Methodological challenges in evaluating performance, impact and ranking of IWRM strategies in the Jordan Valley.

The philosophy of integrated water resource management (IWRM), as formulated in several international summits, yielded numerous interpretations and extensions over the last decade but always focused on the overall objective of maximizing the welfare and livelihood of the people concerned. One of the major constraints of this concept is the gap between the well-defined philosophy and the fuzzy definition of operational and testable indicators for the achievement of its goals. This leads to difficulties in the evaluation of potential contributions from technological and managerial improvements. The experience of the multi-lateral IWRM research initiative SMART in the lower Jordan Valley shows that the evaluation and ranking of alternative IWRM strategies and their elements relies simultaneously on the identification of local goals and their interfaces with the superordinate national water sector policies. The documentation of the, still ongoing, development process of suitable assessment procedures describes their methodological embedding and conclusions drawn for the heterogeneous situation of water-related settings in this transboundary watershed.

The role of dynamin 3 in the testis.

We report here that dynamin 3 in the testis is associated with structures termed tubulobulbar complexes that internalize intact intercellular junctions during sperm release and turnover of the blood-testis barrier. The protein lies adjacent to an actin-Arp2/3 network that cuffs the double plasma membrane tubular invagination at the core of each complex. To explore the possible relationship between dynamin 3 and nectin-based adhesion junctions, we transiently transfected DsRed-tagged dynamin 3 into MDCK cells stably transfected with eGFP-tagged nectin 2, one of the adhesion molecules known to be expressed in Sertoli cells at adhesion junctions. Cells transfected with the dynamin 3 construct had less uniformly distributed nectin 2 at intercellular contacts when compared to control cells expressing only nectin 2 or transfected with the DsRed plasmid alone. Significantly, tubular extensions positive for nectin 2 were visible projecting into the cells from regions of intercellular contact. Our findings are consistent with the conclusion that dynamin 3 is involved with tubulobulbar morphogenesis. Dynamin 3 also occurs in concentrated deposits around the capitulum and striated columns in the connecting piece of sperm tails suggesting that the protein in these cells may function to stabilize the base of the tail or serve as a reservoir for use during or after fertilization.

Non-muscle cofilin is a component of tubulobulbar complexes in the testis.

Tubulobulbar complexes are finger-like structures that form at the interface between maturing spermatids and Sertoli cells prior to sperm release and at the interface between two Sertoli cells near the base of the seminiferous epithelium. They originate in areas previously occupied by actin filament-associated intercellular adhesion plaques known as ectoplasmic specializations. Actin filaments also are associated with tubulobulbar complexes where they appear to form a network, rather than the tightly packed bundles found in ectoplasmic specializations. Cofilin, a calcium-independent actin-depolymerizing protein, previously has been identified in the testis, but has not been localized to specific structures in the seminiferous epithelium. To determine if cofilin is found in Sertoli cells and is concentrated at actin-rich structures, we reacted fixed frozen sections of rat testis, fixed fragmented tissue, and blots of seminiferous epithelium with pan-specific and non-muscle cofilin antibodies. In addition, GeneChip microarrays (Affymetrix, Santa Clara, CA) were utilized to determine the abundance of mRNA for all cofilin isoforms in Sertoli cells. Using the monoclonal pan-specific cofilin antibody, we found specific labeling exclusively at tubulobulbar complexes and not at ectoplasmic specializations. On one-dimensional (1D) Western blots this antibody reacted monospecifically with one band, and on 2D blots reacted with two dots, which we interpret as phosphorylated and nonphosphorylated forms of a single cofilin isotype. Messenger RNA for non-muscle cofilin in Sertoli cells is about 8.5-fold higher than for muscle-type cofilin. To confirm that the non-muscle isoform of cofilin is present at tubulobulbar complexes, we used antibodies specific to non-muscle cofilin for immunofluorescent localization. As with the pan-specific antibody, we found that the non-muscle cofilin antibody exclusively labeled tubulobulbar complexes. Results presented here indicate that non-muscle cofilin is concentrated at tubulobulbar complexes. Our results also indicate that cofilin is not concentrated at ectoplasmic specializations.

Wild-type huntingtin reduces the cellular toxicity of mutant huntingtin in vivo.

