The effects of ghrelin and LEAP-2 in energy homeostasis are modulated by thermoneutrality, high-fat diet and aging.

PURPOSE: Liver-expressed antimicrobial peptide 2 (LEAP-2) has been recently identified as the endogenous non-competitive allosteric antagonist of the growth hormone secretagogue receptor 1a (GHSR1a). In rodents, LEAP-2 blunts ghrelin-induced feeding and its plasma levels are modulated in response to nutritional status, being decreased upon fasting and increased in high-fat diet (HFD) fed mice. Clinical data support the regulation of circulating LEAP-2 by nutrient availability in humans. In this work, our primary objective was to examine the chronic effects of ghrelin and LEAP-2 administration on food intake, adiposity, and energy expenditure in young mice subjected to standard and HFD at both room temperature and at thermoneutrality. Furthermore, we aimed to assess the impact of these two hormones on aging mice. RESULTS: Our results indicate that LEAP-2 produces a significant decrease of body weight and adiposity, an increase in energy expenditure, and activation of the thermogenic program in white and brown adipose tissue depots. However, this effect is not maintained under HFD or under thermoneutral conditions and is only partially observed in aging mice. CONCLUSION: In summary our studies describe the central effects of LEAP-2 within distinct experimental contexts, and contribute to the comprehension of LEAP-2's role in energy metabolism.

Personalized embryo transfer guided by endometrial receptivity analysis: a systematic review with meta-analysis.

STUDY QUESTION: Does a personalized embryo transfer (pET) guided by tests for endometrial receptivity (TER) increase the effectiveness of ART procedures? SUMMARY ANSWER: The use of TER-guided pET is not supported by current published evidence in women without repeated implantation failure (RIF), while in women with RIF more research is needed to assess a potential benefit. WHAT IS KNOWN ALREADY: Implantation rates are still far from ideal, especially in some patients that have RIF with good-quality embryos. As a potential solution, a wide range of diverse TER use different sets of genes to identify displacements of the window of implantation to adjust the individual length of progesterone exposure in a pET. STUDY DESIGN, SIZE, DURATION: A systematic review with meta-analysis was performed. Search terms included endometrial receptivity analysis, ERA, personalized embryo transfer. CENTRAL, PubMed, Embase, reference lists, clinical trials registers, and conference proceedings (search date October 2022) were searched, with no language restrictions. PARTICIPANTS/MATERIALS, SETTING, METHODS: Randomized controlled trials (RCTs) and cohort studies comparing a pET guided by TER vs standard embryo transfer (sET) in different subgroups that undergo ART were identified. We also investigated pET in non-receptive-TER vs sET in receptive-TER, and pET in a specific population vs sET in a general population. Risk of bias (RoB) was assessed with the Cochrane tool and ROBINS-I. Only those with low/moderate RoB underwent meta-analysis. The GRADE approach was used to evaluate the certainty of evidence (CoE). MAIN RESULTS AND THE ROLE OF CHANCE: We screened 2136 studies and included 35 (85% used ERA and 15% used other TER). Two studies were RCTs comparing endometrial receptivity analysis (ERA)-guided pET vs sET in women with no history of RIF. In women without RIF, no important differences (moderate-CoE) were found in live birth rates and clinical pregnancy rates (CPR). We also performed a meta-analysis of four cohort studies that were adjusted for confounding. In agreement with the RCTs, no benefits were found in women without RIF. However, in women with RIF, low CoE suggests that pET might improve the CPR (OR 2.50, 95% CI 1.42-4.40). LIMITATIONS, REASONS FOR CAUTION: We found few studies with low RoB. Only two RCTs in women without RIF were published, and none in women with RIF. Furthermore, the heterogeneity observed in populations, interventions, co-interventions, outcomes, comparisons, and procedures limited the pooling of many of the included studies. WIDER IMPLICATIONS OF THE FINDINGS: In the population of women without RIF, in agreement with previously published reviews, pET did not prove to be more effective than sET and, therefore, it precludes the routine use of this strategy in this population until more evidence is available. However, more research is advisable in women with RIF as low-certainty evidence from observational studies adjusted for confounders suggests that the CPR might be higher with pET guided by TER in this population. Although this review presents the best available evidence, it is still insufficient to change current policies. STUDY FUNDING/COMPETING INTEREST(S): No specific funding was obtained for this study. There are no conflicts of interest to declare. REGISTRATION NUMBER: PROSPERO CRD42022299827.

