Behavioral and thyroid effects of in utero and lactational exposure of Sprague-Dawley rats to the polybrominated diphenyl ether mixture DE71.

Exposure of rodents during gestation and lactation to polybrominated diphenyl ethers (PBDEs) has been reported to disrupt neurobehavioral function in offspring, as well as to disrupt thyroid function. To assess this we evaluated development and behavior after gestational and lactational exposure to the technical PBDE mixture DE71. Pregnant Sprague-Dawley rats were exposed to 0, 0.3, 3.0 or 30 mg/kg/day of DE71 from gestation day 1 to postnatal day (PND) 21 and were assessed on a wide range of behavioral functions from early postnatal period until old age (PND 450). DE71 exposure decreased thyroid hormone levels (T3 and T4) in mothers and offspring with offspring being more sensitive that mothers. Developmental landmarks, neuromotor function, anxiety, learning and memory were not affected by DE71 at any age. DE71 produced small changes in motor activity rearing only at PND 110 but not at any other age and no other activity measure was altered by DE71. Cholinergic sensitivity measured by nicotine-stimulated motor activity was not affected by perinatal DE71 exposure. Acoustic startle responses were potentiated by DE71 at PND 90 indicating delayed effects on sensory reactivity. Habituation was measured in motor activity tests at five ages but was not altered by DE71 at any age. Habituation measured in startle tests was also not affected by exposure to DE71. For thyroid hormone levels at PND 21, the lowest adverse effect level was 3.0 mg/kg. Few behavioral effects were observed and the lowest adverse effect level was 30 mg/kg. Our results confirm that DE71 produces transient effects on thyroid hormone levels but does not result in learning or motor impairment and does not alter non-associative learning (habituation).

Effects of developmental exposure to mixtures of environmental contaminants on the hepatic metabolism of estradiol-17ß in immature female Sprague Dawley rats.

Exposure to environmental contaminants induces the activation of cytochrome P450s (CYP) which lead to the hydroxylation of contaminants and endogenous hormones such as estrogens. The hydroxylation of estrogens forms catecholestrogens (CEs), one of them being the mutagenic 4-hydroxyestradiol-17ß (4-OH-E2). Catecholestrogens are transformed by catechol-o-methyltransferases (COMTs) into nonreactive methoxyestrogens. To investigate the hepatic metabolism of estradiol-17ß in female offspring at postnatal day (PND) 21, pregnant rats were dosed daily from gestation day 1 until PND 21 with 2 dose levels of organochlorine pesticides (OCPs; 0.019 or 1.9 mg/kg per d), methylmercury (MeHg; 0.02 or 2 mg/kg per d), polychlorinated biphenyls (PCBs; 0.011 or 1.1 mg/kg per d), or a mixture (M; 0.05 or 5 mg/kg per d) including all 3 groups of chemicals. Concentrations of organochlorines in the mixture M were based on their proportions in serum of the Canadian Arctic population. The messenger RNA (mRNA) expressions of CYP and COMT were analyzed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). High-performance thin layer chromatography and phosphor imaging were used to measure the transformation of (14)C substrates into estrogen metabolites. The low-dose treatments or the MeHg groups had no effect. The high-dose OCP, PCB, and M group increased the production of 2-OH-E2 and 6α-OH-E2, while only the PCB and M groups increased the 2-OH-CE/methoxyestrogen ratio. In all groups, the cytosolic COMT activity exceeded the microsomal production rate of 4-OH-E2. Although the M treatment included the PCB and OCP mixtures, it did not modify the estrogen metabolism more than did the PCB mixture alone. This endocrine disruption information contributes to our understanding of chemical interactions in the toxicology of chemical mixtures.

Environmental contaminants and human health in the Canadian Arctic.

