bluuebunny/crossref_metadata_2025 huggingface dataset:
Sequence and expression of theCAPA/CAP2bgene in the tobacco hawkmoth,Manduca sexta
Authors: Loi Poh Kheng , Tublitz Nathan J.
Published: September 2004

The gene coding for cardioacceleratory peptide 2b (CAP2b; pELYAFPRV) has been isolated and sequenced from the moth Manduca sexta (GenBank accession #AY649544). Because of its significant homology to the CAPAgene in Drosophila melanogaster, this gene is called the Manduca CAPA gene. The Manduca CAPA gene is 958 nucleotides long with 29 untranslated nucleotides from the beginning of the sequence to the putative start initiation site. The CAPA gene has a single open reading frame,441 nucleotides long, that codes for a predicted precursor protein of 147 amino acids. The predicted prepropeptide encodes a single copy of each of three deduced propeptides, a CAP2b propeptide, with a Q substituted for an E at the N-terminus (QLYAFPRVa), and two novel CAP2b-related propeptides(DGVLNLYPFPRVa and TEGPGMWFGPRLa). To reduce confusion and to adopt a more standardized nomenclature, we rename pELYAFPRVa as Mas-CAPA-1 and assign the names of Mas-CAPA-2 to DGVLNLYPFPRVa and Mas-PK-1 (Pyrokinin-1) to TEGPGMWFGPRLa.

The spatial and temporal expression pattern of the CAPA gene in the Manduca central nervous system (CNS) was determined in all major post-embryonic stages using in situ hybridization techniques. The CAPA gene is expressed in a total of 27 pairs of neurons in the post-embryonic Manduca CNS. A total of 16 pairs of cells is observed in the brain, two pairs in the sub-esophageal ganglion (SEG), one pair in the third thoracic ganglion (T3), one pair in each unfused abdominal ganglion(A1–A6) and two pairs in the fused terminal ganglion. The mRNA from the CAPA gene is present in nearly every ganglion in each post-embryonic stage. The number of cells expressing the CAPA gene varies during post-embryonic life, starting at 54 cells in first-instar larvae and declining to a minimum of 14 cells midway through adult development.
The effects of sustained exercise and hypoxia upon oxygen tensions in the red muscle of rainbow trout
Authors: McKenzie D. J. , Wong S. , Randall D. J. , Egginton S. , Taylor E. W. , Farrell A. P.
Published: September 2004

Teleost fish possess discrete blocks of oxidative red muscle (RM) and glycolytic white muscle, whereas tetrapod skeletal muscles are mixed oxidative/glycolytic. It has been suggested that the anatomy of RM in teleost fish could lead to higher intramuscular O2 partial pressures(PO2) than in mammalian skeletal muscles. This study provides the first direct experimental support for this suggestion by using novel optical fibre sensors to discover a mean (± s.e.m., N=6) normoxic steady-state red muscle PO2(PrmO2) of 61±10 mmHg (1 mmHg=133.3 Pa) in free-swimming rainbow trout Oncorhynchus mykiss. This is significantly higher than literature reports for mammalian muscles,where the PO2 never exceeds 40 mmHg. Aerobic RM powers sustained swimming in rainbow trout. During graded incremental exercise, PrmO2 declined from 62±5 mmHg at the lowest swim speed down to 45±3 mmHg at maximum rates of aerobic work, but then rose again to 51±5 mmHg at exhaustion. These measurements of PrmO2 during exercise indicated, therefore, that O2 supply to the RM was not a major limiting factor at exhaustion in trout. The current study found no evidence that teleost haemoglobins with a Root effect cause extremely elevated O2 tensions in aerobic tissues. Under normoxic conditions, PrmO2 was significantly lower than arterial PO2 (119±5 mmHg), and remained lower when the arterial to tissue PO2 gradient was reduced by exposure to mild hypoxia. When two sequential levels of mild hypoxia (30 min at a water PO2 of 100 mmHg then 30 min at 75 mmHg) caused PaO2 to fall to 84±2 mmHg then 61±3 mmHg, respectively, this elicited simultaneous reductions in PrmO2, to 51±6 mmHg then 41±5 mmHg, respectively. Although these hypoxic reductions in PrmO2 were significantly smaller than those in PaO2, the effect could be attributed to the sigmoid shape of the trout haemoglobin–O2 dissociation curve.
Spatio-temporal patterns of antennal movements in the searching cockroach
Authors: Okada Jiro , Toh Yoshihiro
Published: September 2004

To characterize the spatio-temporal patterns of antennal behavior in insects, the voluntary movement of both right and left antennae was examined in the cockroach Periplaneta americana. The position of the tip of the antenna (flagellum) is controlled by two mobile joints at its base (the scape and the pedicel) and by the neck. Horizontal and vertical components of movement at the antennal basal joints exhibited rhythmic activities during locomotory (walking) and non-locomotory (pausing) states in the searching animal. In both states, the horizontal component was slower than vertical one. Joint-manipulation experiments suggested that the faster vertical component is due mainly to movements of the scape–pedicel joint, while the slower horizontal component may originate from the head–scape joint. Large horizontal deflections of the antenna corresponded consistently with the yaw component of head movement. The trajectories of the antennae showed little patterned regularity in most animals. In a few cases, however, loop-like patterns appeared. The area scanned by an antenna was narrower in the walking state than in the pausing state, mainly because of a decrease in the horizontal angular range. Cross-correlation analyses revealed that the coupling between right and left horizontal antennal motor systems and that for the vertical systems were both significantly stronger in the walking state than during pausing. These results indicate that the spatio-temporal pattern of antennal movements changes dynamically depending on the animal's behavioral state.
Na+ competes with K+ in bumetanide-sensitive transport by Malpighian tubules ofRhodnius prolixus
Authors: Ianowski Juan P. , Christensen Robert J. , O'Donnell Michael J.
Published: September 2004

