The effect of hot beverages, cold beverages, and chewing gum on oral temperature

BACKGROUND

A prospective blood donor's oral temperature is affected by external stimuli such as drinking a hot or cold beverage or chewing gum. These stimuli can cause a deferral or an inappropriate acceptance for a certain unknown time.

STUDY DESIGN AND METHODS

Ten volunteer subjects were exposed to each of the three stimuli in separate studies. Oral and tympanic membrane temperatures were taken before exposure, immediately after exposure, and at various times until the subject's temperature returned to baseline.

RESULTS

The drinking of a hot beverage caused an immediate mean temperature elevation of 2.6 degrees F which would lead to deferral for 7 of 10 subjects. All subjects were acceptable for blood donation (temperature <99.6 degrees F) by 5 minutes. A cold beverage lowered the temperature; the temperature in 6 subjects returned to baseline by 10 minutes and that in 4 did so by 30 minutes. Gum chewing caused minimal temperature elevations; only 1 donor's temperature reached 99.6 degrees F, and it was at acceptable levels for blood donation by 5 minutes.

CONCLUSION

Drinking a hot beverage and, to a much lesser degree, gum chewing can lead to a deferral for elevated temperature, but subjects were acceptable by 5 minutes. Cold beverages are of more concern, because they suppress the temperature for a short time and could theoretically lead to acceptance of a febrile, possibly infectious donor.

HealthSense: how changes in sensory physiology, sensory psychology and sociocognitive factors influence food choice

HealthSense is a multi-centre shared cost research project in sensory and consumer sciences. This project was initiated in response to changing population demographics, which predict a significant increase in the older age group. The primary objective of HealthSense is to determine accurately the effects of ageing on the perceptual abilities of the sensory systems, and ultimately how age-related change determines sensory preferences and food choice. The project is carried out by 24 participating institutes located in 10 different European countries. The project is funded by the European Commission Quality of Life Fifth Framework Programme (QLKI-CT-1999-00010).

Alcohol use in adolescent females: correlates with estradiol and testosterone

This study investigated if self-reports of alcohol use correlated with estradiol and testosterone levels in adolescent females. Ninety-four female senior high school student volunteers from 2 schools completed a questionnaire regarding alcohol use. Twenty cc of blood was assayed for estradiol, testosterone, progesterone, and FSH. Total estradiol levels were higher in females who reported current alcohol use (p < or = 0.05), and females with higher levels of both testosterone and estradiol were more likely to be using alcohol currently (p < or = 0.05). Hormonal relationships associated with adolescent alcohol use may be related to future health risks of alcohol use and/or increased risk of alcohol use.

The association of testosterone with nicotine use in young adult females

This pilot laboratory study examined the relationship of testosterone levels, carbon monoxide (CO) levels, current and adolescent nicotine use, and histories of pubertal onset in 30 young adult female smokers. These females had completed questionnaires regarding nicotine use in the 7th through 10th grades, and again at age 21 as part of a cohort study of drug use. In addition, history of pubertal onset was obtained at age 21, as were testosterone and CO levels. Testosterone levels were positively correlated with cigarette use in the last 30 days (P< or =.01), CO levels (P< or =.05), cigarette use reported in the 7th and 10th grades (P< or =.05), and negatively correlated with age of pubertal onset (P< or =.001). The relationship of testosterone to nicotine will be discussed.

The importance of fulfilling unmet needs of rural and urban adolescents with substance abuse

PROBLEM

Because of the negative impact on health of drug and alcohol use, this study examined adolescent needs and substance use.

METHODS

Subjects (N = 191) were adolescents aged 14 to 19 in a rural and an urban high school. A modified version of the Need Subscale from the Addiction Research Center Maturation Scale measured a feeling of satisfaction related to meeting basic needs, and an investigator's prepared questionnaire elicited current use of alcohol, nicotine, and marijuana.

FINDINGS

Individuals with feelings of unmet needs were more likely to be current drinkers. Rural/urban residence was not a significant predictor in a multivariate analysis, but religiosity was.

