The mediating role of mental toughness in sport.

AIM: We conducted two studies that examined different models, which included mental toughness and psychological constructs that are thought to be related to this construct. METHODS: In Study 1, 531 athletes completed measures of mental toughness, resilience, and emotional intelligence. In Study 2, 522 athletes completed measures of mental toughness, sport motivation, and self-efficacy. RESULTS: There were positive paths between the constructs in the model, which were mediated by mental toughness in Study 1. Further, there was a positive path between mental toughness and self-efficacy, but negative paths with introjected regulation and amotivation in Study 2. CONCLUSION: This two study paper suggests that it might also be the presence of constructs such as resilience, emotional intelligence, motivation, and/or self-efficacy that enable mentally tough individuals to excel under stressful circumstances rather than just coping.

Physiology, structure, and regulation of the cloned organic anion transporters.

1. The transport of negatively charged drugs, xenobiotics, and metabolites by epithelial tissues, particularly the kidney, plays critical roles in controlling their distribution, concentration, and retention in the body. Thus, organic anion transporters (OATs) impact both their therapeutic efficacy and potential toxicity. 2. This review summarizes current knowledge of the properties and functional roles of the cloned OATs, the relationships between transporter structure and function, and those factors that determine the efficacy of transport. Such factors include plasma protein binding of substrates, genetic polymorphisms among the transporters, and regulation of transporter expression. 3. Clearly, much progress has been made in the decade since the first OAT was cloned. However, unresolved questions remain. Several of these issues--drug-drug interactions, functional characterization of newly cloned OATs, tissue differences in expression and function, and details of the nature and consequences of transporter regulation at genomic and intracellular sites--are discussed in the concluding Perspectives section.

Detection of doxepin and its major metabolite desmethyldoxepin in hair following drug therapy.

Doxepin is a tricyclic antidepressant that is widely prescribed for the treatment of mild depression. In this study, hair samples collected from a patient receiving 25 mg of doxepin daily were analyzed. Doxepin was administered to the patient for 4 months (June 15 to October 15, 1996). Five hair samples were collected: 1 and 3 months after doxepin therapy began and 1, 3, and 5 months after drug therapy ended. Solid-phase extraction was employed to isolate doxepin and its major metabolite desmethyldoxepin from the hair matrix, and gas chromatography-mass spectrometry (GC-MS) was used for quantitation of both drugs. Six-point standard curves (0.25-20 ng/mg) were prepared for both compounds with an internal standard (doxepin-d3). The standard curves for doxepin and desmethyldoxepin were linear over the range reported and had correlation coefficients of 0.984 and 0.985, respectively. The limit of quantitation for both analytes was 0.25 ng/mg of hair. In addition, the replicate analysis of control hair preparations was performed at two levels (2 ng/mg and 15 ng/mg) to determine intra- and interday variability. Doxepin and desmethyldoxepin were not detected in the patient's sample collected 1 month after doxepin therapy began. The samples collected 3 months after doxepin therapy began and 5 months after drug therapy was terminated had detectable amounts of doxepin and desmethyldoxepin. The highest concentrations of doxepin (mean, 0.59 ng/mg) and desmethyldoxepin (mean, 0.40 ng/mg) were found 5 months after doxepin therapy began, which was also 1 month after the patient had stopped using the drug. Five months after doxepin therapy was terminated, the drug and its metabolite were still present in the patient's hair. The concentration of doxepin in hair was always significantly higher than the concentration of desmethyldoxepin.

Identification, characterization, and mapping of Ecm1, a locus affecting extracellular matrix production and lesion size in Cochliobolus heterostrophus.

