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Abstract Background The genome of Paramecium tetraurelia, a unicellular model that belongs to the ciliate phylum, has been shaped by at least 3 successive whole genome duplications (WGD). These dramatic events, which have also been documented in plants, animals and fungi, are resolved over evolutionary time by the loss of one duplicate for the majority of genes. Thanks to a low rate of large scale genome rearrangement in Paramecium, an unprecedented large number of gene duplicates of different ages have been identified, making this organism an outstanding model to investigate the evolutionary consequences of polyploidization. The most recent WGD, with 51% of pre-duplication genes still in 2 copies, provides a snapshot of a phase of rapid gene loss that is not accessible in more ancient polyploids such as yeast. Results We designed a custom oligonucleotide microarray platform for P. tetraurelia genome-wide expression profiling and used the platform to measure gene expression during 1) the sexual cycle of autogamy, 2) growth of new cilia in response to deciliation and 3) biogenesis of secretory granules after massive exocytosis. Genes that are differentially expressed during these time course experiments have expression patterns consistent with a very low rate of subfunctionalization (partition of ancestral functions between duplicated genes) in particular since the most recent polyploidization event. Conclusions A public transcriptome resource is now available for Paramecium tetraurelia. The resource has been integrated into the ParameciumDB model organism database, providing searchable access to the data. The microarray platform, freely available through NimbleGen Systems, provides a robust, cost-effective approach for genome-wide expression profiling in P. tetraurelia. The expression data support previous studies showing that at short evolutionary times after a whole genome duplication, gene dosage balance constraints and not functional change are the major determinants of gene retention.

Background: Total intravenous anaesthesia guided by electroencephalography and neurophysiological monitoring may be used for carotid endarterectomy. Reduction of brain metabolic demand during cross-clamping of the internal carotid artery with propofol titrated to burst suppression requires effect-site concentrations that may delay emergence and interfere with intraoperative neurophysiological monitoring., Objective: To test the hypothesis that dexmedetomidine decreases the effect-site concentration of propofol required for burst-suppression in patients undergoing carotid endarterectomy., Design: Randomised controlled trial., Participants: Patients undergoing carotid endarterectomy., Setting: University Hospital of Berne, Switzerland, from October 2018 to September 2024., Interventions: Patients were randomised into a control ( n  = 23) and a dexmedetomidine groups ( n  = 22). Total intravenous anaesthesia was administered to both groups. Patients in the dexmedetomidine group received an intravenous bolus of dexmedetomidine (0.4 μg kg -1 over 10 min) before induction, followed by a continuous intravenous infusion (0.4 μg kg -1  h -1 ). The effect-site concentrations of propofol were titrated against frontal electroencephalography parameters. Burst suppression was induced with propofol during cross-clamping of the internal carotid artery., Outcome Measures: The primary outcome was the effect-site concentration of propofol required for burst-suppression. The secondary outcomes were the requirement for vasoactive substances, neurophysiological monitoring parameters, and postoperative delirium., Results: The effect-site concentration of propofol required for burst suppression was 4.0 μg ml -1 [3.50 to 4.90] (median [interquartile range]) in the dexmedetomidine group compared with 6.0 μg ml -1 [5.5 to 7.3] in the control group ( P  < 0.001). Less norepinephrine was required in the dexmedetomidine group (total 454 μg [246 to 818] compared with 1000 μg [444 to 1326] ( P  = 0.015) in the control group). Dexmedetomidine did not affect intraoperative neurophysiological monitoring., Conclusion: Co-administration of dexmedetomidine to total intravenous anaesthesia for carotid endarterectomy decreased the effect-site concentrations of propofol required for burst suppression by 33%. The propofol-sparing effect and peripheral alpha-agonism of dexmedetomidine may explain the reduced requirement for vasopressors., Trial Registration: Clinicaltrials.gov identifier: NCT04662177., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the European Society of Anaesthesiology and Intensive Care.)

Growth in the online survey market may be increasing response burden and possibly jeopardizing higher response rates. This meta-analysis evaluated survey trends over one decade (2011-2020) to determine: (1) changes in survey publication rates over time, (2) changes in response rates over time, (3) typical response rates within health sciences education research, (4) the factors influencing survey completion levels, and (5) common gaps in survey methods and outcomes reporting. Study I estimated survey publication trends between 2011 and 2020 using articles published in the top three health sciences education research journals. Study II searched the anatomical sciences education literature across six databases and extracted study/survey features and survey response rates. Time plots and a proportional meta-analysis were performed. Per 2926 research articles, the annual estimated proportion of studies with survey methodologies has remained constant, with no linear trend (p > 0.050) over time (Study I). Study II reported a pooled absolute response rate of 67% (95% CI = 63.9-69.0) across 360 studies (k), totaling 115,526 distributed surveys. Despite response rate oscillations over time, no significant linear trend (p = 0.995) was detected. Neither survey length, incentives, sponsorship, nor population type affected absolute response rates (p ≥ 0.070). Only 35% (120 of 339) of studies utilizing a Likert scale reported evidence of survey validity. Survey response rates and the prevalence of studies with survey methodologies have remained stable with no linear trends over time. We recommend researchers strive for a typical absolute response rate of 67% or higher and clearly document evidence of survey validity for empirical studies., (© 2023 American Association for Anatomy.)

Medical education has reported a shortage of anatomy educators since the 1960s. While the faculty pipeline has recently been explored, insights into retirement intentions, a key driver of faculty turnover, have yet to be investigated. With the mean age of anatomists rising, knowledge of retirement intentions among current educators is essential to understanding the anatomy educator shortage. This study explored the retirement intentions of current anatomy educators and their likely effects on the workforce. Surveys were distributed to department heads and the American Association for Anatomy (AAA) membership to inquire about job postings from 2018-2020 and retirement intentions, respectively. Department heads sought to fill open positions due to faculty retirements (36%, 15 of 42), faculty relocations/sabbaticals/new responsibilities (31%), and brand new positions (24%). The retirement intentions survey revealed that 61% (23 of 38) of faculty '55 and older' intend to retire within five years. Based on the extrapolation of AAA membership data, estimates suggest that almost twice as many anatomy faculty could retire per year (n = 40) over the next five years compared to the estimated number of annual PhD graduates (n = 22) likely to enter the workforce. Factors driving retirement intentions were overwhelmingly age and finances, followed by job satisfaction and family. The creation of new anatomy educator positions to address increased student enrollments and new health sciences programs is likely to place even greater strain on workforce demands., (© 2022 American Association for Anatomy.)