CONCLUSIONS

A feeling of unmet needs seems to be an important factor in adolescent substance use.

Water decolorization using UV radiation and hydrogen peroxide: a kinetic study

Sometimes, provision of water for domiciliary consumption faces the problem of natural contamination originated by the presence of organic substances such as humic or fulvic acids. Very often, after conventional sanitary treatments this water exhibits a persistent yellowish coloration that affects its use. Moreover, these substances may act as precursors of tri-halomethanes formation during pre-disinfection with chlorine. This paper presents, with a simplified mechanistic approach, the intrinsic reaction kinetics of natural water decolorization employing UV radiation and hydrogen peroxide. The main variables for the model are: contaminant concentration expressed as TOC, hydrogen peroxide concentration and the photon absorption rate.

Production of intoxication states by actors--acoustic and temporal characteristics

This paper is the second of a series; the first has been published (J Forensic Sci, 1998;43:1153-62). The goal in the initial pair of experiments was to determine if speakers (actors) could effectively mimic the speech of intoxicated individuals and also volitionally reduce the degradation to their speech that resulted from severe inebriation. To this end, two highly controlled experiments involving 12 actor-speakers were carried out. It was found that, even when sober, nearly all of them were judged drunker (when pretending) than when they actually were severely intoxicated. In the second experiment, they tried to sound sober when highly intoxicated; here most were judged less inebriated than they were. The goal of this second paper is to identify some of the speech characteristics that allowed the subjects to achieve the cited illusions. The focus here is on four paralinguistic factors: fundamental frequency (F0), speaking rate, vocal intensity, and nonfluency level. For the simulation of intoxication study, it was found that F0 was raised along with increased intoxication but raised even more when this state was feigned. A slowing of speaking rate was associated with increasing intoxication, but this shift also was greater when the speaker simulated intoxication. The most striking contrast was found for the nonfluencies; they were doubled for actual intoxication, but quadrupled when intoxication was simulated. On the other hand, the shifts exhibited by the subjects when they attempted to sound sober were not as clear cut. Indeed, no systematic relationships were found here for either F0 or vocal intensity. Both speaking rate and the number of nonfluencies shifted appropriately, but these changes were not statistically significant. In sum, discernable suprasegmental relationships occurred for both studies (but especially the first); further, it is predicted that useful cues also will be found embedded in the segmentals (the sounds of speech).

Card Perseveration Task performance and post-task feeling states: relationship to drug use in adolescents

This study examined whether performance on the Card Perseveration Task (Card Task) and self-report of feeling state after the task are related to self-report of drug use. The evaluation was of 64 adolescents from an adolescent psychiatric outpatient clinic (40 males, aged 15.5 years, SD = 1.6; 24 females aged 16.9 years, SD = 1.5). Drug use histories were obtained using a substance dependence symptom checklist based on DSM-III-R. The Card Task was administered, and after completion, a Post-Task Self-Report (PTSR) was administered. A factor analysis with varimax rotation grouped the 28 items of the PTSR into Distress, Happy, Satisfied, and Wanting to Win subscales. Correlations of drug use with performance on the Card Task and the PTSR subscales were obtained. Cards Played on the Card Task were correlated with alcohol (cc = .31, p < or = .01); marijuana (cc = .35, p < or = .01) and polydrug (cc = .26, p < or = .05) dependence symptoms. Money Won on the Card Task was correlated negatively with nicotine (cc = -.26, p < or = .05) and marijuana (cc = -.27, p < or = .05) dependence symptoms. The PTSR Distress subscale correlated with nicotine (cc = .49, p < or = .001), alcohol (cc = .37, p < or = .01), marijuana (cc = .39, p < or = .01), and polydrug (cc = .49, p < or = .001) dependence symptoms. These findings provide evidence that both the Card Task and feeling states associated with task performance are related to self-reports of drug use.