We examined the effects of bathing saline Na+/K+ratio, bumetanide and hydrochlorothiazide on fluid and ion transport by serotonin-stimulated Malpighian tubules of Rhodnius prolixus. Previous pharmacological and electrophysiological studies indicate that a bumetanide-sensitive Na+/K+/2Cl–cotransporter is the primary route for basolateral ion entry into the cell during fluid secretion. The goal of this study was to resolve the apparent conflict between relatively high secretion rates by tubules bathed in K+-free saline and the evidence that Na+/K+/2Cl– cotransporters described in other systems have an absolute requirement for all three ions for translocation. Our measurements of fluid secretion rate, ion fluxes and electrophysiological responses to serotonin show that fluid secretion in K+-free saline is bumetanide sensitive and hydrochlorothiazide insensitive. Dose–response curves of secretion rate versusbumetanide concentration were identical for tubules bathed in K+-free and control saline with IC50 values of 2.6×10–6 mmol l–1 and 2.9×10–6 mmol l–1, respectively. Double-reciprocal plots of K+ flux versus bathing saline K+ concentration showed that increasing Na+concentration in the bathing fluid increased Kt but had no effect on Jmax, consistent with competitive inhibition of K+ transport by Na+. We propose that the competition between Na+ and K+ for transport by the bumetanide-sensitive transporter is part of an autonomous mechanism by which Malpighian tubules regulate haemolymph K+ concentration.
Regulation of serotonin levels by multiple light-entrainable endogenous rhythms
Authors: Wildt M. , Goergen E. M. , Benton J. L. , Sandeman D. C. , Beltz B. S.
Published: September 2004

This study examined whether serotonin levels in the brain of the American lobster, Homarus americanus, are under circadian control. Using high-performance liquid chromatography and semi-quantitative immunocytochemical methods, we measured serotonin levels in the brains of lobsters at six time points during a 24-h period. Lobsters were maintained for 2 weeks on a 12 h:12 h light:dark cycle followed by 3 days of constant darkness. Under these conditions, brain serotonin levels varied rhythmically,with a peak before subjective dusk and a trough before subjective dawn. This persistent circadian rhythm in constant darkness indicates that serotonin levels are controlled by an endogenous clock. Animals exposed to a shifted light cycle for >10 days, followed by 3 days in constant darkness,demonstrate that this rhythm is light entrainable. Separate analyses of two pairs of large deutocerebral neuropils, the accessory and olfactory lobes,show that serotonin levels in these functionally distinct areas also exhibit circadian rhythms but that these rhythms are out of phase with one another. The olfactory and accessory lobe rhythms are also endogenous and light entrainable, suggesting the presence of multiple clock mechanisms regulating serotonin levels in different brain regions.
Electrical and mechanical properties and mode of innervation in scorpionfish sound-producing muscle fibres
Authors: Kobayashi Takakazu , Daimon Tateo , Shirakawa Ibuki , Chaen Shigeru , Sugi Haruo
Published: September 2004

To obtain information about the neural mechanism underlying sound production in teleost fish, we studied the electrical and mechanical properties and mode of innervation in the swimbladder muscle (SBM) fibres of scorpionfish Sebastiscus marmoratus. Action potentials of the SBM fibres in response to direct electrical stimulation neither exhibited overshoot nor propagated along the fibre. Stimulation of the motor nerve,however, uniformly evoked action potentials along the fibre. When neuromuscular transmission was blocked by curare, motor nerve stimulation uniformly evoked endplate potentials along the fibre. These results indicate that action potentials propagate along the nerve branches but not along the SBM fibre membrane. In accordance with the above results, histochemical studies showed that motor nerve branches run along the SBM fibres to form many endplates with cholinesterase activity, indicating multiterminal innervation. The SBM consisted of about 600 fibres, while its motor nerve contained about 100 axons, giving an innervation ratio of about 1:6. Like mammalian fast muscle fibres, the SBM fibres exhibited a low succinic dehydrogenase activity and a high ATPase activity. These results are discussed in connection with the function of the SBM fibres in producing sound.
Structural and functional imaging of bottlenose dolphin (Tursiops truncatus) cranial anatomy
Authors: Houser Dorian S. , Finneran James , Carder Don , Van Bonn William , Smith Cynthia , Hoh Carl , Mattrey Robert , Ridgway Sam
Published: September 2004