Emotion regulation has become ubiquitous in the study of psychopathology and a growing number of treatment outcome studies are collecting data on emotion regulation skill use. However, traditional measures of emotion regulation fail to capture important nuances in emotion regulation processes, their relationship to psychopathology, and how individuals use emotion regulation skills over time and across contexts. Novel methodologies are particularly needed for measuring emotion regulation in the context of treatment studies. In this article, we discuss a proposed methodology, the combination of ecological momentary assessment (EMA), and single-case experimental design (SCED), for measuring emotion regulation strategy use in the context of treatment outcome studies. To inform this discussion, we provide a brief overview of common approaches to assessing emotion regulation skill use in the context of treatment outcome research. We then describe the utility of intensive data capture (EMA) in the context of idiographic treatment studies (SCED), present a case study to illustrate the different uses of data collected through EMA in the context of a SCED study, and discuss considerations for implementing this method in clinical practice.

For over two centuries, the educational landscape both nationally and globally has changed tremendously. The more traditional teaching and learning resources and platforms, such as traditional textbooks, chalkboards and whiteboards, overhead transparency and carousel projectors, and traditional classroom settings, have been either replaced or supplemented in the anatomical sciences by integrated and virtual eBooks, online learning management (OLM) platforms, and virtual learning and meeting apps. Virtual teaching and learning, especially proliferated with the advent and aftermath of the COVID-19 pandemic, and institutions worldwide that had already been utilizing virtual class and lab sessions in their anatomy curricula expanded virtual course offerings. Many institutions have retained virtual course offerings even after the pandemic, given the distance learning benefits. The future of anatomy education holds many promising possibilities given the voracious speed with which technology is advancing. One such promising advancement is the full, seamless incorporation of virtual three-dimensional (3D) immersive and semi-immersive learning into anatomy laboratories and classroom settings globally as well as into students' laptops and handheld devices for easy use at home or anywhere., (© 2023. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

This chapter begins by exploring the current landscape of virtual and augmented reality technologies in a post-pandemic world and asserting the importance of virtual technologies that improve students' learning outcomes while also reducing costs. Next, the chapter describes clinical anatomy instruction concepts in medical education, including applied anatomy content knowledge, pedagogical anatomy content knowledge, and virtual stereoscopic visualization studies that exemplify these concept areas, respectively. The chapter then explores the concept of procedural training with a specific emphasis on virtual stereoscopic anatomy visualization studies that exemplify or have implications for procedural training in medical education. Subsequently, the chapter discusses the benefits and challenges as well as the potential future positive and negative implications of virtual stereoscopic visualizations in medical education before finally concluding with some pensive considerations for the present and future of anatomy education and training using virtual technologies., (© 2023. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

Background: Community Health Education (CHE) programs have been shown to be effective in relieving the burden on healthcare systems in Sub-Saharan Africa., Objective: This project aimed to determine the baseline level of health literacy, behavioral practices, and accessibility to resources in a set of 16 informal settlements located around Lagos, Nigeria in order to identify topics that should be emphasized in a new teaching curriculum directed at local Community Health Educators., Methods: In June of 2017, a unique cross-sectional survey composed of 37 questions was conducted in informal settlements around Lagos. Sites selected were areas in which future CHE trainings were planned to take place and survey participants were chosen by trained community health educators based on convenience sampling with snowball effect. Survey questions included both multiple-choice and open-ended questions and were asked in the local language. We collected demographic information and assessed health literacy, health behaviors, and community practices. Results were analyzed using descriptive statistics to assess for differences between demographic groups., Findings: Our survey collected 348 total responses. Respondents displayed a high level of knowledge regarding the benefits of hand washing (97.1%) and childhood immunizations (81.0%). Knowledge around infectious diseases and reproductive health was lower, including a large proportion of people (50%) incorrectly indicating that HIV could be spread through a mosquito bite. Malaria was reported to be the most prevalent disease affecting both adults (40.0%) and children (58.3%). Health access was limited, with most people not reporting access to a nearby health center (55.8%)., Conclusions: Areas of knowledge that should be emphasized in future versions of CHE training curricula include infectious diseases, reproductive health, and reinforcement of the importance of sanitation and clean water. The curriculum should address the reality of limited health access and develop strategies to improve this., Competing Interests: Dr. Shannon Galvin reports grants from Gilead, outside the submitted work., (Copyright: © 2020 The Author(s).)

Anatomical knowledge, such as gross anatomy, neuroanatomy, histology, and embryology, involve three-dimensional (3D) learning and interpretation. Virtual 3D models especially have been used in the anatomical sciences both as a supplement to traditional anatomical education with cadaveric specimens and as a substitute for cadavers at institutions that do not utilize human donors for educational purposes. This paper discusses the methods used to assess the models' validation and accuracy, as well as suggestions for the models' improvement. This paper also aims to describe students' learning of anatomy using stereoscopic 3D models and provides a summary of the results from the literature concerning students' performance outcomes using virtual stereoscopic models as well as both students' and experts' perceptions of their utilization. There have been mixed results in the literature concerning the effectiveness of virtual 3D anatomical models in general, but there is limited research on stereoscopic anatomical models specifically. Stereoscopic anatomical models have shown to improve the learning of students, particularly for the students with low spatial ability, and they have the potential to enhance students' understanding of 3D relationships.

