Role of a registered dietitian in pediatric type 1 and type 2 diabetes

Type 1 and type 2 diabetes are complex, chronic diseases that are best managed by a multidisciplinary care team. Type 1 diabetes is most commonly diagnosed in the pediatric population, although the prevalence of type 2 diabetes in youth is increasing rapidly. A registered dietitian (RD) is a critical member of the diabetes team who provides focused nutrition education from diagnosis and throughout routine follow-up care. Specifically in the pediatric population, the RD also assesses growth and development, as well as eating behaviors, food choices and meal patterns. Based on a review of research, ongoing support from an RD improves glycemic control and delays onset of diabetes complications. In addition, dietitian-led nutrition education helps better manage lipid levels and aids in weight management. A sample model describing RD involvement in a pediatric diabetes care team is discussed in further detail.

Controlling Phlebotomy Volume Diminishes PICU Transfusion: Implementation Processes and Impact

BACKGROUND AND OBJECTIVES

Phlebotomy excess contributes to anemia in PICU patients and increases the likelihood of red blood cell transfusion, which is associated with risk of adverse outcomes. Excessive phlebotomy reduction (EPR) strategies may reduce the need for transfusion, but have not been evaluated in a PICU population. We hypothesized that EPR strategies, facilitated by implementation science methods, would decrease excess blood drawn and reduce transfusion frequency.

METHODS

Quantitative and qualitative methods were used. Patient and blood draw data were collected with survey and focus group data to evaluate knowledge and attitudes before and after EPR intervention. The Consolidated Framework for Implementation Research was used to interpret qualitative data. Multivariate regression was employed to adjust for potential confounders for blood overdraw volume and transfusion incidence.

RESULTS

Populations were similar pre- and postintervention. EPR strategies decreased blood overdraw volumes 62% from 5.5 mL (interquartile range 1-23) preintervention to 2.1 mL (interquartile range 0-7.9 mL) postintervention (P < .001). Fewer patients received red blood cell transfusions postintervention (32.1% preintervention versus 20.7% postintervention, P = .04). Regression analyses showed that EPR strategies reduced blood overdraw volume (P < .001) and lowered transfusion frequency (P = .05). Postintervention surveys reflected a high degree of satisfaction (93%) with EPR strategies, and 97% agreed EPR was a priority postintervention.

CONCLUSIONS

Implementation science methods aided in the selection of EPR strategies and enhanced acceptance which, in this cohort, reduced excessive overdraw volumes and transfusion frequency. Larger trials are needed to determine if this approach can be applied in broader PICU populations.

A compilation of strategies for implementing clinical innovations in health and mental health

Efforts to identify, develop, refine, and test strategies to disseminate and implement evidence-based treatments have been prioritized in order to improve the quality of health and mental health care delivery. However, this task is complicated by an implementation science literature characterized by inconsistent language use and inadequate descriptions of implementation strategies. This article brings more depth and clarity to implementation research and practice by presenting a consolidated compilation of discrete implementation strategies, based on a review of 205 sources published between 1995 and 2011. The resulting compilation includes 68 implementation strategies and definitions, which are grouped according to six key implementation processes: planning, educating, financing, restructuring, managing quality, and attending to the policy context. This consolidated compilation can serve as a reference to stakeholders who wish to implement clinical innovations in health and mental health care and can facilitate the development of multifaceted, multilevel implementation plans that are tailored to local contexts.

Dopamine activity in the nucleus accumbens during consummatory phases of oral ethanol self-administration

BACKGROUND This present study was designed to clarify the role of dopamine in the nucleus accumbens during operant ethanol self-administration by separating bar pressing (ethanol seeking) from ethanol consumption. Furthermore, we sought to define the relationship between ethanol in the brain and the accumbal dopamine response after oral self-administration of ethanol.

METHODS

Two separate groups of male Long-Evans rats were trained to bar press with 10% ethanol or water. Rats were trained to elicit an escalating number of bar presses across daily sessions before gaining access to the drinking solution for 20 min. Microdialysis was performed before (during a waiting period), during, and after bar pressing and drinking. A handling control group was included, but did not receive training.

RESULTS

A significant increase in dopamine occurred during placement of the rats into the operant chamber in trained rats and handling controls. The lever-pressing period did not produce an increase in dialysate dopamine. Accumbal dopamine was increased in the first 5 min of ethanol, but not water, consumption. Ethanol appeared in the dialysate sample following ethanol availability, and peak concentrations were reached at 10 min. Most of the ethanol and water consumption occurred within 5 min of fluid access. The probes were distributed in the core (32%), shell (32%), and core plus shell (36%) regions of the nucleus accumbens.

CONCLUSIONS

The enhancement of dopamine during transfer into the operant chamber does not depend on anticipation or operant training with ethanol or water reinforcement. Furthermore, the difference between the time course of accumbal dopamine and ethanol in dialysates suggests that the dopamine response is not solely due to pharmacological effects of ethanol. The dopamine response may be associated with the stimulus properties of ethanol presentation, which would be strongest during consumption.

Role of parasympathetic (vagal) cardiac control in elevated heart rates of smokers

Smokers may develop chronic increases in cardiac rate and alterations in cardiovascular control. If the increased mean heart rate (HR) in cigarette smokers is due in part to a deficit in vagal cardiac rate control, this should be reflected in a decreased amplitude of respiratory sinus arrhythmia (RSA). To test this hypothesis we studied 36 smokers and 36 non-smokers, matched for age, race, gender and blood pressure. All subjects were studied in the supine and seated positions. Mean heart rate was determined from the ECG during 30 s of quiet breathing; RSA was determined for 10 consecutive deep (>50% vital capacity) slow (5-7/min) breaths. Mean HRs in smokers were significantly higher than in non-smokers, but the increases in mean HRs evoked by a shift from the supine to seated position were lower in smokers than in non-smokers, suggesting that chronic tobacco use may alter the relative contributions of sympathetic and parasympathetic control of cardiac rate. Because neither the RSAs nor the position-dependent increase in RSA were different between smokers and non-smokers, we conclude that the elevated mean HRs in smokers were not the result of decreased respiratory or vasomotor modulation of vagal cardiac control, but instead were the result primarily of sympathetic stimulation.

Oxidative stress and reactive nitrogen species generation during renal ischemia

Previous evidence suggests that both oxygen radicals and nitric oxide (NO) are important mediators of injury during renal ischemia-reperfusion (I-R) injury. However, the generation of reactive nitrogen species (RNS) has not been evaluated in this model at early time points. The purpose of these studies was to examine the development of oxidant stress and the formation of RNS during I-R injury. Male Sprague-Dawley rats were anesthetized and subjected to 40 min of bilateral renal ischemia followed by 0, 3, or 6 h of reperfusion. Control animals received a sham operation. Plasma urea nitrogen and creatinine levels were monitored as markers of renal injury. Glutathione (GSH) oxidation and 4-hydroxynonenal (4-HNE)-protein adducts were used as markers of oxidant stress. 3-Nitrotyrosine (3-NT) was used as a biomarker of RNS formation. Significant increases in plasma creatinine concentrations and urea nitrogen levels were found following both 3 and 6 h of reperfusion. Increases in GSH oxidation, 4-HNE-protein adduct levels, and 3-NT levels were observed following 40 min of ischemia with no reperfusion. Since these results suggested RNS generation during the 40 min of ischemia, a time course of RNS generation following 0, 5, 10, 20, and 40 min of ischemia was evaluated. Significant increases in 3-NT generation was detected as early as 10 min of ischemia and rose to values nearly 10-fold higher than Control at 40 min of ischemia. No additional increase was observed following reperfusion. The data clearly demonstrate that oxidative stress and RNS generation occur in the kidney during ischemia.

