiatric hospital in Taiwan

AIMS

The causes of death among a series of patients with substance dependence were investigated.

SETTING

A psychiatric teaching hospital in Taipei, Taiwan (Taipei City Psychiatric Center).

PARTICIPANTS

A total of 1698 patients with various diagnostic categories of substance dependence, who had been admitted to TCPC for detoxification were followed-up from 1985 to 1996.

DESIGN

A record-linkage study was performed using the patient's national identification number to link between TCPC chart records and the mortality file compiled by the National Department of Health. Risk factor analyses for mortality included socio-demographic data, clinical diagnosis and cause of death.

FINDINGS

A total of 141 patients died during the study period. Among them, 83 had a diagnosis of alcohol dependence, 41 of heroin dependence and the remaining 17 cases of sedative, glue or hallucinogen dependence. The annual mortality rate of patients with heroin dependence was 1.94%. Accidental death is the leading cause of death among patients with heroin dependence. However, the patients with alcohol dependence had a higher mortality risk than those with heroin dependence (relative hazard = 1.91, p < 0.001) in this study. The proportion of non-violent death was significantly higher among the patients with alcohol dependence than those with heroin dependence (p < 0.005).

CONCLUSION

The causes of death among patients with substance dependence found in this Taiwanese series were very similar to those reported in the western literature. However, differences included the absence of death among heroin addicts due to HIV-related disease and a markedly high percentage of alcoholic patients who died of liver diseases.

Microglia play a role in mediating the effects of cytokines on the structure and function of the rat pineal gland

The role of the pineal gland in regulating immune function has been extensively investigated. However, there is little information about possible feedback mechanisms of immunological factors on pineal gland neuroendocrine functions. Therefore, experiments were designed to test the effects of cytokines (interferon-gamma, IFN-gamma, interleukin-1 beta, IL-1 beta; tumor necrosis factor-alpha, TNF-alpha; transforming growth factor-beta 1, TGF-beta 1) on pinealocytes and the role of pineal microglia in mediating these cytokine effects in the pineal gland of the rat. Our studies showed that IFN-gamma enhanced 5-hydroxytryptamine (5-HT) content (measured by high-performance liquid chromatography, HPLC) and increased pinealocyte process length in pineal cultures. IL-1 beta treatment decreased 5-HT content in both cell and organ culture, but exhibited no effect on pinealocyte process length. 5-HT content and process length were decreased by TNF-alpha treatment. IFN-gamma and IL-1 beta exhibited no significant effect in the absence of microglia in cell cultures. In contrast, TNF-alpha caused a further decline in 5-HT content even in the absence of microglia in the cultures. The effects of TNF-alpha were probably due to toxic effects, since an increased number of pyknotic nuclei were observed in treated cultured explants. TGF-beta 1 treatment caused aggregation of pinealocytes in cultures and suppressed process length and 5-HT content. In conclusion, cytokine effects on pinealocytes may be mediated by microglia (IFN-gamma and IL-1 beta) or act directly on pinealocytes (TNF-alpha). The presence of IL-1 beta and TGF-beta 1 protein in the pineal gland and the suppressive effect of TGF-beta 1 on pinealocytes in cultures further suggest that endogenous cytokines play regulatory roles in response to peripheral homeostatic changes.

Long-term survival of nasopharyngeal carcinoma following concomitant radiotherapy and chemotherapy

PURPOSE

The purpose of this study is to demonstrate long-term survival of nasopharyngeal carcinoma treated with concomitant chemotherapy and radiotherapy (CCRT) followed by adjuvant chemotherapy.

METHODS AND PATIENTS

One hundred and seven patients with Stage III and IV (American Joint Committee on Cancer, AJCC, 1988) nasopharyngeal carcinoma (NPC) were treated with concomitant chemotherapy and radiotherapy (CCRT) followed by adjuvant chemotherapy between April 1990 and December 1997 in Koo Foundation Sun Yat-Sen Cancer Center, Taipei. The dose of radiation was 70 Gray (Gy) given in 35 fractions, 5 fractions per week. Two courses of chemotherapy, consisting of cisplatin and 5-fluorouracil, were delivered simultaneously with radiotherapy in Weeks 1 and 6 and two additional monthly courses were given after radiotherapy. According to the AJCC 1997 staging system, 32 patients had Stage II disease, 44 had Stage III, and 31 had Stage IV disease.

