In vivo kinetics of [F-18]MEFWAY: a comparison with [C-11]WAY100635 and [F-18]MPPF in the nonhuman primate.

UNLABELLED: [F-18]Mefway was developed to provide an F-18 labeled positron emission tomography (PET) neuroligand with high affinity for the serotonin 5-HT(1A) receptor to improve the in vivo assessment of the 5-HT(1A) system. The goal of this work was to compare the in vivo kinetics of [F-18]mefway, [F-18]MPPF, and [C-11]WAY100635 in the rhesus monkey. METHODS: Each of four monkeys were given bolus injections of [F-18]mefway, [C-11]WAY100635, and [F-18]MPPF and scans were acquired with a microPET P4 scanner. Arterial blood was sampled to assay parent compound throughout the time course of the PET experiment. Time activity curves were extracted in the high 5-HT(1A) binding areas of the anterior cingulate cortex (ACG), mesial temporal cortex, raphe nuclei, and insula cortex. Time activity curves were also extracted in the cerebellum, which was used as a reference region. The in vivo kinetics of the radiotracers were compared based on the nondisplaceable distribution volume (V(ND) ) and binding potential (BP(ND) ). RESULTS: At 30 min, the fraction of radioactivity in the plasma due to parent compound was 19%, 28%, and 29% and cleared from the arterial plasma at rates of 0.0031, 0.0078, and 0.0069 (min⁻¹) ([F-18]mefway, [F-18]MPPF, [C-11]WAY100635). The BP(ND) in the brain regions were mesial temporal cortex: 7.4 ± 0.6, 3.1 ± 0.4, 7.0 ± 1.2, ACG: 7.2 ± 1.2, 2.1 ± 0.2, 7.9 ± 1.2; raphe nuclei: 3.7 ± 0.6, 1.3 ± 0.3, 3.3 ± 0.7; and insula cortex: 4.2 ± 0.6, 1.2 ± 0.1, 4.7 ± 1.0 for [F-18]mefway, [F-18]MPPF, and [C-11]WAY100635 respectively. CONCLUSIONS: In the rhesus monkey, [F-18]mefway has similar in vivo kinetics to [C-11]WAY100635 and yields greater than 2-fold higher BP(ND) than [F-18]MPPF. These properties make [F-18]mefway a promising radiotracer for 5-HT(1A) assay, providing higher counting statistics and a greater dynamic range in BP(ND).

Specific α4ß2 nicotinic acetylcholine receptor binding of [F-18]nifene in the rhesus monkey.

OBJECTIVE: [F-18]Nifene is a PET radioligand developed to image α4ß2* nicotinic acetylcholine receptors (nAChR) in the brain. This work assesses the in vivo binding and imaging characteristics of [F-18]nifene in rhesus monkeys for the development of PET experiments examining nAChR binding. METHODS: Dynamic PET imaging experiments with [F-18]nifene were acquired in four anesthetized Macaca mulatta (rhesus) monkeys using a microPET P4 scanner. Data acquisition was initiated with a bolus injection of 109 ± 17 MBq [F-18]nifene and the time course of the radioligand in the brain was measured for up to 120 min. For two experiments, a displacement dose of (-)nicotine (0.03 mg kg(-1) , i.v.) was given 45-60 min post injection and followed 30 min later with a second [F-18]nifene injection to measure radioligand nondisplaceable uptake. Time activity curves were extracted in the regions of the antereoventral thalamus (AVT), lateral geniculate nucleus region (LGN), frontal cortex, and the cerebellum (CB). RESULTS: The highest levels of [F-18]nifene uptake were observed in the AVT and LGN. Target-to-CB ratios reached maximum values of 3.3 ± 0.4 in the AVT and 3.2 ± 0.3 in the LGN 30-45 min postinjection. Significant binding of [F-18]nifene was observed in the subiculum, insula cortex, temporal cortex, cingulate gyrus, frontal cortex, striatum, and midbrain areas. The (-)nicotine displaced bound [F-18]nifene to near background levels within 15 min postdrug injection. No discernable displacement was observed in the CB, suggesting its potential as a reference region. Logan graphical estimates using the CB as a reference region yielded binding potentials of 1.6 ± 0.2 in the AVT and 1.3 ± 0.1 in the LGN. The postnicotine injection displayed uniform nondisplaceable uptake of [F-18]nifene throughout gray and white brain matter. CONCLUSIONS: [F-18]Nifene exhibits rapid equilibration and a moderately high target to background binding profile in the α4ß2* nAChR rich regions of the brain, thus providing favorable imaging characteristics as a PET radiotracer for nAChR assay.

