[A first pilot study on the neonatal screening of primary immunodeficiencies in Spain: TRECS and KRECS identify severe T- and B-cell lymphopenia]. / Primer estudio piloto en España sobre el cribado neonatal de las inmunodeficiencias primarias: TRECS y KRECS identifican linfopenias T y B graves.

INTRODUCTION: Early diagnosis of primary immunodeficiency such as severe combined immunodeficiency (SCID) and X-linked agammaglobulinemia (XLA) improves outcome of affected infants/children. The measurement of T-cell receptor excision circles (TRECS) and kappa-deleting recombination excision circles (KRECS) can identify neonates with severe T or B-cell lymphopenia. OBJECTIVES: To determine TRECS and KRECS levels from prospectively collected dried blood spot samples (DBS) and to correctly identify severe T and B-cell lymphopenia. MATERIAL AND METHODS: Determination of TRECS and KRECS by multiplex PCR from neonates born in two tertiary hospitals in Seville between February 2014 and May 2014. PCR cut-off levels: TRECS<15 copies/µl, KRECS<10 copies/µl, ACTB (ß-actin)>1000 copies/µl. Internal (XLA, ataxia telangiectasia) and external (SCID) controls were included. RESULTS: A total of 1068 out of 1088 neonates (mean GA 39 weeks (38-40) and BW 3238g (2930-3520) were enrolled in the study. Mean (median, min/max) copies/µl, were as follows: TRECS 145 (132, 8/503), KRECS 82 (71, 7/381), and ACTB 2838 (2763, 284/7710). Twenty samples (1.87%) were insufficient. Resampling was needed in one neonate (0.09%), subsequently giving a normal result. When using lower cut-offs (TRECS<8 and KRECS<4 copies/µl), all the samples tested were normal and the internal and external controls were correctly identified. CONCLUSION: This is the first prospective pilot study in Spain using TRECS/KRECS/ACTB-assay, describing the experience and applicability of this method to identify severe lymphopenias. The ideal cut-off remains to be established in our population. Quality of sampling, storage and preparation need to be further improved.

Restricted puckering of mineralized RNA-like riboses.

The pseudorotational motions of highly hydroxylated pentafuranose sugars in the free state and tethered to hydroxyapatite have been compared. The conformation pentafuranose ring remains restricted at the North region of the pseudorotational wheel, which is the one typically observed for nucleosides and nucleotides in the double helix A-RNA, when the phosphate-bearing sugar is anchored to the mineral surface. Results indicate that the severe restrictions imposed by the mineral are responsible of the double helix preservation when DNA and RNA are encapsulated in crystalline nanorods.

Snail1 controls TGF-ß responsiveness and differentiation of mesenchymal stem cells.

The Snail1 transcriptional repressor plays a key role in triggering epithelial-to-mesenchymal transition. Although Snail1 is widely expressed in early development, in adult animals it is limited to a subset of mesenchymal cells where it has a largely unknown function. Using a mouse model with inducible depletion of Snail1, here we demonstrate that Snail1 is required to maintain mesenchymal stem cells (MSCs). This effect is associated to the responsiveness to transforming growth factor (TGF)-ß1 that shows a strong Snail1 dependence. Snail1 depletion in conditional knockout adult animals causes a significant decrease in the number of bone marrow-derived MSCs. In culture, Snail1-deficient MSCs prematurely differentiate to osteoblasts or adipocytes and, in contrast to controls, are resistant to the TGF-ß1-induced differentiation block. These results demonstrate a new role for Snail1 in TGF-ß response and MSC maintenance.

Reactogenicity and immunogenicity profile of a two-dose combined hepatitis A and B vaccine in 1-11-year-old children.

This study was conducted to compare the reactogenicity, immunogenicity and safety of a combined two-dose (0, 6 months) hepatitis A and B vaccine (720ELU HAV, 20 mcg HBsAg) with the established three-dose (0, 1 and 6 months) hepatitis A and B vaccine (360ELU HAV, 10 mcg HBsAg). A total of 511 children aged 1-11 years who had not previously received a hepatitis A or B vaccine were enrolled in the study. Both vaccines were well tolerated, and were shown to be safe and immunogenic. The analysis, stratified according to two age groups (1-5 year and 6-11-year-old children) demonstrated that the reactogenicity profile of the two-dose schedule was at least as good as that of the established schedule. Both vaccines and schedules provided at least 98% seroprotection against hepatitis B and 100% seroconversion against hepatitis A, 1 month after the end of the vaccination course (Month 7).