RESULTS

With median follow-up of 44 months, the 5-year overall survival rate in all 107 patients was 84.1%, disease-free survival rate was 74.4%, and locoregional control rate was 89.8%. The 3-year overall survival for Stage II was 100%, for Stage III it was 92.8%, and for Stage IV, 69. 4% (p = 0.0002). The 3-year disease-free survival for Stage II was 96.9%, for Stage III it was 87.7%, and for Stage IV it was 51.9% (p = 0.0001).

CONCLUSION

CCRT and adjuvant chemotherapy is effective in Taiwanese patients with advanced NPC. The prognosis of AJCC 1997 Stage II and III disease is excellent, but, for Stage IV (M0), it is relatively poor. Future strategies of therapy should focus on high-risk AJCC 1997 Stage IV (M0) cohort.

Characteristics of mentally retarded criminal offenders in Northern Taiwan

The characteristics and criminal behavior in mentally retarded individuals remain largely unstudied. This retrospective study sought to establish a set of reference of criminal behavior characteristics in an ethnic Chinese mentally retarded group. Data were collected from forensic psychiatric evaluation of 32 mentally retarded offenders. Of the 32 offenders, only four (12.5%) cases were female. Mean age at the time of the offenses was 31. By IQ testing, 23 (71.9%) of the group fell into the mild mental retardation range, seven (21.9%) into the moderate mental retardation range, and two (6.2%) into the severe mental retardation range. Nineteen (59.3%) of the group also suffered from additional mental disorder. Eight (25%) had definite neurological deficit. Fourteen (43.8%) were repeat offenders. A total of 24 (75%) of the offenders had committed crimes against property, with 13 having committed petty theft. Furthermore, the pattern of offending shows differences from that of the general population or other mental disorders. The property offenses, especially petty theft and arson, were frequently seen. There was no noteworthy above average frequency of sexual offenses.

Adenovirus-mediated transfer of regulable gene expression

The past several years have seen significant progress in the development of adenoviral vectors with markedly decreased pathological potential and greatly increased capacity for incorporation of foreign DNA. Paralleling these developments in gene transfer technology have been remarkable advances in both the design and optimization of gene regulatory systems. Ultimately, the goal of these gene regulatory systems is control of transgene expression in vivo by the administration of an exogenous compound. With the prospect of clinical human gene therapy on the horizon, the co-evolution of safe and efficient gene transfer strategies, with effective regulation of transgene expression, represents an essential step towards therapeutically viable gene transfer protocols. This review introduces recent advances in both adenoviral-based vectors and gene regulatory systems, and examines those studies in which adenoviral vectors and gene-regulatory systems have been combined in vivo.

Modulation of the murine peroxisome proliferator-activated receptor gamma 2 promoter activity by CCAAT/enhancer-binding proteins

Peroxisome proliferator-activated receptor gamma (PPARgamma) and CCAAT/enhancer-binding proteins (C/EBPs) are transcriptional regulators essential for adipocyte differentiation and function. Previous findings indicate that PPARgamma2 transcription is regulated by members of the C/EBP family. We demonstrate here that C/EBPalpha and C/EBPdelta, but not C/EBPbeta, induce the activity of the PPARgamma2 promoter in transiently transfected 3T3-L1 preadipocytes and bind to two juxtaposed low affinity C/EBP binding sites. Results obtained with chimeras containing interchanged C/EBPalpha-C/EBPbeta N-terminal transactivation domain and C-terminal DNA binding dimerization domain indicate that the N-terminal part of C/EBPbeta prevents it from binding to the PPARgamma2 promoter. Indeed, deletion mutants of C/EBPbeta lacking the N-terminal part of the molecule are able to bind to the PPARgamma2 promoter. We further demonstrate that deletion of a region located between amino acids 184-212, upstream of the DNA binding domain, permits C/EBPbeta binding to the PPARgamma2 promoter, implicating an inhibitory region in C/EBPbeta for modulating DNA binding specificity to the PPARgamma2 promoter. In summary, this study indicates that C/EBPbeta but not C/EBPalpha or C/EBPdelta is unable to bind to C/EBP binding sites in the mouse PPARgamma2 promoter. The lack of binding is due to a region N-terminal of the C/EBPbeta DNA binding domain. Our findings illustrate a mechanism by which C/EBP isoforms differentially modulate the transactivation of the PPARgamma2 promoter.