We have developed yeast artificial chromosome (YAC) transgenic mice expressing normal (YAC18) and mutant (YAC46 or YAC72) human huntingtin (htt), in a developmental- and tissue-specific manner, that is identical to endogenous htt. YAC72 mice develop selective degeneration of medium spiny projection neurons in the lateral striatum, similar to what is observed in Huntington disease. Mutant human htt expressed by YAC transgenes can compensate for the absence of endogenous htt and can rescue the embryonic lethality that characterizes mice homozygous for targeted disruption of the endogenous Hdh gene (-/-). YAC72 mice lacking endogenous htt (YAC72 -/-) manifest a novel phenotype characterized by infertility, testicular atrophy, aspermia, and massive apoptotic cell death in the testes. The testicular cell death in YAC72 -/- mice can be markedly reduced by increasing endogenous htt levels. YAC72 mice with equivalent levels of both wild-type and mutant htt (YAC72 +/+) breed normally and have no evidence of increased testicular cell death. Similar findings are seen in YAC46 -/- mice compared with YAC46 +/+ mice, in which wild-type htt can completely counteract the proapoptotic effects of mutant htt. YAC18 -/- mice display no evidence of increased cellular apoptosis, even in the complete absence of endogenous htt, demonstrating that the massive cellular apoptosis observed in YAC46 -/- mice and YAC72 -/- mice is polyglutamine-mediated toxicity from the mutant transgene. These data provide the first direct in vivo evidence of a role for wild-type htt in decreasing the cellular toxicity of mutant htt.

Cortical plasticity, contingent negative variation, and transcendent experiences during practice of the Transcendental Meditation technique.

This study investigated effects of transcendent experiences on contingent negative variation (CNV) amplitude, CNV rebound, and distraction effects. Three groups of age-matched subjects with few (<1 per year), more frequent (10-20 per year), or daily self-reported transcendent experiences received 31 simple RT trials (flash (S(1))/tone (S(2))/button press) followed by 31 divided-attention trials - randomly intermixed trials with or without a three-letter memory task in the S(1)-S(2) interval). Late CNV amplitudes in the simple trials were smallest in the group with fewest, and largest in the group with most frequent transcendent experiences. Conversely, CNV distraction effects were largest in the group with fewest and smallest in the group with most frequent transcendent experiences (the second group's values were in the middle in each case). These data suggest cumulative effects of transcendent experiences on cortical preparatory response (heightened late CNV amplitude in simple trials) and executive functioning (diminished distraction effects in letter trials).

Dynein and plus-end microtubule-dependent motors are associated with specialized Sertoli cell junction plaques (ectoplasmic specializations).

The mechanism responsible for spermatid translocation in the mammalian seminiferous epithelium was proposed to be the microtubule-based transport of specialized junction plaques (ectoplasmic specializations) that occur in Sertoli cell regions attached to spermatid heads. These plaques each consist of a cistern of endoplasmic reticulum, a layer of actin filaments and the adjacent plasma membrane. It is predicted that motor proteins function to move the junction plaques, and hence the attached spermatids, first towards the base and then back to the apex of the epithelium, along microtubules. If this hypothesis is true, motor proteins should be associated with the cytoplasmic face of the endoplasmic reticulum component of ectoplasmic specializations. In addition, isolated junction plaques should support microtubule movement both in the plus and minus directions to account for the bidirectional translocation of spermatids in vivo. To determine if cytoplasmic dynein is localized to the endoplasmic reticulum of the plaques, perfusion-fixed rat testes were immunologically probed, at the ultrastructural level, for the intermediate chain of cytoplasmic dynein (IC74). In addition, testicular fractions enriched for spermatid/junction complexes were incubated with and without gelsolin, centrifuged and the supernatants compared, by western blot analysis, for Glucose Regulated Protein 94 (a marker for endoplasmic reticulum) and IC74. At the ultrastructural level, the probe for IC74 clearly labelled material associated with the cytoplasmic face of the endoplasmic reticulum component of the junction plaques. In the gelsolin experiments, both probes reacted more strongly with appropriate bands from the gelsolin-treated supernatants than with corresponding bands from controls. To determine if the junction plaques support microtubule transport in both directions, polarity-labelled microtubules were bound to isolated spermatid/junction complexes and then assessed for motility in the presence of ATP and testicular cytosol (2 mg/ml). Of 25 recorded motility events, 17 were in a direction consistent with a plus-end directed motor being present, and 8 were in the minus-end direction. The results are consistent with the conclusion that the junction plaques have the potential for moving along microtubules in both the plus and minus directions and that both a kinesin-type and a dynein-type motor may be associated with the junction plaques. The data also indicate that cytoplasmic dynein is localized to the cytoplasmic face of the endoplasmic reticulum component of the plaques.