A mutant of Cochliobolus heterostrophus lacking the outer layer of extracellular matrix around its germ tubes and hyphae was obtained by mutagenizing protoplasts. The mutant not only lacks the outer matrix, but also produces much smaller lesions on corn leaves than nonmutant strains; the area of mutant lesions averages 0.6 mm2 compared with 5.8 mm2 for nonmutant lesions. Genetic analysis demonstrated that the failure to produce the outer matrix cosegregates with the reduced lesion size, indicating that the two traits are controlled by the same locus, designated Ecm1 (Extracellular Matrix Deficient). The mutant retains normal growth on media and normal abilities to germinate, form appressoria, and penetrate corn leaves. This indicates that the outer matrix is not necessary for infection prior to entrance of the fungus into the leaf. It also indicates that the pathogenicity defect in this mutant is manifested after penetration. To facilitate future tests of whether the pathogenicity defect is caused by the lack of the outer matrix, Ecm1 was mapped. Seven markers linked to Ecm1 were found by analysis of amplified fragment length polymorphisms. Ecm1 maps to chromosome 4; the closest markers to Ecm1 are 5 cM distant, which is estimated to represent about 115 kb.

The association of personality characteristics with parenting problems among alcoholic couples.

This retrospective cross-sectional study explored the associations of personality characteristics with parenting problems among 25 couples, one or both members of which were identified as alcoholics by virtue of their voluntary past completion of a residential program for alcoholics. Most of them (90%) scored lower, indicating their more problematic parental attitudes and behaviors, on all four scales of the Adult-Adolescent Parenting Inventory (AAPI: inappropriate parental expectations of children, lack empathy for children's needs, value physical punishment, and parent-child role reversal) than average "normal" nonalcoholic, nonabusive adults. Such parenting problems were found to be very highly associated with clients' personality characteristics. For example, schizoid, schizotypal, histrionic, and passive aggressive characteristics (DSM-III-R-based) along with a few other personal characteristics of the couples, accounted for nearly all (90.2%, R2 = .902) of their propensity to reverse roles with their children. Findings also suggested that the identified parenting problems among alcoholic couples are amenable to programmatic intervention: the longer couples had participated in aftercare programs offered by the treatment facility the more appropriate and empathetic was their parenting.

Assessment of swab transport systems for aerobic and anaerobic organism recovery.

Saline suspensions of 11 aerobes and anaerobes were used to inoculate swabs from Port-A-Cul (Becton Dickinson), Culturette EZ (Becton Dickinson), and Copan Amies gel (Copan Diagnostics). Swabs were removed from transport devices at 0, 24, and 48 h postinoculation and then extracted by vortexing in 1.0 ml of saline, and organism survival was determined by quantitative plate counts. For the organisms tested, Culturette EZ allowed < 1% of the original inocula to be recovered after 24 h. Port-A-Cul was only slightly better. Recovery was best with the Copan gel-containing system. Agar gel swab systems may be useful for multipurpose transport devices.

Acute and residual effects of alcohol and marijuana, alone and in combination, on mood and performance.

The duration of behavioral impairment after marijuana smoking remains a matter of some debate. Alcohol and marijuana are frequently used together, but there has been little study of the effects of this drug combination on mood and behavior the day after use. The present study was designed to address these issues. Fourteen male and female subjects were each studied under four conditions: alcohol alone, marijuana alone, alcohol and marijuana in combination, and no active treatment. Mood and performance assessments were made during acute intoxication and twice the following day (morning and mid-afternoon). Acutely, each drug alone produced moderate levels of subjective intoxication and some degree of behavioral impairment. The drug combination produced the greatest level of impairment on most tasks and "strong" overall subjective ratings. There were few significant interactions between the two drugs, indicating that their effects tended to be additive. Only weak evidence was obtained for subjective or behavioral effects the day after active drug treatments, although consistent time-of-day effects (morning versus afternoon) were observed on several subjective and behavioral measures. In sum, this study provided little evidence that moderate doses of alcohol and marijuana, consumed either alone or in combination, produce behavioral or subjective impairment the following day.

Effects of alcohol pretreatment on human marijuana self-administration.

Alcohol and marijuana are frequently used together, yet there has been little study of how the presence of one drug might affect consumption of the other. The present study examined the effects of alcohol pretreatments on marijuana self-administration in a group of 15 males and 5 females who were users of both drugs. During evening sessions in a recreational setting, pairs of subjects consumed drinks containing 0.0, 0.3 or 0.6 g/kg alcohol 30 min before a 60-min period of ad libitum marijuana smoking. Marijuana self-administration was assessed in several ways: by measuring the number of cigarettes smoked, the increase in expired air carbon monoxide resulting from marijuana smoke inhalation, and the increase in heart rate due to THC absorption. None of these variables was significantly affected by the alcohol pretreatments, although substantial individual differences were observed. These results indicate that low to moderate doses of alcohol do not systematically influence marijuana self-administration.