3D Synaptic Organization of the Rat CA1 and Alterations Induced by Cocaine Self-Administration.

The hippocampus plays a key role in contextual conditioning and has been proposed as an important component of the cocaine addiction brain circuit. To gain knowledge about cocaine-induced alterations in this circuit, we used focused ion beam milling/scanning electron microscopy to reveal and quantify the three-dimensional synaptic organization of the neuropil of the stratum radiatum of the rat CA1, under normal circumstances and after cocaine-self administration (SA). Most synapses are asymmetric (excitatory), macular-shaped, and in contact with dendritic spine heads. After cocaine-SA, the size and the complexity of the shape of both asymmetric and symmetric (inhibitory) synapses increased but no changes were observed in the synaptic density. This work constitutes the first detailed report on the 3D synaptic organization in the stratum radiatum of the CA1 field of cocaine-SA rats. Our data contribute to the elucidation of the normal and altered synaptic organization of the hippocampus, which is crucial for better understanding the neurobiological mechanisms underlying cocaine addiction.

Schedule-induced polydipsia is associated with increased spine density in dorsolateral striatum neurons.

Schedule-induced polydipsia (SIP) is an adjunctive behavior in which rats exhibit excessive drinking as a consequence of intermittent feeding, and it has been proposed as a candidate model to study the development of compulsive and repetitive behavior. Although several brain structures are involved in compulsive behavior, it has been suggested that alterations in fronto-striatal circuits may underlie compulsive spectrum disorders. In the present work, we examined whether SIP would induce modifications in dorsolateral striatum (DLS) and anterior prefrontal cortex (aPFC) neurons. Specifically, the effects of 20 sessions of SIP were determined in the dendrites of DLS medium spiny neurons and in the basal dendritic arbors of layer V pyramidal cells in the aPFC. The structure, size and branching complexity in aPFC neurons were also studied. Results showed that SIP resulted in an increase in dendritic spine density in DLS neurons. Moreover, dendritic spine density was highly correlated with the level of drinking in animals subjected to SIP. By contrast, we observed no differences either in dendritic spine density or in the morphological structure of the dendrites of the aPFC in SIP rats compared to their control counterparts. We hypothesize that SIP-induced structural plasticity in DLS neurons could be related to inflexible response in compulsive behavior. The findings of this study could provide new insights into the involvement of particular cell populations of the dorsolateral striatum and anterior prefrontal cortex regions in compulsive spectrum disorders.

Cocaine facilitates protein synthesis-dependent LTP: the role of metabotropic glutamate receptors.

Cocaine addiction alters synaptic plasticity in many brain areas involved in learning and memory processes, including the hippocampus. Long-term potentiation (LTP) is one of the best studied examples of hippocampal synaptic plasticity and it is considered as one of the molecular basis of learning and memory. We previously demonstrated that in the presence of cocaine, a long lasting form of hippocampal LTP is induced by a single pulse of high frequency stimulation, which in normal conditions evokes only an early form of LTP. In this study, we further explore the molecular basis of this modulation of synaptic plasticity by cocaine. By performing pharmacological experiments on hippocampal slices, we were able to show that cocaine converts early LTP to a form of LTP dependent on protein synthesis, probably through the cAMP-dependent protein kinase and extracellular signal-regulated kinase signaling cascades. We also found that metabotropic glutamate receptors are involved in this phenomenon. These studies further clarify the molecular machinery used by cocaine to alter synaptic plasticity and modulate learning and memory processes.