Synaptic weighting in single flux quantum neuromorphic computing.

Josephson junctions act as a natural spiking neuron-like device for neuromorphic computing. By leveraging the advances recently demonstrated in digital single flux quantum (SFQ) circuits and using recently demonstrated magnetic Josephson junction (MJJ) synaptic circuits, there is potential to make rapid progress in SFQ-based neuromorphic computing. Here we demonstrate the basic functionality of a synaptic circuit design that takes advantage of the adjustable critical current demonstrated in MJJs and implement a synaptic weighting element. The devices were fabricated with a restively shunted Nb/AlOx-Al/Nb process that did not include MJJs. Instead, the MJJ functionality was tested by making multiple circuits and varying the critical current, but not the external shunt resistance, of the oxide Josephson junction that represents the MJJ. Experimental measurements and simulations of the fabricated circuits are in good agreement.

TOJ3, a target of the v-Jun transcription factor, encodes a protein with transforming activity related to human microspherule protein 1 (MCRS1).

Using the established quail cell line Q/d3 conditionally transformed by the v-jun oncogene, cDNA clones (TOJ2, TOJ3, TOJ5, TOJ6) were isolated by representational difference analysis (RDA) that correspond to genes which were induced immediately upon conditional activation of v-jun. One of these genes, TOJ3, is immediately and specifically activated after doxycycline-mediated v-jun induction, with kinetics similar to the induction of well characterized direct AP-1 target genes. TOJ3 is neither activated upon conditional activation of v-myc, nor in cells or cell lines non-conditionally transformed by oncogenes other than v-jun. Sequence analysis revealed that the TOJ3-specific cDNA encodes a 530-amino acid protein with significant sequence similarities to the murine or human microspherule protein 1 (MCRS1, MSP58), a nucleolar protein that directly interacts with the ICP22 regulatory protein from herpes simplex virus 1 or with p120, a proliferation-related protein expressed at high levels in most human malignant tumor cells. Similar to its mammalian counterparts, the TOJ3 protein contains a bipartite nuclear localization motif and a forkhead associated domain (FHA). Using polyclonal antibodies directed against a recombinant amino-terminal TOJ3 protein segment, the activation of TOJ3 in jun-transformed fibroblasts was also demonstrated at the protein level by specific detection of a polypeptide with an apparent M(r) of 65 000. Retroviral expression of the TOJ3 gene in quail or chicken embryo fibroblasts induces anchorage-independent growth, indicating that the immediate activation of TOJ3 in fibroblasts transformed by the v-jun oncogene contributes to cell transformation.

Structure, function, and dynamics of the dimerization and DNA-binding domain of oncogenic transcription factor v-Myc.

The protein product (c-Myc) of the protooncogene c-myc is a transcriptional regulator playing a key role in cellular growth, differentiation, and apoptosis. Deregulated myc genes, like the transduced retroviral v-myc allele, are oncogenic and cause cell transformation. The C-terminal bHLHZip domain of v-Myc, encompassing protein dimerization (helix-loop-helix, leucine zipper) and DNA contact (basic region) surfaces, was expressed in bacteria as a highly soluble p15(v-myc )recombinant protein. Dissociation constants (K(d)) for the heterodimer formed with the recombinant bHLHZip domain of the Myc binding partner Max (p14(max)) and for the Myc-Max-DNA complex were estimated using circular dichroism (CD) spectroscopy and quantitative electrophoretic mobility shift assay (EMSA). Multi-dimensional NMR spectroscopy was used to characterize the solution structural and dynamic properties of the v-Myc bHLHZip domain. Significant secondary chemical shifts indicate the presence of two separated alpha-helical regions. The C-terminal leucine zipper region forms a compact alpha-helix, while the N-terminal basic region exhibits conformational averaging with substantial alpha-helical content. Both helices lack stabilizing tertiary side-chain interactions and represent exceptional examples for loosely coupled secondary structural segments in a native protein. These results and CD thermal denaturation data indicate a monomeric state of the v-Myc bHLHZip domain. The (15)N relaxation data revealed backbone mobilities which corroborate the existence of a partially folded state, and suggest a "beads-on-a-string" motional behaviour of the v-Myc bHLHZip domain in solution. The preformation of alpha-helical regions was confirmed by CD thermal denaturation studies, and quantification of the entropy changes caused by the hydrophobic effect and the reduction of conformational entropy upon protein dimerization. The restricted conformational space of the v-Myc bHLHZip domain reduces the entropy penalty associated with heterodimerization and allows rapid and accurate recognition by the authentic Myc binding partner Max.