Carboxyl residues in the active site of human phenol sulfotransferase (SULT1A1)

The carboxyl-specific amino acid modification reagent, Woodward's reagent K (WK), was utilized to characterize carboxyl residues (Asp and Glu) in the active site of human phenol sulfotransferase (SULT1A1). SULT1A1 was purified using the pMAL-c2 expression system in E. coli. WK inactivated SULT1A1 activity in a time- and concentration-dependent manner. The inactivation followed first-order kinetics relative to both SULT1A1 and WK. Both phenolic substrates and adenosine 3'-phosphate 5'-phosphosulfate (PAPS) protected against the inactivation, which suggests the carboxyl residue modification causing the inactivation took place within the active site of the enzyme. With partially inactivated SULT1A1, both V(max) and K(m) changed for PAPS, while for phenolic substrates, V(max) decreased and K(m) did not change significantly. A computer model of the three-dimensional structure of SULT1A1 was constructed based on the mouse estrogen sulfotransferase (mSULT1E1) X-ray crystal structure. According to the model, Glu83, Asp134, Glu246, and Asp263 are the residues likely responsible for the inactivation of SULT1A1 by WK. According to these results, five SULT1A1 mutants, E83A, D134A, E246A, D263A, and E151A, were generated (E151A as control mutant). Specific activity determination of the mutants demonstrated that E83A and D134A lost almost 100% of the catalytic activity. E246A and D263A also decreased SULT1A1 activity, while E151A did not change SULT1A1 catalytic activity significantly. This work demonstrates that carboxyl residues are present in the active site and are important for SULT1A1 catalytic activity. Glu83 and E134 are essential amino acids for SULT1A1 catalytic activity.

Clinical significance of alcohol intake parameters at initiation of drinking

A considerable effort is now being focused upon the identification in young adulthood of predictive variables that can be used to detect individuals at risk for developing future alcohol problems. One goal is that such individuals may be targeted for early intervention efforts aimed at preventing the development of serious alcohol-related problems. Another goal is to extend the understanding of the etiology of alcoholism by identifying physiological and behavioral mechanisms underlying the addictive process. Reviewed below are efforts focused upon the importance and predictive value of the response to early exposures to ethanol, including alcohol intake variables at onset of drinking.

Muscle performance in detoxified alcoholics

OBJECTIVE

Although numerous reports have described alcohol muscle dysfunction (myopathy) in histochemical and morphological terms, a description of the relative impact of alcoholism on the functional capabilities (strength, power) of the various muscle groups of the arms and legs has not been reported.

METHOD

The strength of flexor and extensor muscles of the elbow, knee and ankle was evaluated in a group of healthy detoxified white, alcoholic men (N = 83) and lifestyle control subjects (N = 61) using a computer-operated isokinetic dynamometer.

RESULTS

The muscle mass (muscle-plus-bone cross-sectional area) did not differ significantly in alcoholics and controls for any of the limbs studied. Tests of isokinetic torque, work and power revealed small deficits (3-8%) in alcoholics in muscle groups involved in elbow flexion/extension, knee extension and ankle dorsiflexion. Tests of isometric torque in the knee extensors at different degrees of muscle stretch revealed approximately 4-6% lower torque in alcoholics at four different muscle lengths. The force-velocity (isoinertia knee extension) measures indicated slightly slower speeds of contraction (3.9-6.6%) in alcoholics under varying load conditions.

CONCLUSIONS

The small magnitude of the muscle performance deficit in this group of alcoholics was less than expected and is probably related to (1) the elimination of subjects with other medical comorbidities or polydrug abuse, (2) the comparison with a control group of somewhat similar lifestyle and (3) the long (35-day) detoxification period elapsing before testing.

Acute and chronic alcohol-cocaine interactions in rats

The widespread combined use of alcohol and cocaine across the United States underscores the importance of understanding how the actions of those two agents interact upon important physiological regulatory processes. In an experiment exploring acute ethanol-cocaine interactions, 16 rats were given 2.0 g/kg (IP) doses of ethanol at time zero. Two hours later, half of the rats were given cocaine (20 mg/kg, IP), while the other half were given injections of saline. The group given cocaine displayed a prolongation of the hypothermia condition induced by ethanol injection. In a chronic experiment, three groups of rats (n = 6-8) were exposed for an 11-day period to daily IP injections of 10 mg/kg cocaine, 20 mg/kg of cocaine, or saline. On day 12 these groups did not differ in their response to loss of the righting reflex induced by a 3.0 g/kg dose of ethanol. However, recovery from ethanol hypothermia was more rapid in the rats exposed to chronic cocaine. In summary, these initial studies provide evidence for exacerbation of the acute hypothermic effects of ethanol when a cocaine challenge is given 2 h after ethanol. In contrast, ethanol hypothermia was observed to be reduced when tested on day 12 after an 11-day chronic regimen of cocaine. Other dosage regimens and response measures need to be tested to understand the full scope of acute and chronic cocaine-ethanol interactions and the possible health consequences.

The drinking day as a unit of exposure in the epidemiology of alcohol-related medical disorders

Tissue or organ system damage resulting from alcohol ingestion typically requires several years of heavy drinking to reach clinical significance. Based upon earlier empirical findings and theorizing, we hypothesized that the lifetime number of exposures (drinking days) may be of significance in understanding the relationship between chronic alcohol consumption and organ system perturbations in alcoholic populations. To test this hypothesis, detailed lifetime alcohol consumption histories from a racially mixed cohort of detoxified alcoholics (n = 253) and nonalcoholics (n = 61) were examined to determine the lifetime total number of drinking days. Linear regressions corrected for lifetime total dose and pertinent confounding variables yielded statistically significant correlations of moderate size of the number of lifetime alcohol drinking days with diastolic blood pressure and quadriceps muscle strength. The findings were considered to provide evidence that an alcohol exposure (drinking day), independent of dose, is a biologically significant event in the genesis of tissue toxicities in the cohorts studied.

Reduction of MTT by glutathione S-transferase

The reduction of the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) to a blue formazan product is widely used for assaying cell survival and proliferation. The reduction reaction is catalyzed by dehydrogenases localized in the mitochondria of viable cells. As part of an analysis of the ability of glutathione S-transferase (GST) enzymes to protect cells from electrophilic compounds, we found extremely high background levels of the formazan product produced by cells that overexpressed the mouse GST P1-1 enzyme. Further analysis with purified GST enzymes confirmed the ability of these enzymes to reduce MTT in vitro. These data suggest that cytotoxicity assays using MTT should be interpreted with caution, especially when studying the effects of compounds that can influence GST expression.