Bottlenose dolphins were submitted to structural (CT) and functional(SPECT/PET) scans to investigate their in vivo anatomy and physiology with respect to structures important to hearing and echolocation. The spatial arrangement of the nasal passage and sinus air spaces to the auditory bullae and phonic lips was studied in two dolphins via CT. Air volume of the sinuses and nasal passages ranged from 267.4 to 380.9 ml. Relationships of air spaces to the auditory bullae and phonic lips support previous hypotheses that air protects the ears from echolocation clicks generated by the dolphin and contributes to dolphin hearing capabilities (e.g. minimum angular resolution,inter-aural intensity differences). Lung air may replenish reductions in sinus and nasal passage air volume via the palatopharyngeal sphincter, thus permitting the echolocation mechanism to operate at depth. To determine the relative extent of regional blood flow within the head of the dolphin, two dolphins were scanned with SPECT after an intravenous dose of 1850 MBq 99mTc-bicisate. A single dolphin received 740 MBq of 18F-2-fluoro-2-deoxyglucose (FDG) to identify the relative metabolic activity of head tissues. Substantial blood flow was noted across the dorsoanterior curvature of the melon and within the posterior region of the lower jaw fats. Metabolism of these tissues relative to others within the head was nominal. It is suggested that blood flow in these fat bodies serves to thermoregulate lipid density of the melon and jaw canal. Sound velocity is inversely related to the temperature of acoustic lipids (decreasing lipid density), and changes in lipid temperature are likely to impact the wave guide properties of the sound projection and reception pathways. Thermoregulation of lipid density may maintain sound velocity gradients of the acoustic lipid complexes, particularly in the outer shell of the melon, which otherwise might vary in response to changing environmental temperatures.
The anterior stomach of larval mosquitoes (Aedes aegypti):effects of neuropeptides on transepithelial ion transport and muscular motility
Authors: Onken H. , Moffett S. B. , Moffett D. F.
Published: September 2004

The present investigation studied the influence of a number of neuropeptides on semi-open preparations of the isolated and perfused anterior stomach of larval Aedes aegypti. Effects of peptides were observed on the lumen negative transepithelial voltage (Vte) that is present with serotonin in the bath; this voltage most likely reflects active HCO3– secretion involved in alkalization of the larval anterior stomach. The five different A. aegypti allatostatins(allatostatin A 1–5) all affected Vte in almost identical ways, causing a 10–15% reduction of the voltage at 10–7 mol l–1. A. aegyptineuropeptide F and proctolin reduced Vte at submicromolar concentrations. At 10–6 mol l–1,neuropeptide F reduced Vte by 30% and proctolin reduced Vte by 50%. In contrast, A. aegypti allatotropin, A. aegypti head peptides I and III and A. aegypti short neuropeptide F were without effect on Vte. During the investigation it was observed that the peristaltic contractions of the preparations caused a dynamic component of Vte. Peristaltic contractions and the correlated voltage fluctuations depended on the presence of serotonin. Peristaltic activity and Vtedeflections were progressively inhibited by A. aegypti head peptides I and III by A. aegypti short neuropeptide F and by A. aegypti neuropeptide F when the peptide concentrations were increased from 10–8 to 10–6 mol l–1. These observations show that physiological concentrations of some of the tested neuropeptides affect two processes that require coordination: ion transport and motility of the larval anterior stomach.
Synergic effects of tryptamine and octopamine on ophiuroid luminescence(Echinodermata)
Authors: Vanderlinden C. , Mallefet J.
Published: September 2004

In ophiuroids, bioluminescence is under nervous control. Previous studies have shown that acetylcholine is the main neurotransmitter triggering light emission in Amphipholis squamata and Amphiura filiformis. By contrast, none of the neurotransmitters tested so far induced luminescence in two other ophiuroid species, Ophiopsila aranea and Ophiopsila californica. The aim of this work was thus to investigate the putative involvement of two biogenic amines, tryptamine and octopamine, in light emission of three ophiuroid species. A. filiformis responds to both tryptamine and octopamine, mainly on its arm segments, while O. californica only responds to tryptamine stimulation. By contrast,tryptamine and octopamine do not seem to be involved in O. aranealuminescence control since none of these substances induced light emission in this species. The synergic effects of several other drugs with tryptamine and octopamine were also tested.
Transgenic salmon overexpressing growth hormone exhibit decreased myostatin transcript and protein expression
Authors: Roberts Steven B. , McCauley Linda A. R. , Devlin Robert H. , Goetz Frederick W.
Published: September 2004

To characterize the role of myostatin (MSTN) in fast growing animals and to examine the relationship between MSTN and growth hormone (GH), MSTN transcript and protein expression were measured in coho salmon overexpressing GH and in wild-type coho salmon. Quantitative real-time RT-PCR and western analysis were used to measure RNA expression of the two salmonid MSTN genes (1 and 2) and levels of MSTN immunoreactive protein (MIP) in developing embryos and adult coho salmon tissues.

In transgenic and control coho embryos, MSTN1 and MSTN2RNA expression were initially observed at about the time of eying, and a 42 kDa MIP was just detected prior to hatching. Expression of the MSTN1transcript in transgenic salmon was not different from that in wild-type adult coho salmon muscle and brain tissue. However, expression of the MSTN2transcript was less in white muscle, and greater in red muscle, from transgenic fish compared to wild-type salmon of the same size. Northern analysis revealed that expression of the MSTN2 transcript was less in white muscle from wild-type, age-matched salmon than in transgenic fish. In addition, there was less presumed bioactive MIP in muscle taken from adult transgenic fish compared to controls and evidence of differential protein processing. Decreased MSTN expression in faster growing fish suggests that MSTN does act as a negative regulator of muscle growth in fish, as it does in mammals. The results of this study also suggest that the anabolic effects of GH could be mediated through MSTN.
Time-dependent expression of heat shock proteins 70 and 90 in tissues of the anoxic western painted turtle
Authors: Ramaglia Valeria , Buck Leslie T.
Published: September 2004