Early rearing conditions alter immune responses in the developing infant primate.

The influence of early rearing conditions on immunologic development was investigated in infant monkeys. Lymphocyte proliferation, natural killer cell activity, and antibody responses to tetanus vaccination were compared in 30 rhesus monkeys reared under five different conditions. Lymphocyte responses to two mitogens (concanavalin A and pokeweed) were significantly increased in infants from disturbed rearing conditions compared with control infants that had been reared in an undisturbed manner by their mothers. The largest increases occurred in nursery-reared monkeys that had been fed Similac infant formula. The nursery-reared monkeys also tended to show lower natural killer cell activity, but there were no significant differences in response to vaccination. These findings support other research indicating that psychologic and nutritional aspects of the early rearing environment may have long-lasting effects on some, but not all, immune responses in the developing infant.

Cation-dependence of the self-association behavior of guanylyl-(3'-5')-guanosine.

The aggregation behavior of guanylyl-(3'-5')-guanosine, GpG, in the form of the tetramethylammonium (TMA), Li, Na, and K salts in aqueous solution has been investigated by NMR and FTIR techniques. The salts were prepared by a cation-exchange method. The ability of the cations to induce aggregate formation is TMA+ < Li+ < Na+ < K+, where TMA+ has only a weakly promoting action and K+ has a very strong effect. Three types of aggregates have been observed: (a) small aggregates which are in rapid exchange with respect to the NMR time scale; (b) intermediate-sized aggregates which are slow to exchange; (c) very large aggregates which can only be observed by FTIR. In all cases the aggregated species are held together by base stacking and guanine-guanine hydrogen bonding. A stoichiometry of 2 GpG per K+ has been determined by a 1H NMR titration of TMAGpG with KCl. Models have been proposed for the various-sized species. These include stacked dimers, stacked tetramers (similar to G-tetrads), and species in which K+ ion bridges between phosphates in separate tetramers.

Dynamic role of social support in the link between chronic stress and psychological distress.

How a chronic environmental stressor can interfere with the buffering effects of social support by eroding social support was analyzed in this prospective, longitudinal study. A classic buffering effect of support was found after 2 months of exposure to the stressor, household crowding. Crowded residents with low perceived support had greater increases in psychological distress than did crowded residents with high perceived support. However, after 8 months exposure the buffering effect disappeared. Moreover, greater crowding had become directly associated with lower support, which in turn was associated with greater increases in psychological distress. All analyses controlled for prior distress. Under some types of chronic stress, the buffering effects of social support may be short-lived because the stressor eventually erodes social support.

Bacteriology of otorrhea from tympanostomy tubes.

Culture results from 100 consecutive cases of otorrhea from tympanostomy tubes are presented. In children younger than 3 years, the culture results are very similar to those seen in patients with acute otitis media who do not have tubes. In children older than 3 years, the flora resembles that of external otitis. Suggestions for treatment are made.

Prenatal stress, moderate fetal alcohol, and dopamine system function in rhesus monkeys.