Association between blood pressure and lifetime drinking patterns in moderate drinkers

OBJECTIVE

To compare the relationship between blood pressure and recent vs lifetime alcohol intake measures in a nonalcoholic cohort using measures that normalized alcohol intake in terms of the volume of distribution for ethanol (total body water) for each subject.

METHOD

Correlations between blood pressure and alcohol intake measures were determined in a cohort of 84 (48 male) normotensive moderate drinkers, using multiple linear regressions to correct for the influence of potentially confounding variables.

RESULTS

Significant correlations were observed between systolic pressure and measures of both recent and lifetime alcohol consumption in men. Diastolic pressure was found to be significantly associated only with the duration of lifetime drinking, and only in women. Measures of lifetime total dose were not significantly correlated with either systolic or diastolic pressure. Alcohol intake expressed in terms of the number of "drinks" per drinking day was as highly associated with blood pressure (systolic) in men as were measures that normalized alcohol intake in terms of the body water content of each subject. A measure of the mean number of drinks consumed on drinking occasions over the drinking career produced the highest correlations with systolic pressure.

CONCLUSIONS

Measures of both recent and lifetime alcohol intake may be relevant to the understanding of alcohol-blood pressure relationships.

Mosquito hexamerins: characterization during larval development

We report here the first examination of hexamerins expressed during mosquito larval development. Haemolymph proteins from fourth-instar larvae of six species representing the two major subfamilies of mosquitoes were characterized by immunoblotting using antisera to calliphorin, the major hexamerin of the blowfly. Calliphora vicina, or to LSP1 or LSP2, the two distinct hexamerins of Drosophila melanogaster. In each mosquito species the antisera demonstrated the presence of multiple abundant hexamerin polypeptides of 66-85 kDa in molecular weight. According to the subunit composition of native proteins, the larval hexamerins from both Aedes aegypti and Anopheles gambiae form heterohexamers. Furthermore, the two major Aedes hexamerin subunits (AaHex1 and AaHex2) are neither rich in aromatic amino acids nor methionine. cDNA clones encoding AaHex1 and AaHex2 were isolated and used to show that hexamerin mRNA is uniquely expressed in fourth-instar larvae of both A. aegypti and A. gambiae and disappears rapidly at the onset of pupal development.

Differential expression of glutathione S-transferase isoforms in compartments of the testis and segments of the epididymis of the rat

Specific cell types of the mammalian testes demonstrate varying susceptibility to toxic insult by chemical agents. The mammalian testis is divided into two major compartments: seminiferous tubules, the site of spermatogenesis, and interstitium, which contains the Leydig cells. Glutathione S-transferase (GST) expression was examined in isolated compartments of the rat testis and in segments of the epididymis. Western blot analysis revealed the presence of GST class alpha, mu, and pi bands in each of the isolated compartments of the testis, and HPLC analysis of monomeric isoforms provided evidence for differential expression of multiple GST isoforms in testicular compartments. All major isoforms (e.g., forms 1, 2, 3, 4, 6, 7, 8, 9, and 11) were detected in the cytosol of whole testis. Isoform subunit 4 was the major form in the tubule, whereas isoform subunit 11 is the dominant form in the Leydig cells. Isoform subunits 3, 4, and 6 were enriched in the tubules as compared to interstitial or Leydig cells. The preferential action of reproductive toxicants at specific stages of aging may be due to an age-dependent expression of the activating or detoxifying enzymes in the reproductive tract. Therefore, the age-dependent expression of testicular GST isoforms was also examined. Expression of isoform subunits 2 and 4 displayed an age dependence, with the largest increase in these subunits occurring between ages 4 and 15 weeks. Isoform expression did not correlate with serum testosterone levels. HPLC analysis of the GST isoforms in the longitudinal segments of the epididymis and vas deferens revealed differential expression within these segments. Total GST protein and catalytic activity was highest in the caput epididymis and progressively decreased toward the vas deferens. Isoform subunit 2 was the major form expressed in the epididymis. The results of this study indicate that the GSTs are differentially expressed in testicular compartments and epididymal segments, and that this may contribute to susceptibility of different cell types to xenobiotic damage.

Residual pressor effects of chronic alcohol in detoxified alcoholics

Although research in population studies has indicated that recent alcohol intake is positively correlated with blood pressure, there is a need to study the relationship of blood pressure to measures of lifetime alcohol intake in alcoholics. To this end, we assessed systolic and diastolic pressures and lifetime alcohol intake through structured interviews with 253 normotensive recovering alcoholics. Blood pressures were first corrected with multiple linear regression for the influence of confounding or modifying variables and then were regressed against alcohol consumption measures. Systolic pressure was significantly correlated (positively) with only a few measures of recent alcohol intake, and the correlations were not high (r2 = .05 to .11, P < .05). Diastolic pressure was found to be highly and positively correlated with the duration of the drinking career, but more so in blacks than in whites. The total lifetime dose of alcohol was found to be positively correlated with diastolic but not systolic pressure, but only in black male alcoholics. The steeper slope of the regression of blood pressure versus lifetime total alcohol or duration of the drinking career in black alcoholics suggests greater cardiovascular susceptibility to alcohol toxicity as lifetime doses increase and as the drinking career lengthens.

Application of bioelectric impedance methodology and prediction equations to determine the volume of distribution for ethanol

In large-scale epidemiologic studies of drinking behavior there is a need for simple and reliable estimates of the body water compartment of subjects. This, in turn, provides an estimate of the volume of distribution of ingested ethanol and a better estimate of tissue exposure levels than the use of total body weight as the volume of distribution for alcohol. The volume of distribution for ethanol (total body water, TBW) was estimated in a racially mixed group of 276 alcoholics and 166 nonalcoholics (aged 20-59 years) by means of bioelectric impedance methodology (BIA) and by means of prediction equations based upon age, body weight, and height. Estimations of mean TBW from BIA were found to be only slightly higher (1-4%) than those provided by the prediction equations. TBW values generated from both prediction equations were also highly correlated with TBW values obtained by impedance methodology, with the highest correlations observed in females (particularly black) and in alcoholics (particularly female).

Drinking patterns and health status in smoking and nonsmoking alcoholics

Alcoholics who smoked also reported that they drank more frequently and consumed more alcohol on drinking occasions than alcoholics who did not smoke, a practice that resulted in a substantially greater lifetime alcohol consumption in the smokers. Smoking alcoholics also consumed more cigarettes and reported more smoking-related physical symptoms than social drinkers who smoked. The heart rates (HRs) of smoking and nonsmoking alcoholics were similar and both exceeded the HRs for the smoking social drinkers by approximately 13 beats/min (bpm) in males and by approximately 7 bpm in females. Surprisingly, correlations between HR and lifetime alcohol consumption were higher and slopes were steeper in controls than in alcoholics. HRs in a subset of the male alcoholics fell only approximately 3 bpm after 24 weeks of abstinence, but changed no further over an additional 24-week period. Taken together, the findings suggest that HRs may have been higher in this group of alcoholics before the onset of alcohol abuse and that alcohol intake contributed only slightly to the high HR.

