Role of renal prostaglandins during antidiuresis and water diuresis in man

Role of renal prostaglandins during antidiuresis and water diuresis in man. The relationship of renal prostaglandins to antidiuretic hormone action and water diuresis was examined in 13 normal subjects and 2 subjects with diabetes insipidus. Following overnight water deprivation, an oral water load caused a prompt and sustained rise in the rate of urinary PGE2 excretion from 7.7 ± 1.2 to 81.6 ± 26.4 ng/hr (P < 0.0001) in 7 normal subjects. Because the simultaneous increase in urinary excretion of urea was only 17% of the rise in urinary PGE2, passive wash-out of renal PGE2 probably accounts for only a small fraction of the increment in PGE2 excretion. Administration of the antidiuretic hormone analogue DDAVP to 6 normal subjects during sustained water diuresis resulted in a decrease in PGE2 excretion and urine flow rate comparable to that of dehydrated subjects. Thus, PGE2 excretion varied directly with urine flow rate over a wide range of states of hydration in all 13 normal subjects. One patient with central diabetes insipidus and one with nephrogenic diabetes insipidus demonstrated a similar positive correlation of PGE2 excretion rate and urinary flow rate in states of hydration, dehydration, and after administration of DDAVP. In the patient with nephrogenic diabetes insipidus, this relationship of PGE2 excretion rate to urine flow rate was unaffected by DDAVP over a broad range of urine flow rates. Inhibition of prostaglandin synthesis with indomethacin in 6 normal subjects resulted in a significant decline in free water clearance (7.7 ± 1.0 to 4.7 ± 0.9 ml/min, P < 0.001) and an increase in the minimal UOSM (61 ± 4 to 93 ± 19 mOsm/kg, P < 0.01) achieved during water diuresis without a change in creatinine or osmolar clearances. Furthermore, the tightly linked relationship of PGE2 excretion rate to urine flow rate was reduced in 5 of 6 subjects during indomethacin treatment. We conclude that urinary PGE2 excretion varies directly with urine flow rate and is not directly dependent on ADH activity or state of hydration in man. The rise in PGE2 excretion during water diuresis may enhance the excretion of free water since indomethacin treatment blunted free water clearance while suppressing the rise in PGE2 excretion.Rôle des prostaglandines rénales au cours de l'antidiurèse et de la diurèse aqueuse chez l'homme. La relation entre les prostaglandines rénales et l'action de l'hormone antidiurétique et la diurèse aqueuse a été étudiée chez 13 sujets normaux et 2 sujets atteints de diabète insipide. A la suite d'une restriction d'eau pendant la nuit précédant l'étude, une charge d'eau par voie orale a déterminé une augmentation rapide et prolongée du débit urinaire de PGE2 de 7,7 ± 1,2 à 81,6 ± 26,4 ng/hr (P < 0,001) chez 7 sujets normaux. Puisque l'augmentation simultanée de l'excrétion urinaire d'urée était seulement de 17% de l'augmentation de la PGE2 urinaire, un lavage passif de la PGE2 rénale explique probablement une partie seulement de l'augmentation de l'excrétion de PGE2. L'administration d'un analogue de l'hormone antidiurétique, DDAVP, à 6 sujets normaux au cours d'une diurèse aqueuse prolongée a eu pour conséquence une diminution de l'excrétion de PGE2 et du débit urinaire comparable à celle des sujets déshydratés. Ainsi l'excrétion de PGE2 varie directement avec le débit urinaire sur un large éventail d'états d'hydratation chez tous les 13 sujets normaux. Un malade atteint de diabète insipide central et un malade atteint de diabète insipide néphrogénique ont eu une corrélation positive semblable du débit d'excrétion de PGE et du débit urinaire dans les états d'hydratation, de déshydratation, et après l'administration de DDAVP. Chez le malade atteint de diabète insipide néphrogénique, cette relation de l'excrétion de PGE2 au débit urinaire n'a pas été affectée par DDAVP sur un large éventail de valeurs du débit urinaire. L'inhibition de la synthèse de prostaglandine par l'indométhacine chez 6 sujets normaux a eu pour conséquence une diminution significative de la clairance de l'eau libre (7,7 ± 1,0 à 4,7 ± 0,9 ml/mn, P < 0,001) et une augmentation de la valeur minimale de UOSM (61 ± 4 à 93 ± 19 mOsm/kg, P < 0,01) obtenues au cours d'une diurèse aqueuse sans modification de la clairance de la créatinine ou de la clairance osmolaire. De plus, la relation étroite entre l'excrétion de PGE2 et le débit urinaire a été réduite chez 5 des 6 sujets au cours du traitement par l'indométhacine. Nous concluons que l'excrétion urinaire de PGE2 varie directement avec le débit urinaire et n'est pas directement dépendante de l'activité de l'ADH ou de l'état d'hydratation chez l'homme. L'augmentation de l'excrétion de PGE2 au cours de la diurèse aqueuse peut accroître l'excrétion d'eau libre puisque le traitement par l'indométhacine atténue la clairance de l'eau libre en même temps qu'il supprime l'augmentation de l'excrétion de PGE2

