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Studies have been performed in humans to identify changes in gene expression that may account for the relatively weak and variable response of aged muscle to resistance exercise. The gene expression profile of skeletal muscle from elderly (62–75 years old) compared to younger (20–30 years old) men demonstrated elevated expression of genes typical of a stress or damage response. The expression of the majority of these genes was unaffected by a single bout of high-intensity resistance exercise in elderly subjects but was altered acutely by exercise in younger subjects so as to approach the pre-exercise levels observed in older subjects. The inability of muscle from elderly subjects to respond to resistance exercise was also apparent in the expression of inflammatory response genes, which increased within 24 hours of the exercise bout only in younger subjects. Other genes with potentially important roles in the adaptation of muscle to exercise, showed a similar or even more robust response in older compared to younger subjects. Taken together, these results may help to explain the variable hypertrophic response of muscle from older individuals to resistance training.

This column is the fourth in a series describing Health Care Financing Administration initiatives to improve care for Medicare beneficiaries with heart failure. The first three papers addressed the background, design, and baseline results of the Health Care Financing Administration national initiative to improve quality of inpatient care for heart failure through the activities of each state's Health Care Financing Administration contractor Peer Review Organization. This paper describes a smaller-scale but equally important endeavor: the Heart Failure Practice Improvement Effort, a pilot project to test the feasibility of assessing and improving heart failure care in the outpatient setting. (c)2001 by CHF, Inc.

This column is the sixth in a series describing Health Care Financing Administration (HCFA) initiatives to improve care for Medicare beneficiaries with heart failure. The fourth column addressed the Heart Failure Practice Improvement Effort, HCFA's pilot project to test the feasibility of assessing and improving heart failure care in the outpatient setting through the activities of HCFA-contracted peer review organizations in eight states. This column is dedicated to illustrating the progress of the Heart Failure Practice Improvement Effort project at an individual state and practice level, focusing on the quality improvement activities in outpatient heart failure care conducted by the Colorado peer review organization. (c)2001 CHF, Inc.

The Health Care Financing Administration, with its National Heart Failure project, has made heart failure care one of its targets for quality improvement. Previous columns have highlighted the clinical and epidemiologic background for the National Heart Failure project. This column provides "real-world" examples of hospitals improving care for their heart failure patients. (c)2001 by CHF, Inc.

Transplantation of embryonic dopamine (DA) neurons is being studied as an experimental replacement therapy for the DA-deficiency characteristic of Parkinson's disease. Some studies suggest that one of the limitations of this approach is that intrastriatal placement of implants fails to consistently restore completely normal movement. One potential cause of this suboptimal therapeutic outcome is that changes in the neural activity of several structures in the basal ganglia circuitry resulting from striatal DA depletion is not adequately normalized by graft-derived DA replacement in striatum alone. In the present study, we assessed the feasibility of grafting embryonic DA neurons into the substantia nigra (SN) of adult parkinsonian monkeys as an approach to restoration of the DA modulation of striatal-nigral afferents that is lost after degeneration of SN neurons. Sixteen St. Kitts African green monkeys treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) received implants of embryonic monkey ventral mesencephalon (VM), or sham implants, aimed at the rostral SN. At 6 months after grafting, staining for tyrosine hydroxylase (TH) indicated that grafted DA neurons survived at this site, albeit often in reduced numbers compared with VM grafts to striatum. Grafted neurons extended neurites into the parenchyma of the SN, but there was no evidence of lengthy extension of graft-derived neurites rostrally along the trajectory of the mesostriatal fiber system. A region-specific, modest increase in DA levels and TH-positive fiber density in the ventral-medial putamen was detected, accompanied by modest but significant decreases in parkinsonian behaviors at 5-6 months after grafting. Our findings support the view that grafting embryonic tissue to the SN is a feasible procedure in nonhuman primates that provides a modest but detectable benefit of its own. These results encourage the further development of multiple-target grafting strategies as a means of restoring modulation of anatomically widespread basal ganglia structures relevant to treatment of Parkinson's disease.

The current experiments examined the effects of acute or repeated, intermittent administrations of cocaine on the acquisition and reversal of object discriminations by Vervet monkeys in order to test the hypothesis that cocaine treatment affects performance of tasks that depend upon the functions of the orbitofrontal cortex and amygdala. An acute dose of cocaine (1 mg/kg; 20 min prior to testing) impaired reversal of a previously learned object discrimination but had no effect on acquisition of a novel one. Specific impairments of reversal learning were also observed in monkeys 9 and 30 days after repeated administrations of cocaine (2 or 4 mg/kg, once daily for 14 days) that were perseverative in nature, indicating persistent behavioral consequences of repetitive dosing. The results indicate that repeated cocaine administrations produce enduring impairments of object discrimination learning when the inhibition of a previously conditioned response is required. These findings suggest that long-term cocaine administration may disrupt orbitofrontal efferents to the striatum, resulting in impaired inhibition of established conditioned responses.