Differential gene expression in the nucleus accumbens and frontal cortex of lewis and Fischer 344 rats relevant to drug addiction.

Drug addiction results from the interplay between social and biological factors. Among these, genetic variables play a major role. The use of genetically related inbred rat strains that differ in their preference for drugs of abuse is one approach of great importance to explore genetic determinants. Lewis and Fischer 344 rats have been extensively studied and it has been shown that the Lewis strain is especially vulnerable to the addictive properties of several drugs when compared with the Fischer 344 strain. Here, we have used microarrays to analyze gene expression profiles in the frontal cortex and nucleus accumbens of Lewis and Fischer 344 rats. Our results show that only a very limited group of genes were differentially expressed in Lewis rats when compared with the Fischer 344 strain. The genes that were induced in the Lewis strain were related to oxygen transport, neurotransmitter processing and fatty acid metabolism. On the contrary genes that were repressed in Lewis rats were involved in physiological functions such as drug and proton transport, oligodendrocyte survival and lipid catabolism.These data might be useful for the identification of genes which could be potential markers of the vulnerability to the addictive properties of drugs of abuse.

Depotentiation of hippocampal long-term potentiation depends on genetic background and is modulated by cocaine self-administration.

Lewis (LEW) and Fischer 344 (F344) rats differ in their response to drugs and are frequently used as an experimental model to study vulnerability to drug addiction. We have previously reported that significant differences in hippocampal synaptic plasticity exist between LEW and F344 rats after non-contingent chronic cocaine administration. However, given the several biochemical differences between contingent and non-contingent administration of drugs, we have studied here the possible genetic differences in synaptic plasticity after contingent cocaine self-administration. LEW and F344 animals self-administered cocaine (1 mg/kg i.v.) or saline under a fixed ratio 1 schedule of reinforcement for 20 days. After self-administration, electrophysiological experiments were carried out in which hippocampal slices were tetanized with three high frequency pulses in order to induce long-term potentiation (LTP). After a 20 min period of LTP stabilization, a train of low frequency stimulation (LFS; 900 pulses, 1 Hz) was applied to induce depotentiation of LTP. Data showed no differences between cocaine self-administered LEW or F344 rats in the induction of saturated-LTP compared to saline animals. LEW saline self-administered rats showed normal LTP depotentiation whereas cocaine self-administration impaired depotentiation in this rat strain. In the F344 strain, depotentiation of saturated-LTP was impaired both in saline and cocaine self-administered rats. The present results corroborate previous findings showing differences in basal hippocampal synaptic plasticity between LEW and F344 rats. These differences seem to modulate cocaine effects in a manner independent of contingency of drug administration.

Chronic periadolescent cannabinoid treatment enhances adult hippocampal PSA-NCAM expression in male Wistar rats but only has marginal effects on anxiety, learning and memory.

Pubertal and adolescent exposure to cannabinoids is associated with enduring alterations in anxiety and memory. However, periadolescence virtually remains unexplored. Here, we measured anxiety in the Elevated Plus Maze (EPM) in adult Wistar rats treated at periadolescence (P28-P38) with the cannabinoid agonist CP 55,940 (CP) (0.4 mg/kg; 2 ml/kg i.p., 1 daily injection), and we also defined their recognition memory in the novel object paradigm and spatial learning and memory in the water maze. Additionally, we measured the expression of hippocampal PSA-NCAM (Polysialic Acid-Neural Cell Adhesion Molecule) and long-term potentiation (LTP) as well as, given their role in mnemonic processing, the levels of plasma corticosterone and estradiol. We found that CP had no robust effects on anxiety or in recognition memory. In the water maze, only a slight decreased percentage of failed trials in the reference memory task and an improvement in an indirect index of attention were observed. However, we detected an up-regulation of hippocampal PSA-NCAM expression, only in CP-males, although this effect was not related to changes in LTP. No hormonal alterations were evident. Based on our data, minimal long-term effects on anxiety, learning and memory appear to result from cannabinoid exposure during the periadolescent period.