The third Canadian Arctic Human Health Assessment conducted under the Canadian Northern Contaminants Program (NCP), in association with the circumpolar Arctic Monitoring and Assessment Programme (AMAP), addresses concerns about possible adverse health effects in individuals exposed to environmental contaminants through a diet containing country foods. The objectives here are to: 1) provide data on changes in human contaminant concentrations and exposure among Canadian Arctic peoples; 2) identify new contaminants of concern; 3) discuss possible health effects; 4) outline risk communication about contaminants in country food; and 5) identify knowledge gaps for future contaminant research and monitoring. The nutritional and cultural benefits of country foods are substantial; however, some dietary studies suggest declines in the amount of country foods being consumed. Significant declines were found for most contaminants in maternal blood over the last 10 years within all three Arctic regions studied. Inuit continue to have the highest levels of almost all persistent organic pollutants (POPs) and metals among the ethnic groups studied. A greater proportion of people in the East exceed Health Canada's guidelines for PCBs and mercury, although the proportion of mothers exceeding these guidelines has decreased since the previous assessment. Further monitoring and research are required to assess trends and health effects of emerging contaminants. Infant development studies have shown possible subtle effects of prenatal exposure to heavy metals and some POPs on immune system function and neurodevelopment. New data suggest important beneficial effects on brain development for Inuit infants from some country food nutrients. The most successful risk communication processes balance the risks and benefits of a diet of country food through input from a variety of regional experts and the community, to incorporate the many socio-cultural and economic factors to arrive at a risk management decision that will be the most beneficial in Arctic communities.

Viral vector-induced expression of bone morphogenetic protein 2 produces inhibition of tumor growth and bone differentiation of stem cells.

A number of hormonal factors have been shown to be instrumental in the calcification process. This study represents an attempt at using one of these factors to specifically induce calcification of tumors to arrest tumor growth. The gene encoding bone morphogenetic protein 2 (BMP-2) was placed under transcriptional control of the promoter for carcinoembryonic antigen (CEA). This gene cassette was cloned into a herpes simplex virus (HSV) amplicon vector (HSV-CEA-BMP2). This vector was used to induce local BMP-2 production in CEA-expressing tumor cells to retard cell growth. Lysates of tumor cells treated with HSV-CEA-BMP2 were applied to stem cells to determine if BMP-2 expression promotes differentiation to bone lineage. pHSV-CEA-BMP2 efficiently transduced both CEA-expressing and non-expressing cells. BMP-2 was only expressed in CEA-positive cells. BMP-2 expression led to an inhibition of tumor cell growth. BMP-2 released by these CEA-expressing tumors also drove the differentiation of mesenchymal stem cells to bone lineage. This proof-of-concept study demonstrates that tumor cells can be specifically engineered to produce BMP-2, which leads to growth retardation and to the differentiation of non-committed stem cells to bone. This 'Medusa' effect can theoretically be exploited to retard tumor growth.

Extending the transposable payload limit of Sleeping Beauty (SB) using the Herpes Simplex Virus (HSV)/SB amplicon-vector platform.

The ability of a viral vector to safely deliver and stably integrate large transgene units (transgenons), which not only include one or several therapeutic genes, but also requisite native transcriptional regulatory elements, would be of significant benefit for diseases presently refractory to available technologies. The herpes simplex virus type-1 (HSV-1) amplicon vector has the largest known payload capacity of approximately 130 kb, but its episomal maintenance within the transduced cell nucleus and induction of host cell silencing mechanisms limits the duration of the delivered therapeutic gene(s). Our laboratory developed an integration-competent version of the HSV-1 amplicon by adaptation of the Sleeping Beauty (SB) transposon system, which significantly extends transgene expression in vivo. The maximum size limit of the amplicon-vectored transposable element remains unknown, but previously published plasmid-centric studies have established that DNA segments longer than 6-kb are inefficiently transposed. Here, we compared the transposition efficiency of SB transposase in the context of both the HSV amplicon vector as well as the HSV amplicon plasmid harboring 7 and 12-kb transposable reporter transgene units. Our results indicate that the transposition efficiency of the 12-kb transposable unit via SB transposase was significantly reduced as compared with the 7-kb transposable unit when the plasmid version of the HSV amplicon was used. However, the packaged HSV amplicon vector form provided a more amenable platform from which the 12-kb transposable unit was mobilized at efficiency similar to that of the 7-kb transposable unit via the SB transposase. Overall, our results indicate that SB is competent in stably integrating transgenon units of at least 12 kb in size within the human genome upon delivery of the platform via HSV amplicons.

A pilot study of personality pathology in patients with anorexia nervosa: modifiable factors related to outcome after hospitalization.