Positive-ion fast atom bombardment mass spectra of 13 keto acid and keto ester phosphoranes were examined. All compounds gave a protonated molecular ion and characteristic peaks at m/z 303, 279, 262 and 201.

Background: Psychomotor stimulant drugs can produce long-lasting changes in neurochemistry and behavior after multiple doses. In particular, neuroadaptations within corticolimbic brain structures that mediate incentive learning and motivated behavior have been demonstrated after chronic exposure to cocaine, d -amphetamine, and 3,4-methylenedioxymethamphetamine (MDMA). As stimulus–reward learning is likely relevant to addictive behavior (i.e., augmented conditioned reward and stimulus control of behavior), we have investigated whether prior repeated administration of psychomotor stimulant drugs of abuse, including cocaine, d -amphetamine, or MDMA, would affect the acquisition of Pavlovian approach behavior. Methods: Water-deprived rats were tested for the acquisition of Pavlovian approach behavior after 5 days treatment with cocaine (15–20 mg/kg once or twice daily), d -amphetamine (2.5 mg/kg once or twice daily), or MDMA (2.5 mg/kg twice daily) followed by a 7-day, drug-free period. Results: Prior repeated treatment with cocaine or d -amphetamine produced a significant enhancement of acquisition of Pavlovian approach behavior, indicating accelerated stimulus–reward learning, whereas MDMA administration produced increased inappropriate responding, indicating impulsivity. Abnormal drug-induced approach behavior was found to persist throughout the testing period. Conclusions: These studies demonstrate that psychomotor stimulant-induced sensitization can produce long-term alterations in stimulus–reward learning and impulse control that may contribute to the compulsive drug taking that typifies addiction.

The gene expression profile of skeletal muscle from healthy older (62–75 years old) compared with younger (20–34 years old) men demonstrated elevated expression of genes typical of a stress or damage response, and decreased expression of a gene encoding a DNA repair/cell cycle checkpoint protein. Although the expression of these genes was relatively unaffected by a single bout of resistance exercise in older men, acute exercise altered gene expression in younger men such that post-exercise gene expression in younger men was similar to baseline gene expression in older men. The lack of response of muscle from older subjects to resistance exercise was also apparent in the expression of the inflammatory response gene IL-1β, which did not differ between the age groups at baseline, but increased within 24 h of the exercise bout only in younger subjects. Other genes with potentially important roles in the adaptation of muscle to exercise, specifically in the processes of angiogenesis and cell proliferation, showed a similar response to exercise in older compared with younger subjects. Only one gene encoding the multifunctional, early growth response transcription factor EGR-1, showed an opposite pattern of expression in response to exercise, acutely decreasing in younger and increasing in older subjects. These results may provide a molecular basis for the inherent variability in the response of muscle from older as compared with younger individuals to resistance training.

Background: Impulsivity associated with frontal cortical dysfunction appears to be a direct consequence of chronic consumption of drugs of abuse, though few investigations in animals have attempted to directly address this issue. In this study the effects of repeated, intermittent administration of a psychotomimetic drug of abuse, phencyclidine, on the acquisition and performance of a task sensitive to corticostriatal function was examined in nonhuman primates. Methods: Monkeys were repeatedly exposed to phencyclidine (0.3 mg/kg) twice daily for 14 days. Acquisition and performance on an object-retrieval detour task was subsequently examined for up to 28 days after drug withdrawal. Results: Animals treated with phencyclidine exhibited impaired acquisition of the task. The performance of trials requiring inhibitory control (as opposed to solely sensory-guided responding) was specifically impaired by prior phencyclidine administration. Impairments were found to be due to increased perseveration and barrier reaching. As is the case after frontal cortex ablation, the behavioral deficits were particularly evident during acquisition and appeared to be alleviated by prolonged training. Conclusions: The current data demonstrate that subchronic administration of phencyclidine can produce deficits in inhibitory response control that are manifest as impulsivity (increased control of behavior by unconditioned, appetitive stimuli). These data suggest that long-term phencyclidine exposure induces frontostriatal-like cognitive impairments and may represent a potential (drug induced) model for the study of prefrontal cortical cognitive and dopaminergic dysfunction.