Glutamate and aspartate levels in the nucleus accumbens during cocaine self-administration and extinction: a time course microdialysis study.

RATIONALE: Accumbal excitatory amino acid (EAA) transmission has been implicated in cocaine addiction. However, the time course effects of extinction of cocaine self-administration on EAAs are unknown. OBJECTIVES: The objective of this study was to define the time course of cocaine self-administration and extinction effects on glutamate and aspartate levels in the nucleus accumbens. MATERIALS AND METHODS: Rats were trained to self-administer cocaine for 20 days, and the levels of extracellular glutamate and aspartate were measured by in vivo microdialysis both during cocaine self-administration and after a priming cocaine injection at different time points after extinction (1, 5, or 10 days). A food-reinforced control group was also included in this study. Furthermore, the effect of acute i.v. cocaine administration (0, 1, 2, or 4 mg/kg) on glutamate and aspartate levels was also evaluated. RESULTS: At any of the dose tested, acute i.v. cocaine did not affect the levels of glutamate or aspartate in the Nacc. In contrast, glutamate levels were reduced in animals trained to self-administer cocaine, although they augmented substantially during a subsequent session of cocaine self-administration, and similar changes were not observed in food-reinforced controls. After 1 or 5, but not after 10 days of extinction, the glutamate levels were also reduced, and the ability of i.v. cocaine priming injections to increase glutamate levels followed a similar time course. These effects were specific, as aspartate levels were not affected by any administration protocol. CONCLUSIONS: These data suggest that glutamatergic transmission could be involved in the maintenance of cocaine self-administration and in the early phases of abstinence.

Cocaine self-administration improves performance in a highly demanding water maze task.

RATIONALE: Long-term potentiation (LTP) is considered to be a cellular substrate of learning and memory. Indeed, the involvement of LTP-like mechanisms in spatial learning has consistently been demonstrated in the Morris water maze test. We have previously shown that hippocampal LTP in Lewis rats was modulated by cocaine self-administration, although the performance of cocaine-self-administered rats in the Morris water maze was not altered. OBJECTIVE: Given that the ease of the task previously used could have masked any possible effects of the cocaine-induced LTP enhancement on spatial learning, a new and more difficult water maze task was devised to address this issue. MATERIALS AND METHODS: Animals self-administered cocaine (1 mg/kg) or saline under a fixed ratio 1 schedule of reinforcement for 22 days. Spatial learning was assessed in a difficult water maze task (four sessions, two trials per session with a 90-min intertrial interval), and spatial memory was also evaluated 48 h after training (a 90-s test). Additionally, reversal learning and perseverance were also studied. RESULTS: There was a reduced latency in finding the hidden platform during training, as well as improved memory of the platform location in cocaine-self-administered rats with respect to animals that self-administered saline. No differences were observed in reversal learning or perseverance between groups. CONCLUSIONS: Our data suggest that cocaine self-administration facilitates learning and memory in the water maze test only when animals are submitted to highly demanding tasks, involving working memory or consolidation-like processes during the intertrial interval.

The effects of morphine self-administration on cortical pyramidal cell structure in addiction-prone lewis rats.

The consumption of drugs of abuse provokes sensitization, the development of tolerance, dependency, and eventually addiction. It is thought that these events are partially a consequence of drug-induced alterations in the organization of neuronal circuits in specific areas of the brain. In the present study, we have used intracellular injections of lucifer yellow to examine the alterations that may occur in cortical pyramidal neurons of addiction-prone Lewis rats following 15 days of self-administration of morphine. Specifically, the effects of morphine on the structure, size and branching complexity of the basal dendrites, and spine density were determined in the basal dendritic arbors of layer III pyramidal neurons in both the prelimbic and motor cortex. We found that following morphine self-administration, there was a reduction in the size and branching complexity of the dendritic arbors of pyramidal cells in the motor cortex. In contrast, prelimbic pyramidal neurons from these morphine-treated animals had larger and longer basal dendritic arbors. Furthermore, the spine density on pyramidal neurons was higher in both cortical regions of morphine self-administered rats. These results suggest that at least part of the behavioral changes produced by repeated opiate administration may be attributed to alterations in pyramidal cell structure.

