bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ovarian stimulation length, number of follicles higher than 17 mm and estradiol on the day of human chorionic gonadotropin administration are risk factors for multiple pregnancy in intrauterine insemination
Authors: GARRIDO NICOLÁS , MELO MARCO A.B. , SIMÓN CARLOS , REMOHÍ JOSÉ , PELLICER ANTONIO , MESEGUER MARCOS 
Published: February 2007

Aim:  The aim of the present study was to identify the risk factors, their prognostic value on multiple pregnancies (MP) prediction and their thresholds in women undergoing controlled ovarian hyperstimulation (COH) with follicle stimulating hormone (FSH) and intrauterine insemination (IUI).Methods:  A case‐control study was carried out by identifying in our database all the pregnancies reached by donor and conjugal IUI (DIUI and CIUI, respectively), and compared cycle features, patients’ characteristics and sperm analysis results between women achieving single pregnancy (SP) versus MP. The number of gestational sacs, follicular sizes and estradiol levels on the human chorionic gonadotropin (hCG) administration day, COH length and semen parameters were obtained from each cycle and compared. Student's t‐tests for mean comparisons, receiver–operator curve (ROC) analysis to determine the predictive value of each parameter on MP achievement and multiple regression analysis to determine single parameter influence were carried out.Results:  Women with MP in IUI stimulated cycles reached the adequate size of the dominant follicle (17 mm) significantly earlier than those achieving SP. Also, the mean follicles number, and estradiol levels on the hCG day were higher in the CIUI and DIUI MP group. Nevertheless, only ROC curve analysis revealed good prognostic value for estradiol and follicles higher than 17 mm. Multiple regression analysis confirmed these results. No feature of the basic sperm analysis, either in the ejaculate or in the prepared sample, was different or predictive of MP. When using donor sperm, different thresholds of follicle number, stimulation length and estradiol in the prediction of MP were noted, in comparison with CIUI.Conclusions:  MP in stimulated IUI cycles are closely associated to stimulation length, number of developed follicles higher than 17 mm on the day of hCG administration and estradiol levels. Also, estradiol has a good predictive value over MP in IUI stimulated cycles. The establishment of clinical thresholds will certainly help in the management of these couples to avoid undesired multiple pregnancies by canceling cycles or converting them into in vitro fertilization procedures. (Reprod Med Biol 2007; 6: 19–26)
Recombinant‐follicle stimulating hormone is more effective than urinary human menopausal gonadotropin in ovarian hyperstimulation for assisted reproductive technology treatment
Authors: NAKAGAWA KOJI , OHGI SHIREI , KOJIMA RIEKO , SUGAWARA KANA , HORIKAWA TAKASHI , ITO MEGUMU , IRAHARA MINOARU , SAITO HIDEKAZU 
Published: February 2007

Aim:  The aim of the present study was to establish a standard protocol for ovarian stimulation with gonadotropin‐releasing hormone analog (GnRH‐a) long protocol using recombinant‐follicle stimulating hormone (rec‐FSH) preparations for assisted reproductive technology (ART) treatment.Methods:  In 86 patients who underwent ovarian stimulation with GnRH‐a long protocol for ART treatment, 53 were stimulated by rec‐FSH preparations (rec‐FSH group) and the others were stimulated by urinary‐hMG (u‐hMG group) preparations. The subjects were randomly assigned to either of these preparations. Hormonal profiles, total doses of gonadotropins, duration of stimulation and ART results were compared in both groups.Results:  The duration of stimulation was similar in both groups (9.2 ± 0.3 days and 9.2 ± 0.2 days, respectively). The total doses of gonadotropin in the rec‐FSH group (1505.3 ± 29.2 IU) was significantly lower than those in the u‐hMG group (2130.3 ± 54.6 IU, P < 0.0001). The FSH and LH values on the day of human chorionic gonadotropin (hCG) administration in the rec‐FSH group were significantly lower than those in the u‐hMG group. Pregnancy rates were 31.3% in the rec‐FSH group and 33.3% in the u‐hMG group, respectively.Conclusions:  The present study showed that rec‐FSH preparations were more potent than conventional u‐hMG preparations and the protocol of the present study with rec‐FSH was a new ovarian stimulation protocol with GnRH‐a long protocol. (Reprod Med Biol 2007; 6: 27–32)
Stochastic description of complex and simple spike firing in cerebellar Purkinje cells
Authors: Shin Soon‐Lim , Rotter Stefan , Aertsen Ad , De Schutter Erik 
Published: February 2007