This study examined the striatal dopamine system integrity and associated behavior in 5- to 7-year-old rhesus monkeys born from mothers that experienced stress and/or consumed moderate levels of alcohol during pregnancy. Thirty-one young adult rhesus monkeys were derived from females randomly assigned to one of four groups: (1) control group that consumed isocaloric sucrose solution throughout gestation; (2) stress group that experienced prenatal stress (10-min removal from home cage and exposure to three random loud noise bursts, gestational days 90 through 145); (3) alcohol group that consumed alcohol (0.6 g/kg/day) throughout gestation; or (4) combined alcohol plus stress group that received both treatments. The subjects were assessed for striatal dopamine system function using positron emission tomography (PET), in which the dopamine (DA)-rich striatum was evaluated in separate scans for the trapping of [(18)F]-Fallypride (FAL) and 6-[(18)F]fluoro-m-tyrosine (FMT) to assess dopamine D2 receptor binding potential (BP) and DA synthesis via dopa decarboxylase activity, respectively. Subjects were previously assessed for non-matching-to-sample (NMS) task acquisition, with ratings of behavioral inhibition, stereotypies, and activity made after each NMS testing session. Subjects from prenatal stress conditions (Groups 2 and 4) showed an increase in the ratio of striatal dopamine D2 receptor BP and DA synthesis compared to controls (Group 1). An increase in the radiotracer distribution volume ratios (DVRs), which is used to evaluate the balance between striatal DA synthesis and receptor availability, respectively, was significantly correlated with less behavioral inhibition. The latter supports a hypothesis linking striatal function to behavioral inhibitory control.

Evaluation of a community bicycle helmet promotion campaign: what works and why.

PURPOSE: This study identifies effective components of a bicycle helmet promotion campaign, and mechanisms by which these components affect child helmet ownership. DESIGN: A random telephone survey identified parents whose children did not own helmets prior to an educational campaign. A follow-up survey was conducted six months later. Regression analysis estimated the effects of four campaign components on child helmet ownership and tested for mediation by cognitive variables. SETTING: Study participants were residents of a suburban community which undertook a citywide educational campaign to increase child helmet ownership. SUBJECTS: Subjects were 210 parents with at least one school-aged child, none of whom owned helmets. INTERVENTION: A multicomponent campaign was implemented by a community coalition. In addition, random subsamples of the study participants received direct mail or direct telephone communications. RESULTS: Of the eligible respondents identified in the baseline sample, 39% completed the follow-up survey. Regression analysis showed that children whose parents received either helmet advice from a physician or direct telephone communications were 2.6 and 2.2 times more likely, respectively, to own helmets as children whose parents did not experience similar communication. Parental worry mediated the association, but parental beliefs about the effectiveness of helmets did not. CONCLUSION: Future helmet campaigns should use interpersonal strategies to increase parental worry about their children being involved in a bicycle accident. Generalization of these findings is limited by the high socioeconomic status of the study participants, and by the outcome measure, which is helmet ownership, not helmet use.

Repeated social stress during pregnancy impairs neuromotor development of the primate infant.

Neuromotor responses were assessed in 90 infant squirrel monkeys born from normal and stressed pregnancies. Repeated psychological disturbance during pregnancy, evoked by disruption of the pregnant female's social relationships, significantly altered the performance of the young infant on a standardized battery of neuromotor tests. As compared with infants from undisturbed pregnancies, infants from chronically stressed pregnancies had poorer motor abilities, impaired balance reactions, and reduced postrotary nystagmus. They also had shorter attention spans and looking episodes during the administration of orientation items. In contrast, when only a single stressful period was imposed during midgestation, infants were not significantly different from control subjects. These findings indicate that sustained stress across pregnancy can have deleterious effects on fetal development, but a short period of stress, at least when restricted to midgestation, does not appear to adversely affect neuromotor responses of the young primate infant.

Influence of the histologic and cytologic grade and the clinical and postsurgical stage on the rate of endometrial carcinoma detection by cervical cytology.