Progression of alcohol consumption across the drinking career in alcoholics and social drinkers

OBJECTIVE

To document and compare the changes in alcohol intake over the drinking career in alcoholic (n = 273) and social (n = 152) drinkers and to relate the changes to age and to the prevalence of morning drinking.

METHOD

Lifetime alcohol intake was assessed in face-to-face interviews by asking subjects to report drinking patterns during different "phases" of their drinking careers, beginning with the onset of regular drinking and continuing up to the present.

RESULTS

Alcohol consumption began at higher quantities and higher frequencies in alcoholics (prealcoholics) and rapidly escalated within a few years to values well out of the range of moderation. The alcohol intake of social drinkers at the beginning phase was only about 70% that of alcoholics. In contrast to alcoholics, the alcohol intake of social drinkers remained relatively constant across subsequent drinking phases at about three to four drinks per drinking occasion, with only a slight increase in the frequency of drinking over sequential drinking phases. The relationship of total alcohol consumption to age in alcoholics was described best by a curvilinear function, with alcohol consumption peaking near age 40.

CONCLUSIONS

Gender differences in consumption were decreased with adjustment for body water content. The higher initial alcohol intakes in alcoholics may reflect a lower sensitivity to the intoxicating effects of alcohol, or, alternatively, a greater ability of alcoholics to develop tolerance. The high prevalence of morning drinking in alcoholics compared to social drinkers reinforces the usefulness of morning drinking as a diagnostic tool, particularly for female alcoholism.

Depression of an inhibitory reflex, the masseteric silent period, in recovering alcoholics

Because inhibitory deficits may contribute to motor incoordination of alcoholics, we proposed that the duration of the masseteric silent period (SP), an inhibitory reflex, might be shorter in alcoholics (ALs) than in nonalcoholics (NAs). To test this hypothesis, we measured the SP in a racially mixed group of 12 ALs and 12 NAs matched for age (31-49 years) and sex. All subjects were normotensive, had full dentition, and reported no major medical problems. Sensory and motor conduction velocities of the anterior tibialis, ulnar, and medial nerves were measured for each subject, and were not different in ALs and NAs. Jaw jerk and SP were evoked by tapping the chin manually with a rubber hammer containing a circuit to trigger the oscilloscope display of the masseter EMGs. Averaged mean latencies and durations of the SPs were not significantly different between the right and left masseters. SP latencies were significantly (0.7 msec) shorter in ALs than NAs (p < 0.01). The mean SP duration for ALs (13.9 +/- 1.6 msec) was also significantly shorter than that of the NAs (24.4 +/- 2.4 msec; p < 0.001). Results support the hypothesis that chronic alcoholism may interfere with inhibitory mechanisms in the CNS.

Gender comparisons of alcohol consumption in alcoholic and nonalcoholic populations

The purpose of this study was to examine the similarities and differences between male and female drinkers in terms of the estimated functional impact of alcohol intake on drinking occasions. Alcohol consumption on drinking occasions was documented in male and female alcoholics and occasional drinkers in face-to-face interviews and also in a general population statewide sample by means of a telephone survey. Expression of ethanol intake in terms of grams of ethanol consumed per kilogram of total body water yielded data consistent with the notion that blood concentrations of ethanol achieved by females on drinking occasions may have been quite similar to the values achieved by males. However, important gender differences were also found in terms of an older age of onset of regular drinking, less frequent alcohol intake and a higher percentage of abstainers among females.

Age effects on chronic tolerance to ethanol hypnosis and hypothermia

Male Fischer 344 rats of three different ages (young, 4 months; middle, 13 months; and old, 25 months) were tested for their hypnotic and hypothermic response to a 3.5 g/kg dose of ethanol on day 1 and after an 8-day exposure to 4.0 g/kg of ethanol administered via intragastric intubation. All three age groups displayed, to a similar extent, an increased rate of blood ethanol disappearance (metabolic tolerance) on day 10 and day 16, as compared to day 1. Both young and middle-age rats demonstrated tolerance to ethanol hypothermia, but older rats did not. The same test dose of ethanol (3.5 g/kg, IP) administered on day 16, after a 5-day interval with no ethanol, produced a hypnosis response similar to that observed on day 1 (no tolerance), but the response to ethanol hypothermia was still significantly reduced over the day 1 and day 10 value in young and middle-age rats, suggesting a persistence and intensification of tolerance to hypothermia over the 5-day rest interval. However, tolerance to ethanol hypothermia was not observed in old rats. Thus, the effects of age on the development of chronic functional tolerance were complex and depended upon the test measure used.

Influence of self-titration on the relationship between ethanol dose and chronic tissue toxicities: theoretical considerations

Ethanol "titration" is offered as a possible explanation for the poor correlation of typical quantity-frequency measures of alcohol consumption with the extent of neuropsychological and other performance deficits in detoxified alcoholics. This view asserts that there are large variations in the susceptibility of individuals to alcohol toxicities and that individual alcoholics may regulate their ethanol consumption in accordance with their individual susceptibility, such that usual doses and their effects fall within personally acceptable limits. Thus, the dose chosen for chronic administration is determined, in part, by the biological impact of the ethanol ingested during drinking episodes. Owing to individual differences in susceptibilities to toxic effects, this titration behavior may result in a situation in which two- or even threefold differences in alcohol intake are associated with the same levels of toxicity or performance deficits in a group of alcoholics. Under these conditions, a graded dose-response relationship cannot be expected.

Influence of age on the development of rapid tolerance to ethanol

Fischer-344 rats of three different ages (4, 13, and 25 months) were tested to determine the extent and duration of rapid tolerance to ethanol-induced hypothermia and hypnosis. There were no significant differences among groups with regard to maximal ethanol hypothermia (3.0-3.5 g/kg ethanol), nor did any of the groups display a significant change (rapid tolerance) in the maximal hypothermic response when tested with a second identical challenge 48 h later. Rapid tolerance to ethanol hypnosis was observed across groups at 48 h, utilizing two different dosing schemes. No tolerance was observed if 14 days were allowed to elapse between the initial and the test challenge. Young rats were observed to develop a greater degree of rapid tolerance than did middle-aged or old rats, using hypnosis as a measure.

Glutathione S-transferase activity and isoenzyme concentrations in obese Avy/a and lean a/a mice

To assist in defining the mechanism(s) by which the activity of hepatic glutathione S-transferase (GST) is decreased in obese rodents, the cytosolic concentrations of individual GST isozymes were determined by high-performance liquid chromatography. For this purpose, liver cytosols from 8- and 16-week-old obese yellow Avy/a and lean black a/a male and female mice of the inbred VY/WffC3Hf/Nctr-Avy strain were assayed. Obese yellow males contained less hepatic GT-9.0 than lean black males; however, there were no differences between the obese and lean females. GT-9.0 concentration, which is induced by testosterone, was several-fold higher in males than in females, regardless of genotype or body weight. No differences in concentrations of other isozymes were detected. Hepatic GST activity towards 1-chloro-2,4-dinitrobenzene was significantly higher in lean males than in obese males; however, there were no differences between obese and lean females. Lean males had higher activity than lean females; but obese males and females had similar enzyme activities. These changes in enzyme activity can be accounted for by the changes in GT-9.0 concentration measured by HPLC. Lung and testes cytosols were also assayed for GST isozyme concentrations. No differences in any isozyme concentration were found between the sexes or the genotypes in the lung or between genotypes in the testes.