AbstractCerebellar Purkinje cells generate two distinct types of spikes, complex and simple spikes, both of which have conventionally been considered to be highly irregular, suggestive of certain types of stochastic processes as underlying mechanisms. Interestingly, however, the interspike interval structures of complex spikes have not been carefully studied so far. We showed in a previous study that simple spike trains are actually composed of regular patterns and single interspike intervals, a mixture that could not be explained by a simple rate‐modulated Poisson process. In the present study, we systematically investigated the interspike interval structures of separated complex and simple spike trains recorded in anaesthetized rats, and derived an appropriate stochastic model. We found that: (i) complex spike trains do not exhibit any serial correlations, so they can effectively be generated by a renewal process, (ii) the distribution of intervals between complex spikes exhibits two narrow bands, possibly caused by two oscillatory bands (0.5–1 and 4–8 Hz) in the input to Purkinje cells and (iii) the regularity of regular patterns and single interspike intervals in simple spike trains can be represented by gamma processes of orders, which themselves are drawn from gamma distributions, suggesting that multiple sources modulate the regularity of simple spike trains.
Priority of repetitive adaptation to mismatch response following undiscriminable auditory stimulation: a magnetoencephalographic study
Authors: Hoshiyama Minoru , Okamoto Hidehiko , Kakigi Ryusuke 
Published: February 2007

AbstractWe analysed two different neural mechanisms related to the unconscious processing of auditory stimulation, neural adaptation and mismatch negativity (MMN), using magnetoencephalography in healthy non‐musicians. Four kinds of conditioning stimulus (CS): white noise, a 675‐Hz pure tone, and complex tones with six (CT6) and seven components (CT7), were used for analysing neural adaptation. The seven spectral components of CT7 were spaced by 1/7 octaves between 500 and 906 Hz on the logarithmic scale. The CT6 components contained the same spectral components as CT7, except for the center frequency, 675 kHz. Subjects could not distinguish CT6 from CT7 in a discrimination test. A test stimulus (TS), a 675‐Hz tone, was presented after CS, and the effects of the presence of the same 675‐Hz frequency in the CS on the magnetoencephalographic response elicited by TS was evaluated. The P2m component following CT7 was significantly smaller in current strength than that following CT6. The equivalent current dipole for P2m was located approximately 10 mm anterior to the preceding N1m. This result indicated that neural adaptation was taking place in the anterior part of the auditory cortex, even if the sound difference was subthreshold. By contrast, the magnetic counterpart of the MMN was not recorded when CT6 and CT7 were used as standard and deviant stimuli, respectively, being consistent with the discrimination test. In conclusion, neural adaptation is considered to be more sensitive than our consciousness or the MMN, or is caused by an independent mechanism.
Methamphetamine‐induced structural plasticity in the dorsal striatum
Authors: Jedynak Jakub P. , Uslaner Jason M. , Esteban José A. , Robinson Terry E. 
Published: February 2007

AbstractRepeated exposure to psychostimulant drugs produces long‐lasting changes in dendritic structure, presumably reflecting a reorganization in patterns of synaptic connectivity, in brain regions that mediate the psychomotor activating and incentive motivational effects of these drugs, including the nucleus accumbens and prefrontal cortex. However, repeated exposure to psychostimulant drugs also facilitates a transition in the control of some behaviors from action–outcome associations to behavior controlled by stimulus–response (S–R) habits. This latter effect is thought to be due to increasing engagement and control over behavior by the dorsolateral (but not dorsomedial) striatum. We hypothesized therefore that repeated exposure to methamphetamine would differentially alter the density of dendritic spines on medium spiny neurons (MSNs) in the dorsolateral vs. dorsomedial striatum. Rats were treated with repeated injections of methamphetamine, and 3 months later dendrites were visualized using Sindbis virus‐mediated green fluorescent protein (GFP) expression in vivo. We report that prior exposure to methamphetamine produced a significant increase in mushroom and thin spines on MSNs in the dorsolateral striatum, but a significant decrease in mushroom spines in the dorsomedial striatum. This may be due to changes in the glutamatergic innervation of these two subregions of the dorsal striatum. Thus, we speculate that exposure to psychostimulant drugs may facilitate the development of S–R habits because this reorganizes patterns of synaptic connectivity in the dorsal striatum in a way that increases control over behavior by the dorsolateral striatum.
Neuronal death in Drosophila triggered by GAL4 accumulation
Authors: Rezával Carolina , Werbajh Santiago , Ceriani María Fernanda 
Published: February 2007