COUP-TF orphan nuclear receptors in development and differentiation

Chicken ovalbumin upstream promoter transcription factors (COUP-TFs) are orphan members of the steroid/thyroid hormone receptor superfamily. They have been shown to negatively regulate the activation function of vitamin D, thyroid hormone, retinoic acid, the retinoid X and the peroxisome proliferator-activated receptors. COUP-TF genes have been cloned from many species and their sequences are exceptionally conserved through evolution. This suggests a critical role for the COUP-TFs in these organisms. Indeed, the Drosophila COUP-TF, seven-up and mouse COUP-TFII are essential for development and differentiation during embryogenesis. Our current understanding of COUP-TF function suggests that they serve vital physiological roles during development despite extensive overlaps of expression. This defines the COUP-TFs as important factors in regulation of development and differentiation in multiple organisms.

Vibration perception thresholds in workers with long term exposure to lead

OBJECTIVES

To evaluate the impact of long term occupational exposure to lead on function of the peripheral nervous system as reflected by vibration perception threshold (VPT), measured with a portable vibrameter.

METHODS

217 Workers in a lead battery factory were required to have an annual blood lead measurement during each of the 5 years preceding this study. All were invited to take the VPT test. A total of 206 workers were studied. The associations were analysed between VPTs and current blood lead concentration, mean concentration of blood lead over the past 5 years, maximum blood lead concentration during the past 5 years, index of cumulative blood lead (ICL), time weighted index of cumulative blood lead (TWICL), and percentage of lifespan spent at work in the plant, as well as the other potential confounders. Ordinary multiple regressions, generalised additive models, and hockey stick regression analyses were used to explore the potential existence of a threshold effect of blood lead variables on VPT.

RESULTS

VPT at a frequency of 220 Hz ranged from 6 to 100 (10(-2) g, or 0.098 m/s(2)) with a mean (SD) of 19.8 (14.2) for the feet and from 4 to 43 with a mean (SD) of 10.2 (6.1) for the hands. The five variables of exposure to lead were all significantly correlated with VPT of the feet but not the hands. In multiple linear regression analyses, the mean of the blood lead concentrations and the TWICL were significantly associated with VPT of the feet. The relation between VPT of the feet and mean blood lead was shown to be a J shaped curve with a generalised additive model and local smoothing technique. In the hockey stick regression, evidence was found of a threshold effect at a mean blood lead concentration of 31 microgram/dl. Above this threshold it was estimated that each increase of 1 microgram/dl mean blood lead over 5 years would increase VPT of the feet by 0.29 (10(-2) g) or 0.028 m/s(2) (at a frequency of 220 Hz) with other potential confounders held constant.

CONCLUSION

This study suggests that measurement of vibration sensory threshold is a relatively effective tool for detecting lead neuropathy in field studies, and that lead might cause sensory neuropathy with an effect threshold corresponding to a 5 year mean blood lead concentration of 31 microgram/dl.