Expression of the constitutive Hsp73, inducible Hsp72 and Hsp90 was investigated in brain, heart, liver and skeletal muscle of the anoxia-tolerant western painted turtle Chrysemys picta bellii in response to 2, 6,12, 18, 24 and 30 h forced dives and following 1 h recovery from 12, 24 and 30 h forced dives at 17°C. During a dive, expression of all three Hsps examined remained at control levels for at least 12 h in all tissues examined except the liver, where Hsp72 showed a decrease at 12 h, reaching a significant threefold decrease by 24 h. Brain and liver Hsp73, 72 and 90 expression increased two- to threefold at 18, 24 and 30 h. Heart and muscle Hsp73 and heart Hsp90 expression remained at normoxic levels throughout the entire dive, while heart and muscle Hsp72 and muscle Hsp90 increased two- to fourfold at 24 and 30 h. Following reoxygenation, Hsp expression increased in all tissues examined. These data indicate that increased Hsp expression is not critical in the early adaptation to anoxic survival and that short-term anoxia is probably not a stress for species adapted to survive long periods without oxygen. However, the late upregulation of heat shock proteins during anoxia suggests that stress proteins play a role in promoting long-term anoxia tolerance.
Regulation of heat shock genes in isolated hepatocytes from an Antarctic fish,Trematomus bernacchii
Authors: Buckley Bradley A. , Place Sean P. , Hofmann Gretchen E.
Published: September 2004

The Antarctic fishes, isolated over evolutionary history in the sub-zero waters of the Southern Ocean, are an ideal group for studying the processes of cold adaptation. One species of Antarctic notothenioid fish, Trematomus bernacchii, has lost the ability to induce heat shock proteins (Hsps) in response to exposure to acute thermal stress or to the toxic heavy metal cadmium, an important part of the cellular defense response to such stressors. To elucidate the mechanism responsible for the lack of Hsp induction, we examined several stages of the hsp gene expression pathway, including transcription factor activity, Hsp70 mRNA production and protein synthesis patterns, in hepatocytes from T. bernacchii. Hsp70 mRNA was detected,as was heat shock factor 1 (HSF1) with DNA-binding activity. However, exposure to elevated temperature and to chemical inducers of the heat shock response failed to increase Hsp70 mRNA levels, HSF1 activity or the concentration of any size class of Hsps. These results suggest that Hsps, inducible in nearly every other species, are expressed constitutively in the cold-adapted T. bernacchii.
Possible Trimethoprim/Sulfamethoxazole-Induced Aseptic Meningitis
Authors: Therrien Roxane
Published: September 2004

OBJECTIVE

To report a case of trimethoprim/sulfamethoxazole (TMP/SMX)-induced aseptic meningitis.

CASE SUMMARY

An 18-year-old woman diagnosed with acute myeloid leukemia was admitted for a bone marrow transplant. She had already attained remission with daunorubicin, thioguanine, and high-dose cytarabine. A routine lumbar puncture performed on admission revealed an abnormally elevated leukocyte count, and meningitis was suspected. The patient had been taking TMP/SMX (trimethoprim 120 mg) twice daily on Monday, Tuesday, and Wednesday for the past 3 months; no other medication was being used. Upon examination, the patient mentioned having had headaches for the past few weeks. Since viral, bacterial, and fungal cultures were negative, a diagnosis of aseptic meningitis was made. According to the Naranjo probability scale, TMP/SMX was a possible cause of the aseptic meningitis. Eleven days after discontinuation of TMP/SMX, lumbar puncture results had returned to normal.

DISCUSSION

Many drugs have been associated with aseptic meningitis. Antibiotics are often linked with aseptic meningitis, with TMP/SMX being the most frequently associated antibiotic. Many cases of TMP/SMX-induced aseptic meningitis have been reported, while few cases have been reported with trimethoprim and sulfamethoxazole given separately.

CONCLUSIONS

Despite the widespread use of TMP/SMX and the years of experience we have had with the drug, it is important to remain vigilant regarding possible adverse effects, particularly aseptic meningitis.
Muscle Pain Associated with Daptomycin
Authors: Veligandla Shailaja R , Louie Kathy R , Malesker Mark A , Smith Philip W
Published: September 2004

OBJECTIVE

To report a case of muscle pain without pronounced creatine kinase (CK) elevation in a patient receiving daptomycin.

CASE SUMMARY

A 26-year-old African American woman had antibiotic intolerance to vancomycin and quinupristin/dalfopristin. She presented with methicillin-resistant Staphylococcus aureus endocarditis that was treated with intravenous daptomycin 6 mg/kg daily for 14 days. The patient developed muscle aches and pains with only a minor elevation (492 U/L) of CK; both resolved after daptomycin was discontinued.

DISCUSSION

Daptomycin is a newly approved lipopeptide antibiotic derived from Streptomyces roseosporus with rapid bactericidal activity. Daptomycin has excellent coverage against gram-positive bacteria. The adverse effect profile has included rare reports of myopathy and elevated CK levels. Daptomycin is a promising agent with many potential applications. Once-daily dosing has diminished the preclinical incidence of myopathy. The current package labeling recommends discontinuation of daptomycin with significant myopathy symptoms in association with a CK elevation >1000 U/L or in patients without muscle pain and a CK >10 times normal.