Anastrozole as neoadjuvant therapy for patients with hormone-dependent, locally-advanced breast cancer.

BACKGROUND: We investigated the efficacy and safety of anastrozole as neoadjuvant therapy in a group of postmenopausal patients with locally-advanced breast cancer. PATIENTS AND METHODS: This was an open-label trial, which recruited patients with histopathologically-confirmed unilateral, locally-advanced, estrogen-receptor-positive breast cancer (stage IIIA/B). All patients received anastrozole 1 mg/day for 3 months, after which the clinical response was evaluated. All patients with a complete or partial clinical response (cCR or cPR) underwent surgery (radical modified mastectomy), after which patients continued with the same therapy for two years or until progression. Primary end points were clinical response rate (cCR + cPR), surgery rate, pathological complete response rate and tolerability profile. RESULTS: cCR and cPR were seen in 61/112 (54.5%) and 32/112 (28.6%) patients (n=112), respectively, giving an objective response rate of 93/112 (83%) patients. Following surgery in responding patients, 14/61 patients (23%) had a pathological CR and 47/61 (77%) patients had a pathological PR. CONCLUSION: Neoadjuvant anastrozole treatment was highly effective and well-tolerated in postmenopausal women with hormone-dependent locally-advanced breast cancer.

Comparison of the reactogenicity and immunogenicity of a combined diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated polio (DTPa-HBV-IPV) vaccine, mixed with the Haemophilus influenzae type b (Hib) conjugate vaccine and administered as a single injection, with the DTPa-IPV/Hib and hepatitis B vaccines administered in two simultaneous injections to infants at 2, 4 and 6 months of age.

An open, randomised, multicentre trial was performed to compare the reactogenicity and safety profile of the administration of a hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio (DTPa-HBV-IPV) vaccine administered in one injection mixed with Haemophilus influenzae type b (Hib) conjugate vaccine (Group 1) with that of a pentavalent DTPa-IPV vaccine mixed with a Hib vaccine (DTPa-IPV/Hib), simultaneously administered with HBV (Group 2) in two injections in opposite thighs, as a primary vaccination course, to healthy infants at 2, 4 and 6 months of age. A total of 235 completed the study, 120 from Group 1 and 115 from Group 2. Blood samples (pre-vaccination and 1 month after the third dose) were obtained from a subset of infants (Group 1: 40; Group 2: 31) to assess the immune response to vaccination. Local and general solicited symptoms were recorded by parents on diary cards. Seven hundred and five diary cards (Group 1: 360; Group 2: 345) were collected. The clinically relevant and most commonly reported local reaction was pain (infant cried when the limb was moved) in 2.5% (Group 1) and 1.2% (Group 2) of diary cards. Fever was more frequently reported in Group 1 (21% of diary cards) than in Group 2 (12% of diary cards). However only 3 and 2% of doses in Groups 1 and 2, respectively, were responsible for a rectal temperature between 38.6 and 39.5 degrees C and only one case (Group 2) had > or =39.5 degrees C. Other clinically relevant general symptoms were rarely recorded: irritability (2-2.8%), loss of appetite (0.3-0.6%) and drowsiness (0.3-0.3%). All subjects included in the immunogenicity analysis had seroprotective titres to diphtheria, tetanus, polio virus types 1 and 3, Hib. Almost all subjects were seroprotected for anti-polio type 2 and hepatitis B (with the exception of 1 subject in Group 1 for each antigen). The vaccines response rates to pertussis antigens were over 97 and 90% in Groups 1 and 2, respectively. This study shows that, from a clinical perspective, the DTPa-HBV-IPV/Hib vaccine given in a single injection has a similar reactogenicity and safety profile to that of two licensed vaccines (DTPa-IPV/Hib, HBV) given in two simultaneous injections to infants at 2, 4 and 6 months of age. This is a valuable advantage, since in some countries, such as Spain and the UK, an additional injection (for the administration of meningococcal C conjugate vaccine) has been recently included in the infants' vaccination calendars.