Factors influencing self-administration of, and subjective response to, placebo marijuana.

Self-administration of, and subjective response to, placebo marijuana were studied in two groups of regular marijuana smokers. One group received the drug under a set of instructions that informed them that the marijuana was active (deceptive administration); the other group was informed that the marijuana might be inactive (double-blind administration). Subjects were allowed to smoke placebo marijuana freely for 60min during four identical weekly sessions. Subjects smoked an average of 6.0 half-length cigarettes per session, resulting in a mean increase in expired air carbon monoxide of 14.6 ppm. Placebo self-administration did not change significantly across the four sessions. Smoking was associated with marijuana-like subjective effects. Subjects in the deceptive administration group smoked more placebo marijuana and reported a greater subjective response than the other group during the first session only. Several anamnestic factors (drug use history, current pattern of marijuana use, dimensions of personality) correlated with the amount of placebo self-administered, and subjects with less marijuana experience tended to report stronger subjective responses to the placebo. These results demonstrate the importance of including a placebo control when studying the reinforcing effects of marijuana and identify some factors that might predict placebo responses to marijuana or other drugs.

Interpretation of gram-stained sputa containing Moraxella (Branhamella) catarrhalis.

Sputum specimens culture positive for Moraxella (Branhamella) catarrhalis were Gram stained with three decolorizer solutions (slow, 95% ethyl alcohol; intermediate, 1:1 ratio of 95% ethyl alcohol and acetone; and fast, acetone alone) for 5, 10, 20, and 30 s. Optimal results were obtained with acetone alone after 10 s or with a 1:1 mixture of acetone and ethanol after 20 s. Inadequate decolorization of M. catarrhalis in sputa is likely if the decolorization solution and exposure time are not optimal and may contribute to underreporting of this organism.

Parasite detection efficiencies of five stool concentration systems.

Fresh fecal material that was free of ova and parasites was pooled with 10% Formalin in a 1:4 ratio to prepare a standard specimen. Portions of 100 ml of this specimen were individually seeded with Cryptosporidium oocysts, Entamoeba coli, Entamoeba histolytica, and Giardia lamblia cysts; ova of Necator americanus; and Strongyloides larvae. Appropriate volumes of each parasite suspension were used to evaluate the Fecal Concentrator Kit (Remel, Lenexa, Kans.), Fecal Parasite Concentrator (Evergreen Scientific, Los Angeles, Calif.), Para-Pak Macro-Con (Meridian Diagnostics, Inc., Cincinnati, Ohio), and Trend FeKal CON-Trate (Trend Scientific, Inc., St. Paul, Minn.). A standardized gauze filtration method was used as the reference procedure. Tests were performed in triplicate with each individual parasite-concentrator combination, with three slides examined from each sediment. All of the systems effectively concentrated parasites compared with direct examination of unconcentrated fecal material. The Fecal Concentrator Kit provided the best overall performance. Clarity of sediment, lack of debris, and uniformity of background material were found to be important considerations for microscopic detection of parasites in concentrated specimens.

Rapid, colorimetric identification of Candida albicans.

A total of 706 yeast isolates were evaluated in parallel by the Candida albicans Screen (CAS; Carr-Scarborough Microbiologicals, Inc., Stone Mountain, Ga.) test and the germ tube (GT) test in comparison with the API 20C Yeast Identification System. The CAS and GT tests correctly identified 419 of the 422 isolates of C. albicans (99.3%). Two of the false-negative reactions occurring with the CAS were with GT-negative strains of C. albicans. There were two false-positive CAS reactions involving a single strain each of C. parapsilosis and C. tropicalis. Sensitivity and specificity for both tests exceeded 99%, with positive and negative predictive values of 99 and 98%, respectively.

Quality control slide for potassium hydroxide and cellufluor fungal preparations.