CONCLUSIONS

An objective causality assessment revealed that the myopathy was possibly related to daptomycin. Clinicians should recognize that significant myopathy with daptomycin can occur without pronounced CK elevation.
Clinical, Cognitive, and Neurophysiologic Correlates of Short-Term Treatment with Carbamazepine, Oxcarbazepine, and Levetiracetam in Healthy Volunteers
Authors: Mecarelli Oriano , Vicenzini Edoardo , Pulitano Patrizia , Vanacore Nicola , Francesco Saverio Romolo  , Piero Vittorio Di , Lenzi Gian Luigi , Accornero Neri
Published: September 2004

BACKGROUND

The adverse effects of the antiepileptic drugs (AEDs) originally developed are well known, while those of the newer AEDs remain unclear.

OBJECTIVE

To investigate clinical, cognitive, and neurophysiologic effects of carbamazepine, oxcarbazepine, and levetiracetam in healthy volunteers.

METHODS

A double-blind crossover study was conducted in 10 volunteers. Eight-day treatment with carbamazepine, oxcarbazepine, levetiracetam, or placebo was administered in random order. Drug doses were titrated gradually to the daily target doses on day 7: carbamazepine 800 mg, oxcarbazepine 1200 mg, and levetiracetam 1500 mg. At baseline and at the end of each treatment period, participants underwent cognitive and neurophysiologic assessment. A washout period of 14 days between treatment periods was conducted.

RESULTS

More adverse events were self-reported with carbamazepine (63%) than the other treatments (oxcarbazepine 12%, levetiracetam 20%, placebo 5%; p < 0.001 between the 4 groups). Carbamazepine induced the greatest motor slowing (p = 0.002), followed by oxcarbazepine (p = 0.01). Levetiracetam left baseline motor speed unchanged. All AEDs increased attention span from baseline values as shown on the Stroop test. Quantitative electroencephalogram (EEG) analysis showed that carbamazepine significantly increased the delta–theta power and reduced the frequency of alpha rhythm; oxcarbazepine induced smaller changes than carbamazepine. Levetiracetam did not change any EEG measurements. On color visually evoked potential (VEP) tests, carbamazepine induced a constant slowing of P1 latency, while oxcarbazepine induced changes only after the blue–black pattern. All color VEP measures for volunteers receiving levetiracetam were almost unchanged.

CONCLUSIONS

After short-term treatment in healthy volunteers, carbamazepine induced major clinical and neurophysiologic changes. Oxcarbazepine was better tolerated than carbamazepine. Levetiracetam interfered least with clinical and neurophysiologic test results.
Smoking Cessation: A Pilot Study of the Effects on Health-Related Quality of Life and Perceived Work Performance One Week into the Attempt
Authors: Erickson Steven R , Thomas Linda A , Blitz Susan G , Pontius Lindsey R
Published: September 2004

BACKGROUND

Most patients attempting to quit smoking experience symptoms that may influence functioning and sense of well-being.

OBJECTIVE

To conduct a pilot study to assess the acute effects of smoking cessation on health-related quality of life (HRQoL) and perceived work performance.

METHODS

Questionnaires were mailed to patients of a smoking-cessation program just prior to quit date and one week after they quit. The questionnaires included the Smoking Cessation Quality of Life Questionnaire and the Work Performance Scale (WPS). Other data included patient demographics, smoking duration, Fagerström Test for Nicotine Dependence scale, and smoking status. Student's t-tests were used for pre–post comparisons as well as comparison between higher addiction and lower addiction groups, with p  0.05 used for determination of statistical significance.

RESULTS

Thirty-four respondents (higher addiction = 12, lower addiction = 22) averaged 48.6 ± 12.0 (mean ± SD) years of age and were primarily white (97.1%) and female (72.2%). From baseline to one week post-quit, there was significant worsening of anxiety (71.5 ± 25.1 to 61.1 ± 26.0; p = 0.04) and cognitive functioning (72.2 ± 20.4 to 61.3 ± 23.9; p = 0.02) scores and improved general health (65.2 ± 18.4 to 70.5 ± 16.9; p = 0.01). HRQoL scores for the lower addiction group were higher than those for the higher addiction group, significantly for sleep, cognitive functioning, anxiety, role emotional and mental health. Both groups experienced significant improvement in self-control. The lower addiction group had a significant decline in sleep, cognitive function, and anxiety, while only one domain changed significantly for the higher addiction group. There were no significant differences in WPS analyses.

CONCLUSIONS

This pilot study found that, generally, HRQoL changes one week into a smoking cessation attempt. Smokers with higher addiction have lower HRQoL when they begin their cessation attempt, while smokers with lower addiction have greater change in HRQoL.
RNA interference by small hairpin RNAs synthesised under control of the human 7S K RNA promoter
Authors: Koper-Emde Dorota , Herrmann Lutz , Sandrock Björn , Benecke Bernd-Joachim
Published: September 2004

Small interfering RNAs (siRNAs) represent RNA duplexes of 21 nucleotides in length that inhibit gene expression. We have used the human gene-external 7S K RNA promoter for synthesis of short hairpin RNAs (shRNAs) which efficiently target human lamin mRNA via RNA interference (RNAi). Here we demonstrate that orientation of the target sequence within the shRNA construct is important for interference. Furthermore, effective interference also depends on the length and/or structure of the shRNA. Evidence is presented that the human 7S K promoter is more activein vivothan other gene-external promoters, such as the human U6 small nuclear RNA (snRNA) gene promoter.
Inhibition of inducible TNF-α expression by oxaspirodion, a novel spiro-compound from the ascomycete Chaetomium subspirale
Authors: Rether Jan , Erkel Gerhard , Anke Timm , Sterner Olov
Published: September 2004