Regulable expression of inhibin A in wild-type and inhibin alpha null mice

Exogenous regulation of protein expression creates the potential to examine the consequences of homeostatic Dysregulation in many physiological systems and, when used in transgenic mice, provides the capability of restoring a gene product to its knockout background without antigenicity issues. In this study, we used a mifeprisone-inducible system (the GeneSwitch system) to regulate the expression of inhibin A from the liver of mice. Inhibin is a heterodimeric protein (alpha/beta) wherein one of its subunits (beta) is capable of homodimerizing to form its physiological antagonist, activin (beta/beta). Inhibin is also expressed in two forms, A and B, as determined by the subtype of beta-subunit that dimerizes with the alpha-subunit (alpha/betaA or alpha/betaB). To utilize the GeneSwitch system, transgenic transactivator mice with liver-specific expression of a mifepristone-activated chimeric nuclear receptor (GLVP) were crossed with transgenic target mice containing a GVLP-responsive promoter upstream of polio-virus IRES (internal ribosome entry site)-linked sequences coding for the alpha- and beta-subunits of inhibin A. This intercross produced "bigenic" mice capable of regulable expression of inhibin A from the liver. Overexpression of inhibin A in wild-type mice produced a phenotype wherein males had decreased testis size and females had a block in folliculogenesis at the early antral stage, findings similar to activin type IIA receptor (ActRIIA) null mice. These phenotypes were most likely due to suppressed serum FSH, confirming that the liver-derived inhibin A was secreted into the serum to down-regulate pituitary FSH levels. Furthermore, the generation of bigenic mice in the inhibin alpha null background allowed for the induction of inhibin A in inhibin alpha null male mice with subsequent rescue of these mice from their gonadal tumor-induced lethal phenotype. This work demonstrates the in vivo production of a heterodimeric hormone from a single inducible promoter to study its therapeutic and physiological effects. In addition, these studies are the first example of an inducible system being used to prevent a lethal knockout phenotype in an animal model.

Local radiotherapy with or without transcatheter arterial chemoembolization for patients with unresectable hepatocellular carcinoma

PURPOSE

To evaluate the treatment outcome, patterns of failure, and prognostic factors for patients with unresectable hepatocellular carcinoma (HCC) treated with local radiotherapy alone or as an adjunct to transcatheter arterial chemoembolization (TACE).

METHODS AND MATERIALS

From March 1994 to December 1997, 25 patients with unresectable HCC underwent local radiotherapy to a portion of the liver. Twenty-three patients were classified as having cirrhosis in Child-Pugh class A and 2 in class B. Mean diameter of the treated hepatic tumor was 10.3 cm. Mean dose of radiation was 46.9 +/- 5.9 Gy in a daily fraction of 1.8-2 Gy. Sixteen patients were also treated with Lipiodol and chemotherapeutic agents mixed with Ivalon or Gelfoam particles for chemoembolization, either before and/or after radiotherapy. Percutaneous ethanol injection therapy (PEIT) was given to one patient. All patients were monitored for treatment-related toxicity and for survival and patterns of failure.

RESULTS

In a median follow-up period of 23 months, 11 patients were alive and 14 dead. The median survival duration from treatment was 19.2 months with a 2-year survival of 41%. Only 3 of 25 patients had local progression of the treated hepatic tumor. The recurrences were seen within the liver or extrahepatic. The 2-year local, regional, and extrahepatic progression-free survival rates were 78%, 46%, and 39%, respectively. The local control ranked the highest. Patients with Okuda Stage I disease had significantly longer survival than those with Stage II and III (p = 0.02). Patients with T4 disease (p = 0.02) or treated with radiotherapy alone (p = 0.003) had significantly shorter survival. T4 disease (p = 0.03) and pretreatment alpha-fetoprotein level of more than 200 ng/ml (p = 0. 03) were associated with significantly worse regional progression-free survival. A significant difference was observed in both regional progression-free survival (p = 0.0001) and extrahepatic progression-free survival (p = 0.005) between patients with and without portal vein thrombosis before treatment. The presence of satellite nodules had a significantly worse impact on regional progression-free survival (p = 0.04) and extrahepatic progression-free survival (p = 0.03). Patients with hepatic tumor more than 6 cm in diameter or portal vein thrombosis tended to have shorter survival. Radiation-induced liver disease (RILD) and gastrointestinal bleeding were the most common treatment-related toxicities.

CONCLUSION

Radiotherapy is effective in the treatment of patients with unresectable HCC. Its effect appeared to be more prominent within the site to which radiation was given. The combination of TACE and radiation was associated with better control of HCC than radiation given alone, probably due to the selection of patients with favorable prognosis for the combined treatment. A dose-volume model should be established in the next phase of research in the treatment of unresectable HCC.