Strategic quality management consultants at Quorum Health Resources, LLC, headquartered in Brentwood, TN, recently introduced rapid cycle change to hospital clients. The answers to three defined questions, the Plan-Do-Study-Act cycle, and testing the improvements on a small scale under a variety of conditions are the basis of rapid cycle change. The initial results are encouraging. To obtain a deeper evaluation of the clients' experience, a modified qualitative research methodology was utilized to obtain and analyze information. Five themes emerged that support rapid cycle change as an elegantly simple and effective model.

The mesolimbic dopamine (DA) system has been implicated in drug reward, locomotor sensitization, and responding for reward-related stimuli [termed conditioned reinforcers (CR)]. Here, we investigated the effect of brain-derived neurotrophic factor (BDNF), which enhances the survival and function of dopaminergic neurons, on stimulant-induced locomotor sensitization and responding for CR. In experiment 1, BDNF was infused into the nucleus accumbens (NAc) or ventral tegmental area over 2 weeks via chronically implanted minipumps (1–2.5 μg/d), and the psychomotor stimulant effects of cocaine (5–15 mg/kg, i.p.) were studied. We found that BDNF enhanced the initial stimulant effects of cocaine and seemed to facilitate the development of sensitization to repeated cocaine doses. In experiment 2, we studied the effects of intra-NAc BDNF infusions on responding for CR. BDNF-treated rats showed twice as many CR responses compared with controls when saline was first administered. BDNF enhanced responding on the CR lever more than four times that seen in control animals after a cocaine injection (10 mg/kg, i.p.). The enhanced response to cocaine in BDNF-treated animals persisted for more than a month after the BDNF infusions had stopped, indicating long-lasting changes in the mesolimbic DA system caused by BDNF administration. In experiment 3, we examined locomotor sensitization to cocaine in heterozygous BDNF knock-out mice and found that the development of sensitization was delayed compared with wild-type littermates. These results demonstrate the profound effects of BDNF on the enhancement of both cocaine-induced locomotion and facilitation of CR and suggest a possible role for BDNF in long-term adaptations of the brain to cocaine.

Background: Many neuropsychiatric disorders are associated with high levels of noradrenergic turnover, and most antipsychotic medications have α-1 adrenoceptor blocking properties, yet little is known about α-1 influences on higher cortical function. Methods: The α-1 adrenergic agonist, phenylephrine, was infused into the prefrontal cortex (PFC) of rats (0.1 μg/0.5 μL) performing a spatial working memory task, delayed alternation. The phenylephrine response was challenged with coinfusion of the α-1 adrenergic antagonist, uripidil (0.01 μg), or with a dose of lithium chloride (4 mEq/kg, IP, 18 hours) known to suppress phosphotidylinositol (PI) turnover, the second messenger pathway coupled to α-1 adrenoceptors. Results: Phenylephrine infusions in PFC markedly impaired delayed alternation performance. The phenylephrine response was reversed by coinfusion of uripidil, or by pretreatment with lithium, consistent with actions at α-1 adrenoceptors coupled to a PI pathway. Conclusions: These findings demonstrate that α-1 adrenoceptor stimulation in the PFC impairs cognitive function. Excessive stimulation of α-1 adrenoceptors may contribute to PFC deficits (e.g., distractibility, impulsivity) in disorders such as mania, dementia, and anxiety associated with high noradrenergic turnover.

Publisher Summary Parkinson's disease—a neurodegenerative disorder—is characterized by a progressive loss of dopaminergic neurons of the substantia nigra that project to the neostriatum. Initial results from clinical trials have been encouraging; however, there is no consensus regarding the optimal choice of grafting site(s) to achieve clinical benefit, nor of optimal age of the donor tissue. Because reinnervation of the entire striatum is unlikely with tissue from a single donor, the distribution of the implanted tissue within a site(s) also may be of critical functional importance. The complex primate behavioral repertoire and the faithful elicitation of classic parkinsonian symptoms in primates provide a useful and reliable method for investigating the extent and nature of functional changes resulting from fetal tissue grafts. Although several questions remain to be resolved, including when to intervene surgically in the course of a progressive neurological disorder and whether a source of cells can be identified that eliminates the requirement for using human embryonic tissue, it is clear that methodology has been developed and tested to a degree that can potentially support the safe and effective use of this neurosurgical intervention in additional Parkinson's disease patients in the future.

