An evaluation of the mechanism of scopolamine-induced impairment in two passive avoidance protocols

The effects of several doses of the centrally-acting muscarinic antagonist, scopolamine, on subsequent learning and memory were examined using two versions of a standard light versus dark passive avoidance paradigm. The first protocol was employed primarily to examine the effects of scopolamine on the acquisition component of learning and memory as subject performance was measured during five successive (repeated) training trials. The second protocol employed a one-trial twenty-four hour retention task in which subjects were given one training trial followed by one testing trial twenty-four hours later. This latter test encompasses acquisition, retention, and recall components of learning and memory. Dose response studies indicated an effective dose range of 0.4-1.2 mg/kg with 0.8 mg/kg producing maximal performance decrement. Differential scopolamine treatment demonstrated that the drug's primary effect was on the acquisition component only under the present experimental protocols. Furthermore, scopolamine was not found to produce state-dependent learning. Animals administered scopolamine before training and testing failed to perform better than animals receiving pre-training administration only.     

The passive hamstring stretch test: clinical evaluation.

The passive hamstring stretch test is described. Using a modified goniometer it is shown that independent measurements taken by trained examiners approximate very closely to each other. This establishes the test as a valid objective measurement. The possible value of this test as a research tool in low back pain problems is discussed.     

Relationship between two ways of measuring alcohol dependence.

One of the main difficulties hampering research with the concept of the alcohol dependence syndrome is the lack of a set of agreed-upon operational definitions of each element composing the syndrome. To illustrate the possible impact of these different operationalizations of alcohol dependence on research results, this article shows the correlation between two different sets of items used to operationalize DSM-III-R alcohol dependence in a clinical sample. Results show that the correlations between the various sets of items are low. About 60% of the correlations are in between .21 and .40. These results suggest that different operationalizations of dependence may not be measuring the same phenomena, and should not be seen as interchangeable.     

Ocular evaluation of polyvinyl alcohol vehicle in rabbits.

The flow properties and viscosity of the vehicle into which drugs are incorporated can be determining factors in the bioavailability of topically applied ophthalmic drugs. It is shown, in rabbits, that when polyvinyl alcohol and methylcellulose are compared on a viscosity basis, there is essentially no difference in the two vehicles with regard to their influence on ocular drug bioavailability. Moreover, the rate of drainage loss for polyvinyl alcohol solutions, as determined by the radioactive technetium technique, compares favorably to methylcellulose solutions of similar viscosity. The relationship between viscosity and contact time or drainage loss of a drug is not a direct one, but an optimum viscosity range exists for polyvinyl alcohol solutions. This optimum range of 12-15 cps in rabbits is identical to that found for methylcellulose and differs considerably from the commonly employed viscosity in commercial preparations. Based on the methylcellulose-polyvinyl alcohol comparison, it appears that vehicles exhibiting or approximating Newtonian flow properties show comparable effects as ophthalmic vehicles. Finally, a discussion of non-Newtonian vehicles and their expected behavior in the eye is presented.     

The inverse passive hemagglutination reaction. An evaluation of preliminary trials

Studies were conducted on inverse passive haemagglutination to work out more sensitive methods for the detection of serological markers of the hepatitis B virus (HBV). IgG were coupled to human red blood corpuscles (RBC) and some parameters of the RBC sensitization, to the coupling and of the test itself were investigated.     

Cytogenetic evaluation of two nitroimidazole derivatives.

5-Nitroimidazoles are a well-established group of antiprotozoal and antibacterial agents. Thanks to their antimicrobial activity these chemotherapeutic agents inhibit the growth of both anaerobic bacteria and certain anaerobic protozoa such as Trichomonas vaginalis, Entamoeba histolytica and Giardia lamblia. The aim of the present study is to achieve a precise characterization of the genotoxic activity of these compounds and to establish the value of cytogenetic assays in order to determine the effect of these drugs, at therapeutic doses, to settle an improved risk assessment. Two nitroimidazole were studied, metronidazole and ornidazole, at four different concentrations (0.1, 1, 10 and 50 microg/ml of peripheral blood lymphocyte culture). Endpoints analyzed included: mitotic index (MI), replication index (RI), sister chromatid exchange (SCE) and chromosomal aberrations (CA). An analysis of variance test (ANOVA) was performed to evaluate the results. A significant decrease (P<0.0001) in MI as well as an increase in SCE (P<0.0001) and CA (0.0001) frequencies for both drugs was observed. No modifications in RI were found. The results suggest a genotoxic and cytotoxic effect of MTZ and ONZ in human peripheral blood cultures in vitro.     

Cough sensors. V. Pharmacological modulation of cough sensors

Several airway afferent nerve subtypes have been implicated in coughing. These include bronchopulmonary C-fibers, rapidly adapting airway mechanoreceptors and touch-sensitive tracheal Adelta-fibers (also called cough receptors). Although the last two afferent nerve subtypes are primarily sensitive to mechanical stimuli, all can be acted upon by one or more different chemical stimuli. In this review we catalogue the chemical agents that stimulate and/or modulate the activity of the airway afferent nerves involved in cough, and describe the specific mechanisms involved in these effects. In addition, we describe the mechanisms of action of a number of chemical inhibitors of these afferent nerve subtypes, and attempt to relate this information to the regulation of coughing in health and disease.     