An opaque, water-insoluble quality control material with a skinlike microscopic appearance was prepared by inoculating melted xanthine (0.4%) agar with filamentous fungi and dispensing drops onto glass slides. After solidification of the agar, the material was rapidly cleared by 10% KOH, revealing fungal elements stained by Cellufluor reagent.

Umbelliferyl-labeled galactosaminide as an aid in identification of Candida albicans.

The initial evaluation of a fluorescence, nonmicroscopic method of rapid identification of Candida albicans is described. A total of 524 yeast isolates were evaluated in parallel by the umbelliferyl-conjugated N-acetyl-beta-D-galactosaminide (UAG) test and the germ tube (GT) test in comparison with the API 20C Yeast Identification System. The UAG test correctly identified 333 of the 334 isolates of C. albicans (99.7%), and the GT test identified 328 (98%). There were three false-positive GT reactions and five false-positive UAG reactions with 69 isolates of C. tropicalis. The sensitivity and specificity were 99 and 97%, respectively, for the UAG test and were both 98% for the GT test. The UAG test requires less than 2 h for test completion compared with 2 to 4 h for the GT test, is similar in cost, has a nonmicroscopic visual endpoint, and eliminates the health hazards of handling pooled human sera.

The pharmacokinetics of amlodipine in healthy volunteers after single intravenous and oral doses and after 14 repeated oral doses given once daily.

Intravenous administration of amlodipine (single dose, 10 mg) to 12 volunteers gave a mean plasma half-life of 34 h, mean clearance of 7 ml min-1 kg-1 and a mean apparent volume of distribution of 21 l kg-1. Oral administration (single dose, 10 mg) to the same 12 volunteers gave a mean systemic availability of 64% and a mean plasma half-life of 36 h. In a second study, repeated oral administration (once daily for 14 days, 15 mg) to 28 volunteers resulted in steady state plasma drug concentration being reached after seven doses, an accumulation of approximately threefold and a mean half-life of 45 h.

Rapid species identification and biotyping of respiratory isolates of Haemophilus spp.

Three commercially available systems, the 4-h Minitek Enterobacteriaceae III, the Haemophilus Trio-Tube, and the Micro-ID, were evaluated for their capacities to identify and biotype 308 respiratory isolates of Haemophilus spp. When compared with aminolevulinic acid test results, the definitive identification method used in this study, these systems demonstrated no significant differences in their capacities to differentiate Haemophilus influenzae from Haemophilus parainfluenzae. They were in agreement with the standard method of species identification approximately 50% of the time. When sucrose was added to the Minitek and Trio-Tube configurations, the efficiency rate of species identification increased to more than 95%. The Micro-ID could not be modified to incorporate this additional biochemical parameter. The performance of the sucrose-supplemented Minitek and Trio-Tube systems, compared to the combined results of Micro-ID and aminolevulinic acid, produced correlations of 94 and 90%, respectively. Rapid and accurate methodologies are available for combined species identification and biotyping of Haemophilus spp.

Evaluation of leukocyte esterase activity as a rapid screening technique for bacteriuria.

Microscopy and leukocyte esterase activity, both employed as screening techniques for urine cultures, were evaluated with respect to two distinct populations, male and female. When 424 urine specimens from males were examined, 95% of the Gram-stained smears and 91% of the leukocyte esterase tests correctly correlated with culture results, indicating significant bacteriuria. There were no significant differences between the Gram stain and leukocyte esterase activity in predicting a negative culture: 99% and 98%, respectively. Neither microscopy nor esterase activity proved as sensitive or as efficient in predicting a negative culture with the female population.

Management of patients with modified Hunt pouch esophagojejunostomy after total gastrectomy for carcinoma of stomach.

The Hunt pouch and its various modifications have been used as an esophagojujunostomy technic after total gastrectomy or esophagogastrectomy for benign and malignant conditions. This pouch procedure may be particularly useful for palliative gastric resections in which the patient's ability to ingest adequate foodstuffs might be enhanced by a larger reservoir, thereby improving nutritional status and possibly facilitating chemotherapy or radiation therapy or both. Intravenous hyperlimentation has been used to advantage preoperatively and postoperatively to help nutritionally depleted patients better tolerate such an operation and has been useful during treatment of complications related to the procedure. Three recent cases are discussed to illustrate the above propositions.