Comparative effects of the human protein C activator, Protac, on the activated partial thromboplastin clotting times of plasmas, with special reference to the dog

The commercial snake venom extract, Protac, is a specific activator of the anticoagulant zymogen, protein C (PC) in human plasma. This specific action has led to its use in developing coagulation-based and amidolytic-based assays for the diagnosis of quantitative and/or qualitative PC deficiency states in human beings. The purpose of the present study was to compare the effects of Protac on the activated partial thromboplastin times (APTT) of human, bovine, equine, and canine plasmas in order to determine the potential value of this venom extract as an activator in functional PC assays in these domestic animal species. As expected, Protac significantly prolonged the APTT of normal human plasma, but had no effect on plasma known to be devoid of PC. Clotting times were prolonged by 34%-214% with concentrations of venom activator ranging from 0.1-1.0 U/mL. Under identical conditions, Protac prolonged the APTT of equine plasma by 11%-98% over control times. Even more dramatic was the inhibitory effect of Protac on the clotting of bovine plasma, extending the APTT more than 3-fold at a venom concentration of 0.1 U/mL. At higher venom concentrations, most bovine plasmas remained unclotted after 300 s (control time 34.1 s). Under similar conditions, the canine APTT was unaffected by Protac, even when the venom concentration was increased to 3 U/mL. In order to determine the reason for the lack in response of canine plasma, the concentration of the APTT reagent was altered (decreased), exposure time of the plasma to the Protac was increased from 2 min to 9 min, and the plasma was diluted to assess for the potential existence of plasma PC inhibitors. Protac caused an unexpected shortening of the APTT when the contact activator reagent was diluted. Increasing the exposure time had no effect. Although a slight prolongation of the canine APTT was detected when the plasma was diluted, the presence of strong plasma PC inhibition was considered an unlikely cause of the lack of significant anticoagulant action. The failure of Protac to exert a strong inhibitory effect on the canine APTT, as well as to generate amidolytic activity, suggests that this venom extract does not stimulate the production of activated PC activity in canine plasma. This may result from molecular differences in the canine PC molecule that prevent the formation of the stoichiometric complex of venom extract, APTT reagent, and canine protein, a complex thought to be essential for the PC-activating function of Protac. Protac may be suitable as an activator of PC in bovine and equine plasmas; however, it appears ineffective in generating anticoagulant activity in canine plasma.

Axial length decrease accompanying successful glaucoma filtration surgery

OBJECTIVE

To evaluate change in axial length measurement after successful glaucoma filtering surgery.

DESIGN

Retrospective consecutive case series.

PARTICIPANTS

Sixty-two patients with phakia who underwent primary trabeculectomy.

INTERVENTION

The A-scan biometry of ocular axial length before and after trabeculectomy.

MAIN OUTCOME MEASURES

Changes in ocular axial length measurement after successful trabeculectomy were analyzed.

RESULTS

The mean decrease in axial length measurement was 0.423 mm (range, -2.8 to +0.5 mm). Regression analysis yielded a statistically significant association between decrease in axial length measurement and age (P = 0.0001) and post-trabeculectomy intraocular pressure decrease greater than 30 mmHg (P = 0.01). Analysis of variance revealed a significant association between decrease in axial length measurement and use of antimetabolite (P = 0.005). Pseudophakic axial length measurements increased an average of 0.275 mm compared to the axial length after trabeculectomy and before cataract surgery.

CONCLUSIONS

Axial length measurement decreased in 32 of 62 eyes after successful initial trabeculectomy. A decrease in axial length measurement may have an influence on intraocular lens calculations. Therefore, the authors recommend that an axial length measurement be obtained on phakic eyes before an initial trabeculectomy to reduce the risk of an inaccurate intraocular lens power calculation based on post-trabeculectomy axial length measurements.

Intraoperative MR imaging guidance for intracranial neurosurgery: experience with the first 200 cases

PURPOSE

To review preliminary experience with an open-bore magnetic resonance (MR) imaging system for guidance in intracranial surgical procedures.