Absence of acute tolerance to ethanol hypnosis in F-344 and BN/BIRIJ rats

Male Fischer 344 (F-344) rats of three different ages (4, 13, and 25 months) and male Brown Norway (BN/BIRIJ) rats (4 months) were injected (IP) with a hypnotic dose of ethanol (3.0 g/kg, 10% w/v in saline). Half of the animals were decapitated and brains extracted immediately upon loss of the righting reflex (LRR), while the other half were allowed to reach recovery of the righting reflex (RRR), at which time brains were extracted. Brain alcohol analyses revealed significantly higher concentrations in young F-344 rats at both LRR and RRR, indicating less sensitivity of target tissue to ethanol hypnosis in the young of that strain. All age groups of the F-344 rats as well as the young BN/BIRIJ rats displayed lower brain concentrations of ethanol at RRR than at LRR, a finding opposite to that characteristic of acute tolerance. The relationship of LRR to RRR values did not differ among the age groups of F-344 rats. We conclude that the F-344 and BN/BIRIJ strains do not develop acute tolerance to ethanol hypnosis. The findings are consistent with the hypothesis that animals with low ethanol preferences, such as the F-344 and BN/BIRIJ strains, also have low capabilities to develop acute tolerance to ethanol hypnosis.

Graduate nursing education: developmental disabilities and special health care needs

As children and adults with developmental disabilities and special health care needs are integrated into home, school, and community life, nurses are being required to provide leadership, advocacy, and training in community settings to a much greater extent than in the past. To assess the school and community need for formal graduate preparation for nurses who work with individuals with developmental disabilities and/or special health care needs, 25 nurses in leadership positions representing urban and rural health agencies throughout Minnesota took part in a 5-hour focus group discussion. Analysis of data summarized from this process shows five features of the recommended curriculum necessary for advanced practitioners in this specialty area: (a) discipline-specific core competencies, (b) discipline-specific specialty competencies, (c) genetic competencies not specific to nursing but necessary to function in nursing roles, (d) interdisciplinary and intradisciplinary learning experiences, and (e) clinical experiences with preceptors. The authors recommend the development of interdisciplinary graduate programs designed to prepare nurses to assume leadership roles in school health, public health, home health care, and systems management that will affect public policy and, ultimately, promote change in the systems charged with responsibility to serve this population.

GDP-mannose pyrophosphorylase. Purification to homogeneity, properties, and utilization to prepare photoaffinity analogs

Pig liver GDP-mannose pyrophosphorylase was purified 5,000-fold to apparent homogeneity using standard techniques. The native enzyme showed a single band on gels of about 450 kDa and two subunits of 43 and 37 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The 37-kDa (beta-) subunit had only methionine at its amino terminus and a surprisingly hydrophobic sequence: Met-Lys-Ala-Leu-Ile-Leu-Val-Gly-Gly-Tyr-Gly-Thr-Arg-Leu- Arg-Pro-Leu-Thr-Leu-Ser-Ile-Pro-Lys. The 43-kDa (alpha-) subunit was blocked at the amino terminus, but a 29-kDa CNBr fragment had the following sequence: Leu-Asp-Ala-His-Arg-His-Arg-Pro-His-Pro- Phe-Leu-Leu-. Substrate specificity studies done in the direction of formation of nucleoside triphosphate and sugar-1-P indicated that the enzyme was most effective with GDP-glucose as substrate (100%) followed by IDP-mannose (72%) and then GDP-mannose (61%). That GDP-mannose and GDP-glucose activities were indeed catalyzed by the same enzyme was indicated by the following. (i) Various studies indicated that the enzyme was homogeneous. (ii) A staining procedure for production of GTP stained the same single band on native gels when either GDP-mannose or GDP-glucose was the substrate. (iii). GDP-mannose inhibited the utilization of GDP-glucose by the enzyme, and vice versa. When 8-azido-[32P]GTP was incubated with native enzyme and exposed to UV light, both the 43-kDa and the 37-kDa subunits became labeled, although the 37-kDa subunit reacted more strongly. On the other hand, 8-azido-GDP-[32P]mannose only photolabeled the 43-kDa band. Most importantly, the purified enzyme can be utilized to produce 8-azido-[32P]GDP mannose or 8-azido-[32P]GDP glucose.

Age-related differences in sensitivity to alcohol in the rat

Female F344 rats of three different ages (4, 13, and 25 months) were tested for sensitivity to the ataxic, hypothermic, and hypnotic effects of injected ethanol. Challenges with ethanol sufficient to produce similar blood alcohol concentrations (BACs) in all age groups at the time of testing were observed to produce greater ataxia in old rats (25 months > 13 months > 4 months). Old rats also were observed to recover the righting reflex at lower BACs than those present in young or middle age rats. BAC at a target rectal temperature of 36 degrees C was observed to be lower in old than in young or middle-age rats when measured as body temperature was falling after doses of 3.0 g/kg to old and 3.5 g/kg to young and middle rats. However, no differences among groups in BAC at target temperature (36 degrees C) were observed as body temperature was recovering from peak hypothermia back up to 36 degrees C. With the exception of the last observation cited, these findings appear to confirm and extend earlier reports of increased target tissue sensitivity to ethanol with advancing age in rodents.

Inhibition studies of some serine and thiol proteinases by new leupeptin analogues

Fifteen tripeptide analogues of leupeptin containing either a C-terminal argininal or lysinal were synthesized. The synthetic analogues were tested, using spectrophotometric assay techniques, as inhibitors of trypsin, kallikrein, thrombin, plasmin, and cathepsin B. The lysinal analogues were fairly selective as inhibitors of cathepsin B activity. Acetyl-L-leucyl-L-valyl-L-lysinal (21) showed a stronger inhibition of cathepsin B (IC50 = 4 nanomolar) than leupeptin. Acetyl-L-phenylalanyl-L-valyl-L-argininal (2i) was found to be a good inhibitor of cathepsin B (IC50 = 0.039 microM), thrombin (IC50 = 1.8 microM), and plasmin (IC50 = 2.2 microM).