[Surgical management of the capsular contraction syndrome]. / Manejo quirúrgico del síndrome de contracción capsular.

PURPOSE/METHODS: To describe a surgical technique to treat severe capsular contraction syndrome. A secondary continuous curvilinear capsulorhexis was performed in four cases of capsular phymosis, attended in our clinic. CONCLUSIONS/RESULTS: All of them resolved with good anatomic and functional results, no recurrence occurred and best correct visual acuity BCVA was preserved after a twelve- month follow-up. This surgical procedure could solve severe capsular contraction syndrome occurring after continuous curvilinear capsulorhexis, phacoemulsification and intraocular lens implantation.

Control of dorsal raphe serotonergic neurons by the medial prefrontal cortex: Involvement of serotonin-1A, GABA(A), and glutamate receptors.

Anatomical evidence indicates that medial prefrontal cortex (mPFC) neurons project to the dorsal raphe nucleus (DR). In this study, we functionally characterized this descending pathway in rat brain. Projection neurons in the mPFC were identified by antidromic stimulation from the DR. Electrical stimulation of the mPFC mainly inhibited the activity of DR 5-HT neurons (55 of 66). Peristimulus time histograms showed a silence of 150 +/- 9 msec poststimulus (latency, 36 +/- 1 msec). The administration of WAY-100635 and picrotoxinin partly reversed this inhibition, indicating the involvement of 5-HT(1A) and GABA(A) receptors. In rats depleted of 5-HT with p-chlorophenylalanine, the electrical stimulation of mPFC mainly activated 5-HT neurons (31 of 40). The excitations (latency, 17 +/- 1 msec) were antagonized by MK-801 and NBQX. Likewise, MK-801 prevented the rise in DR 5-HT release induced by electrical stimulation of mPFC. The application of 8-OH-DPAT in mPFC significantly inhibited the firing rate of DR 5-HT neurons and, in dual-probe microdialysis experiments, reduced the 5-HT output in mPFC and DR. Furthermore, the application of WAY-100635 in mPFC significantly antagonized the reduction of 5-HT release produced by systemic 8-OH-DPAT administration in both areas. These results indicate the existence of a complex regulation of DR 5-HT neurons by mPFC afferents. The stimulus-induced excitation of some 5-HT neurons by descending excitatory fibers releases 5-HT, which inhibits the same or other DR neurons by acting on 5-HT(1A) autoreceptors. Afferents from the mPFC also inhibit 5-HT neurons through the activation of GABAergic interneurons. Ascending serotonergic pathways may control the activity of this descending pathway by acting on postsynaptic 5-HT(1A) receptors.

Calculated and experimental NMR chemical shifts of p-menthane-3,9-diols. A combination of molecular dynamics and quantum mechanics to determine the structure and the solvent effects.

NMR chemical shifts have been experimentally measured and theoretically estimated for all the carbon atoms of (1R,3S,4S,8S)-p-menthane-3,9-diol in chloroform solution. Theoretical estimations were performed using a combination of molecular dynamics simulations and quantum mechanical calculations. Molecular dynamics simulations were used to obtain the most populated conformations of the (1R,3S:4S,8S)-p-menthane-3,9-diol as well as the distribution of the solvent molecules around it. Quantum mechanical calculations of NMR chemical shifts were performed on the most relevant conformations employing the GIAO-DFT formalism. A special emphasis was put in evaluating the effects of the surrounding solvent molecules. For this purpose, supermolecule calculations were performed on complexes constituted by the solute and n chloroform molecules, where n ranges from 3 to 16. An excellent agreement with experimental data has been obtained following this computational strategy.

In vivo actions of the selective 5-HT1A receptor agonist BAY x 3702 on serotonergic cell firing and release.