In a search for compounds inhibiting the inducible TNF-αa promoter activity in T cells, a new spiro-compound, designated oxaspirodion, was isolated from fermentations of the ascomyceteChaetomium subspirale. Oxaspirodion inhibited TNF-α promoter-driven luciferase reporter gene expression with an IC50value of 2.5 µg/ml (10 µM) in TPA/ionomycin-stimulated Jurkat T cells. Studies on the mode of action of the compound revealed that the inhibition of the TNF-α promoter activity is caused by an inhibition of the phosphorylation of the ERK1/2 kinases. In addition, oxaspirodion inhibited the activation of the transcription factor NF-κB, which is involved in the inducible expression of many proinflammatory genes.
Comprehensive analysis of metabolites in Corynebacterium glutamicum by gas chromatography/mass spectrometry
Authors: Strelkov Sergey , von Elstermann Mirko , Schomburg Dietmar
Published: September 2004

An analytical method based on gas chromatography/mass spectrometry was developed for metabolome investigation ofCorynebacterium glutamicum. For the first time a fast method for metabolic screening that can be automated is described for this organism. More than 1000 compounds could be detected per experiment, ca. 330 of those showed a peak area significantly above background. Out of these 164 compounds were identified so far, representing derivatives of 121 different metabolites, which were quantified in one sample. In spite of the different chemical nature of metabolites and high matrix content, a measurement reproducibility in the range of 6% error was achieved. The application of this method for the analysis of the adaptation ofC. glutamicumto different growth conditions is demonstrated.
Mena and Vasodilator-Stimulated Phosphoprotein Are Required for Multiple Actin-Dependent Processes That Shape the Vertebrate Nervous System
Authors: Menzies A. Sheila , Aszodi Attila , Williams Scott E. , Pfeifer Alexander , Wehman Ann M. , Goh Keow Lin , Mason Carol A. , Fassler Reinhard , Gertler Frank B.
Published: September 2004

Ena/vasodilator-stimulated phosphoprotein (VASP) proteins regulate the geometry of the actin cytoskeleton, thereby influencing cell morphology and motility. Analysis of invertebrate mutants implicates Ena/VASP function in several actin-dependent processes such as axon and dendritic guidance, cell migration, and dorsal closure. In vertebrates, genetic analysis of Ena/VASP function is hindered by the broad and overlapping expression of the three highly related family members Mena (Mammalian enabled), VASP, and EVL (Ena-VASP like). Mice deficient in either Mena or VASP exhibit subtle defects in forebrain commissure formation and platelet aggregation, respectively. In this study, we investigated the consequence of deleting both Mena and VASP.Mena-/-VASP-/-double mutants die perinatally and display defects in neurulation, craniofacial structures, and the formation of several fiber tracts in the CNS and peripheral nervous system.
Highly Selective and Prolonged Depletion of Mitochondrial Glutathione in Astrocytes Markedly Increases Sensitivity to Peroxynitrite
Authors: Muyderman Håkan , Nilsson Michael , Sims Neil R.
Published: September 2004

Glutathione, a major endogenous antioxidant, is found in two intracellular pools in the cytoplasm and the mitochondria. To investigate the importance of the smaller mitochondrial pool, we developed conditions based on treatment with ethacrynic acid that produced near-complete and highly selective depletion of mitochondrial glutathione in cultured astrocytes. Recovery of mitochondrial glutathione was only partial over several hours, suggesting slow net uptake from the cytoplasm. Glutathione depletion alone did not significantly affect mitochondrial membrane potential, ATP content, or cell viability when assessed after 24 hr, although the activities of respiratory chain complexes were altered. However, these astrocytes showed a greatly enhanced sensitivity to 3-morpholinosydnonimine, a peroxynitrite generator. Treatment with 200 μm3-morpholinosydnonimine produced decreases within 3 hr in mitochondrial membrane potential and ATP content and caused the release of lactate dehydrogenase, contrasting with preservation of these properties in control cells. These properties deteriorated further by 24 hr in the glutathione-depleted cells and were associated with morphological changes indicative of necrotic cell death. This treatment enhanced the alterations in activities of the respiratory chain complexes observed with glutathione depletion alone. Cell viability was markedly improved by cyclosporin A, suggesting a role for the mitochondrial permeability transition in the astrocytic death. These studies provide the most direct evidence available for any cell type on the roles of mitochondrial glutathione. They demonstrate the critical importance of this metabolite pool in protecting against peroxynitrite-induced damage in astrocytes and indicate a key contribution in determining the activities of respiratory chain components.
β1 Integrins in Muscle, But Not in Motor Neurons, Are Required for Skeletal Muscle Innervation
Authors: Schwander Martin , Shirasaki Ryuichi , Pfaff Samuel L. , Müller Ulrich
Published: September 2004

In vitrostudies have provided evidence thatβ1 integrins in motor neurons promote neurite outgrowth, whereasβ1 integrins in myotubes regulate acetylcholine receptor (AChR) clustering. Surprisingly, using genetic studies in mice, we show here that motor axon outgrowth and neuromuscular junction (NMJ) formation in large part are unaffected when the integrin β1 gene (Itgb1) is inactivated in motor neurons. In the absence ofItgb1expression in skeletal muscle, interactions between motor neurons and muscle are defective, preventing normal presynaptic differentiation. Motor neurons fail to terminate their growth at the muscle midline, branch excessively, and develop abnormal nerve terminals. These defects resemble the phenotype of agrin-null mice, suggesting that signaling molecules such as agrin, which coordinate presynaptic and postsynaptic differentiation, are not presented properly to nerve terminals. We conclude thatItgb1expression in muscle, but not in motor neurons, is critical for NMJ development.
Vulnerability of Central Neurons to Secondary Insults afterIn VitroMechanical Stretch
Authors: Arundine Mark , Aarts Michelle , Lau Anthony , Tymianski Michael
Published: September 2004