MATERIALS AND METHODS

A vertically oriented, open-configuration 0.5-T MR imager was housed in a sterile procedure room. Receive and transmit surface coils were wrapped around the patient's head, and images were displayed on monitors mounted in the gap of the magnet and visible to surgeons. During 2 years, 200 intracranial procedures were performed.

RESULTS

There were 111 craniotomies, 68 biopsies, 12 intracranial cyst evaluations, four subdural drainages, and five transsphenoidal pituitary resections performed with the intraoperative MR unit. In each case, the intraoperative MR system yielded satisfactory results by allowing the radiologist to guide surgeons toward lesions and to assist in treatment. In two patients, hyperacute hemorrhage was noted and removed. The duration of the procedure and the complication rate were similar to those of conventional surgery.

CONCLUSION

Intraoperative MR imaging was successfully implemented for a variety of intracranial procedures and provided continuous visual feedback, which can be helpful in all stages of neurosurgical intervention without affecting the duration of the procedure or the incidence of complications. This system has potential advantages over conventional frame-based and frameless stereotactic procedures with respect to the safety and effectiveness of neurosurgical interventions.

The mechanisms of action of interleukin-1 on rabbit intestinal epithelial cells

Interleukin-1 (IL-1) is an inflammatory mediator that increases Cl- secretion in intestinal epithelial cells. To identify the signal transduction pathway(s) involved in IL-1's action, cells were treated with IL-1 and the levels of cyclooxygenase (COX) enzymes, prostaglandin E2 (PGE2) and phospholipase A2-activating protein (PLAP), and the activity of phospholipase A2 (PLA2) were measured. IL-1 caused concentration- and time-dependent increases in the levels of PLA2 activity, and/or in the levels of PLAP, COX-2 and PGE2. The IL-induced increase in PGE2 levels was biphasic, with the first peak due to the increase in PLAP levels, and the second peak due to the increase in COX-2 levels. This increase in PGE2 levels may provide a mechanism for acute and chronic inflammation in the intestine.

Production of intoxication states by actors: perception by lay listeners

The effects of ingesting ethanol have been shown to be somewhat variable in humans; there appear to be but few universals. Yet, questions about intoxication often are asked by law enforcement personnel (especially relative to DUI), clinicians and various individuals in social settings. A key question: Is it possible to determine if a person is intoxicated by observing them in some manner? A closely associated one: Can speech be used for that purpose? Two of the many issues related to the second of these questions involve the possibility that (1) speakers, especially actors, can effectively mimic the speech of intoxicated individuals, and (2) they may be able to volitionally reduce any speech degradation which results from intoxication. The approach used to test these two questions tasked auditors to determine if these simulations were possible. To this end, young, healthy actors chosen on the basis of a large number of selection criteria were asked to produce several types of controlled utterances (1) during a learning phase, (2) when sober, (3) at three simulated levels of intoxication (mildly, legally and severely drunk), (4) during actual, and parallel, levels of intoxication, and (5) at the highest intoxication level attained but when attempting to sound completely sober. Two aural-perceptual studies were conducted; both involved counterbalanced ABX procedures where each subject was paired with him/herself. Listeners were normally hearing university students drawn from undergraduate phonetics and linguistics courses. In the first study, they rated the actors as being more intoxicated--when they actually were sober but simulating drunkenness--88% more often than when they actually were intoxicated. In the second study, they were judged as sounding less inebriated when attempting to sound sober (than they actually were) 61% of the time. These relationships would appear to impact a number of situations; one of special importance would be the detection of intoxication in motorists.