AbstractThe GAL4/UAS system has been extensively employed in Drosophila to control gene expression in defined spatial patterns. More recently this system has been successfully applied to express genes involved in neurodegeneration to model various diseases in the fruit fly. We used transgenic lines expressing different levels of GAL4 in a particular subset of neurons involved in the control of rhythmic behaviour, so that its impact on neuronal physiology would result in altered locomotor activity, which could be readily assessed. We observed a striking correlation between gal4 dosage and behavioural defects associated with apoptotic neuronal loss in the specific GAL4‐expressing neurons. Increased gal4 dosage correlated with accumulation of insoluble GAL4, suggesting that the cascade of events leading to apoptosis might be triggered by protein deposits of either GAL4 or protein intermediates. Behavioural defects were rescued by expression of hsp70, a classic chaperone that also interferes with cell death pathways. In agreement with the latter, the viral caspase inhibitor p35 also rescued GAL4‐induced behavioural defects. Our observations demonstrate the intrinsic effects of GAL4 deregulation on neuronal viability and suggest that an excess of GAL4 might enhance neuronal deficits observed in models of neurodegeneration.
The midbrain raphe nuclei mediate primary reinforcement via GABAA receptors
Authors: Liu Zhong‐Hua , Ikemoto Satoshi 
Published: February 2007

AbstractBecause rats learn to lever‐press for brief electrical stimulation of the median and dorsal raphe nuclei (MRN and DRN, respectively), these brain sites have long been implicated in reward processes. However, it is not clear whether the MRN and DRN integrate reward‐related signals or merely contain fibers of passage involved in reward processes. To shed light on this issue, the present study employed chemicals that selectively modulate neurotransmission, in particular the GABAA receptor agonist muscimol. Rats quickly learned to lever‐press for muscimol infusions (50 and 100 µm) into the MRN or DRN. Muscimol was not self‐administered when cannulae were placed just outside these nuclei. The reinforcing effects of muscimol appeared to be greater when the drug was administered into the MRN than into the DRN, as demonstrated by higher infusion rates and better response discrimination. These observations are consistent with the additional finding that muscimol administration into the MRN, but not the DRN, induced conditioned place preference. The reinforcing effects of muscimol administration into the MRN were blocked by coadministration of the GABAA antagonist picrotoxin (100 µm) and by pretreatment with the dopamine receptor antagonist SCH 23390 (0.025 mg/kg, i.p.). The present results suggest that median and dorsal raphe neurons presumably inhibited by muscimol via GABAA receptors are involved in integration of primary reinforcement, and that median raphe neurons exert tonic inhibition over dopamine‐dependent reward circuitry. The midbrain raphe nuclei may be involved in a variety of reward‐related phenomena including drug addiction.
CB2 cannabinoid receptors promote mouse neural stem cell proliferation
Authors: Molina‐Holgado Francisco , Rubio‐Araiz Ana , García‐Ovejero Daniel , Williams Robert J. , Moore Jonathan D. , Arévalo‐Martín Ángel , Gómez‐Torres Oscar , Molina‐Holgado Eduardo 
Published: February 2007

