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Background: Nonmedical prescription opioid use (NPOU) is a major public health concern and few studies have described this phenomenon among victimized women involved in the criminal justice system., Objective: This study will describe the relationship between victimization, psychological distress, health status and NPOU among the vulnerable population of victimized women on probation and parole., Methods: A sample of 406 women on probation and parole responded to items assessing victimization history, self-reported health status, physical pain, psychological distress, and post-traumatic stress disorder. Multiple logistic regression analysis was utilized to differentiate NPOUs versus nonusers., Results: Overall, 169 (41.6%) women reported lifetime NPOU, and 20% reported use in the past year. Compared to women who did not report NPOU, NPOUs were more likely to be White, have poorer general health, and more severe psychological distress across nine symptom domains. In multiple logistic regression models, each year of age reduced the odds of NPOU by 4%; White women were twice as likely as women of other races to report NPOU; each unit increase in the measure for physical pain was associated with a 30% increase in the odds of NPOU; and participants who met diagnostic criteria for PTSD were 60% more likely to report NPOU compared to individuals who did not., Conclusion: Victimized women on probation and parole report high rates of NPOU and comorbid mental and physical health problems. The criminal justice system should routinely screen for NPOU, as well as untreated or poorly managed physical pain and psychological distress, which may increase risk of NPOU., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

This study investigated the dynamics of parasitism, host plant resistance, pathogens, and predation on the demography of wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), developing in susceptible (hollow stem) and resistant (solid stem) wheat hosts. This study is also the first to investigate the prevalence and impact of cannibalism on wheat stem sawfly mortality. Wheat stem sawflies were sampled in two commercial wheat fields over 4 yr from the egg stage through adult emergence, and multiple decrement life tables were constructed and analyzed. Cannibalism, host plant resistance, or unknown factors were the most prevalent factors causing egg mortality. Summer mortality of prediapause larvae ranged from 28 to 84%, mainly due to parasitism by Bracon cephi (Gahan) and Bracon lissogaster Muesebeck, cannibalism, and host plant resistance. Winter mortality ranged from 6 to 54% of the overwintering larvae, mainly due to unknown factors or pathogens. Cannibalism is a major cause of irreplaceable mortality because it is absolute, with only a single survivor in every multiple infested stem. Subsequent to obligate cannibalism, mortality of feeding larvae due to host plant resistance was lower in hollow stem wheat than in solid stem wheat. Mortality from host plant resistance was largely irreplaceable. Irreplaceable mortality due to parasitoids was greater in hollow stem wheat than in solid stem wheat. Host plant resistance due to stem solidness and parasitism in hollow stems cause substantial mortality in populations of actively feeding larvae responsible for all crop losses. Therefore, enhancing these mortality factors is vital to effective integrated pest management of wheat stem sawfly., (© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Manganese (Mn) oxides are among the strongest sorbents and oxidants in environmental systems. A number of biotic and abiotic pathways induce the oxidation of Mn(II) to Mn oxides. Here, we use a combination of proteomic analyses and activity assays, to identify the enzyme(s) responsible for extracellular superoxide-mediated Mn oxide formation by a bacterium within the ubiquitous Roseobacter clade. We show that animal haem peroxidases (AHPs) located on the outer membrane and within the secretome are responsible for Mn(II) oxidation. These novel peroxidases have previously been implicated in direct Mn(II) oxidation by phylogenetically diverse bacteria. Yet, we show that in this Roseobacter species, AHPs mediate Mn(II) oxidation not through a direct reaction but by producing superoxide and likely also by degrading hydrogen peroxide. These findings point to a eukaryotic-like oscillatory oxidative-peroxidative enzymatic cycle by these AHPs that leads to Mn oxide formation by this organism. AHP expression appears unaffected by Mn(II), yet the large energetic investment required to produce and secrete these enzymes points to an as yet unknown physiological function. These findings are further evidence that bacterial peroxidases and secreted enzymes, in general, are unappreciated controls on the cycling of metals and reactive oxygen species (ROS), and by extension carbon, in natural systems., (© 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.)