Recovery of respiratory sinus arrhythmia in detoxified alcoholic subjects

Although most alcoholic subjects show little autonomic dysfunction, severe alcoholic subjects may have pathological changes in autonomic nerves. We asked if respiratory sinus arrhythmia amplitude (RSA), an index of vagal cardiac control, is decreased in alcoholism and, if so, whether the decrease is reversed with abstinence. RSA was assessed in 17 normotensive alcoholic subjects (A) at 1, 4, 12, and 24 wk of abstinence after detoxification and at similar intervals in 17 controls (C) matched for age, race, and gender. Subjects were studied in both supine and seated positions while breathing in a prescribed deep (> 50% vital capacity) and slow (5-7/min) pattern. Mean heart rate (HR) was determined over 30 s from the electrocardiogram; RSA (the difference between maximum and minimum instantaneous HRs after inspiratory onset) was determined from 10 consecutive breaths. In C, both HR (supine: 61.5 +/- 2.2 beats/min; seated: 71.3 +/- 1.7 beats/min; P < 0.002) and RSA (supine: 22.5 +/- 1.0 beats/min; seated: 28.4 +/- 1.4 beats/min; P < 0.003) were higher when seated than when supine, but neither HR nor RSA varied over 24 wk. At week 1 of abstinence, HRs for A were higher than those for C (supine: 74.2 +/- 2.3 beats/min, P < 0.001; seated: 83.2 +/- 2.7 beats/min, P < 0.003), but by week 24, both seated and supine values returned to control levels. RSA in A at week 1, was only one-half that of C (supine: 11.1 +/- 1.4 beats/min, P < 0.001; seated: 14.7 +/- 1.9 beats/min, P < 0.001) and independent of body position.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced glutathione S-transferase 7-7 expression in rat hepatic cytosol following treatment with pyrrole

Rat hepatic GST 7-7 expression in cytosol and in the S-hexylglutathione-agarose affinity purified fraction of cytosol from saline- (control) and pyrrole-treated animals was examined using metabolic activity, SDS-PAGE, immunoblot, and HPLC analyses. Metabolic activity of hepatic cytosol from pyrrole-treated animals was assayed using the substrates 1-chloro-2,4-dinitrobenzene, ethacrynic acid, and acrolein, and an approximately 1.5-, 1.2-, and 1.3-fold increase, respectively, was monitored in the rate of GST-catalyzed substrate conjugation to reduced glutathione. SDS-PAGE and immunoblot analysis using Class Pi GST-specific IgG confirmed that the GST 7 subunit was expressed in hepatic cytosol and in the affinity purified fractions from pyrrole-treated rats. In contrast, the GST 7 subunit was below the limit of detection in hepatic cytosol of saline-treated animals. HPLC analysis demonstrated the presence of the GST 7 subunit in the affinity purified fraction from pyrrole-treated rat hepatic tissue and showed that the level of this subunit was increased approximately 8-fold relative to the barely detectable level present in control tissue. N-terminal amino acid sequencing analysis confirmed the identity of the HPLC peak as GST 7-7. GST subunits 3, 1a, and 1b were elevated approximately 1.7-, 2.0-, and 2.4-fold respectively, in response to pyrrole treatment. These data provide evidence that pyrrole treatment results in de novo expression of GST 7-7 in rat hepatic tissue and suggest that pyrrole-containing compounds potentially generated during disease and/or altered heme metabolism, or those ingested in food products, may alter GST expression in hepatic tissue.

Nitroreductases and glutathione transferases that act on 4-nitroquinoline 1-oxide and their differential induction by butylated hydroxyanisole in mice

These studies concern the initial steps in 4-nitroquinoline 1-oxide (4NQO) metabolism in relation to mechanisms of anticarcinogenesis. Butylated hydroxyanisole (BHA) administration by a protocol known to inhibit the pulmonary tumorigenicity of 4NQO in A/HeJ mice enhanced hepatic and pulmonary activities for 4NQO metabolism by two major pathways, conjugative detoxification and nitroreductive activation. High-performance liquid chromatography analysis showed approximate doubling of two types of glutathione transferase subunits with 4NQO-conjugating activity in livers of BHA-treated mice. Similar increases were observed in hepatic 4NQO-conjugating activity and in Vmax, while Km for 4NQO was 39 to 43 microM. Pulmonary 4NQO-glutathione transferase activity increased 24 to 29%. DT diaphorase activity toward 4NQO was elevated 3.3-fold in livers and 2.7-fold in lungs of BHA-treated mice. However, the predominant 4NQO reductase of liver and lung was dicumarol resistant, had a strong preference for NADH, and showed little if any response to BHA. This Mr 200,000 enzyme, partially purified from livers of Swiss mice, exhibited the stoichiometry of 2-NADH/4NQO expected for reduction of 4NQO to 4-hydroxyaminoquinoline 1-oxide. Its high affinity for 4NQO (Km, 15 microM) signified a much greater influence on 4NQO metabolism than DT diaphorase (Km, 208 microM). The dicumarol-resistant 4NQO reductase differed from several known cytosolic nitroreductases. The results suggest that protection by BHA may result from alteration of the balance between 4NQO activation and conjugation.

Hand movement speed and accuracy in detoxified alcoholics

Detoxified alcoholics (n = 192) were found to be 9.3% slower than age-matched controls (n = 112) with regard to the composite speed (movement time, MT) with which they were able to strike targets of various sizes and distances with a hand-held stylus at onset of a light stimulus (Fitts's Task). Females (n = 102) were 8% slower than males (n = 202), and blacks (n = 103) about 15.6% slower than whites (n = 201). Gender was the only significant factor with regard to errors (target misses), with women committing 28% fewer errors than men. Women, in contrast to men, appear to trade speed for accuracy in this task. Favorable socioeconomic/medical status and target misses were directly related to movement speed. Thus, when the MT data were corrected for lifestyle variables, the significance of the alcohol effects on MT disappeared, but gender differences persisted. The alcohol effect became statistically significant, the ethnic group differences remained statistically significant, and the gender effect became insignificant when MT scores were corrected for accuracy of performance (target misses). The slope of the linear function relating MT to target difficulty was similar for all subgroups. Prior knowledge of the direction of movement was found to affect MT performance more in white than in black subjects. With regard to reaction times, ethnic group and alcohol use effects remained statistically significant after corrections for lifestyle and errors were made, with values for blacks about 5% slower than values for whites, and values for alcoholics about 4.6% slower than those for controls. Prior knowledge of the direction of movement significantly improved (shortened) reaction time in all subgroups (14%-19%).

Works in progress #7. Age-dependent fibrin clot invasion by human meniscal fibrochondrocytes. A preliminary report

This study was performed to determine whether human fibrochondrocytes possess the same biologic potential for initiating a reparative response in a meniscal defect as that found in lower vertebrates. Small, circular defects were created in meniscal fragments obtained from nine men aged 14 to 72 years. The defects were filled with purified fibrin and placed in a culture medium. By 4 weeks, there was excellent cellular penetration into all clots. This study suggests that human meniscal fibrochondrocytes are also capable of initiating a reparative response, and the rapidity of this response appears to be age dependent. The 14- and 16-year-old menisci mounted a more rapid healing response in vitro than did those obtained from skeletally mature individuals.