Mild traumatic brain injuries are of major public health significance. Neurons in such injuries often survive the primary mechanical deformation only to succumb to subsequent insults. To study mechanisms of vulnerability of injured neurons to secondary insults, we used anin vitromodel of sublethal mechanical stretch. Stretch enhanced the vulnerability of the neurons to excitotoxic insults, causing nuclear irregularities, DNA fragmentation, and death suggestive of apoptosis. However, the DNA degradation was not attributable to classical (caspase mediated) or caspase-independent apoptosis. Rather, it was associated with profound stretch-induced mitochondrial dysfunction and the overproduction of reactive oxygen species (ROS). Sublethally stretched neurons produced surprisingly high levels of ROS, but these in isolation were insufficient to kill the cells. To be lethal, the ROS also needed to combine with nitric oxide (NO) to form the highly reactive species peroxynitrite. Peroxynitrite was not produced after stretch alone and arose only after combining stretch with an insult capable of stimulating NO production, such as NMDA or an NO donor. This explained the exquisite sensitivity of sublethally stretched neurons to a secondary NMDA insult. ROS scavengers and NO synthase (NOS) inhibitors prevented cell death and DNA degradation. Moreover, inhibiting neuronal NOS activation by NMDA using peptides that perturb NMDA receptor-postsynaptic density-95 interactions also reduced protein nitration and cell death, indicating that the reactive nitrogen species produced were neuronal in origin. Our data explain the mechanism of enhanced vulnerability of sublethally injured neurons to secondary excitotoxic insults and highlight the importance of secondary mechanisms to the ultimate outcome of neurons in mild neurotrauma.
Long-Lasting Rescue of Age-Associated Deficits in Cognition and the CNS Cholinergic Phenotype by a Partial Agonist Peptidomimetic Ligand of TrkA
Authors: Bruno Martin A. , Clarke Paul B. S. , Seltzer Alicia , Quirion Rémi , Burgess Kevin , Cuello A. Claudio , Saragovi H. Uri
Published: September 2004

Previously, we developed a proteolytically stable small molecule peptidomimetic termed D3 as a selective ligand of the extracellular domain of the TrkA receptor for the NGF.Ex vivoD3 was defined as a selective, partial TrkA agonist. Here, thein vivoefficacy of D3 as a potential therapeutic for cholinergic neurons was tested in cognitively impaired aged rats, and we compared the consequence of partial TrkA activation (D3) versus full TrkA/p75 activation (NGF). We show thatin vivoD3 binds to TrkA receptors and affords a significant and long-lived phenotypic rescue of the cholinergic phenotype both in the cortex and in the nucleus basalis. The cholinergic rescue was selective and correlates with a significant improvement of memory/learning in cognitively impaired aged rats. The effects of the synthetic ligand D3 and the natural ligand NGF were comparable. Small, proteolytically stable ligands with selective agonistic activity at a growth factor receptor may have therapeutic potential for neurodegenerative disorders.
Glucagon-Like Peptide 1 Excites Hypocretin/Orexin Neurons by Direct and Indirect Mechanisms: Implications for Viscera-Mediated Arousal
Authors: Acuna-Goycolea Claudio , van den Pol Anthony
Published: September 2004

Glucagon-like peptide 1 (GLP-1) is produced by neurons in the caudal brainstem that receive sensory information from the gut and project to several hypothalamic regions involved in arousal, interoceptive stress, and energy homeostasis. GLP-1 axons and receptors have been detected in the lateral hypothalamus, where hypocretin neurons are found. The electrophysiological actions of GLP-1 in the CNS have not been studied. Here, we explored the GLP-1 effects on GFP (green fluorescent protein)-expressing hypocretin neurons in mouse hypothalamic slices. GLP-1 receptor agonists depolarized hypocretin neurons and increased their spike frequency; the antagonist exendin (9-39) blocked this depolarization. Direct GLP-1 agonist actions on membrane potential were abolished by choline substitution for extracellular Na+, and dependent on intracellular GDP, suggesting that they were mediated by sodium-dependent conductances in a G-protein-dependent manner. In voltage clamp, the GLP-1 agonist Exn4 (exendin-4) induced an inward current that reversed near -28 mV and persisted in nominally Ca2+-free extracellular solution, consistent with a nonselective cationic conductance. GLP-1 decreased afterhyperpolarization currents. GLP-1 agonists enhanced the frequency of miniature and spontaneous EPSCs with no effect on their amplitude, suggesting presynaptic modulation of glutamate axons innervating hypocretin neurons. Paraventricular hypothalamic neurons were also directly excited by GLP-1 agonists. In contrast, GLP-1 agonists had no detectable effect on neurons that synthesize melanin-concentrating hormone (MCH). Together, our results show that GLP-1 agonists modulate the activity of hypocretin, but not MCH, neurons in the lateral hypothalamus, suggesting a role for GLP-1 in the excitation of the hypothalamic arousal system possibly initiated by activation by viscera sensory input.
Is Interlimb Transfer of Force-Field Adaptation a Cognitive Response to the Sudden Introduction of Load?
Authors: Malfait Nicole , Ostry David J.
Published: September 2004