Gap junctional communication between murine macrophages and intestinal epithelial cell lines

In intestinal inflammation, inflammatory cells infiltrate the submucosa and are found juxtaposed to intestinal epithelial cell (IEC) basolateral membranes and may directly regulate IEC function. In this study we determined whether macrophage (M phi), P388D1 and J774A.1, are coupled by gap junctions to IEC lines, Mode-K and IEC6. Using flow cytometric analysis, we show bi-directional transfer of the fluorescent dye, calcein (700 Da) between IEC and M phi resulting in a 3.5-20-fold increase in recipient cell fluorescence. Homocellular and heterocellular dye transfer between M phi and/or IEC was detected in cocultures of P388D1, J774A.1, Mode-K, IEC6 and CMT93. However, transfer between P388D1 and Mode-K was asymmetrical in that transfer from P388D1 to Mode-K was always more efficient than transfer from Mode-K to P388D1. Dye transfer was strictly dependent on IEC-M phi adhesion which in turn was dependent on the polarity of IEC adhesion molecule expression. Both calcein dye transfer and adhesion were inhibited by the addition of heptanol to cocultures. Furthermore we demonstrate both IEC homocellular, and M phi-IEC heterocellular propagation of calcium waves in response to mechanical stimulation, typical of gap junctional communication. Finally, areas of close membrane apposition were seen in electron micrographs of IEC-M phi cocultures, suggestive of gap junction formation. These data indicate that IEC and M phi are coupled by gap junctions suggesting that gap junctional communication may provide a means by which inflammatory cells might regulate IEC function.

Adhesion and cytosolic dye transfer between macrophages and intestinal epithelial cells

Activated macrophages (M phi) found in the intestinal lesions of patients with inflammatory bowel disease (IBD) secrete many inflammatory mediators which can regulate intestinal epithelial cell (IEC) function. However, little is known about direct M phi-IEC interactions. Two potential mechanisms by which cells may interact are through specific receptor-ligand binding of adhesion molecules, such as integrins or cadherins, and by exchange of cytoplasmic substances through transmembraneous channels called gap junctions. We investigated whether M phi could adhere to epithelial cells in culture and form transmembrane communication channels as defined by dye transfer. Primary cultures of murine M phi and a M phi cell line, P388D1, adhered to Mode-K and IEC6, but not CMT-93 IEC. Antibody blocking studies determined that P388D1-Mode-K binding was partially dependent on beta 2 integrin (CD18) function, Mode-K constitutively expressed CD106 (VCAM-1) and cell associated fibronectin, while P388D1 expressed low levels of CD49d/CD29 (VLA4) but blocking antibodies to these surface molecules did not inhibit P388D1-Mode-K adherence. Transfer of calcein dye from M phi to IEC was quantitated by flow cytometry and was dependent on M phi-IEC adhesion. Dye transfer was concentration dependent in that the fluorescence intensity of Mode-K was proportional to the number of adherent P388D1 cells as well as the dye load of the M phi. These results indicate that M phi interact with IEC by adhesion and possibly through gap junctions and may thus regulate IEC function by direct cell-cell communication.

Caffeine consumption habits do not influence the exercise blood pressure response following caffeine ingestion

BACKGROUND

The purpose of this study was to determine if the BP response during walking following caffeine ingestion differed between those who regularly consume caffeine and those who do not.

METHODS

A double-blind cross-over experimental design was used. Data were collected in a research laboratory with a clinical exercise testing room. Eight regular caffeine users and eight men who did not habitually consume caffeine were studied. Each subject consumed of a beverage once with and once without 4.5 mg caffeine/kg fat-free mass added to the drink. Following consumption each subject walked at three intensities of exercise (30, 50, and 70% of VO2peak). Measures of BP were obtained by the auscultatory technique.

RESULTS

Caffeine consumption resulted in significant increases in both systolic BP and diastolic BP at rest and during exercise. The elevation during exercise was 7-8 mmHg at all three exercise intensities for systolic BP; however, for diastolic BP there was only a significant elevation (4 mmHg) at the highest exercise intensity. No differences were noted between those men who regularly consume and those who regularly abstain from caffeine. There was a wide range in the resting BP response to caffeine (combined SBP and DBP ranged from 10-39 mmHg) suggesting that there are marked differences in sensitivity to caffeine, irrespective of individuals' consumption habits.

CONCLUSIONS

Consideration should be given to caffeine intake prior to exercise in patients for whom an additional increase in BP during exercise would not be desirable.