OBJECTIVE: To assess improvement in aspects of personality in patients hospitalized with anorexia nervosa (AN) and its relationship to improved depression, body mass index (BMI), and eating disorder outcome after treatment. METHOD: Twenty females hospitalized with AN completed intake and discharge assessments of BMI, depression and eating disorder severity, as well as personality pathology with the Minnesota Multiphasic Personality Inventory (MMPI-2) and the Revised NEO Personality Inventory (NEO PI-R). Clinical outcome for a subset of patients at 1-year post-hospitalization was determined. RESULTS: The only factor that predicted better versus worse outcome at 1-year post-hospitalization was change in Low Self-Esteem (LSE) from the MMPI-2. Improved LSE from admission to discharge predicted remission at 1-year post-hospitalization, while worsening LSE predicted relapse. Regardless of outcome, NEO PI-R Neuroticism remained pathologically elevated in AN patients during hospitalization. DISCUSSION: Pathological levels of neuroticism may represent a vulnerability factor for AN. In contrast, self-esteem appears to be a modifiable factor that predicts outcome following hospitalization, and may be an important target for treatment.

Gene expression profiling in rat cerebellum following in utero and lactational exposure to mixtures of methylmercury, polychlorinated biphenyls and organochlorine pesticides.

Although human populations are continuously exposed to complex mixtures of contaminants, the effects of such exposure on the developing brain transcriptome are poorly characterized. Rats were exposed perinatally to the northern contaminant mixture (NCM) which was designed to reflect the blood contaminant profile of Canadian arctic populations, to components of the NCM administered separately (methylmercury (MeHg), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs)) or to the goitrogen propylthiouracyl. Post-natal day (PND) 14 cerebellum global gene expression resulting from such exposures was investigated using high-density cDNA microarrays. Fifty known genes were identified as differentially expressed between the control group and at least one other treatment group. The microarray data were validated by quantitative PCR (qPCR) on a subset of 10 genes. The differentially expressed genes are involved in a variety of processes, including nerve cell differentiation, migration, myelination and synaptic transmission. The comparison of cerebellum gene expression profiles resulting from exposure to the NCM and its individual components in male and female pups revealed that (i) gender is a crucial biological variable influencing genomic response to environmental contaminants and (ii) contaminant co-exposure significantly masks the effects of individual mixture components on cerebellum gene expression.

Improved HSV-1 amplicon packaging using virion host shutoff mutants lacking mRNAse activity.

Given their generous transgene capacity and inherent neurotropism, herpes simplex virus (HSV-1)-based viral vectors are promising tools for gene delivery to the central nervous system. Despite their widespread pre-clinical use, vector toxicity remains a concern with regard to the use of herpes vectors in humans. One potential source of toxicity stems from the tegument-associated virion host shutoff protein (vhs), which induces translational arrest in the host cell through non-specific mRNAse activity. In the current study we utilized a series of HSV-1 viruses containing a deletion in the U(L)41 open reading frame to investigate: (1) the requirement of intact vhs function in amplicon packaging and (2) whether vhs influences the post-transduction survival of dissociated cortical neurons. Our results demonstrate that while amplicon yield was reduced an order of magnitude, U(L)41 deletion was associated with reduced vector toxicity. Furthermore, partial reconstitution of vhs function using mRNAse-inactive point mutants improved amplicon titers without imparting the toxicity observed with wild-type controls. These findings offer a novel approach to improving the titer and toxicity profiles of HSV-based viral vectors.

Effects of an ethanol-gasoline mixture: results of a 4-week inhalation study in rats.