Effects of age and sex on reciprocal tapping performance

Using a reciprocal tapping task (Fitts's task), the speed and accuracy of small-amplitude motor movements of the hand were measured for 62 men and 84 women, 20 to 89 yr. of age. Men and women in their 20s and 30s performed similarly, although men in their 20s displayed a tendency to trade accuracy in favor of speed. Movement time increased noticeably for both men and women beginning with the 40s decade and continued to increase through the 80s decade. Error rates were lower for women than men and were relatively uniform for both men and women across all age decades past 30 yr. Older subjects of both sexes appeared to sacrifice speed (slowed down) to maintain accuracy on the task. The slope of the linear regression relating movement time to task difficulty was steeper for men than for women and increased more for men than women with advancing age, indicating that older men slowed down relatively more than older women on more difficult tasks.

A survey of muscle function in detoxified alcoholics

Selected characteristics of arm and leg muscle contraction were examined in a racially mixed group of male detoxified alcoholics (N = 45, ages 20-49) and age-matched controls (N = 75). Lifetime drinking histories estimated the mean lifetime consumption of ethanol to be 8.96, 12.1 and 20.4 kg ethanol/kg body weight for alcoholic subjects aged 20-29, 30-39 and 40-49, respectively. The severity of the alcohol dependence syndrome (ADS scale) was marked in alcoholics, but was not age-dependent. Alcoholics did not differ significantly from controls on health status or physical activity scales. The performance of alcoholic subjects was impaired on all muscle function measures, with relatively more impairment found in older alcoholics. Maximal knee extension force generated at 3 muscle lengths (hip, angle, 45 degrees, 90 degrees, 180 degrees) was impaired only in alcoholics 30-49 years of age. Forearm (handgrip) muscle strength was impaired in all age groups of alcoholics. Maximal muscle (biceps) contraction speed at 3 levels of resistance was impaired only in alcoholics in their fifth decade of life. The greatest deficit in alcoholics (all age groups) was observed in the anaerobic power (bicycle ergometer) test. Thus, the magnitude of dysfunction and the extent of age-relatedness was found to be a function of the muscle test employed.

Body composition in detoxified alcoholics

Body composition was evaluated in healthy detoxified alcoholics (aged 20-39) and lifestyle controls, with the expectation that prolonged, excessive consumption of alcohol may bring about nutritional or toxicologic alterations in the relationship between body fat and lean body mass. Body fat was assessed by measurements of skin-fold thickness and by means of bioelectric impedance methodology. No noteworthy differences were observed between alcoholics and controls with regard to the relationship between lean body mass and body fat or in the relationship between extracellular and intracellular water. It would appear that 15-20 years of heavy alcohol consumption does not necessarily alter body composition in healthy, young alcoholics.

Mouse hepatic glutathione transferase isoenzymes and their differential induction by anticarcinogens. Specificities of butylated hydroxyanisole and bisethylxanthogen as inducers of glutathione transferases in male and female CD-1 mice

GSH transferase isoenzymes of class Mu (two forms), class Pi (one form) and class Alpha (two forms) were purified from liver cytosols of female CD-1 mice pretreated with an anticarcinogenic inducer, 2(3)-t-butyl-4-hydroxyanisole. GSH transferases GT-8.7, GT-8.8a and GT-8.8b, GT-9.0, GT-9.3, GT-10.3 and GT-10.6 contained a minimum of six types of subunits distinguishable by structural, catalytic and immunological characteristics. H.p.l.c. analysis of the subunit compositions of affinity-purified GSH transferases from liver cytosols of induced and non-induced male and female CD-1 mice showed that two anticarcinogenic compounds, 2(3)-t-butyl-4-hydroxyanisole and bisethylxanthogen, differed markedly in their specificities as inducers of GSH transferase.

An organ culture model for assaying wound repair of the fibrocartilaginous knee joint meniscus

We describe an in vitro organ culture system that can be used to test the effect of various substances and compounds on the wound healing process in the fibrocartilaginous substance of the knee joint meniscus. Using culture medium containing either 10% fetal bovine serum (FBS) or our recently developed serum-free, defined culture medium (DM), we have demonstrated the ability of meniscal fibrochondrocytes from intact rabbit menisci to extricate themselves from their surrounding matrix and migrate into an exogenous, purified fibrin clot in vitro. After 4 weeks of culture in FBS-containing medium, the cells which had invaded the clot had initiated the early aspects of a typical reparative response; the same response did not occur in DM alone. Morphologically, the cells on the surface of the clot resembled the original superficial fibrochondrocytes, whereas those cells within the substance of the clot more closely resembled the original deep fibrochondrocytes. After 10 weeks, the reparative response had progressed only to a certain point and then failed to progress further under these culture conditions. However, use of this culture system should now make it possible to rapidly identify and quantitate those factors which would most likely be useful in continuing the reparative response and in affecting meniscal wound repair. Elucidation of the mechanisms and requirements for meniscal healing will eventually allow the practicing orthopaedic surgeon to effect in situ meniscal repair and obviate the need for meniscectomy and its morbid sequelae.

After-effects of acute alcohol intoxication

Female, Long-Evans hooded rats (N = 10, 4 months of age) were given ethanol via intragastric intubation in doses of 2.0, 3.0 or 4.0 g/kg (repeated measures design). After-effects (hypothermia, free operant activity, motor performance) were measured at six, twelve and sixteen hours, respectively, for the above doses and were compared to the effects observed after the intubation of equivolume amounts of tap water. The after-effects of ethanol on rectal temperature were varied. Both rotarod performance and free operant activity were impaired after each of the above doses of ethanol. Blood ethanol analyses revealed low blood levels of ethanol (range 6.6 +/- 1.5 to 24.6 +/- 3.4 mg/100 ml) at the time behavioral tests were performed. Thus, quantifiable behavioral impairment was observed after blood ethanol values had declined following acute intoxication episodes. These changes may be related to "hangover" symptomatology in man and may serve as a model for investigating the influence of a variety of factors related to drug dosage, rate of ethanol ingestion, type of alcoholic beverage, and prophylactic or acute intervention therapeutics.

Motor performance in detoxified alcoholics

Detoxified male and female alcoholics (aged 20-49 years) and age-matched controls performed a series of 15-sec target-tapping tasks in which they alternatively marked two target strips with a felt marker as rapidly and as accurately as possible. Consistent with "Fitts' Law" (Fitts PM: J Exp Psych 47:381-391, 1954), a highly linear relationship between movement time and task difficulty was observed in all four groups. Overall, the alcoholics were slower and made more errors than the controls, although the pattern of deficit differed for males and females. Accuracy, but not speed, was impaired in male alcoholics. The production of undershoot errors was increased more in alcoholics than nonalcoholics in targets of narrower width, whereas the production of overshoot errors was increased more in alcoholics as target separation decreased. Female alcoholics displayed impairment in speed of movement, but not accuracy. However, both alcoholic groups displayed elevated error rates for the more difficult targets. It is thus possible that detoxified alcoholics might mimic the speed functions of nonalcoholic individuals at the occasional cost of an erroneous response at a difficult target.