We present the formulation, simulations, and results for multicomponent mutual diffusion coefficients in the warm, dense matter regime. While binary mixtures have received considerable attention for mass transport, far fewer studies have addressed ternary and more complex systems. We therefore explicitly examine ternary systems utilizing the Maxwell-Stefan formulation that relates diffusion to gradients in the chemical potential. Onsager coefficients then connect the macroscopic diffusion to microscopic particle motions, evinced in trajectories characterized by positions and velocities, through various autocorrelation functions (ACFs). These trajectories are generated by molecular dynamics (MD) simulations either through the Born-Oppenheimer approximation, which treats the ions classically and the electrons quantum-mechanically by an orbital-free density-functional theory, or through a classical MD approach with Yukawa pair-potentials, whose effective ionizations and electron screening length derive from quantal considerations. We employ the reference-mean form of the ACFs and determine the center-of-mass coefficients through a simple reference-frame-dependent similarity transformation. The Onsager terms in turn determine the mutual diffusion coefficients. We examine a representative sample of ternary mixtures as a function of density and temperature from those with only light elements (D-Li-C, D-Li-Al) to those with highly asymmetric mass components (D-Li-Cu, D-Li-Ag, H-C-Ag). We also follow trends in the diffusion as a function of number concentration and evaluated the efficacy of various approximations such as the Darken approximation.

We present an alternative method for interpreting the velocity autocorrelation function (VACF) of a fluid with application to extracting the entropy in a manner similar to the methods developed by Lin et al. [J. Chem. Phys. 119, 11792 (2003)]JCPSA60021-960610.1063/1.1624057 and improved upon by Desjarlais [Phys. Rev. E 88, 062145 (2013)]PLEEE81539-375510.1103/PhysRevE.88.062145. The liquid VACF is decomposed into two components, one gas and one solid, and each contribution's entropic portion is calculated. However, we fit both the gas and solid portions of the VACF in the time domain. This approach is applied to a single-component liquid (a two-phase model of liquid Al at the melt line) and two different two-component systems: a superionic-to-superionic (bcc to fcc) phase transition in H&#95;{2}O at high temperatures and pressures and a metastable liquid state of MgO. For all three examples, comparisons to existing results in the literature demonstrate the validity of our alternative.

We have performed finite-temperature density functional theory molecular dynamics simulations on dense methane, ammonia, and water mixtures (CH4:NH3:H2O) for various compositions and temperatures (2000 K ≤ T ≤ 10,000 K) that span a set of possible conditions in the interiors of ice-giant exoplanets. The equation-of-state, pair distribution functions, and bond autocorrelation functions (BACF) were used to probe the structure and dynamics of these complex fluids. In particular, an improvement to the choice of the cutoff in the BACF was developed that allowed analysis refinements for density and temperature effects. We note the relative changes in the nature of these systems engendered by variations in the concentration ratios. A basic tenet emerges from all these comparisons that varying the relative amounts of the three heavy components (C,N,O) can effect considerable changes in the nature of the fluid and may in turn have ramifications for the structure and composition of various planetary layers.

In the warm dense matter (WDM) regime, material properties like diffusion and viscosity can be obtained from lengthy quantum molecular dynamics simulations, where the quantum behavior of the electrons is represented using either Kohn-Sham or orbital-free density functional theory. To reduce the simulation duration, we fit the time dependence of the autocorrelation functions (ACFs) and then use the fit to find values of the diffusion and viscosity. This fitting procedure avoids noise in the long time behavior of the ACFs. We present a detailed analysis of the functional form used to fit the ACFs, which is always a more efficient means to obtain mass transport properties. We use the fits to estimate the statistical error of the transport properties. We apply this methodology to a dense correlated plasma of copper and a mixture of carbon and hydrogen. Both systems show structure in their ACFs and exhibit multiple time scales. The mixture contains different structural forms of the ACFs for each component in the mixture.

Polar molecules are desirable systems for quantum simulations and cold chemistry. Molecular ions are easily trapped, but a bias electric field applied to polarize them tends to accelerate them out of the trap. We present a general solution to this issue by rotating the bias field slowly enough for the molecular polarization axis to follow but rapidly enough for the ions to stay trapped. We demonstrate Ramsey spectroscopy between Stark-Zeeman sublevels in (180)Hf(19)F(+) with a coherence time of 100 milliseconds. Frequency shifts arising from well-controlled topological (Berry) phases are used to determine magnetic g factors. The rotating-bias-field technique may enable using trapped polar molecules for precision measurement and quantum information science, including the search for an electron electric dipole moment.

Gender differences have been observed in a number of aspects of the pharmacology of opiates, including their antinociceptive activity, discriminative stimulus properties, the generation of physical dependence, and their positive reinforcing properties. The current experiments were carried out to rigorously examine whether gender differences exist in the intravenous (IV) self-administration of opiates in an operant conditioning paradigm. Both dose-response analyses and the determination of the strength of the reinforcing properties of opiates using a "breakpoint" analysis were examined. We found strong gender differences in the IV self-administration of two mu opiate agonists-heroin and morphine. At a standard fixed ratio (FR) of responding, females consumed significantly greater amounts of heroin and morphine than did males in a dose-dependent fashion. In addition, females also showed much higher breakpoints than did males: the highest FR breakpoint achieved in females was more than double that observed in males and the frequency distribution of breakpoints was shifted significantly to the right in females when compared to males. These data collectively show that mu opiate agonists may serve as reinforcing agents in females over a broader dose range than males and that they also self-administer considerably more opiates on a milligram per kilogram basis. Finally, we conclude that they will also expend much greater effort in an operant conditioning task to obtain opiate reinforcement.

In earlier studies, it was shown that there were gender differences in several aspects of the pharmacological profile of morphine, including its antinociceptive activity, discriminative stimulus properties and its reinforcing effects. The purpose of the present studies was to examine whether there might also be gender-related differences in the development of physical dependence, as reflected in the expression of an opiate withdrawal syndrome upon cessation of chronic morphine administration. We found that a more severe spontaneous withdrawal syndrome was produced by chronic morphine injections or morphine pellet implantation in male rats than in females. The duration of the withdrawal syndrome was also longer. In contrast to our observations with spontaneous withdrawal, we found no gender differences in the naloxone-precipitated withdrawal syndrome induced by chronic morphine administration. These observations suggest that there are gender differences only in the expression of the spontaneous withdrawal syndrome, but not in the neuro-adaptive changes associated with the generation of physical dependence as reflected by naloxone-precipitated withdrawal.