Discriminative stimulus effects of alcohol in humans

The discriminative stimulus effects of alcohol were examined in 11 healthy moderate alcohol users. Study days occurred 5 days per week for 12-25 total days. Each day, participants completed visual-analog reports of drug effect and drug-discrimination tasks at 30-min intervals for 2.5 h following oral alcohol administration. Participants completed three phases. During the training phase, which occurred on the first 4 study days, participants were trained to discriminate color-coded placebo and alcohol doses (0 vs. 0.45 g per liter of body water (g/lbw)). Participants then completed a control phase, during which accurate drug-discrimination performance was verified. Finally, participants completed a testing phase, during which both training and intermediate doses (0.15 and 0.30 g/lbw) were administered. During the testing phase, 25 and 100% of responses occurred on the alcohol key at the 0- and 0.45-g/lbw doses, respectively, indicating that discrimination responding remained intact. At the low dose (0.15 g/lbw), 25% of the subjects responded on the alcohol key, whereas 75% of the subjects responded on the alcohol key at the moderate dose (0.30 g/lbw), indicating dose-related generalization to the training doses. These results confirm cross-species generality in the discriminative stimulus effects of alcohol, and further establishes the utility of human laboratory drug-discrimination procedures for analysis of the functional effects of alcohol.

Ganglioside hydration study by 2H-NMR: dependence on temperature and water/lipid ratio

Dynamic properties of 2H2O in samples of ganglioside aggregates hydrated at water/lipid ratios ranging from 25:1 to 8000:1 mole/mole were studied by using deuterium nuclear magnetic resonance (2H-NMR). We present a physical model for the interpretation of the measured spin-spin relaxation times (T2). For all the concentrations studied the model provides evidence for the existence of at least two kinds of water environments: one in which the rotational correlation time is in the range of 10(-9) to 10(-8) s, and a second in which it lies between 10(-11) to 10(-10) s. A detailed study on the temperature dependence was performed for two of the concentrations, one corresponding to the hexagonal phase (100:1 mole/mole) and the other involving a micellar phase (200:1 mole/mole). In the 100:1 2H2O/ganglioside molar ratio sample, most of the water is tightly bound to long cylindrical structures. For the 200: 1 sample, there are on average approximately 30 water molecules tightly bound to the polar head group of each ganglioside molecule. The relative number and dynamics of molecules in this environment are essentially insensitive to temperature variations in the range 220-300K The rest of water molecules are also influenced by the aggregate, having a different mobility from that observed in the free liquid state.

Gender differences in adolescent psychiatric outpatient substance use: associated behaviors and feelings

OBJECTIVE

To investigate gender differences in substance use and associated high-risk behaviors and feeling states in 220 adolescent psychiatric outpatients.

METHOD

One hundred seven females and 113 males with a mean age of 15.6 (SD +/- 1.4), seen in a tertiary care center adolescent psychiatry clinic, completed scales tapping substance use and associated feelings and behaviors. Approximately half had used nicotine and alcohol, one third had used marijuana, and 10% reported narcotic use.

RESULTS

Conduct disorder behavior, suicidality, and impulsivity scale scores decreased with age in females while marijuana use, conduct disorder behavior, and Hypophoria scale scores increased with age in males. Alcohol use in males, as contrasted with females, correlated more significantly with other substance use and high-risk behaviors. Suicidality tended to correlate more with polysubstance use in females and with sexual behaviors in females only. Substance use correlated with the Impulsivity and Need scale scores in males and scores on the Sociopathy scale in females.

CONCLUSIONS

Substance use in males correlates with high-risk behaviors and is associated with feelings of impulsivity and need. Substance use correlates with self-destructive behaviors and sociopathic feelings in females. There is evidence of more persistent high-risk behaviors, including substance use, in males than in females.