Both the locus coeruleus (LC) and the amygdala have been implicated in aspects of opiate dependence and withdrawal. The LC is known to be one of the most sensitive sites for precipitating withdrawal behaviors after local opiate antagonist infusions in morphine-dependent subjects. The amygdala is also known to mediate antagonist-induced withdrawal behaviors and aversive motivational states. The goal of the present study was to evaluate directly the ability of noradrenergic agonists and glutamatergic antagonists to attenuate naloxone-precipitated withdrawal behaviors when infused into the LC or the central nucleus of the amygdala (CeA). The alpha-2-noradrenergic agonists clonidine or ST-91 were infused into the CeA to compare the effects of noradrenergic activation in the CeA to the attenuation of withdrawal previously observed in rats infused with clonidine into the LC, since the LC and CeA are known to contain co-localized opiate and noradrenergic receptors. The effects of microinfusions of the non-NMDA excitatory amino acid antagonist 6-cyano-2,3-dihydroxy-7-nitroquinoxaline (CNQX) were also infused into the LC and CeA since opiate withdrawal is associated with increased glutamatergic transmission. Intra-CeA clonidine or ST-91 (2.4 microg/0.5 microl or 1.0 microl) produced significant reductions primarily in the occurrence of irritability. Conversely, intra-CeA or intra-LC infusions of CNQX (2.5 microg/0.5 microl) significantly attenuated naloxone-precipitated withdrawal, an effect similar to the attenuation previously observed after intra-LC clonidine infusions. These data demonstrate the specific behavioral effects of altering glutamatergic and noradrenergic neurotransmission in the LC or CeA during naloxone-precipitated opiate withdrawal. Elucidation of the neuroanatomical circuitry involved in opiate withdrawal should increase our understanding of the neuroadaptations associated with drug dependence and subsequent withdrawal behavior.

Chronic opiate administration upregulates the cAMP pathway in the locus coeruleus (LC). This adaptation is thought to increase the electrical excitability of LC neurons and contribute to the dramatic increase in LC firing induced by opioid receptor antagonists in opiate-dependent animals. The goal of the present study was to evaluate directly a role of the cAMP pathway in opiate withdrawal behaviors by studying,in vivo, whether withdrawal is influenced by intra-LC infusion of compounds known to activate or inhibit protein kinase A (PKA). Infusions into amygdala or periaqueductal gray (PAG) were studied for comparison. In one series of experiments the effect of intra-LC, intra-amygdala, or intra-PAG infusions of the PKA inhibitor Rp-cAMPS on naloxone-precipitated withdrawal from morphine was examined. Intra-LC infusions of Rp-cAMPS significantly attenuated several prominent behavioral signs of morphine withdrawal. Intra-PAG infusions of Rp-cAMPS also significantly attenuated opiate withdrawal behaviors, although different behaviors were affected. In contrast, intra-amygdala infusions of Rp-cAMPS were without significant effect. In a second series of experiments the effect of intra-LC or intra-PAG infusions of the PKA activator Sp-cAMPS on behavior in nondependent drug-naive animals was determined. Sp-cAMPS infusions into either brain region induced a quasi-withdrawal syndrome, but the observed behaviors differed between the two groups. Analysis of the phosphorylation state of tyrosine hydroxylase, a well characterized substrate for PKA, confirmed the ability of Rp-cAMPS and Sp-cAMPS to inhibit and activate, respectively, PKA activityin vivo. Together, these data provide direct evidence for involvement of the cAMP–PKA system in the LC, as well as in the PAG, in opiate withdrawal and withdrawal-related behaviors.

Activation of adult myoblasts called satellite cells during muscle degeneration is an important aspect of muscle regeneration. Satellite cells are believed to be the only myogenic stem cells in adult skeletal muscle and the source of regenerating muscle fibers. Upon activation, satellite cells proliferate, migrate to the site of degeneration, and become competent to fuse and differentiate. We show here that the transcription factor polyomavirus enhancer activator 3 (PEA3) is expressed in adult myoblasts in vitro when they are proliferative and during the early stages of differentiation. Overexpression of PEA3 accelerates differentiation, whereas blocking of PEA3 function delays myoblast fusion. PEA3 activates gene expression following binding to the ets motif most efficiently in conjunction with the transcription factor myocyte enhancer factor 2 (MEF2). In vivo, PEA3 is expressed in satellite cells only after muscle degeneration. Taken together, these results suggest that PEA3 is an important regulator of activated satellite cell function.

The effects of the psychotomimetic drug phencyclidine on the neurochemistry and function of the prefrontal cortex in vervet monkeys were investigated. Monkeys treated with phencyclidine twice a day for 14 days displayed performance deficits on a task that was sensitive to prefrontal cortex function; the deficits were ameliorated by the atypical antipsychotic drug clozapine. Repeated exposure to phencyclidine caused a reduction in both basal and evoked dopamine utilization in the dorsolateral prefrontal cortex, a brain region that has long been associated with cognitive function. Behavioral deficits and decreased dopamine utilization remained after phencyclidine treatment was stopped, an indication that these effects were not simply due to direct drug effects. The data suggest that repeated administration of phencyclidine in monkeys may be useful for studying psychiatric disorders associated with cognitive dysfunction and dopamine hypofunction in the prefrontal cortex, particularly schizophrenia.