Latent class analysis was used to identify subgroups of victimized women (N = 406) on probation and parole differentiated by levels of general psychological distress. The 9 primary symptom dimensions from the Brief Symptom Inventory (BSI) were used individually as latent class indicators (Derogatis, 1993). Results identified 3 classes of women characterized by increasing levels of psychological distress; classes were further differentiated by posttraumatic stress disorder symptoms, cumulative victimization, substance use and other domains of psychosocial functioning (i.e., sociodemographic characteristics; informal social support and formal service utilization; perceived life stress; and resource loss). The present research was effective in uncovering important heterogeneity in psychological distress using a highly reliable and easily accessible measure of general psychological distress. Differentiating levels of psychological distress and associated patterns of psychosocial risk can be used to develop intervention strategies targeting the needs of different subgroups of women. Implications for treatment and future research are presented., ((c) 2015 APA, all rights reserved).)

The Sobriety Treatment and Recovery Teams (START) model is designed for families with co-occurring substance use and child maltreatment. This study describes the implementation and outcomes of START in a rural Appalachian county with high rates of poverty, non-medical prescription drug use, and child maltreatment. Despite a severely limited addiction treatment infrastructure at baseline, children served by START were less likely to experience recurrence of child abuse or neglect within 6 months or re-enter foster care at 12 months compared with a matched control group.

Background: Although integrated programs between child welfare and substance abuse treatment are recommended for families with co-occurring child maltreatment and substance use disorders, implementing integrated service delivery strategies with fidelity is a challenging process., Objective: This study of the first five years of the Sobriety Treatment and Recovery Team (START) program examines implementation fidelity using a model proposed by Carroll et al. (2007). The study describes the process of strengthening moderators of implementation fidelity, trends in adherence to START service delivery standards, and trends in parent and child outcomes., Methods: Qualitative and quantitative measures were used to prospectively study three START sites serving 341 families with 550 parents and 717 children., Results: To achieve implementation fidelity to service delivery standards required a pre-service year and two full years of operation, persistent leadership, and facilitative actions that challenged the existing paradigm. Over four years of service delivery, the time from the child protective services report to completion of five drug treatment sessions was reduced by an average of 75 days. This trend was associated with an increase in parent retention, parental sobriety, and parent retention of child custody. Conclusions/Importance: Understanding the implementation processes necessary to establish complex integrated programs may support realistic allocation of resources. Although implementation fidelity is a moderator of program outcome, complex inter-agency interventions may benefit from innovative measures of fidelity that promote improvement without extensive cost and data collection burden. The implementation framework applied in this study was useful in examining implementation processes, fidelity, and related outcomes.

Guided by the Comprehensive Health Seeking and Coping Paradigm (CHSCP; Nyamathi, 1989), the present research sought to examine associations between victimization, psychological distress, lawbreaking and recent drug use (past 12 months) among 406 victimized women on probation and parole. Bivariate differences between women who reported recent drug use and those who did not report recent use were compared across the 4 domains of the CHSCP (sociodemographic characteristics, personal resources, lifetime victimization, dynamic crime and drug factors). Variables significantly related to recent drug use at the bivariate level were retained in the multivariate analysis. The final multivariate model, using stepwise logistic regression via backward elimination, retained five candidate variables indicating women who recently used drugs, were younger, were not sexually victimized as children, began using drugs before they were 13 years of age, were on probation, and had engaged in more recent lawbreaking. The final model accounted for approximately 30% of the variance in drug use over the past 12 months. Implications for intervention and future research are discussed.

Victimized women within the criminal justice system are an important group and understanding their substance use is critical. Substance use was examined among 406 victimized women on probation and parole in an urban community from 2010 to 2013. Ninety-three percent reported lifetime use of an illicit substance, whereas 58% and 45% reported use of at least one illicit substance in the past 2 years and 12 months, respectively. Among probationers, having been in a controlled environment was associated with a higher prevalence of illicit substance use as compared to parolees. Implications for practice, policy, and future research are discussed.

Parents are usually appreciated as possessing legitimate moral authority to compel children to make at least modest sacrifices in the service of widely shared values of moral decency. This essay argues that such authority justifies allowing parents to authorize a child to serve as an organ or tissue donor in certain circumstances, such as to authorize bone marrow donations to save a sibling with whom the potential donor shares a deep emotional bond. The approach explored here suggests, however, that at least under some conditions, parents have legitimate authority to authorize donations forbidden by current guidelines.