We investigated the effects of the novel 5-HT1A receptor agonist BAY x 3702 on the serotonergic function in rat brain using single unit recordings in the dorsal raphe nucleus (DR) of anesthetized rats and in vivo microdialysis in freely moving rats. The administration of BAY x 3702 (0.25-4 microg/kg i.v.) suppressed the firing activity of 5-HT neurones. This effect was antagonized by a low dose of the selective 5-HT1A receptor antagonist WAY 100635 (5 microg/kg i.v.). In microdialysis experiments, BAY x 3702 (10-100 microg/ kg s.c.) reduced dose-dependently the 5-HT output in the dorsal and median raphe (MnR) nucleus, dorsal hippocampus (DHPC) and medial prefrontal cortex (mPFC) in a regionally selective manner. Maximal effects were observed in the MnR and mPFC, with reductions to approximately 15% of baseline at a dose of 0.1 mg/kg s.c. The decrease in 5-HT output produced in the DR and DHPC was more moderate, to 45% of baseline at 0.1 mg/kg s.c. BAY x 3702. WAY 100635 (0.3 mg/kg s.c.) completely antagonized the effect of BAY x 3702 (30 microg/kg s.c.). The application of BAY x 3702 in the DR (1-100 microM) reduced the local 5-HT output to 25% of baseline. In rats implanted with two dialysis probes (in DR and mPFC) the application of BAY x 3702 (30 microM) in the DR reduced the 5-HT output in the DR and that in mPFC. These effects were significantly antagonized by the co-perfusion of WAY 100635 (100 microM) in the DR. Overall, these results indicate that the systemic administration of BAY x 3702 reduces the 5-HT release with high potency through the activation of midbrain 5-HT1A receptors.

Postsynaptic 5-HT1A receptors control 5-HT release in the rat medial prefrontal cortex.

5-HTt1A receptor agonists reduce the neuronal release of 5-hydroxytryptamine (5-HT) by activation of raphe 5-HT1A autoreceptors. Using in vivo microdialysis in unanesthetized rats, we show that the local application of the selective 5-HT1A receptor agonist 8-OH-DPAT decreased the 5-HT output to approximately 50% of controls in medial prefrontal cortex (mPFC) but not in dorsal hippocampus. The decrease in 5-HT output was counteracted by the concurrent application of the selective 5-HT1A receptor antagonist WAY-100635. This agent also reversed the decrease in 5-HT output elicited by the novel 5-HT1A receptor agonist BAY x 3702 (30 microM) in mPFC and dorsal raphe nucleus. These results indicate that postsynaptic 5-HT1A receptors in mPFC also participate in the control of serotonergic activity.

Differential regulation of somatodendritic serotonin 5-HT1A receptors by 2-week treatments with the selective agonists alnespirone (S-20499) and 8-hydroxy-2-(Di-n-propylamino)tetralin: microdialysis and autoradiographic studies in rat brain.

Single treatment with the serotonin (5-hydroxytryptamine) 5-HT1A receptor agonists 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) and alnespirone (S-20499) reduces the extracellular 5-HT concentration (5-HText) in the rat midbrain and forebrain. Given the therapeutic potential of selective 5-HT1A agonists in the treatment of affective disorders, we have examined the changes in 5-HT1A receptors induced by 2-week minipump administration of alnespirone (0.3 and 3 mg/kg/day) and 8-OH-DPAT (0.1 and 0.3 mg/kg/day). The treatment with alnespirone did not modify baseline 5-HText but significantly attenuated the ability of 0.3 mg/kg s.c. alnespirone to reduce 5-HText in the dorsal raphe nucleus (DRN) and frontal cortex. In contrast, the ability of 8-OH-DPAT (0.025 and 0.1 mg/kg s.c.) to reduce 5-HText in both areas was unchanged by 8-OH-DPAT pretreatment. Autoradiographic analysis revealed a significant reduction of [3H]8-OH-DPAT and [3H]WAY-100635 [3H-labeled N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridyl)cyclohexa necarboxamide x 3HCl] binding to somatodendritic 5-HT1A receptors (but not to postsynaptic 5-HT1A receptors) of rats pretreated with alnespirone but not with 8-OH-DPAT. In situ hybridization analysis revealed no change of the density of the mRNA encoding the 5-HT1A receptors in the DRN after either treatment. These data indicate that continuous treatment for 2 weeks with alnespirone, but not with 8-OH-DPAT, causes a functional desensitization of somatodendritic 5-HT1A receptors controlling 5-HT release in the DRN and frontal cortex.

PAPQMD parametrization of molecular systems with cyclopropyl rings: conformational study of homopeptides constituted by 1-aminocyclopropane-1-carboxylic acid.