AbstractNeurospheres are clonal cellular aggregates of neural stem/precursor cells that grow in culture as free‐floating clusters. Activation of CB1 cannabinoid receptors, which are expressed by these cells, promotes proliferation. In the present study we investigated the expression of CB2 cannabinoid receptors and the effect of exogenous cannabinoids on neural stem/precursor cell proliferation. Neurospheres containing nestin‐positive and sn‐1 diacylglycerol lipase α‐positive cells expressed both CB1 and CB2 receptors, which were maintained through several passages. Application of the non‐selective cannabinoid agonist (HU‐210, 0.5 µm) stimulated bromodeoxyuridine incorporation and neurosphere formation. This action involved both CB1 and CB2 receptors as neurosphere formation was stimulated by either selective CB1 [arachidonyl‐2’chloroethylamide/(all Z)‐N‐(2‐cycloethyl)‐5,8,11,14‐eicosatetraenamide (ACEA), 200 nm and 1 µm] or CB2 (JWH‐056, 0.5 µm) agonists. In addition, CB1 or CB2 antagonists (1 µm SR‐141716A and SR‐144528, respectively) blocked basal proliferation, suggesting that endogenous cannabinoids are implicated in neurosphere proliferation. In addition, cannabinoid agonist‐stimulated proliferation was reduced by the Akt translocation inhibitor BML‐257 (12.5 µm), suggesting a role for phosphoinositide‐3 kinase signalling. Together, our results suggest that cannabinoids stimulate proliferation of neural stem/precursor cells acting on both CB1 and CB2 cannabinoid receptors through a phosphoinositide‐3 kinase/Akt pathway.
Hydrogen peroxide increases GABAergic mIPSC through presynaptic release of calcium from IP3 receptor‐sensitive stores in spinal cord substantia gelatinosa neurons
Authors: Takahashi Ayako , Mikami Maya , Yang Jay 
Published: February 2007

AbstractGABAergic interneurons of the spinal cord substantia gelatinosa regulate the transmission of nociceptive information. Hydrogen peroxide (H2O2) is likely a diffusible messenger contributing to the development of long‐lasting pathological pain states after nerve injury. In this study, we examined the presynaptic effects of H2O2 on the inhibitory interneurons of mouse substantia gelatinosa (SG) using whole‐cell patch‐clamp recordings from spinal cord slices. H2O2 increased the frequency of GABAergic miniature inhibitory postsynaptic current (mIPSC) in a concentration‐dependent (10–1000 µm) manner. The profound increase in mIPSC frequency was diminished by thapsigargin or cyclopiazonic acid suggesting that the intracellular stored pool was the source of presynaptic calcium. Further examination revealed the 2‐aminoethoxydiphenil borate blockable inositol‐(1,4,5) trisphosphate receptor (IP3R) regulated pool of stored calcium as the likely source. The phospholipase C (PLC) blocker, 1‐(6‐[([17β]‐3‐methoxyestra‐1,3,5[10]‐trien‐17‐yl)‐amino]hexyl)‐1H‐pyrrole‐2,5‐dione (U73122), did not block the frequency increase, which suggested that the site of action of H2O2 lies downstream in the IP3 signalling pathway, and nifedipine‐sensitivity of the frequency increase indicated a possible role of calcium‐induced calcium‐release. However, a direct examination of L‐type voltage‐gated calcium channels (VGCC) demonstrated that H2O2 did not increase the calcium influx through these channels. The H2O2 effect on mIPSC frequency was markedly reduced in the opisthotonus (Opt) mutant mice with a known deletion in the IP3R1 gene. We demonstrated that H2O2 increased presynaptic activity in the GABAergic interneurons by the release of calcium from the IP3R‐regulated intracellular pool. The presynaptic IP3R could emerge as a novel target for preventing H2O2‐induced synaptic plasticity in substantia gelatinosa leading to pathological pain states.
Potassium currents in the hair cells of vestibular epithelium: position‐dependent expression of two types of A channels
Authors: Russo Giancarlo , Calzi Daniela , Martini Marta , Rossi Maria Lisa , Fesce Riccardo , Prigioni Ivo 
Published: February 2007