The inhalation toxicity of an ethanol-gasoline mixture was investigated in rats. Groups of 15 male and 15 female rats were exposed by inhalation to 6130 ppm ethanol, 500 ppm gasoline or a mixture of 85% ethanol and 15% gasoline (by volume, 6130 ppm ethanol and 500 ppm gasoline), 6 h a day, 5 days per week for 4 weeks. Control rats of both genders received HEPA/charcoal-filtered room air. Ten males and ten females from each group were killed after 4 weeks of treatment and the remaining rats were exposed to filtered room air for an additional 4 weeks to determine the reversibility of toxic injuries. Female rats treated with the mixture showed growth suppression, which was reversed after 4 weeks of recovery. Increased kidney weight and elevated liver microsomal ethoxyresorufin-O-deethylase (EROD) activity, urinary ascorbic acid, hippuric acid and blood lymphocytes were observed and most of the effects were associated with gasoline exposure. Combined exposure to ethanol and gasoline appeared to exert an additive effect on growth suppression. Inflammation of the upper respiratory tract was observed only in the ethanol-gasoline mixture groups, and exposure to either ethanol and gasoline had no effect on the organ, suggesting that an irritating effect was produced when the two liquids were mixed. Morphology in the adrenal gland was characterized by vacuolation of the cortical area. Although histological changes were generally mild in male and female rats and were reversed after 4 weeks, the changes tended to be more severe in male rats. Brain biogenic amine levels were altered in ethanol- and gasoline-treated groups; their levels varied with respect to gender and brain region. Although no general interactions were observed in the brain neurotransmitters, gasoline appeared to suppress dopamine concentrations in the nucleus accumbens region co-exposed to ethanol. It was concluded that treatment with ethanol and gasoline, at the levels studied, produced mild, reversible biochemical hematological and histological effects, with some indications of interactions when they were co-administered.

HSV amplicon delivery of glial cell line-derived neurotrophic factor is neuroprotective against ischemic injury.

Direct intracerebral administration of glial cell line-derived neurotrophic factor (GDNF) is neuroprotective against ischemia-induced cerebral injury. Utilizing viral vectors to deliver and express therapeutic genes presents an opportunity to produce GDNF within localized regions of an evolving infarct. We investigated whether a herpes simplex virus (HSV) amplicon-based vector encoding GDNF (HSVgdnf) would protect neurons against ischemic injury. In primary cortical cultures HSVgdnf reduced oxidant-induced injury compared to the control vector HSVlac. To test protective effects in vivo, HSVgdnf or HSVlac was injected into the cerebral cortex 4 days prior to, or 3 days, after a 60-min unilateral occlusion of the middle cerebral artery. Control stroke animals developed bradykinesia and motor asymmetry; pretreatment with HSVgdnf significantly reduced such motor deficits. Animals receiving HSVlac or HSVgdnf after the ischemic insult did not exhibit any behavioral improvement. Histological analyses performed 1 month after stroke revealed a reduction in ischemic tissue loss in rats pretreated with HSVgdnf. Similarly, these animals exhibited less immunostaining for glial fibrillary acidic protein and the apoptotic marker caspase-3. Taken together, our data indicate that HSVgdnf pretreatment provides protection against cerebral ischemia and supports the utilization of the HSV amplicon for therapeutic delivery of trophic factors to the CNS.

Immune responses to replication-defective HSV-1 type vectors within the CNS: implications for gene therapy.

Herpes simplex virus (HSV) is a naturally occurring double-stranded DNA virus that has been adapted into an efficient vector for in vivo gene transfer. HSV-based vectors exhibit wide tropism, large transgene size capacity, and moderately prolonged transgene expression profiles. Clinical implementation of HSV vector-based gene therapy for prevention and/or amelioration of human diseases eventually will be realized, but inherently this goal presents a series of significant challenges, one of which relates to issues of immune system involvement. Few experimental reports have detailed HSV vector-engendered immune responses and subsequent resolution events primarily within the confines of the central nervous system. Herein, we describe the immunobiology of HSV and its derived vector platforms, thus providing an initiation point from where to propose requisite experimental investigation and potential approaches to prevent and/or counter adverse antivector immune responses.

HSV vector-mediated gene delivery to the central nervous system.

The efficient and targeted transfer of genes is the goal of gene therapy. In the central nervous system (CNS), this is challenging due in part to the exquisite anatomy of the brain. Herpes simplex virus (HSV) vectors are particularly amenable to CNS therapies as they are capable of transducing a variety of cells, have a large transgene capacity and can exist as either oncolytic or non-immunogenic vectors. The versatility of this vector platform and its potential molecular therapeutic use in two CNS disorders, Alzheimer's disease and malignant brain tumors, will be discussed.

Ultrastructural and histological effects of exposure to CEES or heat in a human epidermal model.

