Stanley J. Nazian

Comparison of trait and ability measures of emotional intelligence in medical students

Context  Emotional intelligence (EI), the ability to perceive emotions in the self and others, and to understand, regulate and use such information in productive ways, is believed to be important in health care delivery for both recipients and providers of health care. There are two types of EI measure: ability and trait. Ability and trait measures differ in terms of both the definition of constructs and the methods of assessment. Ability measures conceive of EI as a capacity that spans the border between reason and feeling. Items on such a measure include showing a person a picture of a face and asking what emotion the pictured person is feeling; such items are scored by comparing the test‐taker’s response to a keyed emotion. Trait measures include a very large array of non‐cognitive abilities related to success, such as self‐control. Items on such measures ask individuals to rate themselves on such statements as: ‘I generally know what other people are feeling.’ Items are scored by giving higher scores to greater self‐assessments. We compared one of each type of test with the other for evidence of reliability, convergence and overlap with personality.

Corticosterone-attenuating and anxiolytic properties of mecamylamine in the rat

1. The available evidence suggests that stress induced release of acetylcholine (ACh) in the brain has a significant role in mediating neuroendocrine, emotional, and physiological responses to stress. Recent findings also suggest that stress indirectly (via acetylcholine) and nicotine directly stimulates the HPA axis through activation of nAChRs. 2. Our working hypothesis is that under stressful conditions, nicotinic receptor antagonists, such as mecamylamine, should act to attenuate the activation of the HPA axis and exhibit anxiolytic behavioral effects. The purpose of this study was to determine whether or not mecamylamine would: a) produce anxiolytic effects in rats on the elevated plus maze and b) blunt the plasma corticosterone response to predator stress in rats. 3. Results suggested that mecamylamine has anxiolytic properties under stressful conditions. In the EPM experiment, mecamylamine (0.3 mg/kg) produced increased time spent in the open arms. Similarly, in the predator stressor experiment, mecamylamine blunted the stress-induced plasma corticosterone response, with the lowest dose of mecamylamine (0.1 mg/kg). 4. These findings may have important therapeutic implications since clinical observations have shown that low doses of mecamylamine reduce tension and anxiety in patients with Tourette syndrome.

Hypothalamic, Pituitary, Testicular, and Secondary Organ Functions and Interactions During the Sexual Maturation of the Male Rat

Puberty in the male rat is a complex process that involves maturational changes in the hypothalamus, pituitary, testes, and secondary sexual organs and in their interrelationships. During the course of sexual maturation the negative feedback control systems for the gonadotropins become less responsive to testosterone while the testes become more responsive to LH. In the immature rat testosterone can potentiate the effect of LH--RH on pituitary LH release; this response is lost with sexual maturation. LH--RH sensitizes the mature male pituitary glands for subsequent LH--RH administration; this self-priming effect is not present in the immature rat. The responsiveness of the secondary organs to testosterone is also altered with age, as is the relative proportion of testosterone and androstendione secreted by the testes. Experiments designed to prevent or mimic the transition in testicular steroid secretion suggest that it may be a critical component of sexual maturation in the male rat. An elevation in androstendione appears to be capable of delaying the maturation of the LH negative feedback system, the prostate gland, and the LH--RH self-priming effect.

Sexual maturation of the male rat. Influence of androgens on the pituitary response to single or multiple injections of LH-RH.