Background: In recent years there has been a sharp increase in the use of illicit methadone as well as methadone-related overdose deaths., Objective: The purpose of this study was to describe factors associated with low- and high-frequency methadone use in a cohort of rural Appalachian drug users., Methods: Interviews assessing sociodemographics, illicit drug use and drug treatment, psychiatric disorders, health and sociometric drug network characteristics were conducted with 503 rural drug users between 2008 and 2010. A two-level mixed effects regression model was utilized to differentiate low- (one use per month or less in the past six months) versus high-frequency (daily or weekly use in the past six months) illicit methadone users., Results: The lifetime prevalence of illicit methadone use in this population was 94.7% (n = 476) and slightly less than half (46.3%) were high-frequency users. In the mixed effects regression model, initiating illicit methadone use at a younger age was associated with high-frequency illicit methadone use. Taking a prescribed medication for a physical problem, undergoing additional weeks of outpatient drug free treatment, daily OxyContin® use in the past month, and having fewer ties and second-order connections in the drug network reduced the odds of high-frequency illicit methadone use., Conclusions: Rates of illicit methadone use and high-frequency illicit methadone use among this sample of rural drug users were considerably higher than those previously reported in the literature. Health practitioners in rural areas should routinely screen for illicit opioid use, including methadone.

HIV is a health issue for women offenders who are at particularly high risk. Women's prisons can be opportune settings for HIV prevention interventions. How women perceive partner relationships could be central to targeting HIV interventions. Consequently, this study examines changes in women offenders' risky relationships. Baseline and follow-up data are presented from 344 women offenders. Intent-to-treat analysis is used as well as analysis of covariance to control for baseline values. Findings indicate that women released to the community from prison who were randomized into the prevention intervention were significantly more likely to report changes in five of seven risky relationship thinking myths. Findings suggest that a relationship theory-based prevention intervention for reducing HIV risk could be promising for women offenders reentering the community after prison. Additional research is suggested.

Rise in the availability of fast-food restaurants has been blamed, at least partly, for the increasing obesity in the U.S. The existing studies of obesity have focused primarily on children, adolescents, and adults, and this paper extends the literature by raising a little-studied question and using nationally representative data to answer it. It examines the relationship between the supply of fast-food restaurants and weight gain of pregnant women and their newborns. I study prenatal weight gain because excessive weight gain has been linked to postpartum overweight/obesity and I study both tails of the birthweight distribution because the origin of obesity may be traced to the prenatal period and both tail outcomes have been associated with obesity later in life. I merge the 1998 and 2004 Natality Detail Files with the Area Resource File, and County Business Patterns, which provide data on the number of fast-food restaurants in the metropolitan area where the mother resides. The empirical model includes an extensive list of MSA characteristics and MSA fixed effects to control for factors that may be correlated with both health outcomes and restaurants' location decision. Results reveal that the fast-food and weight gain relationship is robust to the inclusion of these controls but these controls greatly mitigate the fast food-infant health relationship. Greater access to fast-food restaurants is positively related to mothers' probability of excessive weight gain but it does not share a statistically significant relationship with birthweight. These relationships hold in all the socioeconomic and demographic subgroups studied., (2011 Elsevier B.V. All rights reserved.)

Background: Few empirically-based taxonomies of nonmedical prescription drug misusers have been published. This study used latent profile analysis (LPA) to identify classes of adolescent sedative/anxiolytic misusers., Methods: Interviews assessing substance use, psychiatric symptoms, antisocial traits/behavior, and traumatic life experiences were conducted with 723 Missouri youth in residential care for antisocial behavior. Sedative/anxiolytic misusers (N=247) averaged 15.8 (S.D.=1.1) years of age; a majority were male (83.8%), White (70.0%), and resided in rural/small town areas (53.8%)., Results: LPA yielded a three-class solution. Class 1 (59.1%) was comprised of youth with significantly lower levels of currently distressing psychiatric symptoms, fewer lifetime traumatic experiences, less problematic substance use histories, less frequent antisocial behavior, and less impulsivity than youth in Classes 2 and 3. Class 2 (11.3%) youth had high levels of currently distressing psychiatric symptoms and more frequent antisocial behavior compared to youth in Classes 1 and 3. Class 3 (29.5%) youth evidenced levels of psychiatric and behavioral problems that were intermediate to those of Class 1 and 2 youth. Frequency of sedative/anxiolytic misuse was significantly higher in Classes 2 and 3 compared to Class 1. Members of Class 2 and Class 3 also had the highest levels of psychiatric symptoms for which sedatives/anxiolytics are commonly prescribed. Significant differences between classes were observed across a range of health, mental health, personality, and behavioral variables., Conclusions: Adolescents who misused prescription sedatives/anxiolytics evidenced significant heterogeneity across measures of psychiatric and behavioral dysfunction. Youth with comparatively high levels of anxiety and depression reported significantly more intensive sedative/anxiolytic misuse than their counterparts and may be at high risk for sedative/anxiolytic abuse and dependence., (2010 Elsevier Ltd. All rights reserved.)