The present study assessed the ability of cocaethylene to induce sensitization to the behavioral activating effects of cocaine in the male Sprague-Dawley rat. Preexposure to cocaethylene (15 or 25 mg/kg) significantly enhanced the locomotor activating effects of a subsequent cocaine (15 mg/kg) challenge injection. In addition, acute intraperitonecal administration at several doses (10, 15, or 25 mg/kg) confirmed previous reports of increased bioavailability of cocaine in brain and plasma relative to cocaethylene. These data are discussed in terms of previous work in which a significant augmentation of cocaine-induced locomotor activity was not observed following cocaethylene preexposure.

Cocaethylene, an active metabolite that arises through hepatic transesterification of cocaine when cocaine and ethanol are used together, shares many neurochemical and pharmacological properties with cocaine. Cocaethylene is similar to cocaine in its properties as an indirect dopamine agonist, and human subjects cannot distinguish its effects from those of cocaine. Cocaethylene, and especially its isopropyl analog, are more selective indirect dopamine agonists than cocaine, with relatively weak potency at the serotonin transporter. Cocaethylene may contribute to the manifestations and consequences of combined cocaine and ethanol use, although its relative importance remains unclear.

A cDNA encoding a metallothionein-like protein has been isolated from a cDNA library from the abscission zones of ethylene-treated Sambucus nigra leaflets. The precise function of this group of proteins in plants has yet to be confirmed but in animals there is convincing evidence that they bind heavy metals. Several of these proteins have recently been characterised from plants and it has been demonstrated that heavy metals have no stimulatory effect on their expression. In this paper we describe the isolation and characterisation of a metallothionein-like mRNA identified as a consequence of differentially screening a cDNA library for messages up-regulated during abscission. The accumulation of the mRNA occurred in the abscission zone tissue within 18 h of exposure to ethylene while, in contrast, no expression was detectable in adjacent non-abscission-zone tissue. The transcript size of the message was approximately 0.6 kb. Northern analysis revealed that the cDNA insert (JET12) did not hybridise to mRNA from either green or senescing leaflets but a signal was detectable with mRNA extracted from senescent tissue. The size of this hybridising transcript was approximately 0.5 kb. The predicted metallothionein-like protein encoded by JET12 was cysteinerich (18.4%) and had a molecular weight of approximately 7.5 kDa. Southern analysis of S. nigra genomic DNA showed that the mRNA was encoded by a small gene family. The protein exhibited greatest homology to other metallothioneins belonging to the Type 2 family including those from Mimulus (62%) and Arabidopsis (57%). This homology was greatest around the cysteine-rich amino and carboxy termini. The possible role of the protein encoded by JET12 during ethylene-promoted leaflet abscission is discussed.

A cDNA clone (MEL5), encoding a protein homologous to phytoene synthase (PSY), has been isolated from a climacteric melon fruit cDNA library, using the tomato cDNA clone TOM5 [34] as a heterologous probe. MEL5 hybridised to a transcript of 1.65 kb which suggested that the 1.36 kb clone, isolated originally, was not full-length. The missing 5' end was isolated by a reverse transcriptase-polymerase chain reaction (RT-PCR)-based method. This enabled the full sequence of the protein to be deduced and the cleavage site of the transit peptide for chromoplast import to be predicted. Northern analysis of RNA extracted from fruit samples of different ripening stages as well as from roots, leaves and flower petals was used to examine the expression pattern of the corresponding mRNA. The corresponding mRNA. The transcript corresponding to MEL5 is present at low quantities in unripe (green) fruit, reaches its highest levels when the fruit turns from green to orange and persists at lower levels during later ripening stages. A similar transcript was also detected in flower petals and in trace amounts in leaves and roots. Genomic Southern analysis indicates that the clone is homologous to a low-copy-number gene family. Sequence analysis showed a high degree of conservation among plant PSYs.