Unique and multifunctional adhesion junctions in the testis: ectoplasmic specializations.

In this paper, we review the structure and function of a unique type of actin-related intercellular adhesion junctions in the testis. Based on their ultrastructure, the junctions are divided into five distinct domains. The currently identified molecular components of each domain are summarized. In addition, the architecture of the mammalian system is compared with that of non-mammalian vertebrates. Functionally, the junctions are related to the turnover of adhesion between Sertoli cells, to the attachment of spermatids to the seminiferous epithelium, and to sperm release. They also are part of the mechanism by which spermatids are moved through the epithelium. Evidence consistent with adhesion and motility related functions is discussed. Control, both of junction turnover and of microtubule-based transport, is identified as an important avenue for future research.

Plectin is concentrated at intercellular junctions and at the nuclear surface in morphologically differentiated rat Sertoli cells.

Intermediate filaments in Sertoli cells have a well-defined pattern of distribution. They form a basally situated perinuclear network from which filaments extend peripherally to adhesion plaques at the plasma membrane and to sites of codistribution with other major elements of the cytoskeleton, particularly with microtubules. Although the general pattern of intermediate filament distribution is known, the molecular components involved with linking the filaments to organelles and attachment plaques in these cells have not been identified. One candidate for such a linking element is plectin. In this study we test for the presence of, and determine the distribution of, plectin in Sertoli cells of the rat testis. Fixed frozen sections and fixed epithelial fragments of rat testis were probed for plectin and vimentin using antibodies. Tissue was evaluated using standard fluorescence microscopy and confocal microscopy. Plectin in Sertoli cells was concentrated in a narrow zone surrounding the nucleus, and at focal sites, presumably desmosome-like plaques, at interfaces with adjacent cells. Plectin was also concentrated at sites where intermediate filament bundles project into specialized actin-filament containing plaques at sites of attachment to elongate spermatids. Plectin in Sertoli cells is concentrated at the nuclear surface and in junction plaques associated with the plasma membrane. The pattern of distribution is consistent with plectin being involved with linking intermediate filaments centrally (basally) to the nucleus and peripherally to intercellular attachment sites.

Evidence for a frizzled-mediated wnt pathway required for zebrafish dorsal mesoderm formation.

We have used zebrafish as a model system for the study of vertebrate dorsoventral patterning. We isolated a maternally expressed and dorsal organizer localized member of the frizzled family of wnt receptors. Wild-type and dominant, loss-of-function molecules in misexpression studies demonstrate frizzled function is necessary and sufficient for dorsal mesoderm specification. frizzled activity is antagonized by the action of GSK-3, and we show GSK-3 is also required for zebrafish dorsal mesoderm formation. frizzled cooperatively interacts with the maternally encoded zebrafish wnt8 protein in dorsal mesodermal fate determination. This frizzled -mediated wnt pathway for dorsal mesoderm specification provides the first evidence for the requirement of a wnt-like signal in vertebrate axis determination.

Pediatric sertraline overdose.

Sertraline (Zoloft) is a selective serotonin reuptake inhibitor that is commonly used in adults in the treatment of mood and anxiety disorders. Whereas it also is used to treat these illnesses in children, it is not currently approved by the Food and Drug Administration for use in this population. Sertraline use has been increasing secondary to its efficacy and its more tolerable side effect profile than the tricyclic antidepressants. It is also much safer in overdose than the tricyclic antidepressants. Although there have been numerous reports of sertraline overdose in adults, reports in the pediatric population are much less common. We review the literature regarding sertraline overdose in children, describe a case of sertraline ingestion in a 22-month-old infant, and discuss the treatment of such an overdose.

The integration of pharmacological therapy for comorbid psychiatric and addictive disorders.