We examined whether morphine administration to adult male rats adversely affected pregnancy outcome after mating with drug-naive females and at what point in the complex series of steps leading to viable offspring it exerted its actions. The results indicate that chronic paternal morphine exposure markedly influenced fertility measures in a number of important ways. There was a pronounced increase in pseudopregnancies in females mated with males treated chronically with morphine (40%) when compared to controls (<6%), indicating that vaginal penetration occurred, but successful impregnation failed; only 33% of matings between drug-naive females and morphine-treated males resulted in pregnancies, as compared to 74.5% in controls. In addition, there were fewer implantation sites in gravid females mated with morphine-treated males than in controls. Taken together, these observations suggest that morphine-exposed male rats were apparently able to copulate, but there was a failure in successful impregnation of the females. These findings suggest a primary defect in either the quality of male sexual behavior or a complete failure of the fertilization or conception processes in females mated with morphine-exposed males. This potentially important effect of paternal morphine administration on conception and/or preimplementation loss of embryos has not been previously noted and deserves more systematic study.

The purpose of the present studies was to determine the role of either the organizational or activational sex steroids in mediating the sex differences observed in morphine-induced antinociception in the rat. To examine the organizational aspects, male pups were castrated at postnatal days 1 and 2; females were masculinized by large doses of testosterone on postnatal days 1 and 2. Adult male and female rats were also castrated over a period of 2 months to examine the role of the acute activational effects of the opiates in the already sexually differentiated adult rat brain. The results of these studies demonstrate that there were no alterations in the sex differences in opiate analgesia in castrated adult male and female rats; thus, male- and female-specific responses to opiate-induced antinociception were maintained even in the absence of the acute membrane-mediated effects of sex steroids. On the other hand, in male rats, castrated at postnatal days 1 and 2, the morphine dose-response curve shifted markedly to the right and, in fact, was almost identical to that observed in untreated females. Conversely, in female rats, masculinized by large doses of testosterone early in prenatal life, the morphine dose-response curve shifted to the left, yielding a dose-response curve that resembled that in normal males. These results strongly suggest that the sex differences that have been observed in morphine-induced analgesia are due to the organizational effects of sex steroids in the developing rat brain, rather than their acute activational effects in adulthood.

The purpose of the present studies was to examine whether gender differences could be observed in an important aspect of morphine's pharmacology: its reinforcing properties. Our results showed that morphine served as a positive reinforcing agent in both male and female rats in a place conditioning paradigm, but that the dose-response curves displayed marked sex-related differences. At doses from 0.2 up to 10.0 mg/kg, morphine induced an equally strong preference for the drug-associated chamber in males and females. However, as the dose was increased from 10-17.5 mg/kg, morphine ceased to act as a positive reinforcer in males. In contrast, a very strong preference for the morphine-associated chamber was still observed in females at doses up to 30 mg/kg. No gender differences in the blood and brain levels of morphine were observed subsequent to morphine administration during the conditioning phase, suggesting that pharmacokinetic factors were not involved in the sex-related differences observed. Consequently, these results suggest that there are intrinsic sex-linked differences in the doses of morphine that can induce a preference for the drug-associated chamber in a place-conditioning paradigm that are most likely related to differences in the sensitivity of the central nervous system to morphine's reinforcing properties in males and females.

The aim of these studies was to examine the effects of imidazoles on testosterone secretion and testicular interstitial fluid (TIF) formation through measurement of serum LH, serum testosterone, TIF testosterone, and TIF volumes. Imidazole, 1-methylimidazole, 4-methylimidazole (4-MI), and ketoconazole, an oral imidazole antifungal agent, caused dose-dependent decreases in testosterone secretion and TIF formation. Imidazole, 2-methylimidazole, and 4-MI decreased LH secretion. 4-MI decreased testosterone secretion 1-6 h after injection, increased testosterone at 8-16 h, decreased LH secretion at 4 h, decreased TIF volumes at 1-8 h, and slightly increased TIF volumes at 24 h. 4-MI blocked the stimulatory effects of hCG on testosterone secretion and prevented an expected increase in LH secretion after the 4-MI-induced decrease in testosterone secretion. 4-MI also reversed the effects of three other stimulants of testosterone secretion that presumably act through three different testicular regulatory systems: N-methyl-D,L-aspartate, an excitatory amino acid; NG-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor; and naltrexone, an opioid antagonist. These results support the hypothesis that imidazoles inhibit testicular function and male reproductive function through inhibition of testosterone secretion, TIF formation, and LH secretion regulatory systems.

In earlier studies, it was shown that male rats were considerably more sensitive to the antinociceptive properties of morphine than females in several antinociceptive assays. The purpose of our studies was to examine whether these male-female differences might be due to differences in the blood and brain levels of morphine attained after its s.c. injection rather than to intrinsic differences in the central nervous system sensitivity to the drug. Our results confirmed that males were considerably more sensitive than females to the antinociceptive properties of morphine on the hot-plate test; the ED50 in males was approximately half that found in females. These sex differences were not unique to morphine because males were also more sensitive to the antinociceptive properties of the potent mu agonist, alfentanil. With respect to the pharmacokinetics of morphine, we found that there was a linear relationship in both males and females between the dose of morphine injected and the blood and brain levels achieved 60 min after the injection when the sex-linked differences in morphine-induced antinociception was greatest; no sex differences were found in the peak levels of morphine attained in blood or brain at any dose of morphine. Furthermore, there were no sex-linked differences in the elimination half-life of morphine from blood and, similarly, there were no differences in the disappearance of morphine from brain. On the basis of these data, it appears that the sex-related differences we have observed between males and females in the response to morphine's antinociceptive activity cannot be explained by differences in the pharmacokinetics of morphine. Rather, it appears that sex differences in morphine-induced antinociception are related to inherent differences in the sensitivity of the brain to morphine.