Repeated administration of cocaine results in a reverse tolerance or sensitization to the locomotor stimulant properties of cocaine. In this study, we examined the effect of an antagonist for the strychinine-insensitive glycine receptor of the NMDA receptor complex, R-(+)-HA-966, on the development of locomotor sensitization to cocaine. Co-administration of R-(+)-HA-966 with repeated cocaine prevented locomotor sensitization to a subsequent challenge dose of cocaine. However, R-(+)-HA-966 (15 mg/kg i.p.) did not attenuate locomotor activation to an acute dose of cocaine (15 mg/kg). These results indicate that the glycine/NMDA receptor is involved in locomotor sensitization to repeated cocaine administration but not in the locomotor activation to the acute stimulant effects of cocaine administration.

The muscle-specific beta-enolase gene is expressed in proliferating adult myoblasts as well as in differentiated myotubes. Through deletion-transfection analysis, we identified a 79-base pair enhancer from the beta-enolase gene that leads to high level expression of a reporter gene in myoblasts, but not in fibroblasts. Following myoblast differentiation into myotubes, the activity of the enhancer declined, indicating that beta-enolase gene expression in myotubes is mediated by other regulators, possibly the myogenic helix-loop-helix family of transcription factors. Electrophoretic mobility shift assays indicated that proteins present in myoblast nuclear extracts specifically bind to the 3' half of the 79-base pair enhancer. This region contains an ets DNA-binding motif which is required not only for high level activity in myoblasts, but also for repressing activity in fibroblasts. Furthermore, the beta-enolase myoblast-specific enhancer shows limited similarity to the myoblast-specific enhancer associated with the human desmin gene, suggesting that gene expression in adult myoblasts may be coordinately regulated.

Parkinsonism has been reported to improve following transplantation of fetal mesencephalic tissue into the striatum of MPTP-exposed monkeys and humans and in patients with idiopathic Parkinson's disease. While there is good evidence for the survival of grafted tyrosine hydroxylase (TH)-positive cells in animal studies, it is not known whether they produce neuronal effects that account for behavioral improvement after transplantation or whether spontaneous or graft-induced changes in the host striatum are at least partly responsible. Are neuronal synaptic connections and dopamine release necessary, or would “toenails and talcum powder” do the job equally well? We have addressed these questions by studying several types of implantation surgeries, including sham surgery, the implantation of cerebellar tissue, and the implantation of mesencephalic TH-positive fetal tissue of various gestational ages into the striatum. Adult male African green monkeys received systemic MPTP administration (cumulative doses of 2.0-2.5 mg/kg) prior to these stereotaxic surgical manipulations. Subjects were matched for quantitative behavioral deficits prior to surgery. Subjects were examined and assessments made by “blinded” observers who scored individual spontaneous and elicited behaviors. Observers were trained and tested repeatedly for inter-rater reliability. A “parkinsonian summary score” derived and determined using a principal component factor analysis of a large sample of data from MPTP-treated and normal monkeys of the same species was used to assess behavior. Postmortem brain tissue was prepared for biochemical analysis of dopamine concentrations and TH immunohistochemical studies. The most dramatic improvement was seen in monkeys with “early” (14 cm fetal crown rump length) substantia nigra-grafted monkeys. These changes in monkeys which did not have surviving dopamine-producing grafts probably represent the recovery capacity of MPTP-treated host brain during this time interval since un-operated subjects showed similar changes. More variable effects were seen with substantia nigra grafts in the putamen. The most consistent correlate of behavioral improvement in all experimental groups was elevation in dopamine concentrations near the grafts compared with a distant striatal location which is believed to represent the depletion without the effects of the grafts. While these data do not establish the precise mechanism of action, they point to a hierarchy of factors which provide increasingly larger restorative effects, including sprouting of host neurons and increased dopamine production by grafted fetal dopamine neurons. Sham surgery appears to be significantly less effective than early fetal mesencephalic tissue which survives and releases dopamine.

A cDNA clone (TAB2) encoding a nucleoside diphosphate (NDP) kinase has been isolated from a tomato (Lycopersicon esculentum Mill. cv. Ailsa Craig) cDNA library. The clone is 590 bp long and exhibits a high degree of sequence identity with spinach NDP kinases I and II, Pisum sativum NDP kinase I, Arabidopsis thaliana NDP kinase, Drosophila melanogaster NDP kinase, Dictyostelium discoideum NDP kinase and human Nm 23-H1 and Nm23-H2. Northern analysis has revealed that the mRNA encoded by TAB2 is up-regulated in both leaf and stem tissue in response to wounding. The increase is apparent within 1 h of wounding and is not further elevated by application of ethylene. Southern blot analysis indicates that TAB2 is a member of a small gene family.