Hippocampal synaptic plasticity and water maze learning in cocaine self-administered rats.

Previously, we have shown that long-term potentiation (LTP) in hippocampus of Lewis rats was significantly modulated by cocaine self-administration. Using a single train of high-frequency stimulation of 100 Hz for 1s (HFS), we found an enhancement of LTP after cocaine self-administration that was maintained even during the extinction of this behavior. However, the effects of cocaine self-administration on a hippocampal-dependent spatial learning task were unknown. Therefore, in the present study our first objective was to analyze if cocaine self-administration might affect the performance in a hippocampus-dependent task, such as the Morris water maze test. Male adult Lewis (LEW) rats self-administered cocaine (1 mg/kg/injection) or saline (0.9% NaCl) for 3 weeks. Three hours after finishing the last self-administration session, animals were submitted to Morris water maze training for 3 consecutives days. A memory test was carried out 24 h after the last training session. No significant differences were found in escape latencies and time spent in the quadrant where the platform was located during training. Given that we did not find any cocaine effect on this spatial learning task, our second objective was to estimate indirectly if brain cocaine levels have failed to modulate LTP in animals that were performing the water maze trials. To this end, we tested if cocaine application to hippocampal slices of naïve subjects was able to evoke LTP. The results indicated that cocaine produced an enhanced LTP in these hippocampal slices. Taking together, the results of the present study suggest that hippocampal LTP-like processes generated after cocaine self-administration are not related to spatial learning hippocampal-dependent tasks, such as the water maze test.

HPLC method development for testosterone propionate and cipionate in oil-based injectables.

Two isocratic liquid chromatographic methods for the determination of testosterone propionate (TP) and cipionate (TC) in oil-based injectables using methyltestosterone and bolasterone as internal standards, respectively, have been developed and validated. Mobile phases 57% water:acetonitrile 43% (v:v) and 54% water:acetonitrile 46% (v:v) were used for TP and TC, respectively. For both methods, a bonded-silica Luna CN (250 mm x 4.6 mm i.d., 5 microm) (25 degrees C) column, a flow-rate 1 ml min(-1) and UV absorbance detection at 245 nm were used and two separations up to base line were achieved. Prior to HPLC analysis, sample preparation was required, including extraction of TP and TC from oil-based injectables using the surfactant sodium dodecyl sulphate.

[Dermatophytes isolated in Hospital Universitario 12 de Octubre (Madrid, Spain).]. / Cambios epidemiológicos observados en un decenio en las dermatofitosis del hospital universitario 12 de Octubre de Madrid: nuevas especies emergentes.

Over a 10 year period (January 1988 - December 1997), 3,241 dermatophyte strains were isolated from 18,465 specimens from patients in whom dermatophytosis was suspected clinically. This represents a 17.5% rate of isolation. Trichophyton rubrum (38.44%), Microsporum canis (28.75%), Epidermophyton floccosum (14.5%) and Trichophyton mentagrophytes (13.5%) were the dominant species, and Trichophyton tonsurans (2.09%) has emerged, whilst in the previous decade it had virtually disappeared. Our study is basically based on an out-patient selected population, and tinea corporis (30.79%), followed by tinea cruris (16.69%) and tinea unguium (16.69%) were the most prevalent clinical forms.

Widespread dermatophytosis due to Microsporum (Trichophyton) gallinae in a patient with AIDS--a case report from Spain.