Redefining Aging in HIV Infection Using Phenotypes

Purpose of review: This article critically reviews the utility of “phenotypes” as behavioral descriptors in aging/HIV research that inform biological underpinnings and treatment development. We adopt a phenotypic redefinition of aging conceptualized within a broader context of HIV infection and of aging. Phenotypes are defined as dimensions of behavior, closely related to fundamental mechanisms, and, thus, may be more informative than chronological age. Primary emphasis in this review is given to comorbid aging and cognitive aging, though other phenotypes (i.e., disability, frailty, accelerated aging, successful aging) are also discussed in relation to comorbid aging and cognitive aging. Recent findings: The main findings that emerged from this review are as follows: (1) the phenotypes, comorbid aging and cognitive aging, are distinct from each other, yet overlapping; (2) associative relationships are the rule in HIV for comorbid and cognitive aging phenotypes; and (3) HIV behavioral interventions for both comorbid aging and cognitive aging have been limited. Summary: Three paths for research progress are identified for phenotype-defined aging/HIV research (i.e., clinical and behavioral specification, biological mechanisms, intervention targets), and some important research questions are suggested within each of these research paths

Serotonin Transporter Promoter Polymorphism Genotype Is Associated With Behavioral Disinhibition and Negative Affect in Children of Alcoholics

Serotonergic (5-HT) dysfunction has been implicated in the etiology of both behavioral disinhibition (BD) and negative affect (NA). This work extends our previous finding of relationships between whole blood 5-HT and both BD and NA in pubescent, but not prepubescent, children of alcoholics and continues examination of a hypothesized role of 5-HT dysfunction in alcoholism risk. The long and short (L and S) variants of the 5-HT transporter gene-linked polymorphic region (5-HTTLPR) are responsible for differing transcriptional efficiencies in 5-HT uptake. Although associations have been found between the SS 5-HTTLPR genotype and severe alcoholism and neuroticism, recent reports describe relationships between the LL genotype and both low level of response to alcohol and alcoholism diagnosis and a predominance of the LL genotype in early-onset alcoholics. Methods : This report is from an ongoing prospective study of the development of risk for alcoholism and other problematic outcomes in a sample of families classified by father's alcoholism subtype. This study examines relationships between 5-HTTLPR genotype and both child BD (Child Behavior Checklist Aggressive Behavior) and NA (Child Behavior Checklist Anxious/Depressed) in offspring from 47 families. Results : Results showed significantly higher levels of BD and NA in the 16 children with the LL genotype than the 46 SS or SL children. Conclusions : Behaviors of undercontrol, which occur at increased rates in children of alcoholics, may be genetically influenced through the regulation of the 5-HT transporter. Due to the small sample size and the preliminary nature of our findings, replication is necessary.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65855/1/j.1530-0277.2001.tb02302.x.pd

Anticancer Gene Transfer for Cancer Gene Therapy

Gene therapy vectors are among the treatments currently used to treat malignant tumors. Gene therapy vectors use a specific therapeutic transgene that causes death in cancer cells. In early attempts at gene therapy, therapeutic transgenes were driven by non-specific vectors which induced toxicity to normal cells in addition to the cancer cells. Recently, novel cancer specific viral vectors have been developed that target cancer cells leaving normal cells unharmed. Here we review such cancer specific gene therapy systems currently used in the treatment of cancer and discuss the major challenges and future directions in this field

Preclinical evaluation of transcriptional targeting strategies for carcinoma of the breast in a tissue slice model system