Ultrastructural and terminal deoxynucleotidyl transferase nick end labeling (TUNEL) studies were conducted to compare mechanisms of 2-chloroethyl ethyl sulfide (CEES) and heat-induced injury to EpiDerm. Twenty-two hours after 2-h exposure to the monofunctional alkylating agent CEES, budding of cytoplasm, clumping of nuclear chromatin, disintegration of nuclear membranes and cytoplasmic structures, and cytoplasmic vacuolization were detected, especially in the basal cells near the pseudobasement membrane. TUNEL techniques revealed DNA fragmentation distinct from that normally associated with terminal keratinocyte differentiation. Similar evaluations 22.5 h after 90 min exposure of EpiDerm to elevated temperature (45 degrees C) produced a different pattern of cell damage. Swelling of intercellular spaces, extensive cytoplasmic vacuolization, disruption of normal nuclear shape, reduced cell membrane integrity, and release of cellular material in the basal region characterized heat injury. Heat did not alter the DNA fragmentation normally associated with keratinocyte maturation. These data suggest that CEES elicited an apoptotic mechanism of cell death with features of terminal differentiation such as nuclear membrane disintegration and loss of cytoplasmic structures. Heat, alternatively, produced changes more typical of oncotic necrosis.

Dendritic cells transduced with HSV-1 amplicons expressing prostate-specific antigen generate antitumor immunity in mice.

There is currently much interest in generating cytotoxic T lymphocyte (CTL) responses against tumor antigens as a therapy for cancer. This work describes a novel gene transfer technique utilizing dendritic cells (DCs), an extremely potent form of antigen-presenting cell (APC), and herpes simplex virus-1 (HSV-1) amplicons. HSV-1 amplicons are plasmid-based viral vectors that are packaged into HSV-1 capsids, but lack viral coding sequences. Amplicon vectors have been constructed that encode the model tumor antigen ovalbumin (HSV-OVA) and human prostate-specific antigen (HSV-PSA), a protein that is expressed specifically in prostate epithelium and prostate carcinoma cells. These amplicons were packaged using a helper virus-free system that produces vector stocks that are devoid of contaminating cytotoxic helper virus. Transduction of DCs with HSV-OVA or HSV-PSA and co-culture with CTL hybridomas results in specific activation, indicating that transduced DCs express these transgenes and process the tumor antigens for class I MHC presentation to CTL. Mice immunized with HSV-PSA-transduced DCs generate a specific CTL response that can be detected in vitro by a (51)Cr-release assay and are protected from challenge with tumors that express PSA. These results indicate that DCs transduced with HSV-1 amplicon vectors may provide a tool for investigation of the biology of CTL activation by DCs and a new modality for immunotherapy of cancer.

Regulation of neuronal traits by a novel transcriptional complex.

The transcriptional repressor, REST, helps restrict neuronal traits to neurons by blocking their expression in nonneuronal cells. To examine the repercussions of REST expression in neurons, we generated a neuronal cell line that expresses REST conditionally. REST expression inhibited differentiation by nerve growth factor, suppressing both sodium current and neurite growth. A novel corepressor complex, CoREST/HDAC2, was shown to be required for REST repression. In the presence of REST, the CoREST/HDAC2 complex occupied the native Nav1.2 sodium channel gene in chromatin. In neuronal cells that lack REST and express sodium channels, the corepressor complex was not present on the gene. Collectively, these studies define a novel HDAC complex that is recruited by the C-terminal repressor domain of REST to actively repress genes essential to the neuronal phenotype.

Development of herpes simplex virus-1 amplicon-based immunotherapy for chronic lymphocytic leukemia.

Herpes simplex virus (HSV)-based vectors have favorable biologic features for gene therapy of leukemia and lymphoma. These include high transduction efficiency, ability to infect postmitotic cells, and large packaging capacity. The usefulness of HSV amplicon vectors for the transduction of primary human B-cell chronic lymphocytic leukemia (CLL) was explored. Vectors were constructed encoding beta-galactosidase (LacZ), CD80 (B7.1), or CD154 (CD40L) and were packaged using either a standard helper virus (HSVlac, HSVB7.1, and HSVCD40L) or a helper virus-free method (hf-HSVlac, hf-HSVB7.1, and hf-HSVCD40L). Both helper-containing and helper-free vector stocks were studied for their ability to transduce CLL cells, up-regulate costimulatory molecules, stimulate allogeneic T-cell proliferation in a mixed lymphocyte tumor reaction, and generate autologous cytotoxic T lymphocytes (CTLs). Although helper-containing and helper-free amplicon stocks were equivalent in their ability to transduce CLL cells, a vigorous T-cell proliferative response was obtained using cells transduced with hf-HSVB7.1 but not with HSVB7.1. CLL cells transduced with either HSVCD40L or hf-HSVCD40L were compared for their ability to up-regulate resident B7.1 and to function as T-cell stimulators. Significantly enhanced B7.1 expression in response to CD40L was observed using hf-HSVCD40L but not with HSVCD40L. CLL cells transduced with hf-HSVCD40L were also more effective at stimulating T-cell proliferation than those transduced with HSVCD40L stocks and were successful in stimulating autologous CTL activity. It is concluded that HSV amplicons are efficient vectors for gene therapy of hematologic malignancies and that helper virus-free HSV amplicon preparations are better suited for immunotherapy.