The suitability of ab initio, semiempirical and density functional methods as sources of stretching and bending parameters has been explored using the PAPQMD (Program for Approximate Parametrization from Quantum Mechanical Data) strategy. Results show that semiempirical methods provide parameters comparable to those compiled on empirical force fields. In this respect the AMI method seems to be a good method to obtain parameters at a minimum computational cost. On the other hand, harmonic force fields initially developed for proteins and DNA have been extended to include compounds containing highly strained three-membered rings, like 1-aminocyclopropane-1-carboxylic acid. For this purpose the cyclopropyl ring has been explicitly parametrized at the AMI level considering different chemical environments. Finally, the new set of parameters has been used to investigate the conformational preferences of homopeptides constituted by 1-aminocyclopropane-1-carboxylic acid. Results indicate that such compounds tend to adopt a helical conformation stabilized by intramolecular hydrogen bonds between residues i and i + 3. This conformation allows the arrangement of the cyclic side chains without steric clashes.

Is the potent 5-HT1A receptor agonist, alnespirone (S-20499), affecting dopaminergic systems in the rat brain?

The effects of the new methoxy-chroman 5-HT1A receptor agonist, alnespirone (S-20499), on the dopamine systems in the rat brain were assessed in vivo by means of electrophysiological and neurochemical techniques. Cumulative doses of alnespirone (0.032-4.1 mg kg(-1), i.v.) did not modify the spontaneous firing rate of dopamine neurons in the substantia nigra as well as in the ventral tegmental area. The local application of alnespirone (0.1-10 microM) by reverse microdialysis into the dorsal striatum did not affect the dopamine output but induced a moderate, although dose-independent, increase of 5-HT (5-hydroxytryptamine, serotonin) concentrations in the dialysate. As expected of a 5-HT1A receptor agonist, intraperitoneal (i.p.) administration of alnespirone at 2-32 mg kg(-1) markedly decreased 5-HT turnover in the striatum. Parallel measurements of dopamine turnover showed that alnespirone exerted no effect except at the highest dose (32 mg kg(-1), i.p.) for which a significant increase was observed. Interestingly, both alnespirone-induced reduction in 5-HT turnover and increase in dopamine turnover could be prevented by pretreatment with the selective 5-HT1A receptor antagonist WAY-100635 (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclohexa ne carboxamide). Altogether, these data indicate that alnespirone does not exert any direct influence on central dopamine systems. The enhanced dopamine turnover due to alnespirone at high dose appeared to result from 5-HT1A receptor stimulation, further supporting the idea that this receptor type may play a key role in 5-HT-dopamine interactions in brain.

[Influence of pregnancy in chronic hepatitis C virus infection]. / Influencia del embarazo en la infección crónica por el virus C de la hepatitis.

BACKGROUND: There is scarce information about the influence of pregnancy in patients with chronic hepatitis C virus infection is little know. PATIENTS AND METHODS: 6,556 pregnant women were screened for anti-HCV (ELISA II). We determine ALT, HCV-RNA by PCR (Amplicor Roche) and HCV viraemia (Amplicor-HCV-Monitor Roche) in the third trimester of pregnancy and after 6 months of delivery. HBsAg, anti-HIV and HCV serotype (Murex 1-3) were also determined. STATISTICAL ANALYSIS: Fisher test, paired-t and U Mann Whitney. RESULTS: Anti-HCV was positive in 59 out of 6,556 (0.9%). Mean (SD) age: 27 (9) years (range, 18-40). Drug users: 34 (57%), post-transfusion: 10 (18%) and unknown: 15 (25%). HIV positive 11 (19%). Serotype 1, 30 (51%), setotype 3, 7 (20%), and nontypeable, 22 (37%). We studied HCV-RNA before and after delivery in 35 women, 8 out of 35 (23%) had HCV-RNA negative in both analysis. ALT was normal in 88% of women during pregnancy and in 42% after delivery. ALT levels in pregnancy were 32.6 (39.5) and in postpartum 64.5 (53.4) U/l (p < 0.005). 6 women were RNA-VHC negative during pregnancy and positive in postpartum. HCV viraemia during pregnancy and postpartum was 503 (1,203) and 1,014 (1,907) thousand copies/ml (p < 0.05). No relation was found among ALT or HCV viraemia with risk factors, serotype or coinfection with HIV. CONCLUSIONS: The prevalence of anti-HCV in pregnant women is 0.9%. ALT is usually normal in pregnancy. A quarter of women were HCV-RNA negative in pregnancy and positive after delivery. The viraemia was lower in pregnancy than after delivery, which is consistent with the fact of the low mother-to-infant HCV transmission rate.