This study describes the number and characteristics of accidental deaths associated with recreational inhalant misuse in North Carolina from 2000 to 2008. Inhalant-related deaths were identified via an electronic search of records of the North Carolina Office of the Chief Medical Examiner. Thirty deaths were attributed to recreational inhalant use, and nearly a third involved the inhalation of compressed-air products. Polydrug use and comorbid psychiatric disorders were common among decedents. The types of inhalants most often resulting in death differed from previous studies, as did the somewhat older mean age of decedents. Further research on inhalant-related mortality is warranted.

Purpose: To develop a method to quickly calculate equal-spaced Zernike polynomial expansion samples on a rectangular or polar grid for analysis or display., Methods: It is well known that a Zernike polynomial expansion can be converted into an equivalent rectangular or polar two-dimensional Taylor polynomial expansion. It is also known how to quickly calculate equal-spaced polynomial samples using difference equations. Using these two techniques, a software class was developed that provides fast evaluation of Zernike polynomial expansion samples on a rectangular or polar grid. To test the method, the time for the direct calculation of 10th order Zernike polynomial expansion was compared to the difference equation approach for a 1000x1000 sample grid., Results: The direct calculation of the 10th order Zernike polynomial expansion required over 400 times more processing time than the difference equation technique for a 1000x1000 sample grid. The largest difference in calculated values between the two techniques was negligible, indicating 11 digits of accuracy when using double precision variables., Conclusions: The difference equation approach proves to be a fast and accurate method to calculate equal-spaced Zernike polynomial expansion samples on a rectangular or polar grid. This algorithm has application in both the analysis of optical systems and display of results., (Copyright 2010, SLACK Incorporated.)

The purpose of this study was to examine the prevalence, patterns, and predictors of nitrite inhalant use in antisocial adolescents. Face-to-face interviews were conducted with 723 Missouri youth (M age = 15.5, SD = 1.2) in residential care for antisocial behavior. The lifetime prevalence of nitrite inhalant use was 1.7% (1.3% for boys; 4.3% for girls, p = .06), a figure somewhat higher than comparable estimates from the MTF and NSDUH national surveys. Most lifetime users reported nitrite use in the prior year (92%) and experienced intoxication (83%) during periods of nitrite inhalation. Nitrite users had significantly higher scores on measures of somatization, obsessive-compulsive traits, interpersonal sensitivity, impulsivity, fearlessness, suicidality, and polydrug use and were significantly more likely to have suffered a serious head injury and to be White than their non-nitrite-using counterparts. Nitrite users also reported significantly higher levels of current psychiatric distress related to periods of faintness or dizziness, hot or cold spells, difficulty making decisions, and their "mind going blank" than did non-nitrite users. Antisocial adolescent nitrite users are at substantially elevated risk for serious functional impairments given their high rates of lifetime head injury, comparatively more varied and intensive levels of involvement with psychoactive drugs, and symptom reports suggestive of psychiatric and cognitive dysfunction.

Do people realize the danger of asking misinformed children yes-no questions? Study 1 confirmed that disclosures children made during free recall in an earlier suggestibility study were more accurate than disclosures following "yes" responses to yes-no questions, which in turn were more accurate than disclosures following "no" responses. In Studies 2 and 3, college students watched interviews of children and judged the veracity of these three disclosure patterns. Participants generally believed false reports representing the first two patterns, although watching expert testimony that included a videotaped example of a false report reduced trust in prompted disclosures. Results document the need to inform forensic decision-makers about the circumstances associated with erroneous responses to yes-no questions.