INTRODUCTION: In view of the limited success of available treatment modalities for metastatic breast cancer, alternative and complementary strategies need to be developed. Adenoviral vector mediated strategies for breast cancer gene therapy and virotherapy are a promising novel therapeutic platform for the treatment of breast cancer. However, the promiscuous tropism of adenoviruses (Ads) is a major concern. Employing tissue specific promoters (TSPs) to restrict transgene expression or viral replication is an effective way to increase specificity towards tumor tissues and to reduce adverse effects in non-target tissues such as the liver. In this regard, candidate breast cancer TSPs include promoters of the genes for the epithelial glycoprotein 2 (EGP-2), cyclooxygenase-2 (Cox-2), α-chemokine SDF-1 receptor (stromal-cell-derived factor, CXCR4), secretory leukoprotease inhibitor (SLPI) and survivin. METHODS: We employed E1-deleted Ads that express the reporter gene luciferase under the control of the promoters of interest. We evaluated this class of vectors in various established breast cancer cell lines, primary breast cancer cells and finally in the most stringent preclinical available substrate system, constituted by precision cut tissue slices of human breast cancer and liver. RESULTS: Overall, the CXCR4 promoter exhibited the highest luciferase activity in breast cancer cell lines, primary breast cancer cells and breast cancer tissue slices. Importantly, the CXCR4 promoter displayed a very low activity in human primary fibroblasts and human liver tissue slices. Interestingly, gene expression profiles correlated with the promoter activities both in breast cancer cell lines and primary breast cancer cells. CONCLUSION: These data suggest that the CXCR4 promoter has an ideal 'breast cancer-on/liver-off' profile, and could, therefore, be a powerful tool in Ad vector based gene therapy or virotherapy of the carcinoma of the breast

Tumor Immunotherapy Using Gene-Modified Human Mesenchymal Stem Cells Loaded into Synthetic Extracellular Matrix Scaffolds

Mesenchymal stem cells (MSCs) are appealing as gene therapy cell vehicles given their ease of expansion and transduction. However, MSCs exhibit immunomodulatory and proangiogenic properties that may pose a risk in their use in anticancer therapy. For this reason, we looked for a strategy to confine MSCs to a determined location, compatible with a clinical application. Human MSCs genetically modified to express luciferase (MSCluc), seeded in a synthetic extracellular matrix (sECM) scaffold (sentinel scaffold) and injected subcutaneously in immunodeficient mice, persisted for more than 40 days, as assessed by bioluminescence imaging in vivo. MSCs modified to express a bispecific α-carcinoembryonic antigen (αCEA)/αCD3 diabody (MSCdAb) and seeded in an sECM scaffold (therapeutic scaffolds) supported the release of functional diabody into the bloodstream at detectable levels for at least 6 weeks after implantation. Furthermore, when therapeutic scaffolds were implanted into CEA-positive human colon cancer xenograft-bearing mice and human T lymphocytes were subsequently transferred, circulating αCEA/αCD3 diabody activated T cells and promoted tumor cell lysis. Reduction of tumor growth in MSCdAb-treated mice was statistically significant compared with animals that only received MSCluc. In summary, we report here for the first time that human MSCs genetically engineered to secrete a bispecific diabody, seeded in an sECM scaffold and implanted in a location distant from the primary tumor, induce an effective antitumor response and tumor regression

When does the co-evolution of technology and science overturn into technoscience?

In this paper, the relations between science and technology, intervention and representation, the natural and the artificial are analysed on the background of the formation of modern science in the sixteenth century. Due to the fact that technique has been essential for modern science from its early beginning, modern science is characterised by a hybridisation of knowledge and intervention. The manipulation of nature in order to measure its properties has steadily increased until artificial things have been produced, such as laser beams, chemical compounds, elementary particles. Furthermore, the structural bracing of natural science, technological development, and industrial exploitation of nature go also back to the foundation of modern science. In order to strengthen the debate on technoscience against this background, the specific characteristics of technoscientific objects have to be clarified as have the specific characteristics of the social organisation of technoscience and its performance

Transduction of Brain Dopamine Neurons by Adenoviral Vectors Is Modulated by CAR Expression: Rationale for Tropism Modified Vectors in PD Gene Therapy