To examine interactions between alcohol and endogenous opioids in their suppressive effects on rat testicular function, the opioid antagonist naltrexone or the opioid agonist morphine was administered to adult male rats alone or in combination with alcohol. Serum testosterone, testicular interstitial fluid (TIF) testosterone, and TIF volumes were measured to assess testicular function. Naltrexone induced dose-dependent increases in serum and TIF testosterone levels without changes in TIF volume. Alcohol (0.5 g/kg) inhibited naltrexone-induced stimulation of testosterone secretion and shifted the naltrexone dose-response curve to the right. Conversely, naltrexone (0.05 mg/kg) inhibited alcohol-induced suppression of testosterone secretion and shifted the alcohol dose-response curve to the right. Relatively high doses of naltrexone (5 to 30 mg/kg) were needed to stimulate testosterone secretion maximally in rats treated with a low dose of alcohol (0.5 g/kg) and to stimulate normal levels of testosterone secretion in rats treated with a high dose of alcohol (2 g/kg). In addition, combined treatment with 1 and 30 mg/kg of naltrexone and 0.5 to 2 g/kg of alcohol did not alter blood alcohol concentrations significantly, suggesting that the interactions between alcohol and naltrexone were unrelated to gross changes in alcohol metabolism or bioavailability factors. Simultaneous treatments with a low dose of alcohol (0.3 g/kg), near the threshold of efficacy, and low-moderate doses of morphine (0.3 to 3 mg/kg) were not additive in suppressing testosterone secretion, compared with either agent alone. These results support the hypothesis that opioid antagonists can reverse the suppressive effect of alcohol on testicular steroidogenesis, but the results also suggest that endogenous opioids do not exclusively mediate alcohol's effects on testosterone secretion.

As part of an effort to examine gender-related differences in the abuse liability of morphine, the present parametric study was undertaken to systematically establish whether there are gender-related differences in the antinociceptive activity of morphine in rats. Our results showed that male rats were uniformly more sensitive to the antinociceptive properties of morphine than were females in three different assays, i.e., the hot-plate, tail-flick and abdominal-constriction tests. This enhanced sensitivity to morphine was reflected in the peak antinociceptive effect, the magnitude of antinociception (i.e., area under the time-action curve), the duration of the antinociceptive response and the 50% effective dose. These differences appear to reflect markedly enhanced central nervous system sensitivity to morphine in males, compared with females, because we observed no gender-linked differences in serum levels of morphine after its injection, at the time when peak antinociceptive effects were observed. Furthermore, these gender-related differences appear to be reflected in antinociception thought to be mediated by both spinal and supraspinal mechanisms. Finally, our results suggest that the acute effects of steroids play little role in the gender-related differences observed, because short-term castration did not alter the gender-related differences we observed. Rather, it appears more probable that the organizational effects of steroids during critical periods in development, which determine gender-related distinctions, may be significant in the male-female differences we have observed. In view of a great deal of largely anecdotal data for humans that suggest that there may be gender-related differences in the abuse liability of psychoactive substances, the model described in this paper may provide a means to examine this important issue.

These studies examined whether nitric oxide (NO) mediates opioid suppression of testicular steroidogenesis. Adult male rats were treated with various combinations of a NO synthase (NOS) inhibitor (NG-nitro-L-arginine methyl ester; NAME), a NO donor (isosorbide dinitrate; ISDN), an opioid agonist (morphine, and an opioid antagonist (naltrexone). Serum LH and testosterone and testicular interstitial fluid (TIF) testosterone concentrations were then measured. Inhibition of NO production by NAME reversed morphine-suppressed testosterone secretion; treatment with the NO donor, ISDN, reversed naltrexone-stimulated testosterone secretion. NAME did not alter morphine's effects on LH secretion and attenuated morphine's suppression of hCG-stimulated testosterone secretion, indicating that these effects occur directly in the testes and are not dependent on LH secretion. Even though these effects suggested possible interactions between NO and opioid systems, no additive or synergistic effects were found with suppressive combinations of morphine and ISDN, or with stimulatory combinations of naltrexone and NAME at does that had little effect on testosterone secretion when given alone. These results indicate that opioid and NO exert independent effects on testicular steroidogenesis through separate pathways or mechanisms and that NO does not mediate opioid-induced testicular suppression.

We have shown previously that chronic morphine administration to adolescent male rats produced a number of gender specific deficits in their offspring. The purpose of the present studies was to extend our earlier observations by examining the acute, direct effects of morphine exposure to male rats on their fertility and the development of viable offspring. Sexually mature male rats were injected with a single dose of morphine (25 mg/kg) and 24 hr later were bred with drug-naive females. Fertility rates (vaginal plugs and pregnancies) were monitored throughout the breeding period as was the development of the offspring. Our results showed that a large, acute dose of morphine given to drug-naive male rats 24 hr before the initiation of breeding had no effect on fertility rates, but produced several adverse effects on fetal outcome. Litter sizes in morphine-derived offspring were considerably smaller than in controls and mortality rates were more than 6 times higher. Moreover, morphine-derived male, but not female, offspring had a significantly enhanced sensitivity to the antinociceptive effects of morphine. Collectively, these data suggest that acute paternal morphine exposure just before breeding with drug-naive females had no effect on fertility, but exerted negative effects on the viability and development of their offspring. These results represent the most compelling evidence to date that paternal opiate exposure can adversely affect fetal outcome and are particularly striking in that they were produced by a single injection of morphine. We are aware of no animal studies, clinical cases or anecdotal reports in humans in which such a phenomenon has been described.

Evidence has been reported supporting the hypothesis that nitric oxide (NO) partially mediates the expression of morphine dependence. To examine whether NO-related agents also affect the expression of alcohol dependence, adult male rats were treated chronically with alcohol. Upon withdrawal of alcohol administration, abstinence signs were observed after treatment with a NO synthase (NOS) inhibitor, NG-nitro-L-arginine methyl ester (NAME), or a NO donor, isosorbide dinitrate (ISDN). Withdrawal severity was based primarily on the presence and intensity of tremors, rigidity, hyperactivity, and spontaneous and audiogenic convulsions. The NOS inhibitor, NAME (10-100 mg/kg), injected during alcohol withdrawal significantly inhibited withdrawal severity decreasing the intensity of signs of hyperactivity, tremors, and rigidity, but not affecting the occurrence of convulsions. The NO donor, ISDN (30 mg/kg), administered during alcohol withdrawal significantly increased the severity of most withdrawal signs. These results suggest that NO mediates some aspects of the expression of alcohol dependence.