There is a dearth of evidence relative to the identification and the variability between the prevalence of chronic conditions in the greater geographic community and the prevalence of these chronic conditions reported through community-based primary care practices. Described is the content and context of a research registry and the variation in panels given the means of recruitment. Patients complete a medical form that includes their self-reported demographics, current and past medical conditions, current medications, family history of selected medical conditions, and a release for full access to their medical records. Two panels were examined, those patients served by community-based primary care practices and assessment of those citizens living in the greater underserved population. These results suggest that the recorded frequency of conditions is similar to those found in the most frequent diagnostic clusters reported in literature for primary care visits. Despite the equity of the demographic and geographical area for recruitment, the identified chronic conditions of those recruited from medical practices differed significantly than the participants from community venues. These findings are provocative in that they have an impact on the understanding of the content and context of a primary care community-based research registry, but also the possible variations in panels given the means of recruitment into a registry. These data are relevant not only as a measure of prevalence of conditions seen in primary care, but perhaps more importantly as a measure of the prevention of chronic diseases that disproportionately affect the underserved.

We introduce the Skill Plot, a method that it is directly relevant to a decision maker who must use a diagnostic test. In contrast to ROC curves, the skill curve allows easy graphical inspection of the optimal cutoff or decision rule for a diagnostic test. The skill curve and test also determine whether diagnoses based on this cutoff improve upon a naive forecast (of always present or of always absent). The skill measure makes it easy to directly compare the predictive utility of two different classifiers in an analogy to the area under the curve statistic related to ROC analysis. Finally, this article shows that the skill-based cutoff inferred from the plot is equivalent to the cutoff indicated by optimizing the posterior odds in accordance with Bayesian decision theory. A method for constructing a confidence interval for this optimal point is presented and briefly discussed.

Purpose: To calculate the spectacle correction from a Talbot Moiré wavefront sensor using the location of peaks in the Fourier transform of the interferogram image., Methods: A relationship was developed between the spectacle correction for an ocular wavefront and the location of Fourier transform peaks in the aberrated interferogram. These spectral peaks were located to sub-pixel accuracy using a two-dimensional polynomial fit. A Talbot Moiré wavefront system was developed to collect examination images from an astigmatic model eye and human eyes. The authors' Fourier transform calculation procedure was applied to captured interferogram and results were tabulated., Results: Five examinations were made of the astigmatic model eye. The mean sphere and cylinder were -4.26 D (SD = 0.004) and -2.90 D (SD = 0.008), respectively. The axis for all measurements was 92 degrees. These values were consistent with the model eye design parameters. The patient was a 46-year-old man with best spectacle-corrected visual acuity of 20/20. Ten examinations were made of the patient's eye. The mean sphere and cylinder were -0.09 D (SD = 0.11) and -1.45 D (SD = 0.14), respectively. The mean axis was 69.1 degrees (SD = 1.29 degrees). The calculation time was 46 ms per image running on a 3.6-GHz PC using 512x512 fast Fourier transforms. This processing time is fast enough for real-time acquisition and display of a patient's refractive state., Conclusions: The Fourier transform calculations provided a fast and simple method of determining the spectacle correction in an aberrated ocular wavefront imaged by a Talbot Moiré wavefront sensor.

Twenty-two children, ages 5 to 17, described their experiences living within a family that included a parent with a psychiatric disability who was involved in community mental health agency services. The children's descriptions of parents' "good days" and "bad days" were captured in a secondary data analysis of a study that included face-to-face children's interviews. Children also discussed their perceptions of psychiatric disabilities and rehabilitation. Children reported more attention from parents on "good days." They expressed concerns about multiple family stressors and bias associated with psychiatric disability. They had little information about psychiatric disabilities and/or rehabilitation. Children recommended "Get help earlier."

Thirty students with profound mental retardation (age range: 3-5 to 19-11) and 30 healthy, full-term infants (5-8 months) were shown 12 stimuli, three times each. Four patterned stimuli were presented one to a card and each pattern appeared in black-and-white, black-and-yellow, and red-and-yellow. Both groups looked significantly longer at face patterns than other patterns. Students with profound mental retardation looked longer at black-and-white patterns than other color combinations. Infants looked longer at red and yellow cards than did students with profound mental retardation. The measurement method was practical, reliable, and sensitive to both within and between group differences. Results from this assessment method may help determine the most salient visual stimuli for evoking active-alert states for students with profound mental retardation. Individual variability was evident in the data, which demonstrates the importance of examining preferences for each individual when planning intervention. Implications for future research and intervention are discussed.