Dehiscence of oilseed rape pods, commonly known as pod shatter, is a process of agronomic importance that results in seed loss causing yield reductions and carry-over of the crop into the following growing season. In an effort to understand the mechanisms underlying this developmental event, the changes in gene expression that accompany pod shatter have been examined with a view to understanding how the process is regulated. In order to achieve this, a cDNA library was constructed using mRNA extracted from the dehiscence zone of developing pods. Differential screening with non-dehiscence zone cDNA led to the isolation of a pod-specific clone, SAC25, with a transcript size of 1100 nucleotide encoding a predicted polypeptide of 34 kDa. The level of SAC25 mRNA accumulation increased during pod development. The sequence shows no significant homology to others within the databases but has two identifiable amino acid motifs, one is an adenine nucleotide binding site for NAD/FAD dehydrogenases and the other is a conserved feature of the ribitol dehydrogenase family. The amino acid sequence has four putative glycosylation sites and contains four cysteine residues. Genomic Southern analysis indicates that SAC25 may be encoded by a single gene or a small gene family. The function of this mRNA is unknown but possible roles in dehiscence and pod development are discussed.

Pod development in oilseed rape (Brassica napus) culminates in a process known as dehiscence (shatter) which can result in the loss of seed before the crop is harvested. In order to investigate the biochemical and the genetic basis controlling this process, a cDNA library was constructed from the dehiscence zone of developing pods. This resulted in the isolation of a cDNA clone (SAC51). The mRNA encoded by SAC51 had a transcript size of ca. 700 nucleotides and was found, by northern analysis, to accumulate preferentially in the dehiscence zone of the pod and in no other part of the plant analysed. The predicted polypeptide is rich in the amino acids proline (14.2%) and leucine (14.2%). The sequence of the polypeptide has more than 40% amino acid sequence identity with polypeptides isolated from carrot embryos, maize roots, soybean seeds and young tomato fruit. The function of these proteins is unknown. Genomic Southern analysis suggests that SAC51 is encoded by a single gene or small gene family. The role of the peptide in the development of pods of oilseed rape is discussed.

Abscission of the leaflets of Sambucus nigra is stimulated by ethylene. Associated with cell separation is an increase in the activity of β 1,4 glucanase (cellulase) and polygalacturonase (PG) and this rise is restricted to the cells comprising the abscission zone. A cDNA library has been generated from mRNA extracted from separating abscission zone cells and screened using a heterologous s 1,4 glucanase probe from Phaseolus vulgaris. A number of positive cDNAs have been isolated from the S. nigra library and the largest clone designated pJET1 has a size of 1.7Kb. pJET1 has been sequenced and exhibits over 70% deduced amino acid homology with the protein encoded by the P. vulgaris cDNA. Using a differential screening strategy over 20 abscission-related cDNAs have been isolated from the library. None of these hybridizes to pJET1 and their role in abscission remains to be determined.

The increasing incidence of multidrug-resistant (MDR) pulmonary infections in the cystic fibrosis (CF) population has prompted the investigation of innovative silver based therapeutics. The functionalization of the naturally occurring xanthine theobromine at the N(1) nitrogen atom with an ethanol substituent followed by the methylation of the N(9) nitrogen atom gives the N-heterocyclic carbene precursor 1-(2-hydroxyethyl)-3,7,9-trimethylxanthinium iodide. The reaction of this xanthinium salt with silver acetate produces the highly hydrophilic silver carbene complex SCC8. The in vitro antimicrobial efficacy of this newly synthesized complex was evaluated with excellent results on a variety of virulent and MDR pathogens isolated from CF patients. A comparative in vivo study between the known caffeine derived silver carbene SCC1 and SCC8 demonstrated the ability of both complexes to improve the survival rates of mice in a pneumonia model utilizing the clinically isolated infectious strain of Pseudomonas aeruginosa PA M57-15.

Polygalacturonase (PG, EC 3.2.1.15), an enzyme commonly found in ripening fruit, has also been shown to be associated with abscission. A zone-specific rise in PG activity accompanies the abscission of both leaves and flowers of tomato (Lycopersicon esculentum Mill.) plants. Studies of transgenic plants expressing an antisense RNA for fruit PG indicate that although the enzyme activity in transgenic fruit is < 1 % of that in untransformed fruit, the PG activity in the leaf abscission zone increases during separation to a similar value to that in untransformed plants. The timing and rate of leaf abscission in transgenic plants are unaffected by the introduction of the antisense gene. A polyclonal antibody raised against tomato fruit PG does not recognise the leaf abscission protein. Furthermore a complementary DNA (cDNA) clone (pTOM6), which has been demonstrated to code for fruit PG, does not hybridise to mRNA isolated from the abscission-zone region of tomato leaves. These results indicate that the PG protein in abscission zones of tomato is different from that in the fruit, and that the gene coding for this protein may also be different.