To examine whether nitric oxide (NO) affects alcohol (ethanol) narcosis, adult male rats were pretreated with a NO synthase (NOS) inhibitor, NG-nitro-l-arginine methyl ester (NAME); a NOS substrate, l-arginine methyl ester (AME); or a NO donor, isosorbide dinitrate (ISDN); then treated with anesthetic doses (3-5 g/kg, ip) of alcohol. Pretreatment with NAME (30-100 mg/kg, sc) 40 min before alcohol treatment delayed the onset of alcohol-induced loss of the righting reflex (LORR) and increased the duration of the LORR. NAME (100 mg/kg) pretreatment combined with high doses of alcohol (4-5 g/kg) exerted significant lethal effects, even though treatment with either agent alone or NAME combined with lower doses of alcohol (3-3.5 g/kg) was not lethal. Simultaneous treatment with the NOS substrate AME (100 mg/kg, subcutaneous) blocked the effects of NAME on LORR duration times, but did not alter LORR onset times. The NO donor ISDN (30 mg/kg) given by oral gavage 2 hr before alcohol decreased LORR duration times without affecting the onset of LORR. In addition, ISDN dose-dependently inhibited NAME-induced LORR duration increases during alcohol narcosis without significantly altering LORR onset times. Neither ISDN nor NAME significantly altered blood alcohol concentrations. These results suggest that NOS inhibition and subsequent decreases in NO production enhance alcohol-induced narcosis and that increases in NO concentrations inhibit alcohol narcosis, supporting the hypothesis that inhibition of arginine-NOS-NO systems mediates part of the sedative-hypnotic effect of alcohol.

The effects of nitric oxide (NO)-related agents on testicular function were examined in male rats with measurements of serum luteinizing hormone, serum testosterone, testicular interstitial fluid (TIF) testosterone, and TIF volumes. Serum and TIF testosterone levels and luteinizing hormone secretion were significantly decreased by the NO donor, isosorbide dinitrate (ISDN), and the NO synthase (NOS) substrate, L-arginine methyl ester, a source for the endogenous production of NO. The effects of ISDN on TIF volumes were inconsistent, but L-arginine methyl ester decreased TIF formation in a dose-dependent manner. In addition, ISDN dose dependently suppressed testosterone secretion stimulated by human chorionic gonadotropin treatment, suggesting that the effects on testosterone secretion were independent of changes in secretion of the endogenous gonadotropin luteinizing hormone. ISDN, L-arginine methyl ester, and the endogenous NOS substrate L-arginine completely blocked testosterone secretion stimulated by the NOS inhibitor NG-nitro-L-arginine methyl ester (NAME), whereas the relatively inactive NOS substrate, D-arginine, only partially blocked NAME-stimulated testosterone secretion. Hydralazine and nicardipine, two vasodilators that do not exhibit prominent NO-related effects, also blocked basal testosterone secretion and testosterone secretion stimulated by the vasoconstrictor NAME.(ABSTRACT TRUNCATED AT 250 WORDS)

An acute injection of an intoxicating dose of alcohol to male rats 24 hours prior to breeding with drug-naive females produced no discernible effect on copulatory activity, as reflected in vaginal plugs, but resulted in markedly (> 50%) reduced pregnancy rates. Fetal outcome was also markedly affected in offspring sired by alcohol-treated males: litter sizes were appreciably smaller (30%) and fetal mortality was more than 2 times higher than in controls. These results suggest that paternal alcohol use, like maternal alcohol abuse, may adversely affect fertility and fetal outcome.

Although it is recognized that drugs ingested by pregnant females produce marked cognitive and physiological deficits in their offspring, the possibility that paternal exposure to drugs prior to mating may have adverse effects on fertility and fetal outcome has not received much attention. The purpose of the present studies was to examine whether a single, acute exposure to alcohol influences the subsequent ability of adult male rats to mate and produce healthy and viable litters. Our results showed that a relatively large dose of alcohol 24 hours prior to breeding had little effect on the mating behavior of male rats, but there were markedly fewer pregnancies in females mated with alcohol-exposed male rats than in controls. Of equal importance, we found that, even when conception occurred and live births were produced, there were striking differences in fetal outcome. Alcohol-treated males sired many fewer pups than control males and there was a markedly enhanced mortality rate in their offspring. Collectively, these data suggest that acute paternal alcohol administration 24 hours prior to breeding does not affect mating behavior, but results in a greatly diminished fertility rate and fewer and less viable offspring. These studies suggest that paternal alcohol use may be as important as maternal alcohol abuse as a negative variable in pregnancy and fetal outcome.

The effects of opioids on testicular function were assessed in the rat through measurements of serum testosterone levels, testicular interstitial fluid (TIF) formation and TIF testosterone levels after morphine and opioid antagonist (naloxone, naltrexone) treatment. Serum and TIF levels of testosterone were significantly decreased 1 to 6 h after morphine (10 mg/kg) injection, and TIF volumes were decreased 2-3 h after injection morphine. Each of these decreases was dose-related. In contrast to the effects of morphine, the opioid antagonist naloxone increased TIF testosterone but did not alter TIF volumes. Moreover, the opioid antagonist naltrexone totally blocked morphine's effects on both testosterone secretion and TIF volume, suggesting that morphine's testicular effects were mediated by naltrexone-sensitive opioid receptors in the testes. The possible role of morphine-induced reductions in gonadotropin secretion in morphine's testicular effects was also examined. Morphine suppressed testosterone secretion and TIF volumes after pretreatment with human chorionic gonadotropin, which reverses morphine's suppression of luteinizing hormone (LH). Our results, therefore, indicate that morphine exerts effects on testicular function that are independent of its effects on LH. They furthermore support the hypothesis that both endogenous and exogenous opioids disrupt two major aspects of testicular function: Testosterone secretion and TIF formation. Because of the role of TIF in maintaining testicular function, our results suggest that opioid-induced changes in testosterone secretion into TIF and TIF formation may, at least in part, explain the well-established effects of opioids on reproductive endocrinology and function in the male.