1. Contractions of isolated vascular and cardiac preparations taken from rabbits with perinephritis (one kidney, one wrapped) hypertension were compared with those of preparations from control operated animals. 2. Significantly increased sensitivity to noradrenaline, which acts on alpha 1-adrenoceptors, was found in mesenteric arterial rings but not in aortic rings. The degree of hypersensitivity was the same in the presence and absence of cocaine, suggesting that there is no increase in uptake of noradrenaline into adrenergic nerves in this model of hypertension. In contrast to these agonist-induced contractions, no increased sensitivity was found to potassium chloride, suggesting that hypersensitivity is specific for receptor mediated rather than membrane potential mediated effects. 3. No hypersensitivity to noradrenaline was found in the isolated left or right atria, which suggests that the hypertension is associated with changes in excitation-contraction coupling in blood vessels but not in cardiac muscle. 4. Hypertension increased basal 45Ca uptake in the mesenteric artery but not in the aorta. However, there was no significant difference between preparations from normotensive and hypertensive rabbits in 45Ca uptake or efflux stimulated by noradrenaline or KCl. 5. Increased basal 45Ca uptake could contribute to the increased sensitivity to noradrenaline found in the mesenteric artery in rabbit perinephritis hypertension.

1 A study was made of desensitization in chronically denervated and in normally innervated mouse soleus muscles. 2 Very high concentrations of acetylcholine produced small contractions of the innervated muscles; these were reduced in size when the addition was repeated 1 min after wash-out. 3 Desensitization in innervated muscles was receptor specific: contractions in response to KCl and caffeine were not reduced following acetylcholine, nor did KCl produce desensitization. 4 In chronically denervated muscles non-specific desensitization was observed if acetylcholine was added in the presence of low concentrations of acetylcholine or carbachol. Contractions to KCl but not to caffeine were reduced. KCl produced a similar kind of desensitization. 5 After washing out moderate or supramaximal concentrations from the chronically denervated muscle no desensitization was observed. However, 1 min after washout of very high concentrations the muscle was non-specifically desensitized. 6 It is concluded that relatively high concentrations of acetylcholine are required to produce specific desensitization in the soleus muscle. Chronically denervated muscles, being supersensitive, show non-specific loss of sensitivity with concentrations of acetylcholine too low to produce specific desensitization.

Following injury, there is a major redistribution of zinc, as demonstrated by 65Zn tracer studies in rats receiving 20 per cent burns. This injury resulted in a rapid uptake of 65Zn into spleen, lung, wound, kidney and, particularly, liver, while the uptake of 65Zn was decreased in the brain, some muscle groups and, particularly, in bone. Simultaneously, plasma 65Zn occurred predominantly as the albumin bound fraction decreased. The total amount of tracer appearing in the wound was considerably less than that in the liver, where the induction of zinc binding protein was demonstrated in the cytosol. The synthesis of this protein may have an important regulatory role in zinc homeostasis following injury. These widespread changes in 65Zn distribution are consistent with the essential role of zinc in numerous metabolic processes and the increased metabolic activity of such tissues as the liver and the wound that follows injury. It is apparent that the liver has a central role in the early postinjury changes in zinc metabolism and that bone as well as muscle provides an available source of zinc in these circumstances.

The administration of nembutal and chloral hydrate anesthetic agents in the rat produces an increase in the uptake of zinc, as Zn-65, in the liver. Associated with this is the appearance of a low-molecular-weight Zn-binding protein in the soluble cytosol fraction. This protein is comparable to that induced by the stress of severe exercise, by burn injury, and by Zn injection, and is probably Zn metallothionein. This is an example of the induction of a Zn binding protein in the liver by a drug, and confirms that anesthesia significantly effects Zn metabolism in the liver. Consequently this effect of anesthetic agents should be taken into account in the investigation of the regulation of Zn metabolism.

1 In the isolated chronically denervated soleus muscle of the mouse acetylcholine produced a biphasic contraction. 2 In muscles detubulated by glycerol treatment, the first phase of the acetylcholine contraction was almost abolished, but the second was only slightly reduced or was unaffected. 3 Manganese ions (10 mM) reduced the first phase of the acetylcholine response, but enhanced the second. 4 Dantrolene sodium (5.94 x 10(-5) M) reduced the first phase of the acetylcholine response, but not the second. 5 Nitrate ions (118 mM) augmented the first phase but not the second. 6 It was concluded that the first phase requires the excitation-contraction-coupling sequence: membrane depolarization-T-tubules-Ca2+ release from sarcoplasmic reticulum. In contrast, the second phase appears to occur independently of these processes.