Recently, Criscimagna-Hemminger et al. (2003) reported a pattern of generalization of force-field adaptation between arms that differs from the pattern that occurs across different configurations of the same arm. Although the intralimb pattern of generalization points to an intrinsic encoding of dynamics, the interlimb transfer described by these authors indicates that information about force is represented in a frame of reference external to the body. In the present study, subjects adapted to a viscous curl-field in two experimental conditions. In one condition, the field was introduced suddenly and produced clear deviations in hand paths; in the second condition, the field was introduced gradually so that at no point during the adaptation process could subjects observe or did they have to correct for a substantial kinematic error. In the first case, a pattern of interlimb transfer consistent with Criscimagna-Hemminger et al. (2003) was observed, whereas no transfer of learning between limbs occurred in the second condition. The findings suggest that there is limited transfer of fine compensatory-force adjustment between limbs. Transfer, when it does occur, may be primarily the result of a cognitive strategy that arises as a result of the sudden introduction of load and associated kinematic error.
Hippocampal Long-Term Potentiation Suppressed by Increased Inhibition in the Ts65Dn Mouse, a Genetic Model of Down Syndrome
Authors: Kleschevnikov Alexander M. , Belichenko Pavel V. , Villar Angela J. , Epstein Charles J. , Malenka Robert C. , Mobley William C.
Published: September 2004

Although many genetic disorders are characterized by cognitive failure during development, there is little insight into the neurobiological basis for the abnormalities. Down syndrome (DS), a disorder caused by the presence of three copies of chromosome 21 (trisomy 21), is characterized by impairments in learning and memory attributable to dysfunction of the hippocampus. We explored the cellular basis for these abnormalities in Ts65Dn mice, a genetic model for DS. Although basal synaptic transmission in the dentate gyrus was normal, there was severe impairment of long-term potentiation (LTP) as a result of reduced activation of NMDA receptors. After suppressing inhibition with picrotoxin, a GABAAreceptor antagonist, NMDA receptor-mediated currents were normalized and induction of LTP was restored. Several lines of evidence suggest that inhibition in the Ts65Dn dentate gyrus was enhanced, at least in part, because of presynaptic abnormalities. These findings raise the possibility that similar changes contribute to abnormalities in learning and memory in people with DS and, perhaps, in other developmental disorders with cognitive failure.
Nonlinear Response Properties of Combination-Sensitive Electrosensory Neurons in the Midbrain ofGymnarchus niloticus
Authors: Carlson Bruce A. , Kawasaki Masashi
Published: September 2004

The jamming avoidance response of the weakly electric fishGymnarchus niloticusrelies on determining the sign of the frequency difference (Df) between the fish's own electric organ discharge (EOD) and that of a neighbor, which is achieved by comparing modulations in amplitude (AM) and phase (PM) that result from the summation of their EODs. These two stimulus features are processed in separate pathways that converge in the torus semicircularis on combination-sensitive neurons, many of which are selective for the sign of Df. We recorded extracellular single-unit responses to independent stimulation with AM and PM and combined AM-PM stimulation to determine how sign selectivity is established. Responses to AM and PM frequently summated nonlinearly, leading to sign-selective responses as a result of facilitation to the preferred sign of Df and/or suppression to the nonpreferred sign of Df. Facilitation typically occurred when responses to AM and PM were aligned, whereas suppression typically occurred when they were offset. By experimentally manipulating the degree of alignment between these two responses, we found that the summed response was dependent on their relative timing. In addition, we found a unique class of units that were sensitive to differences in amplitude between two body surfaces. This sensitivity rendered such units immune to the problem of orientation ambiguity, in which the sign selectivity of a single neuron reverses with changes in stimulus orientation. We discuss potential synaptic mechanisms for driving nonlinear responses in these and other combination-sensitive neurons.
Dopamine Inhibits Mitral/Tufted→ Granule Cell Synapses in the Frog Olfactory Bulb
Authors: Davison Ian G. , Boyd Jamie D. , Delaney Kerry R.
Published: September 2004

Synaptic interactions between the dendrites of mitral/tufted (MT) and granule cells (GCs) in the olfactory bulb are important for the determination of spatiotemporal firing patterns of MTs, which form an odor representation passed to higher brain centers. These synapses are subject to modulation from several sources originating both within and outside the bulb. We show that dopamine, presumably released by TH-positive local interneurons, reduces synaptic transmission from MTs to GCs. MT neurons express D2-like receptors (D2Rs), and both dopamine and the D2 agonist quinpirole decrease EPSC amplitude at the MT→ GC synapse. D2R activation also increases paired pulse facilitation and decreases the frequency of action potential-independent spontaneous miniature EPSCs in GCs, consistent with an effect on MT glutamate release downstream from Ca2+influx. Analysis of spike-evoked Ca2+transients in MT lateral dendrites additionally shows that quinpirole reduces Ca2+influx preferentially at distal locations, possibly by reducing dendritic excitability via increased transient K+channel availability. When the OB is activated physiologically by using odor stimuli, blocking D2Rs increases the power of GABAA-dependent oscillations in the local field potential. This demonstrates a functional role for the dopaminergic circuit during normal odor-evoked responses and for the modulation of dendritic release and excitability in neuronal circuit function. Regulation of spike invasion of lateral dendrites by transient K+currents also may provide a mechanism for local outputs of MTs to be controlled dynamically via other neuromodulators or by postsynaptic potentials.