The integration of pharmacological therapies for comorbid disorders requires an acceptance of independence and interactions of respective addictive and psychiatric disorders. At the same time, alcohol and other drugs induce psychiatric states that are indistinguishable from psychiatric disorders. On the other hand, while psychiatric disorders do not induce addictive use of alcohol and drugs, they do pose vulnerabilities to the development of addictive disorders. Generally, the treatment of comorbid disorders begins with abstinence and evaluation of the effects of alcohol and other drugs in contributing to the psychiatric picture. In the case of comorbid disorders, stabilization and standard treatments can be employed with certain cautions, namely, to avoid the use of addicting medications such as benzodiazepines and opiates beyond the detoxification stage. High potency neuroleptics and antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs) can be used to treat continuing psychiatric states after the exclusionary criteria in DSM-IV for substance-related disorders have been applied to the clinical case. If the psychiatric symptoms clear with sustained abstinence, little or no medications may be required. Specific treatment of the addictive disorders will often determine the extent that addictive disorders are responsible for psychiatric symptomatology. Alternatively, treatment of the psychiatric disorder will enhance compliance with addiction treatment.

Integration of generalized vulnerability to drug and alcohol addiction.

The vulnerability to develop addiction to alcohol has been well established in familial and genetic studies. Similar familial and genetic studies have supported a vulnerability to drug addiction. The co-occurrence of alcohol and drug addiction in the same individuals is highly prevalent in clinical populations. Common putative neurochemical mechanisms underlie addiction to both alcohol and drugs, namely, in the mesolimbic pathway and the locus ceruleus in the brain. Treatment strategies are directed at both alcohol and multiple drug addictions in patient populations. The formulation of a generalized vulnerability that extends to both alcohol and drug addiction is not only possible but necessary to explain the substantial numbers of individuals who develop both alcohol and drug addictions. Future research that is pertinent and relevant may depend on the understanding of a generalized vulnerability to develop alcohol and drug addiction and its application in diagnostic strategies and treatment models.

Comparison of coupling of humans to electric and magnetic fields with frequencies between 100 Hz and 100 kHz.

Recent laboratory and epidemiological results have stimulated interest in the hypothesis that human beings may exhibit biological responses to magnetic and/or electric field transients with frequencies in the range between 100 Hz and 100 kHz. Much can be learned about the response of a system to a transient stimulation by understanding its response to sinusoidal disturbances over the entire frequency range of interest. Thus, the main effort of this paper was to compare the strengths of the electric fields induced in homogeneous ellipsoidal models by uniform 100 Hz through 100 kHz electric and magnetic fields. Over this frequency range, external electric fields of about 25-2000 V/m (depending primarily on the orientation of the body relative to the field) are required to induce electric fields inside models of adults and children that are similar in strength to those induced by an external 1 microT magnetic field. Additional analysis indicates that electric fields induced by uniform external electric and magnetic fields and by the nonuniform electric and magnetic fields produced by idealized point sources will not differ by more than a factor of two until the sources are brought close to the body. Published data on electric and magnetic field transients in residential environments indicate that, for most field orientations, the magnetic component will induce stronger electric fields inside adults and children than the electric component. This conclusion is also true for the currents induced in humans by typical levels of 60 Hz electric and magnetic fields in U.S. residences.

Drosophila cAMP-dependent protein kinase.

cAMP-dependent protein kinase has been purified to homogeneity from adult bodies of Drosophila melanogaster. It is tetrameric in structure with two regulatory and two catalytic subunits that dissociate when activated by cAMP. The regulatory subunit exists in phospho and dephospho forms, which have electrophoretic mobilities in sodium dodecyl sulfate-polyacrylamide gels corresponding to Mr = 58,000 and 52,000, respectively. The catalytic subunit has a molecular weight of 40,000. The holoenzyme has a Stokes radius of 4.7 nm. The Km for activation by cAMP is substrate-dependent with Km values of 20 nM with histone H2B and 100 nM with the peptide, Leu-Arg-Arg-Ala-Ser-Leu-Gly. These physical and kinetic properties are very similar to those of the bovine heart Type II cAMP-dependent protein kinase. A Drosophila Type I cAMP-dependent protein kinase was also found in larval stages and during the first half of pupation but was absent in embryos and adults. The fly Type II enzyme was present in all developmental stages. Three regions of the Drosophila genome were found which, when present in three copies, significantly alter the specific activity of cAMP-dependent protein kinase. These are located at 29F-33F (30% increase), 46A-50C (17% increase), and 66B-67D (16% decrease).