AbstractThe complement of voltage‐dependent K+ currents was investigated in hair cells of the frog crista ampullaris. The currents were recorded in transversal slices of the peripheral, intermediate and central regions of the crista by applying the patch clamp technique to cells located at different positions in the slices. Voltage‐clamp recordings confirmed that cells located in each region have a distinctive complement of K+ channels. Detailed investigation of the currents in each region revealed that the complement of K+ channels in intermediate and central regions showed no variations among cells, whereas peripheral hair cells differed in the expression of two classes of A‐type currents. These currents showed different kinetics of inactivation as well as steady‐state inactivation properties. We termed these currents fast IA and slow IA based on their inactivation speed. The magnitude of both currents exhibited a significant gradient along the transversal axis of the peripheral regions. Fast IA magnitude was maximal in cells located in the external zone of the crista slice and decreased gradually to become very small in the median zone (centre) of the section, while the gradient of slow IA magnitude was reversed. A‐type currents appear to act as a transient buffer that opposes hair cell depolarization induced by positive current injections. However, fast IA is partially active at the cell resting potential, while slow IA can be recruited only following large hyperpolarizations. Thus, two types of A currents are differentially distributed in vestibular hair cells and have different roles in shaping receptor potential.
Nitrogenase gene expression in the Chesapeake Bay Estuary
Authors: Short Steven M. , Zehr Jonathan P. 
Published: February 2007

SummaryLike many estuaries, the Chesapeake Bay has pronounced gradients in salinity and nutrients. Previous studies have shown that there is a high diversity of nitrogenase (nifH) genes in the estuary, and that there are specific distributions of individual nifH phylotypes. In contrast to previous work that revealed the remarkable diversity of nifH phylotypes in the Chesapeake estuary, in this study of nifH expression we only detected two phylotypes, and both were phylogenetically related to cyanobacterial nifH genes. One of the phylotypes was closely related to a nifH sequence from the filamentous, heterocystous cyanobacterium Anabaena cylindrica, and was found at the head of the estuary. The other phylotype was found in a sample collected near the mouth of the estuary and was closely related to nifH sequences from Group A unicellular cyanobacteria, which has previously been reported in oceanic waters only. These nifH phylotypes had distinct patterns of expression that were restricted to different regions of the Chesapeake Bay. This study provides the first evidence of nifH expression in the Chesapeake Bay, and suggests that diazotrophic unicellular cyanobacteria have a broader distribution and activity than previously recognized.
Earthquake relief: Iranian nurses’ responses in Bam, 2003, and lessons learned
Authors: Nasrabadi A. N. , Naji H. , Mirzabeigi G. , Dadbakhs M. 
Published: February 2007

Background:  Man‐made or natural disasters appear to be occurring more frequently around the world. It is important that nurses in all specialties should be prepared to care for people affected by disasters.Aim:  To explore Iranian Registered Nurses’ experiences in disaster relief in the Bam earthquake, Iran in 2003.Methods:  This study was qualitative with 13 participant nurses. Data were obtained through semi‐structured serial interviews and analysed using the latent content method.Findings:  Three general themes emerged: (a) the need for previously prepared practical protocols, (b) the need for qualified and real teamworking in the situation, and (c) the need to establish periodic comprehensive training programmes in disaster relief nursing.Conclusion:  It has become urgent for health agencies and related public services to collaborate, and for all health professionals to become knowledgeable about disaster preparedness. Crisis management, which has become more prevalent for many organizations, is an important strategic initiative for nursing, helping them provide the infrastructure to respond effectively to emergencies and unpredictable events. It is important in today’s world that hospital and nursing organizations develop a strategic system to handle disaster situations.
Narrative inquiry into life experiences of refugee women and men
Authors: Pavlish C. 
Published: February 2007

Background:  Africa is the site of many refugee camps, and non‐governmental agencies are often responsible for providing programmes and services to improve refugees’ quality of life and health in temporary encampments. Rwanda hosts three refugee camps as a result of the 1994 genocide.Aim:  This research examines meaningful life experiences as narrated by women and men Congolese refugees residing in a refugee camp in Rwanda.Methods:  Two in‐depth interviews were conducted with 15 refugee men and 14 refugee women. Content in the research text was analysed separately by gender.Findings:  Women’s experiences revealed themes of leaving the good life behind, worrying about their daughters, feeling ambivalent about marriage and lacking hope. Men’s experiences revealed themes of leaving the good life behind, having no peace in the heart and fearing the future.Conclusions:  Listening to refugee voices in narrated life experiences provides an opportunity for non‐governmental organizations to create programmes and services that pertain closely to refugees’ life experiences.