In an attempt to mimic the events surrounding the natural onset of puberty in the male rat, animals were castrated and implanted with Silastic capsules filled with testosterone (T). Capsule size was adjusted to maintain serum-luteinizing hormone (LH) at sham-castrated values. To these animals implanted with T capsules, androstenedione (delta 4), 5 alpha-androstane-17 beta-ol-3-one (DHT), 5 alpha-androstane-3 alpha-17 beta-diol (3 alpha-OL) or T were administered by subcutaneous injections (40 micrograms/100 g body weight). 12 h later, the animals received an intravenous injection of 50 ng LH-RH. Pre- and post-LH-RH injection blood samples were assayed for serum content of LH and follicle-stimulating hormone (FSH) by radioimmunoassay. Compared to sham animals, prepubertal males showed a potentiation in the LH response with testosterone alone. This effect was not prevented by delta 4; DHT or 3 alpha-OL injection returned the LH response to that of sham-operated animals. No such effects of androgens were present in pubertal or postpubertal rats. There was no effect on the FSH response in any age group. Different groups of animals received 3 doses of 10 ng LH-RH or saline prior to a single 50 ng LH-RH injection. Pubertal and postpubertal males showed a self-priming effect of LH-RH on the LH response. This effect was not present in prepubertal rats nor in any group of animals that had been castrated, regardless of whether or not T replacement was performed. The results indicate that complex alterations in pituitary function take place during the sexual maturation of the male rat. These changes may be inherent in the pituitary and/or related to variation in testicular androgen secretion.

Reduced Testosterone During Puberty Results in a Midspermiogenic Lesion

Abstract The aim of this study was to determine the role of testosterone, as reflected in the testicular interstitial fluid, in the completion of the first wave of spermatogenesis and to further elucidate its role in spermiogenesis. At weekly intervals beginning with 26-day-old rats, body and testis weights were obtained, testicular interstitial fluid testosterone (TIF-T) was assayed, daily sperm production (DSP) was determined, and testicular tissue was structurally analyzed by light and electron microscopy. At 40 days postpartum, half the rats were treated with ethane dimethanesulphonate (EDS) to temporarily reduce Leydig cells. The other half served as controls and were treated with the vehicle. The timing of EDS treatment was just prior to the elongation of spermatids. At Day 47 (1 week after EDS treatment), TIF-T, testis weight, DSP, and number of Leydig cells were significantly reduced. At Day 54 (2 weeks after treatment), TIF-T had returned to the normal adult level, Leydig cell repopulation was apparent, and testis weight was normal. The DSP returned to normal by Day 61 (3 weeks after treatment). At 1 and 2 weeks after treatment, Step 8-9 spermatids were partially or completely detached from Sertoli cells. Results indicate that a temporary reduction of testosterone during the peripubertal period leads to a temporary reduction of the DSP approximately 1 week later. It is suggested that reduced testosterone is associated with a mid-spermiogenic lesion interfering with stable attachment of Step 8–9 spermatids to Sertoli cells during Stage VIII-IX of the spermatogenic cycle.

Serum Concentrations of Reproductive Hormones after Administration of Various Anesthetics to Immature and Young Adult Male Rats

Abstract Immature and young adult male rats were either castrated or unoperated. One of seven anesthetic agents (Rompun, Bio-Tal, Thiopental, pentobarbital, ketamine, halothane, or ether) was administered. When the animals were clearly anesthetized, they were decapitated. Control rats were decapitated without anesthesia. Serum concentrations of luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, testosterone, and androstenedione were determined by radioimmunoassay. None of the anesthetics was clearly suitable for study of all these hormones. Most would be suitable for acute LH studies. Ketamine and halothane appeared inappropriate for FSH studies in immature rats. Pentobarbital, Rompun, and ether caused increases in serum prolactin. Most of the agents appeared to cause a reduction in serum testosterone in intact rats but an increase in castrated animals, suggesting an inhibition of testicular androgen secretion and a stimulation of adrenal androgen secretion.