Since there are reasons to hypothetize that appropriate occupation of D 1 receptors may be an essential component of efficacious antiparkinsonian therapy (Brewster et al., 1990), we tested dihydrexidine in non-human primates pretreated with the dopaminergic neurotoxicant 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-HCl (MPTP), which results in a parkinsonian syndrome in humans and non-human primates

An estimated 18 million American adults and several million adolescents are experiencing physical, psychological, and social problems from the consumption of alcoholic beverages. 1, 2 These problems include traumatic injury, cirrhosis of the liver, certain types of cancer, emotional disorders, interpersonal conflicts, alcohol-related violence, absenteeism, and loss of productivity. Deaths attributable Io the consumption of alcohol in the US approx 100,000/yr, and it is predicted that by 1995 the annual cost of alcohol abuse and alcoholism in the US will approach 150 billion dollars. 1, 3*

Objective To investigate whether offering volunteer support from counsellors in breast feeding would result in more women breast feeding. Design Randomised controlled trial. Setting 32 general practices in London and south Essex. Participants 720 women considering breast feeding. Main outcome measures Primary outcome was prevalence of any breast feeding at six weeks. Secondary outcomes were the proportion of women giving any breast feeds, or bottle feeds at four months, duration of any breast feeding, time to introduction of bottle feeds, and satisfaction with breast feeding. Results Offering support in breast feeding did not significantly increase the prevalence of any breast feeding to six weeks (65% (218/336) in the intervention group and 63% (213/336) in the control group; relative risk 1.02, 95% confidence interval 0.84 to 1.24). Survival analysis up to four months confirmed that neither duration of breast feeding nor time to introduction of formula feeds differed significantly between control and intervention groups. Not all women in the intervention group contacted counsellors postnatally, but 73% (123/179) of those who did rated them as very helpful. More women in the intervention group than in the control group said that their most helpful advice came from counsellors rather than from other sources. Conclusions Women valued the support of a counsellor in breast feeding, but the intervention did not significantly increase breastfeeding rates, perhaps because some women did not ask for help.

Many plant RNA isolation techniques aim to prevent contamination by means of secondary phenolics, carbohydrates, RNase, and other chemicals. However, when applied in our laboratory to the isolation of RNA fromRumex obtusifolius, these protocols failed to produce good quality RNA. A major problem was contamination of the RNA samples with the secondary metabolite oxalate. The relative quantities of guanidine isothiocyanate extraction buffer to plant tissue used in the protocol had significant effects on oxalate contamination. An increase in extraction buffer, from 1.5 mL in the original method to 15 mL per 200–300 mg of tissue in our protocol, removed the oxalate from the RNA. This RNA was of a good quality and was suitable for molecular biology applications.

The acylated cyclic enamino ester dipeptide analogues 12, 13, and 17-10 have been prepared via lactonization of the keto acid phosphorane 8 followed by incorporation of an amino acid into the product enol lactones

Activation of the adenylyl cyclase-cAMP-protein kinase A (PKA) intracellular signaling cascade is necessary for long-term memory consolidation in brain regions such as the hippocampus. However, the role of the PKA cascade in the working memory functions of the prefrontal cortex (PFC) is unknown. The present study examined the effects of manipulating PKA activity in the PFC using the cAMP stereoisomers Sp-cAMPS and Rp-cAMPS, which activate and inhibit PKA, respectively. Animals received bilateral infusions of Sp-cAMPS and/or Rp-cAMPS into the PFC immediately before testing on the delayed alternation task, a test of spatial working memory that depends on the integrity of the PFC. Low doses of Sp-cAMPS (0.21, 2. 1, or 21 nmol/0.5 microl) produced a marked, dose-dependent impairment in working memory performance. The impairment produced by infusion of Sp-cAMPS (21 nmol/0.5 microl) was fully reversed by co-infusion of Rp-cAMPS (21 nmol/0.5 microl), consistent with actions on PKA. Rp-cAMPS (21 or 42 nmol/0.5 microl) by itself had no effect on performance. These results indicate that activation of the PKA intracellular signaling cascade in the PFC impairs working memory performance. The current findings contrast with studies of long-term memory consolidation, in which inhibition of PKA with agents such as Rp-cAMPS impaired memory consolidation (Bernabeu et al., 1997; Bourtchouladze et al., 1998), whereas enhancement of the PKA pathway improved memory (Bernabeu et al., 1997; Barad et al., 1998). These results demonstrate that discrete cognitive processes subserved by different cortical regions are mediated by distinct intracellular mechanisms.