Concomitant radiotherapy and chemotherapy for early-stage nasopharyngeal carcinoma

PURPOSE

Early-stage nasopharyngeal carcinoma (NPC) continues to carry a failure rate of 15% to 30% when treated with radiotherapy alone; the benefit of concomitant radiotherapy and chemotherapy (CCRT) in early-stage NPC is unclear. The purpose of this report is to describe our efforts to improve treatment outcome in early-stage NPC after CCRT.

PATIENTS AND METHODS

Of 189 newly diagnosed NPC patients without evidence of distant metastases who were treated in our institution between 1990 and 1997, 44 presented with early-stage (stage I and II) disease according to the American Joint Committee on Cancer (AJCC) 1997 NPC staging system. Twelve of these patients were treated with radiotherapy alone and 32 with CCRT. Each patient's head and neck area was evaluated by magnetic resonance imaging or computed tomography. Radiotherapy was administered at 2 Gy per fraction per day, Monday through Friday, for 35 fractions for a total dose of 70 Gy. Chemotherapy consisting of cis-diamine-dichloroplatinum and fluorouracil was delivered simultaneously with radiotherapy in weeks 1 and 6 and sequentially for two monthly cycles after radiotherapy.

RESULTS

Patients who were treated with radiotherapy alone primarily had stage I disease, whereas none of those who were treated with CCRT had stage I disease (11 of 12 patients v none of 32 patients; P =.001). The locoregional control rate at 3 years for the radiotherapy group was 91.7% (median follow-up period, 34 months) and was 100% for the CCRT group (median follow-up period, 44 months) (P =.10). The 3-year disease-free survival rate in the radiotherapy group was 91.7% and was 96.9% in the CCRT group (P =.66).

CONCLUSION

Our results reveal excellent prognosis of AJCC 1997 stage II NPC treated with CCRT. Stage II patients with a greater tumor burden treated with CCRT showed an equal disease-free survival, compared with stage I patients treated with radiotherapy alone. A prospective randomized trial is underway to confirm the role of CCRT in stage II NPC.

The nuclear orphan receptor COUP-TFI is required for differentiation of subplate neurons and guidance of thalamocortical axons

Chicken ovalbumin upstream promotor-transcription factor I (COUP-TFI), an orphan member of the nuclear receptor superfamily, is highly expressed in the developing nervous systems. In the cerebral cortex of Coup-tfl mutants, cortical layer IV was absent due to excessive cell death, a consequence of the failure of thalamocortical projections. Moreover, subplate neurons underwent improper differentiation and premature cell death during corticogenesis. Our results indicate that the subplate neuron defects lead to the failure of guidance and innervation of thalamocortical projections. Thus, our findings demonstrate a critical role of the subplate in early corticothalamic connectivity and confirm the importance of afferent innervation for the survival of layer IV neurons. These results also substantiate COUP-TFI as an important regulator of neuronal development and differentiation.

Molecular mechanisms of androgen-independent growth of human prostate cancer LNCaP-AI cells

The goal of this study is to investigate the molecular mechanisms of androgen-independent growth in prostate cancer. We have established an androgen-independent prostatic carcinoma LNCaP-AI (defined as a LNCaP cell line that is capable of growing in charcoal-stripped serum) from the androgen-dependent LNCaP-FGC cells. In contrast to the androgen-independent PC-3 human prostate cancer cells, LNCaP-AI cells still express a similar level of androgen receptor as their parental cells and are sensitive to androgen stimulation. Compared with the parental LNCaP-FGC cells, LNCaP-AI cells are more resistant to apoptosis induced by 12-O-tetradecanoylphorbol-13-acetate and express a much higher level of antiapoptotic gene bcl-2 and cyclin-dependent kinase inhibitor p21, which may confer an enhanced antiapoptosis phenotype. On the other hand, expression of cyclin-dependent kinase inhibitor p16 is significantly reduced in the LNCaP-AI cells, implying the release of an inhibitory effect of p16 on cell cycle progression. Taken together, our results suggest that multiple factors contribute to the development of androgen-independent growth of prostatic carcinoma cells, including enhancement of cell antiapoptosis function, release of cell cycle inhibition, and stimulation of cell proliferation by alternative signaling pathways.