A slimming program for eating disorders not otherwise specified. Reconceptualizing a confusing, residual diagnostic category.

This study suggests that the category of EDNOS as currently defined is overly broad, representing many cases that could be more helpfully subsumed within AN or BN diagnostic criteria without changing the essential features of these categories but by rethinking the currently overly restrictive, perhaps research-derived criteria. The reconceptualizing of AN as a syndrome resulting from a decrement between setpoint versus illness-driven final weight avoids the inherent problems of imposing a category on a dimension. A rethinking of AN suggests that a specific female-only abnormality of reproductive hormone functioning, 3 months of amenorrhea, is too restrictive. Instead, a more encompassing criterion recognizing the multiple medical, social, and psychologic functional impairments that result from substantial starvation would be appropriate in its place. Clinicians who otherwise confidently treat AN and BN patients would welcome the clearer diagnostic categorization of the potentially confusing EDNOS category. Third party payers who currently, albeit wrongly, exclude EDNOS diagnoses from insurance payment, would have less difficulty with a smaller group of EDNOS. In summary, the currently overly broad category of EDNOS as currently used would benefit from a thoughtful dieting regimen.

Basic principles for applying cognitive-behavioral therapy to anorexia nervosa.

Cognitive-behavioral therapy continues to be one of the recommended evidenced-based interventions in the treatment of eating disorders. Cognitive-behavioral therapy is clearly of benefit in anorexia and bulimia nervosa, can be learned in a reasonable time, and is guided by manuals on cognitive-behavioral therapy. This article looks at theoretic and clinical interventions in the treatment of anorexia nervosa and suggests strategies related to effective psychotherapeutic treatment that can be used across a continuum of care.

HSV amplicon-mediated neurotrophin-3 expression protects murine spiral ganglion neurons from cisplatin-induced damage.

Ototoxicity is a major dose-limiting side effect of cisplatin (DDP) administration due to its propensity to induce destruction of hair cells and neurons in the auditory system. Previous studies demonstrated that TrkC-expressing spiral ganglion neurons (SGN) are protected from the cytotoxic effects of DDP by localized delivery of the trophic factor neurotrophin-3 (NT-3). Successful in vivo implementation of such a therapy requires the development of an efficient gene delivery vehicle for expression of NT-3 within the cochlea. To this end, we constructed a herpes simplex virus (HSV) amplicon vector that expressed a c-Myc-tagged NT-3 chimera (HSVnt-3myc). Helper virus-free vector stocks were initially evaluated in vitro for their capacity to direct expression of NT-3 mRNA and protein. Transduction of cultured murine cochlear explants with HSVnt-3myc resulted in production of NT-3 mRNA and protein up to 3 ng/ml as measured over a 48-h period in culture supernatants. To determine whether NT-3 overexpression could abrogate DDP toxicity, cochlear explants were transduced with HSVnt-3myc or a murine intestinal alkaline phosphatase-expressing control vector, HSVmiap, and then exposed to cisplatin. HSVnt-3myc-transduced cochlear explants harbored significantly greater numbers of surviving SGNs than those infected with control virus. These data demonstrate that amplicon-mediated NT-3 transduction can attenuate the ototoxic action of DDP on organotypic culture. The potency of NT-3 in protecting spiral ganglion neurons from degeneration suggests that in vivo neurotrophin-based gene therapy may be useful for the prevention and/or treatment of hearing disorders.