To examine whether nitric oxide (NO) mediates the suppression of testosterone secretion by alcohol (ethanol), adult male rats were pretreated with a NO synthase inhibitor, NG-nitro-L-arginine methyl ester (NAME), then treated with alcohol. Serum and testicular interstitial fluid (TIF) testosterone concentrations, serum luteinizing hormone (LH) concentrations, blood alcohol concentrations (BAC), and TIF volumes were measured 2 hr after alcohol treatment at a time of peak effects of alcohol and NAME on testosterone secretion. Pretreatment with NAME (30 or 100 mg/kg, subcutaneous) 30 min before alcohol treatment (0.5-3 g/kg, intraperitoneal) completely blocked the alcohol-induced suppression of testosterone secretion into the general circulation and into TIF without significantly altering blood alcohol concentrations (BAC) or TIF volumes. These results support the hypotheses that NO synthase inhibitors can antagonize alcohol-induced suppression of testicular steroidogenesis, that alcohol interacts with arginine-NO synthase systems that regulate testicular steroidogenesis, and that NO is involved in mediating alcohol's testicular and reproductive effects.

The hypothesis that an arginine-nitric oxide (NO) synthase-NO system mediates the morphine abstinence syndrome was tested in adult male rats implanted subcutaneously for 3 days with one morphine (75 mg) pellet followed by naloxone-precipitated withdrawal (0.5 mg/kg). Injection with a NO synthase inhibitor, NG-nitro-L-arginine methyl ester (NAME, 100 mg/kg subcutaneous), shortly before naloxone-induced withdrawal significantly inhibited abstinence signs by 25-80%. Continuous infusion of NAME via subcutaneous osmotic pumps during the development of morphine physical dependence and during naloxone-precipitated withdrawal also inhibited morphine abstinence signs. In addition, treatment with isosorbide dinitrate, a NO donor, induced a quasi morphine-abstinence syndrome (QMAS) that was significantly suppressed by implantation of a morphine pellet 3 days before isosorbide dinitrate treatment. These results indicate that NO mediates part of the expression of the morphine abstinence syndrome.

Pubescent (30 day old) male rats were maintained on an alcohol liquid diet containing 35% ethanol-derived calories (ALC) for 39 days or were pairfed an isocaloric control diet (PF). The concentration of alcohol in the diet was gradually increased to permit adaptation, then stabilized and then gradually tapered to prevent an alcohol withdrawal syndrome. Following a drug-free period (2 weeks), the males were mated with nontreated females. Offspring were evaluated on several developmental indices and on various learning/memory tasks to assess functional deficits in adulthood. Offspring sired by ALC-treated males did not differ from the offspring of PF males on several developmental parameters including body weights, when developmental landmarks appeared, or on tests of sensorimotor development. As adults, male offspring groups did not differ on tests of activity or on an object exploration/recognition task. However, male offspring of ALC-treated males demonstrated impaired acquisition performance (days and errors to criterion) on a win-shift spatial discrimination in an eight-arm radial maze and on a win-stay discrimination (days to criterion) conducted in a T-maze at a later age. The radial maze results were replicated in a subsequent experiment using different groups of rats.

The effects of chronic alcohol administration on reproductive endocrinology in the developing male rat were examined. Prepubescent male rats (25 days of age) were maintained on an alcohol liquid diet or were pair-fed a control diet until early adulthood and selected indices of sexual maturation were examined at weekly intervals. To determine whether sexually immature animals were more sensitive to the effects of alcohol than adults, fully mature male animals were exposed to an identical period of alcohol exposure and comparisons were made between the two groups. The results demonstrated that alcohol significantly affected many of the primary indices of puberty and sexual maturation. The normal pubertal increases in serum testosterone levels, the weights of the testes and secondary sex organs and beta-endorphin levels in the hypothalamus were substantially reduced in alcohol-exposed animals compared with controls. In contrast to these results, the effects of alcohol on reproductive endocrinology in the fully mature animal were transitory and of considerably less magnitude. After a 2-week alcohol-free period, male rats exposed to alcohol during development were bred with drug-naive primiparous females. Although the same number of pregnancies resulted from matings between alcohol-exposed males and drug-naive females compared with controls, litter sizes were significantly smaller in alcohol-derived offspring than in controls. In all other respects, such as body weights, sex ratios, mortality rates and gross developmental features (eye opening, incisor eruption and testes descent), alcohol-derived offspring were identical with controls. Upon closer examination, however, significant disturbances were detected in alcohol-derived male offspring.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of various agents on the specific tissue binding of 3H-naloxone and 3H-naltrexone were examined. In addition to the narcotics, alpha-adrenergic blockers and dopamine antagonists also significantly inhibited the specific bindings of these opiates. The binding of naloxone or naltrexone was not significantly altered by beta-adrenergic blockers, agents which block the effects of acetylcholine, serotonin and histamine at the receptor level, and a number of other drugs. Kinetic analyses revealed that the alpha-adrenergic and dopamine antagonists competitively inhibited the binding of naloxone. The results of these studies provide additional evidence for an interaction between the narcotics and catecholaminergic agents.

The effects of narcotics on several aspects of the hypothalamic-pituitary-gonadal axis were examined in the male rat. Our results indicate that a large number of narcotics acutely depress serum luteinizing hormone levels and that these reduced gonadotropin levels lead to a subsequent fall (1-2 hours later) in serum testosterone levels. The luteinizing hormone-depleting effect of the narcotics appears to represent a specific narcotic action since the (-)-isomers of the narcotics were much more effective than the ()-isomers, naloxone antagonized their effects and tolerance rapidly developed. Further, our studies indicate that the impairment of the functional and structural integrity of the secondary sex organs produced by chronic narcotic administration is not due to a direct effect of these drugs since they have no effect on the uptake of subcellular distribution of testosterone in the secondary sex organs or on the androgen-dependent accumulation of myo-inositol. Consequently, it appears that the testosterone depletion produced by the narcotics is solely responsible for their adverse effect on the secondary sex organs. The results of these studies suggest that the effects of the narcotics on the hypothalamic-pituitary-gonadal axis are confined to either the hypthalamus or the pituitary gland.