Cross-cultural evaluation of two drinking assessment instruments: alcohol timeline followback and inventory of drinking situations

This article describes the psychometric characteristics of two major assessment instruments used in a World Health Organization (WHO) clinical trial: (a) Alcohol Timeline Followback (TLFB, which assesses daily drinking patterns), and (b) Inventory of Drinking Situations (IDS, which assesses antecedents to "heavy" drinking). Clients (N = 308) were outpatient alcohol abusers from four countries (Australia, Canada, Mexico, and Sweden). Generally, the Alcohol TLFB and IDS were shown to be reliable and valid with outpatient alcohol abusers in four countries, and in three languages. These results suggest that the Alcohol TLFB and the IDS can be used in clinical and research settings with Swedish-, Spanish-, and English-speaking alcohol abusers.     

被动皮肤过敏性评价中阳性对照的建立

目的：建立被动皮肤过敏性试验中准确且具可重复的阳性对照。方法：30只SD大鼠随机分为1个阴性对照(氯化钠注射液 弗氏不完全佐剂)和4个阳性处理组(阳性1组：卵白蛋白,阳性2组：卵白蛋白 百白破疫苗,阳性3组：卵白蛋白 弗氏不完全佐剂,阳性4组：卵白蛋白 弗氏完全佐剂及弗氏不完全佐剂),分别致敏5次制备抗血清,通过皮内注射被动致敏、48 h后激发,以皮内蓝斑有无及直径判定结果。结果：阴性对照和阳性1组、2组均未见蓝斑,阳性3和4组出现蓝斑,其1:2和1:8注射点蓝斑直径均大于5 mm。结论：被动皮肤过敏性试验中,致敏时结合使用弗氏佐剂可使阳性率达到100%,以保证试验的准确性和可重复性。     

Validity of the passive alcohol sensor for estimating BACs in DWI-enforcement operations

OBJECTIVE: The effectiveness of driving while intoxicated (DWI) operations in deterring impaired driving depends on the ability of police officers to detect heavy drinkers. The passive alcohol sensor (PAS), which can detect alcohol in expired breath at a distance of 6 inches from the face, provides a means for detecting heavy drinking within 15-30 seconds. The objective of this study was to determine the accuracy of the PAS unit for estimating the blood alcohol concentration (BAC) of drivers and study its potential use as a screening device for estimating BAC in relation to several factors related to its use (age, gender, light conditions, and police confidence in the PAS measure). METHOD: A recent study funded by the National Highway Traffic Safety Administration of the BAC levels of crash-involved and randomly stopped drivers as a control group for comparison provided 12,587 cases in which both a breath test and a PAS measure of BAC were obtained for each driver studied. This research involved a secondary analysis of that data set using regression and receiver operator curves methodology to determine the accuracy and utility of the PA S for use as a screening device for DWI violations. RESULTS: PAS scores were a strong predictor of a driver's BAC status. The only other variable having a significant and consistent relationship independent of PA S was police confidence. Detection sensitivity and specificity for each PA S cut-point score were estimated. CONCLUSIONS: By selecting a PAS cut-point score appropriate to the enforcement operation being undertaken, the PA S can be an effective tool for officers when deciding whether to initiate a DWI investigation.     

Agreement between two measures of alcohol consumption

Responses on the Quantity-Frequency Questionnaire (QF) were compared with those on the self-report diary. The QF was administered to 778 general practice patients prior to their consultation and the same patients completed the diary at home within 24 hours. The diary overestimated the number of nondrinkers in the population relative to the QF and classified a higher proportion of patients as heavy drinkers. The QF failed to detect 78% of heavy drinkers identified by the diary. Significantly (p less than .001) more alcohol was reported to be consumed overall on the diary (mean, 10.51 drinks/week) than on the QF (mean, 6.87 drinks/week). The relationship between responses on the two measures was nonlinear. At low consumption levels patients indicated drinking twice as much on the diary as on the QF, but the magnitude of the reported consumption difference decreased with increasing consumption levels. The results are discussed in terms of their implications for self-report measures of alcohol consumption.     

Cardiovascular evaluation after withdrawal from chronic alcohol or cocaine-alcohol abuse.

Alcohol ingestion commonly accompanies cocaine abuse, but the effects of chronic cocaine-alcohol abuse on the circulation are undefined. Therefore, to test for evidence of cocaine-alcohol cardiac dysfunction and interference with cardiovascular nervous system reflexes, 10 normal volunteers (group I), 8 asymptomatic alcoholic patients (group II), and 15 age matched, asymptomatic cocaine and alcohol abusers (group III) underwent screening two-dimensional echocardiography, electrocardiography, a series of autonomic nervous system tests, and upright bicycle exercises. Echocardiographic indices did not differ among groups. R wave voltage was increased in group III, probably primarily due to a smaller body surface area. Heart rate (HR) and/or systolic blood pressure (SBP) responses to 60 degree tilt and to hyperventilation differed in group III (decreased HR response, while SBP increased inappropriately). Despite excellent exercise tolerance, HR response to exercise in group III (compared to group I) was decreased. These results suggest impairment of certain autonomic nervous system reflexes and, possibly, sinus node dysfunction from cocaine-alcohol abuse.     

Experimental approaches to the evaluation of alcohol abuse and dependence development.

In rats, a complex longitudinal analysis of alcohol intake behaviour and electrophysiological sleep pattern was performed during different periods of stable voluntary alcohol consumption. By the sleep pattern, the existence of alcohol abuse and dependence development could be confirmed. Acute ethanol withdrawal was shown to be the obligatory and necessary element in alcohol abuse and dependence evaluation. The proposed behavioural and sleep pattern models might be used in the search for anti-alcoholic drugs in combination with the study of alcoholic aging processes.