The influence of postsurgical stage, histologic grade and cytologic grade of the tumor on the rate of detection of endometrial carcinoma by cervical smear was examined in a retrospective study. Cervical smears from 220 patients with endometrial carcinoma seen in the years between 1965 and 1981 were reevaluated for the presence of normal, suspicious or frankly malignant endometrial cells. The smears were positive in 33.2% of the patients, suspicious in 25.5% and negative in 40%. In three cases (1.4%), the smear was technically inadequate. Positive or suspicious smears indicated the presence of a higher grade as well as a higher stage of the lesion. In this material, the presence of normal endometrial cells as an indicator of endometrial disease, as emphasized in the literature, proved useless since normal endometrial cells without accompanying malignant cells were not seen in a single case. It appears that the reason for the lower rate of detection of low-grade endometrial carcinoma is the complete absence of any exfoliation in these lesions.

Morphological criteria for prognosis of endometrial carcinoma with special regard to nuclear grading.

Histological and cytological prognostic factors have nowadays become indispensible criteria in planning the individualized surgical therapy of endometrial carcinoma. These factors can already be determined preoperatively on the basis of the fractionated curettage specimen with great reliability. A correction might be necessary after surgery in order to induce an individual postoperative therapy, if required, or to do without further treatment with benefit for the patient. In our investigations, nuclear grading has proved to be the most reliable prognostic factor.

Maternal endocrine activation during pregnancy alters neurobehavioral state in primate infants.

OBJECTIVES: The purpose of this study was to investigate whether maternal endocrine activation during pregnancy would affect the neurobehavioral state of primate offspring in a manner similar to that observed in human infants from pregnancies involving maternal substance abuse or maternal stress. METHOD: Twenty-two rhesus monkey (Macaca mulatta) infants were derived from females administered either adrenocorticotrophic hormone (ACTH), which increased the mother's endocrine activity, or saline solutions for 14 consecutive days during mid-pregnancy. On days 15 and 30 postpartum, infants underwent brief separations from their mothers and were videotaped for later evaluation of neurobehavioral state. RESULTS: Infants from mothers administered ACTH spent significantly more time in a drowsy state than did controls (p < .04), and the increased drowsiness tended to be most pronounced during the postseparation period, when acute stress was highest. In contrast, controls remained in a more active alert state (p < .03), presumably searching for their mother, a species-typical adaptive response to maternal separation. Female infants spent more time in distressed state than did males on day 15, and the proportion of time in distressed state decreased in all infants after administration of .2 ml of 24% sucrose solution. CONCLUSION: The results demonstrate that neurobehavioral state alterations are found in infants from mothers with increased endocrine activity during pregnancy. Neurobehavioral state disorganization can have an adverse impact on the human infant's concurrent and subsequent occupational performance. These findings establish the usefulness of the nonhuman primate model for advancing knowledge on early contributions to the development of human infant occupational behavior.

An efficient synthesis of dopamine transporter tracer [¹8F]FECNT.

A simple synthesis of the dopamine transporter ligand [(18)F]FECNT with high radiochemical yield and short synthesis time, suitable for routine production is reported. Reaction of 2ß-carbomethoxy-3ß-(4-chlorophenyl)nortropane with [(18)F]2-fluoroethyl triflate ([(18)F]FEtOTf) at room temperature for 4 min provided [(18)F]FECNT in 84% decay corrected radiochemical yield. Since [(18)F]FEtOTf was prepared from [(18)F]2-fluoroethyl bromide that was isolated from its starting material, formation of unwanted side products and the amount of expensive precursor used could be greatly reduced. The overall radiochemical yields of [(18)F]FECNT were 40% (n=29) and the total synthesis time was ca. 100 min. The average specific activity of [(18)F]FECNT was 377.4 GBq/µmol (10.2 Ci/µmol).

[Prevention of tumor implantation during surgery of cervical and endometrial carcinoma]. / Vermeidung von Implantationsmetastasen bei der Operation des Zervix- und des Endometriumkarzinoms.

The careful cleansing of the vagina with physiologic saline and 96% ethyl alcohol, the insert of a big, dry swab for two minutes in front of the portio vaginalis cervicis and the cleansing once more again with a dry swab are an effective prophylaxis against tumor implantation from a carcinoma of the endometrium or of the cervix. This could be confirmed not only by cytology prior to operation and by cytology antecedent to cleansing the vagina immediately prior to the removal of the uterus from the vagina but also by the follow-up study of 517 surgically treated cancers of the endometrium and 241 cervical cancers.