Steroid receptor coactivator-1 (SRC-1) enhances ligand-dependent and receptor-dependent cell-free transcription of chromatin

Progesterone receptor (PR) functions as a transcription factor that modulates the transcription of target genes in response to progesterone and other signals. The transcriptional activity of PR requires the involvement of coactivators such as steroid receptor coactivator-1 (SRC-1). To dissect the role of SRC-1 in PR transactivation, we established an in vitro transcription system with chromatin templates, in which PR induced transcription in a ligand-dependent and PRE-dependent manner. In the presence of ligand, purified PR bound to chromatin templates, resulting in chromatin remodeling. With this system, the ability of purified SRC-1 to act as a coactivator of PR was examined. SRC-1 potentiated transcription by ligand-activated PR, whereas it had no effect on transcription in the absence of ligands. As SRC-1 possesses intrinsic histone acetyltransferase activity, we tested the role of acetylation in PR-mediated transcription by using a histone deacetylase inhibitor, trichostatin A (TSA). We found that addition of TSA strongly enhanced PR-dependent transcription on chromatin but not on naked DNA template, and the effects of SRC-1 and TSA on PR transactivation were partially redundant. In addition, SRC-1 was able to potentiate PR transactivation with nonchromatin templates. Thus, our results substantiate a two-step mechanism whereby recruitment of coactivator SRC-1 by the ligand-activated PR in vivo leads to (i) chromatin remodeling through histone acetylation and (ii) recruitment/stabilization of the preinitiation complex.

Induction of mammary gland hyperplasia in transgenic mice over-expressing human Cdc25B

Cdc25 A and B are dual-specificity phosphatases which have been implicated in neoplastic transformation. Although Cdc25A and Cdc25B have been found to be over-expressed in many cancer cell lines and primary tumors, the physiological roles of Cdc25A and B in vivo are largely undefined. To investigate the roles of these proteins in the oncogenic transformation of the mammary gland we used the mouse mammary tumor virus (MMTV) promoter to target over-expression of the Cdc25B transgene in the mammary glands of transgenic mouse lines. Here we report that the over-expression of Cdc25B enhances the proliferation of mammary epithelial cells resulting in the formation of precocious alveolar hyperplasia. At the molecular level, marked increases in cyclin D1 protein have been found in transgenic mammary epithelial cells. The accelerated growth rate of the mammary epithelial cells could also be attributed to the increased levels of cyclin E/cdk2 activity. In addition, a pronounced decrease in apoptosis was also observed during the involution of mammary gland. The reduction of apoptosis during involution correlated well with the reduced expression of c-myc and p53, both of which have been implicated in apoptosis. Taken together, our results clearly indicate that the deregulated expression of Cdc25B generates mammary gland hyperplasia.

Interleukin-1beta expression in the pineal gland of the rat

Increasing evidence of the neuroimmunomodulatory role of the pineal gland prompted the present study of pineal gland expression of the immunoregulatory cytokine, interleukin (IL)-1beta. IL-1beta was constitutively expressed in the adult gland, with mRNA levels higher in glands collected during the photophase than in those collected during the scotophase of the light:dark cycle. IL-1beta was up-regulated in pineal cultures, after treatment with either norepinephrine (NE) or interferon (IFN)/lipopolysaccharide (LPS). Although both astrocytes and microglia expressed IL-1beta, important differences were found in the cellular expression of this cytokine under in vivo and in vitro conditions. Increased IL-1beta expression by NE ex vivo and the decline in IL-1 expression at night, when NE levels are elevated, can be explained by immunocytochemical data showing that astrocytes are the predominant cell type expressing this cytokine in vivo, whereas IL-1beta-positive cells are predominantly microglia in pineal explants and dispersed cell cultures. These results are consistent with the hypothesis that cytokines secreted by pineal glia (astrocytes and microglia) may have an important regulatory role in the pineal gland.