3-Hydroxybutyrate co-infused with noradrenaline decreases resulting plasma levels of noradrenaline in Wistar rats.

Pentobarbital-anaesthetized male Wistar rats were infused with 6microgkg-1min-1 of noradrenaline. The infusion was supplemented with 8.5 mgkg-1min-1 of D-3-hydroxybutyrate (3-OHB) for 15 min in order to determine its effect on the adrenergic response of the rat. Plasma levels of noradrenaline rose to a plateau of approximately 50 nmoll-1 with infusion. In the group infused with noradrenaline alone, noradrenaline levels were maintained for 1h. Supplementation with 3-OHB induced a decrease in plasma noradrenaline level that was inversely correlated with 3-OHB level. Aortic and interscapular brown adipose tissue temperatures increased with noradrenaline infusion, but the rise was arrested by 3-OHB; replacing 3-OHB with glucose had no effect. Infusion of saline, glucose or 3-OHB in the absence of noradrenaline did not induce a rise in temperature in either tissue. Blood 3-OHB concentration increased to 1.2 mmoll-1 during 3-OHB infusion, decreasing rapidly at the end of infusion. Blood glucose levels increased with noradrenaline infusion; the presence of high 3-OHB levels decreased glucose concentration. The effects observed were transient and dependent on 3-OHB concentration; these effects may help explain most of the other effects of noradrenaline described here. The role of 3-OHB as a regulator of adrenergic responses seems to be part of a complex fail-safe mechanism which prevents wasting.

Comparative study in the rat of the actions of different types of stress on the release of 5-HT in raphe nuclei and forebrain areas.

The effects of several stress procedures on the release of 5-HT in the dorsal and median raphe nuclei (DRN and MRN, respectively) and in forebrain structures of the rat brain innervated by both nuclei have been studied using intracerebral microdialysis. Handling for 30 sec, a saline injection and forced swimming for 5 min elevated significantly the 5-HT output in the MRN. The 5-HT output in the DRN was also enhanced by a saline injection. With regard to the forebrain structure examined, handling and forced swimming increased dialysate 5-HT in the amygdala. The injection of saline induced a slight, but significant, elevation of 5-HT in the medial prefrontal cortex. In contrast, the outflow of 5-HT was significantly reduced in the ventral hippocampus and medial prefrontal cortex following forced swimming and this effect persisted well beyond the cessation of the swim session. These results indicate that the efflux of 5-HT in the MRN appears to respond to different forms of stress, whereas that in the DRN only increases after the injection of saline. The release of 5-HT in the forebrain structures is also dependent on the type of stress procedure and the region studied.

The effect of the selective 5-HT1A agonists alnespirone (S-20499) and 8-OH-DPAT on extracellular 5-hydroxytryptamine in different regions of rat brain.