Stimulation of Rb+ influx by bradykinin through Na+/K+/Cl- cotransport and Na+/K(+)-ATPase in NIH-3T3 fibroblasts

Bradykinin receptor stimulation results in G-protein-coupled phospholipase activation, initiating protein kinase C (PKC) stimulation and cytosolic free Ca2+ concentration ([Ca2+]i) rises as signalling pathways. Using Rb+ as a tracer for K+, we have studied the mechanisms involved in bradykinin-stimulated Rb+ influx in NIH-3T3 fibroblasts. The furosemide-sensitive Na+/K+/Cl- cotransport and the ouabain-sensitive Na+/K(+)-ATPase were both involved in Rb+ influx under resting conditions with a ratio Na+/K+/Cl- cotransport/Na+/K(+)-ATPase (r) = 0.73. Bradykinin stimulated Rb+ influx (+82.6%) through both systems without changing their ratio (r = 0.72). PKC stimulation by a 15-min-treatment with phorbol 12-myristate 13-acetate (PMA) (2x10(-7) M) increased Rb+ influx in resting cells by 75.7% without affecting r (0.75). PKC inhibition by H-7, and PKC down-regulation by 24-h PMA (10(-6) M) treatment decreased the bradykinin-induced stimulation of Rb+ influx (+31% and +14.9% above control, respectively). Both down-regulation and inhibition of PKC dramatically reduced the furosemide-sensitive Na+/K+/Cl- cotransport, as r fell to 0.239 and 0.032 in bradykinin-stimulated cells after H-7 and 24-h PMA treatments, respectively. BAPTA/AM pretreatment (10(-4) M, 60 min), which complexed with [Ca2+]i, not only prevented the bradykinin-induced [Ca2+]i raise, but also partially inhibited bradykinin-induced Rb+ influx stimulation (+39% above control), without modifying r (0.76). We conclude that stimulation of PKC is a major pathway involved in bradykinin stimulation of Rb+ influx in NIH-3T3 fibroblasts, and that rises in [Ca2+]i participate in bradykinin signalling, possibly through PKC activation. Our data also suggest that active PKC is required for basal and bradykinin-stimulated Na+/K+/Cl- cotransport activity in these cells.

In vitro pharmacological effects of S 12370 (2-[4-benzhydryloxypiperidinoethyl]isoxindole; an antibronchoconstrictor agent) in normal and sensitized tissue

The effects of S 12370 (2-[4-benzhydryloxypiperidinoethyl]isoxindole), were studied in vitro. In guinea pig isolated tracheal rings, S 12370 induced a similar competitive inhibition of the contractile responses produced by acetylcholine, histamine and serotonin. However, it did not affect the contractions induced by leukotriene D4 (LTD4), substance P and U 46619, a stable analogue of thromboxane A2. S 12370 induced a concentration dependent inhibition of the cholinergic component of the contraction induced by electrical field stimulation, whereas it did not influence the sustained nonadrenergic noncholinergic (NANC) excitatory response observed in guinea pig isolated bronchi. S 12370 did not influence the relaxations induced by prostaglandin E2, isoprenaline and salbutamol, and did not modify the nonadrenergic noncholinergic inhibitory response induced by electrical field stimulation. In isolated left atria, the negative inotropic effect of acetylcholine was competitively inhibited by S 12370. In binding experiments, S 12370 exhibited similar affinity for M1, M2, M3, M4 muscarinic receptors and also recognized 5-HT2 serotonin and H1 histamine receptor subtypes. In ovalbumin-sensitized animals, the contractile response of isolated tracheal rings produced by exposure to the allergen was not influenced by S 12370. Tracheal rings from sensitized animals preexposed in vitro to the allergen developed a hyporesponsiveness to beta-adrenoceptor stimulation. S 12370 prevented the inhibitory effect caused by ovalbumin immune sensitization in the relaxation to isoprenaline. In rat polymorphonuclear neutrophil (PMN) cells, S 12370 up to 10(-5) M did not inhibit the arachidonic acid metabolism. These results suggest that in guinea pig tracheal smooth muscle, S 12370 is a competitive inhibitor of muscarinic, serotonin and histamine receptors and can modulate the beta-adrenergic dysfunction induced by immune sensitization. S 12370 may present some therapeutic interest in inflammatory airway diseases.