Gene-based therapy is a new paradigm for the treatment of Parkinson disease (PD) and offers considerable promise for precise targeting and flexibility to impact multiple pathobiological processes for which small molecule agents are not available. Some success has been achieved utilizing adeno-associated virus for this approach, but it is likely that the characteristics of this vector system will ultimately create barriers to progress in clinical therapy. Adenovirus (Ad) vector overcomes limitations in payload size and targeting. The cellular tropism of Ad serotype 5 (Ad5)-based vectors is regulated by the Ad attachment protein binding to its primary cellular receptor, the coxsackie and adenovirus receptor (CAR). Many clinically relevant tissues are refractory to Ad5 infection due to negligible CAR levels but can be targeted by tropism-modified, CAR-independent forms of Ad. Our objective was to evaluate the role of CAR protein in transduction of dopamine (DA) neurons in vivo.Ad5 was delivered to the substantia nigra (SN) in wild type (wt) and CAR transgenic animals. Cellular tropism was assessed by immunohistochemistry (IHC) in the SN and striatal terminals. CAR expression was assessed by western blot and IHC. We found in wt animals, Ad5 results in robust transgene expression in astrocytes and other non-neuronal cells but poor infection of DA neurons. In contrast, in transgenic animals, Ad5 infects SNc neurons resulting in expression of transduced protein in their striatal terminals. Western blot showed low CAR expression in the ventral midbrain of wt animals compared to transgenic animals. Interestingly, hCAR protein localizes with markers of post-synaptic structures, suggesting synapses are the point of entry into dopaminergic neurons in transgenic animals.These findings demonstrate that CAR deficiency limits infection of wild type DA neurons by Ad5 and provide a rationale for the development of tropism-modified, CAR-independent Ad-vectors for use in gene therapy of human PD

Serotonergic Contribution to Boys' Behavioral Regulation

Animal and human adult studies reveal a contribution of serotonin to behavior regulation. Whether these findings apply to children is unclear. The present study investigated serotonergic functioning in boys with a history of behavior regulation difficulties through a double-blind, acute tryptophan supplementation procedure.Participants were 23 boys (age 10 years) with a history of elevated physical aggression, recruited from a community sample. Eleven were given a chocolate milkshake supplemented with 500 mg tryptophan, and 12 received a chocolate milkshake without tryptophan. Boys engaged in a competitive reaction time game against a fictitious opponent, which assessed response to provocation, impulsivity, perspective taking, and sharing. Impulsivity was further assessed through a Go/No-Go paradigm. A computerized emotion recognition task and a staged instrumental help incident were also administered.Boys, regardless of group, responded similarly to high provocation by the fictitious opponent. However, boys in the tryptophan group adjusted their level of responding optimally as a function of the level of provocation, whereas boys in the control group significantly decreased their level of responding towards the end of the competition. Boys in the tryptophan group tended to show greater perspective taking, tended to better distinguish facial expressions of fear and happiness, and tended to provide greater instrumental help to the experimenter.The present study provides initial evidence for the feasibility of acute tryptophan supplementation in children and some effect of tryptophan supplementation on children's behaviors. Further studies are warranted to explore the potential impact of increased serotonergic functioning on boys' dominant and affiliative behaviors

Adenovirus Gene Transfer to Amelogenesis Imperfecta Ameloblast-Like Cells

To explore gene therapy strategies for amelogenesis imperfecta (AI), a human ameloblast-like cell population was established from third molars of an AI-affected patient. These cells were characterized by expression of cytokeratin 14, major enamel proteins and alkaline phosphatase staining. Suboptimal transduction of the ameloblast-like cells by an adenovirus type 5 (Ad5) vector was consistent with lower levels of the coxsackie-and-adenovirus receptor (CAR) on those cells relative to CAR-positive A549 cells. To overcome CAR -deficiency, we evaluated capsid-modified Ad5 vectors with various genetic capsid modifications including “pK7” and/or “RGD” motif-containing short peptides incorporated in the capsid protein fiber as well as fiber chimera with the Ad serotype 3 (Ad3) fiber “knob” domain. All fiber modifications provided an augmented transduction of AI-ameloblasts, revealed following vector dose normalization in A549 cells with a superior effect (up to 404-fold) of pK7/RGD double modification. This robust infectivity enhancement occurred through vector binding to both αvβ3/αvβ5 integrins and heparan sulfate proteoglycans (HSPGs) highly expressed by AI-ameloblasts as revealed by gene transfer blocking experiments. This work thus not only pioneers establishment of human AI ameloblast-like cell population as a model for in vitro studies but also reveals an optimal infectivity-enhancement strategy for a potential Ad5 vector-mediated gene therapy for AI