1. We have examined the effects of the systemic administration of the selective 5-HT1A agonist alnespirone (S-20499) on in vivo 5-hydroxytryptamine (5-HT) release in the dorsal raphe nucleus, the median raphe nucleus and four forebrain areas innervated differentially by both (dorsal striatum, frontal cortex, ventral hippocampus and dorsal hippocampus). 2. Alnespirone (0.1-3 mg kg(-1), s.c.) dose-dependently reduced extracellular 5-HT in the six areas examined. In forebrain, the maximal reductions occurred in striatum and frontal cortex (maximal reduction to 23 and 29% of baseline, respectively). Those in dorsal and ventral hippocampus were more moderate (to ca 65% of baseline). In contrast, the decrease in 5-HT elicited in the median raphe nucleus was more marked than that in the dorsal raphe nucleus (to ca 30 and 60% of baseline, respectively). The selective 5-HT1A antagonist WAY-100635 (0.5 mg kg(-1), s.c.) prevented the decrease in 5-HT induced by alnespirone (0.3 mg kg(-1), s.c.) in frontal cortex. 3. 8-OH-DPAT (0.025, 0.1 and 0.3 mg kg(-1), s.c.) also reduced extracellular 5-HT in a regionally-selective manner (e.g., to 32% of baseline in striatum and to 69% in dorsal hippocampus at 0.1 mg kg(-1), s.c.). In midbrain, 8-OH-DPAT reduced the dialysate 5-HT slightly more in the median than in the dorsal raphe nucleus at all doses examined. 4. Doses of both compounds close to their respective ED50 values (0.3 mg kg(-1) alnespirone, 0.025 mg kg(-1) 8-OH-DPAT) reduced 5-HT to a comparable extent in all regions examined. However, the reductions attained at higher doses were more pronounced for 8-OH-DPAT. 5. These data show that the reduction of 5-HT release elicited by alnespirone and 8-OH-DPAT is more important in forebrain areas innervated by 5-hydroxytryptaminergic neurones of the dorsal raphe nucleus. This regional selectivity seems unlikely to be accounted for by differences in the sensitivity of 5-HT1A autoreceptors controlling 5-HT release, given the dissimilar effects of these two 5-HT1A agonists in regions rich in cell bodies and nerve terminals. This suggests the presence of complex mechanisms of control of 5-HT release by 5-HT1A receptors.

Strain Effects in Protonated Carbonyl Compounds. An Experimental and ab Initio Treatment of Acyclic Carboxamides and Ketones.

Strain effects have been quantitatively evaluated for a set of 22 compounds including ketones (R(2)CO), carboxamides (RCONH(2)), and N,N-dimethylcarboxamides (RCONMe(2)), where R = Me, Et, i-Pr, t-Bu, 1-adamantyl (1-Ad), in their neutral and protonated forms. To this end, use was made of the gas-phase proton affinities and standard enthalpies of formation of these compounds in the gas phase, as determined by Fourier transform ion cyclotron resonance mass spectrometry (FT ICR) and thermochemical techniques, respectively. The structures of 1-AdCOMe and (1-Ad)(2)CO were determined by X-ray crystallography. Quantum-mechanical calculations, at levels ranging from AM1 to MP2/6-311+G(d,p)//6-31G(d), were performed on the various neutral and protonated species. Constrained space orbital variation (CSOV) calculations were carried out on selected protonated species to further assess the contributions of the various stabilizing factors. Taking neutral and protonated methyl ketones as references, we constructed isodesmic reactions that provided, seemingly for the first time, quantitative measures of strain in the protonated species. A combination of these data with the results of theoretical calculations (which also included several "computational experiments") lead to a unified, conceptually satisfactory, quantitative description of these effects and their physical link to structural properties of the neutral and protonated species.

Differential effects of ipsapirone on 5-hydroxytryptamine release in the dorsal and median raphe neuronal pathways.

Serotonergic neurons of the dorsal and median raphe nuclei are morphologically dissimilar. Recent results challenge previous evidence indicating a greater inhibition of dorsal raphe neurons after 5-hydroxytryptamine1A (5-HT1A) autoreceptor activation. As both nuclei innervate different forebrain territories, this issue is critical to understanding the changes in brain function induced by anxiolytic and antidepressant drugs. Using microdialysis, we examined the modifications of 5-HT release induced by the selective 5-HT1A agonist ipsapirone in both neuronal pathways. Maximal and minimal basal 5-HT values (in the presence of 1 microM citalopram) were 45.0 +/- 4.8 fmol/fraction in the median raphe nucleus and 8.4 +/- 0.4 fmol/fraction in the dorsal hippocampus. Ipsapirone (0.3, 3, and 10 mg/kg s.c.) reduced dose-dependently 5-HT in the two raphe nuclei and four forebrain areas. Maximal reductions (to approximately 25% of predrug values) were observed in cortex and striatum and in median raphe nucleus. The effects were more moderate in dorsal and ventral hippocampus (to 66 and 50% of baseline, respectively). These results are consistent with a higher sensitivity of dorsal raphe neurons to 5-HT1A autoreceptor activation. Yet the differential reduction of 5-HT release in the median raphe nucleus and hippocampus suggests the presence of complex mechanisms of control of 5-HT release in these neurons.