FORMATION OF INSULIN-SECRETING, SERTOLI-ENRICHED TISSUE CONSTRUCTS BY MICROGRAVITY COCULTURE OF ISOLATED PIG ISLETS AND RAT SERTOLI CELLS

SummaryPancreatic islets, isolated from neonatal pigs, and Sertoli cells, isolated from prepubertal rats, were cocultured in simulated microgravity utilizing the NASA-developed highly accelerating, rotating vessel (HARV) biochamber. Following 5 d of incubation, three-dimensional Sertoli-islet cell aggregates (SICA) retained the ability to secrete insulin when exposed to elevated glucose. SICA contained FasL-positive Sertoli cells and insulin-positive β-cells randomly organized within the spherical construct. The addition of 1% Matrigel induced the reorganization of aggregates (SICAs formed in the presence of Matrigel [SICAmgs]) showing the peripherialization and epithelialization of Sertoli cells and the centralization of islets in association with lumen-like spaces. The Sertoli cells, but not Matrigel, aided in preserving the structural integrity of HARV-incubated islets. Neither Matrigel nor Sertoli cells appeared to interfere with the ability of SICA or SICAmg to secrete insulin and express FasL.

The THC‐induced suppression of Th1 polarization in response to Legionella pneumophila infection is not mediated by increases in corticosterone and PGE2

T helper cell type 1 (Th1)‐polarizing cytokines are induced by Legionella pneumophila infection and are suppressed by pretreatment with marijuana cannabinoids (CB). Glucocorticoids and prostaglandin E2(PGE2) are also reported to suppress Th1 polarization and are induced by Δ9‐tetrahydrocannabinol (THC), so their role in the suppression of polarizing cytokines was examined. Injection of L. pneumophila or THC alone into BALB/c mice induced a rapid and transient rise in serum corticosterone (CS), and the injection of both agents significantly augmented the CS response, demonstrating that THC increased CS in Legionella‐infected mice. Pretreatment with the CB receptor 1 (CB1) antagonist SR141716A had no effect on the THC‐induced CS response, but CB2 antagonist (SR144528) treatment increased the CS response. To see if increased CS contributed to the down‐regulation of Th1 cytokines, mice were pretreated with the steroid antagonist RU486 before THC injection and Legionella infection. The results showed that RU486 did not attenuate the THC‐induced suppression of serum interleukin (IL)‐12 or interferon‐γ (IFN‐γ). In addition to CS, THC injection increased urinary PGE2 metabolites, and the CB1 antagonist attenuated this increase. Although L. pneumophila infection increased urinary PGE2, THC pretreatment did not enhance this response; in addition, treatment with the cyclooxygenase inhibitor, indomethacin, did not block the THC‐induced suppression of IL‐12 and IFN‐γ. These results suggest that the elevation of CS and PGE2 does not account for the THC‐induced attenuation of the Th1 cytokine response, and it is concluded that other suppressive mediators are induced by THC or that the drug acts directly on immune cells to suppress cytokine production.

SECRETION AND RENAL EFFECTS OF ANF PROHORMONE PEPTIDES

1. Atrial natriuretic factor (ANF) and pro ANF peptides appear to be secreted simultaneously from the atria in response to atrial stretch.

Development and Control of the Opioid Inhibition of Gonadotropin Secretion during the Sexual Maturation of the Male Rat

The endogenous opioid system tonically inhibits the LH-releasing apparatus in adult male rats but not in immature animals. To determine the relationship between the onset of this effect and the peripubertal testosterone rise, male rats were examined at 5-day intervals from day 25 through day 65. They were injected subcutaneously with saline, 0.25 or 1.0 mg/kg body weight naloxone and sacrificed 20 min later. Another group of immature males was castrated, implanted with testosterone-filled capsules and tested with naloxone 4 days later. The peripubertal increase in testosterone and the ability of naloxone to increase serum LH concentrations were both first statistically significant on day 45. Testosterone treatment of immature rats did not induce a naloxone effect. The ability of hypothalamic fragments to release LHRH in vitro in response to naloxone also appeared to occur at the same time as the peripubertal testosterone rise. Hypothalamic fragments obtained from immature male rats treated in vivo with testosterone were capable of responding to naloxone with LHRH release in vitro. These data suggest that in the rat the maturation of the endogenous opioid system is a component of male puberty that is induced by the peripubertal testosterone rise.