Morphine levels in rat brain were measured by the multiple ion detection method (mass fragmentography), using a computer-controlled gas chromatograph-mass spectrometer, and were correlated with the analgesic activity of the narcotic at intervals up to 6 hours after the injection. Morphine levels in brain reached a peak of 346 ng/g of tissue wet weight 30 minutes after the subcutaneous injection of 10 mg/kg of morphine sulfate and then declined rapidly over the next 3 hours. Between 3 and 6 hours after the injection of morphine, the brain concentration decreased slightly but was still readily detectable at 6 hours after injection. An excellent correlation (r = 0.923) was found between the concentration of morphine in brain and analgesic activity, as measured by the hot plate method. The multiple ion detection method for the measurement of morphine appears to meet all of the criteria necessary for any drug assay: sensitivity, specificity and ease of analysis.

It has been previously reported that the excitatory amino acid, N-methyl-D-aspartic acid (NMDA), elicits prompt increases in serum luteinizing hormone (LH) levels in young male rats. The present studies were carried out to determine whether the effects of NMDA on LH were mediated by the release of LHRH from the hypothalamus. We also examined whether NMDA-sensitive neuronal pathways interacted with the endogenous opioid system regulating LHRH release and the ontogeny of NMDA-evoked increases in serum LH. We found that the age-response curve for NMDA-induced increases in LH was an inverted U; at early ages (10 and 15 days) the amino acid was marginally effective in increasing LH levels, it became maximally effective from post-natal days 20-40 and thereafter rapidly lost its efficacy such that it was virtually inactive in adult animals. Dose-response curves revealed that adult animals were more than 10-fold less sensitive to NMDA than their younger counterparts. Our studies also demonstrated that NMDA increased LH via a direct effect on the hypothalamic release of LHRH since a potent LHRH antagonist competitively inhibited the effects of NMDA. Finally, we observed that morphine competitively inhibited the effects of NMDA on LH release, suggesting a relationship between NMDA-sensitive neuronal pathways and those endogenous opioid-containing systems which are known to regulate LH release.

The effects of ethanol and acetaldehyde on testicular steroidogenesis were examined. We found that ethanol markedly inhibited the gonadotropin-stimulated production of testosterone in enzymatically dispersed cell preparations of the testes of adult rats. The effects of ethanol on testicular steroidogenesis appeared to be noncompetitive since testosterone production could not be restored to nondrug-treated levels even by extremely high concentrations of gonadotropin. Acetaldehyde also inhibited testicular steroidogenesis in vitro but was between 1000 and 4000 times more effective than ethanol. As little as 50 microM acetaldehyde was effective in suppressing testicular steroidogenesis, whereas much higher (200 mM) concentrations of ethanol were required. Our results further demonstrated that cell viability was unaffected by incubation with very high concentrations of ethanol and acetaldehyde, indicating that the two drugs did not simply irreversibly impair the ability of the dispersed cells to appropriately respond to stimulation by gonadotropins. These results suggest that ethanol directly inhibits testicular steroidogenesis, but that acetaldehyde is much more potent.

The effects of a single injection of morphine (20 mg/kg) on serum testosterone levels were examined in the male rat. Within 2 hours after the morphine injection, testosterone levels were significantly lower than control levels. The decline in testosterone levels reached a maximum 4 hours after the administration of morphine, at which time testosterone levels were reduced by more than 85% with respect to controls. The ability of a large number of narcotics to depress serum testosterone levels, 4 hours after their administration, was also examined. All narcotics depressed testosterone levels significantly and their potency relative to morphine was comparable to that observed in several other preparations, such as the guinea-pig ileum and mouse vas deferens. The testosterone-depleting effects of the narcotics appear to represent specific narcotic effects since the (-)-isomers of the narcotics were considerably more potent than the (+)-isomers, naloxone competitively inhibited the effects of morphine on testosterone levels and tolerance developed to the testosterone-depleting effects of these drugs. Acute treatment with morphine also lowered serum luteinizing hormone levels, and this reduction preceded the fall in testosterone levels by 1 to 2 hours.

A case of an oral melanoma occurring simultaneously with an oral squamous carcinoma has been presented. This combination is not thought to have been reported in the literature before. The histologic diagnosis is discussed as are the incidence, prognosis, and possible treatment of oral melanoma.

In previous studies, it was demonstrated that morphine pellet implantation markedly sensitized adult male rats to the subsequent elevations in serum luteinizing hormone (LH) levels produced by the opiate antagonist, naloxone. The present studies were carried out to examine the persistence of this phenomenon upon pellet removal and to characterize the relationship between naloxone-induced alterations in serum LH and the development and dissipation of precipitated withdrawal behavior. We found an excellent correlation between both the development and dissipation of naloxone-precipitated withdrawal behavior and hypersensitivity to naloxone's effects on serum LH. However, although there was no evidence of protracted effects of chronic morphine administration upon pellet removal as assessed by withdrawal behavior, the effects of naloxone on serum LH levels did not return to normal for nearly a week postwithdrawal. The markedly enhanced sensitivity to naloxone normally observed in the pellet-implanted animal dissipated immediately after pellet removal (6-24 hr), but, rather than exhibiting normal levels of responding, morphine-withdrawn animals were markedly hypo-sensitive to naloxone. The antagonist did not increase LH at all in pellet-withdrawn animals and, in fact, appeared to depress them at many doses in the acutely withdrawn animal; normal responses did not return until 4 to 7 days after pellet removal. The mechanisms underlying the striking withdrawal-induced reversal of naloxone's effects on serum LH levels are presently unclear, but our data are consistent with the hypothesis that chronic morphine administration induces a fundamental change in the sensitivity of the endogenous opioid-mediated control of LH, which takes some time to revert to normal upon abrupt termination of opiate administration.