Muscle fiber composition and length-tension relationships in rats chronically exposed to alcohol

Adult Fischer 344 rats were fed an alcohol diet (7-9 g/kg/day) for 12 weeks and were compared to pair-fed controls with regard to the contraction and fiber characteristics of the gastrocnemius and plantaris muscles of the leg. Muscles were isolated in situ with blood and nerve supplies intact. The muscles were stretched by 1 mm increments and were stimulated at each muscle length with a voltage (1 msec pulse) that had been observed to produce maximal twitch force at the initial muscle length. Maximal twitch tension was found to be only 10% less in alcohol than pair-fed rats and the increase in force resulting from stretching was approximately 15% less in alcohol than pair-fed rats. No significant changes in sciatic nerve conduction velocities were produced by alcohol exposure. Moreover, no significant differences in muscle weight or the number and size of Type I, Type IIa or Type IIb muscle fibers were observed. Although the 12 weeks of alcohol exposure affected muscle physiology and histology in the direction of increased impairment, the differences were not large enough to be statistically significant.

The role of congeners in the effects of different alcoholic beverages

Five different alcoholic beverages were tested in rats to determine if congener content contributed to the hypothermia or motor impairment produced by the beverages. Solutions of cognac, scotch, tequila, vodka, and commercially supplied ethanol were diluted with physiological saline to form solutions containing 16% w/v ethanol, as verified by gas chromatographic analysis. All beverages were administered in doses containing 0 (saline), 1.6, 3.2, 4.8, or 6.4 g/kg ethanol (gastric intubation) in test sessions separated by 7 days (repeated measures design, N = 8 rats per group). Measurements of rectal temperature and motor impairment (rotarod performance) made at 0, 60, and 120 minutes postinjection revealed no noteworthy differences in either measure at 60 or 120 minutes postinjection at any of the 4 doses tested. Thus, no evidence for a contribution of congeners to beverage effects was observed.

Increased responsiveness to ethanol with advancing age in rats

Male CD strain rats of three different ages (young-5 months; middle-15 months; old-27 months) were tested for their responsiveness to doses of ethanol sufficient to produce hypothermia or hypnosis. Comparison dosages of ethanol across age groups were based upon the estimated equivalent dilution of the drug into the body water compartments of subjects. In the hypnosis study, there were no statistically significant differences among the groups with regard to the time elapsed until the righting reflex was lost or in total sleep time. However, old animals recovered the righting reflex in the presence of lower blood ethanol concentrations than those observed for young and middle animals, suggesting a greater sensitivity of target tissues to the hypnotic effects of ethanol in old rats. The responsiveness of old rats to the hypothermic effect of ethanol was greater than that of younger rats only when the experiment was conducted at an ambient room temperature of 10 degrees C.

Comparative study of the iodination of tyrosines in the amino terminal domain of fibrinogen and in N-DSK and fibrin-N-DSK

Lactoperoxidase catalyzed iodination has been used to probe for differences in surface orientation of tyrosine residues in the amino-terminal disulfide knot (N-DSK) domain of fibrinogen, in N-DSK and in Fb-N-DSK prepared from fibrin. The central region of N-DSK containing the beta chain Tyr 41 and gamma chain Tyr 18 and 32 are much more susceptible to iodination than when an integral part of the fibrinogen molecule. Cleavage of the N-DSK domain from fibrinogen "loosens" up the tertiary structure of N-DSK and allows iodination of its central region. The iodination pattern of comparable tyrosine residues did not change between N-DSK and Fb-N-DSK. This result implies that no significant change occurs in the tertiary structure of N-DSK upon thrombin activation. These results favor the concept that removal of the fibrinopeptides removes a steric hindrance or exposes a binding site for polymerization.

Conditioned and unconditioned influences on body temperature and ethanol hypothermia in laboratory rats

Both a naive group and a group of chronically handled rats were observed to develop hyperthermia when their cages (rats in situ) were removed from their usual positions on cage rack shelving and placed upon the laboratory bench for a period of 60 minutes. That procedure apparently functioned as a stressful unconditioned stimulus for the naive group. The extent of hyperthermia was more pronounced in the chronic group, presumably owing to the classical conditioning of environmental cues to the stressful events that had repeatedly been associated in the past with placement of the cage onto the benchtop. Doses of naloxone (10 mg/kg) and of ethanol (1 g/kg) that normally produced negligible effects on body temperature were found to significantly reduce the hyperthermia that developed when cages were placed onto the benchtop. The hypothermic response to 2 g/kg of ethanol was lessened in both groups by placement of the cages onto the benchtop.

Studies on the discriminative stimulus properties of ethanol in squirrel monkeys

Eight male squirrel monkeys were trained to use the pharmacological effects of ethanol [orally via gastric intubation 1600 mg/kg (IG), in normal saline] versus those produced by equivolume saline as discriminative stimuli in an operant conditioning (bar pressing) procedure in which the availability of banana-flavored food pellets was made contingent upon the drug condition of the animal (ethanol SD, saline S delta for four monkeys; saline SD, ethanol S delta for the other four monkeys). Test doses of 7.5 mg/kg pentobarbital IG and 80 mg/kg barbital IG closely mimicked the cue properties of ethanol, while doses of morphine sulfate (5.0-20 mg/kg IG) failed to elicit ethanol-appropriate responding. Other ethanolic beverages containing 1600 mg/kg ethanol in the same volume as the training dose, and found to mimic the cue properties of pure ethanol were bourbon, gin, beer, vodka, and red wine. The single test dose of cognac, scotch, and tequila elicited responding different from that of the training dose of ethanol. Thus, the pharmacological effects of ethanolic beverages containing the same dose of ethanol (1600 mg/kg) may be noticeably different to some subjects. Blood levels of ethanol produced by the different beverages may be an important variable. There was no differential effect of the beverages upon free-feeding behavior of the monkeys at the time of testing. Ethanol preference tests conducted at the end of the study (i.e., after nearly 2 years of drug discrimination training) indicated that the assignment of ethanol as the condition under which food pellets were available (SD condition) moderately increased the ethanol preference of those subjects as compared to monkeys for whom ethanol had served as the S delta condition.

Body water content, ethanol pharmacokinetics, and the responsiveness to ethanol in young and old rats

Total body water was determined by desiccation of samples of 6 young (5-7 months) and 6 old (24-26 months) female CD strain rats and was observed to contribute 58.8 +/- 1.4 and 45.8 +/- 1.7% to the total body mass of the respective groups. The values obtained were used to construct an equation (linear regression: body weight vs. percent body water) with which to estimate the body water content of living subjects (n = 10 each) of the same populations, using body weight as the predictive variable. Doses of ethanol estimated to produce similar drug concentrations in the body water compartments were administered to old and young subjects and were observed to produce similar blood ethanol disappearance curves in both groups of rats. The regional brain concentrations of ethanol were found to be highest in the pons-medulla and lowest in the midbrain. On a region-by-region basis the values obtained for young rats were observed to more closely approximate the concentrations of ethanol in the neck blood than were the values obtained from the analysis of brain tissue from old rats. Old and young subjects dosed on the basis of predicted equivalent dilution of ethanol in body water did not differ noticeably in their response to ethanol hypothermia.