We report the case of a 25-year-old, HIV-positive patient (group IV, A, C2 clinical stage) with a widespread dermatophyte infection. He was a male gypsy with a known history of intravenous drug abuse. After an episode of cerebral toxoplasmosis for which he was treated with systemic steroids (because of cerebral oedema) he developed, over 16 days, a remarkably extensive ringworm of the trunk due to an unusual zoophilic dermatophyte, Microsporum (Trichophyton) gallinae. Human infection with this dermatophyte species is unusual: there are as few as seven proven reported cases, all of whom had localized lesions. This is the first widespread and severe case reported in man and also the first reported from Spain.

Review of dermatophytoses in Galicia from 1951 to 1987, and comparison with other areas of Spain.

We have reviewed all the dermatophytoses diagnosed in Galicia during four consecutive 9-year periods 1951-86 and 1987. From 4571 patients, we isolated 3351 fungal strains belonging, in decreasing order of frequency, to the following dermatophyte species: Microsporum canis (25.5%), Trichophyton rubrum (24.6%), T. mentagrophytes (21.4%), Epidermophyton floccosum (11.8%), M. gypseum (5.2%), T. tonsurans (3.9%), T. verrucosum (3.1%), T. schoenlenii (2.5%), T. violaceum (1.2%), T. mengninii (0.3%), M. audouinii (0.2%), T. equinum (0.1%) and T. soudanense (0.1%). Tinea capitis has diminished in frequency since 1951, though there was been a slight increase since 1978; M. canis has always been the most common agent, and between 1951 and 1959 T. schoenleinii was also very frequent but is no longer found. The frequency of tinea corporis, on the other hand, has experienced a considerable increase. Its most common causal agents in the last few years have been T. mentagrophytes, M. canis and T. rubrum. Until 1977 the most common tinea cruris dermatophyte was E. floccosum, but since then it has been T. rubrum. The commonest tinea pedis dermatophytes have been T. rubrum and T. mentagrophytes. Tinea unguium and tinea barbae have been the most frequent dermatophytoses, and their commonest causal agents T. rubrum and T. mentagrophytes respectively. We have documented the distribution of the various causal agents by location of the lesions, age and source of the patients (private or National Health Service patients), and we have compared the results with those obtained in other regions of Spain.

Some remarks concerning Trichophyton proliferans.

We have had the opportunity to study an dermatophyte isolated from the face of a woman, as a result of a fall on the ground. We identified the strain as Trichophyton proliferans whose characteristics, together with a review of the works published about this dermatophyte, lead us to believe that we are dealing with an independent species and not a synonym of T. mentagrophytes var. erinacei.

[Mycoses caused by Trichophyton megninii in Galicia (with review of the taxonomy of this dermatophyte)]. / Las micosis por trichophyton megninii en galicia (con revisión de la taxonomia de este dermatofito).

The taxonomy of the dermatophyte Trichophyton megninii has been the subject of much discussion since it was first isolated by Sabouraud in 1893. Initially he named it Trichophyton à culture rose and later T. rosaceum. It has been confused with the Microsporum (Epidermophyton) gallinae described by Megnin. Nowadays most mycologists consider T. rosaceum to be a synonym of the T. megninii, although some French authors still use Sabouraud's denomination. It is an exclusively anthropophilic dermatophyte with a broad geographic distribution, but in general a low incidence in most countries, except in Portugal, Corsica and Sardinia where it causes infections of both hairy and glabrous skin zones and nails in humans. T. megninii is an uncommon cause of ringworm in Spain and is mainly restricted to Galicia, and even there the incidence is low; it has been isolated only five times in our clinical practice with two more cases described previously in the literature, and predominantly affects females. Case reports show that it produces slowly evolving lesions with little local symptomatology on the scalp and is recalcitrant to conventional antifungal treatment. Its identification in culture should be based on the macroscopical appearance of the colony and by its absolute requirement for 1-histidine.