1 Acetylcholine-induced contractions of the isolated chronically denervated soleus muscle of the mouse consist of two phases, but both phases are equivalent to the contracture phase seen in vivo.2 Low [Ca(2+)](0) (0.5-1.5 mM) augmented peak tension, as well as the rate of relaxation, of the first phase, but inhibited the second phase. Ethyleneglycol-bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid (EGTA) or La(3+) (2 mM) also inhibited the second phase, but not the first.3 It was concluded that the first phase requires Ca(2+) release from the sarcoplasmic reticulum, and is terminated by inactivation of the contractile process. The second phase is caused by the entry of activator Ca(2+) from the extracellular space.4 Increasing [Ca(2+)](o) to 5 or 10 mM after the addition of acetylcholine caused a contraction, starting after a delay of about 50 seconds. EGTA or La(3+) added during the second phase of the acetylcholine contraction caused relaxation after a much shorter lag time.5 It is concluded that most of the Ca(2+) entering from the extracellular fluid is taken up by the sarcoplasmic reticulum.6 The acetylcholine second phase was augmented in low (25 mM) [Na(+)](0). It is concluded that Na(+) and Ca(2+) compete for the acetylcholine controlled ionic channels.7 Isolated chronically denervated diaphragm muscles were less sensitive to acetylcholine and the contraction usually consisted of a first phase only.8 It is concluded that sequestration of Ca(2+) entering from the extracellular fluid is more complete in the diaphragm.

Changes in zinc (Zn) availability in muscle tissue that influence muscle performance in vitro have been observed. The effect of exercise of plasma Zn levels and urinary excretion of Zn was observed in sever untrained volunteers following brief intensive exercise and in seven trained volunteers after more prolonged road-running exercise. With brief exercise, plasma Zn decreased predominantly in the more loosely bound albumin fraction. Prolonged exercise resulted in a greater plasma Zn decrease of 30%. Urinary Zn excretion increased transiently with minimal effect on daily losses. However, weight loss by sweating was significant, and sweat Zn losses were greater than those in the urine. Exercise resulted in changes in Zn metabolism that may influence performance.

In the rabbit isolated intestine, tachyphylaxis was evident in the inhibitory responses to isoprenaline, but not in those to phenylephrine, ATP or dibutyryl cyclic AMP. The tachyphylaxis to isoprenaline was associated with a spontaneous fall in the tissue glycogen concentration and was enhanced when the glycogen concentration was markedly reduced by incubation of the tissue under anaerobic conditions in glucose-free Krebs solution. Doubling the glucose concentration of the Krebs solution slowly restored the response to isoprenaline and prevented the development of tachyphylaxis to it. The results support the concept that the beta-adrenoceptor mediated response is dependent on some product of cellular metabolism.

1. The effects of some alpha- and beta-adrenoceptor agonists and antagonists were studied on isolated segments of rabbit intestine in an attempt to characterize the two types of inhibitory response produced by sympathomimetic amines.2. Phenylephrine, an alpha-adrenoceptor agonist, produced an inhibition of rapid onset, from which recovery occurred despite the continued presence of the drug. On washout there was an overshoot in contraction height. Isoprenaline, a beta-adrenoceptor agonist, produced an inhibition of slow onset which was maintained throughout the presence of the drug and there was no overshoot on washout.3. Adrenaline resembled phenylephrine more closely than it resembled isoprenaline, in that it showed more affinity for alpha-adrenoceptors, whereas noradrenaline, and the transmitter released on periarterial nerve stimulation, behaved more like isoprenaline, although both types of receptor were affected.4. Adenosine-5'-triphosphate produced an inhibition resembling that produced by an alpha-adrenoceptor agonist, whereas the dibutyryl analogue of cyclic adenosine 3',5'-monophosphate (cyclic 3',5'-AMP) produced an inhibition resembling that produced by a beta-adrenoceptor agonist.5. In critical concentrations theophylline augmented and imidazole inhibited beta-adrenoceptor mediated responses, as well as responses to dibutyryl cyclic AMP. However, additional actions of theophylline and imidazole were also demonstrated.6. Responses mediated by alpha-adrenoceptors, but not those mediated by beta-adrenoceptors, were blocked by membrane stabilizers, quinidine being the most potent of those studied.7. The results are discussed in relation to the possible mechanisms of action of alpha- and beta-adrenoceptor agonists.