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Biomedical subjects

I L Bernstein

Publications and source records attributed to I L Bernstein.

At least 19 recordsLinked to original sources
PubMed1992

Area postrema mediation of physiological and behavioral effects of lithium chloride in the rat.

The area postrema (AP), a chemoreceptor trigger zone for nausea and vomiting, has been implicated in taste aversion conditioning with LiCl. In addition to taste aversion acquisition, the present studies indicate that a number of other responses to LiCl administration are eliminated by lesions of the AP. These include a behavioral response, 'lying-on-belly' as well as two physiological responses, delayed stomach emptying and hypothermia. These findings suggest that the area postrema is critically involved in the detection of LiCl and in a wide range of responses to this toxin. They also provide strong evidence that the failure to acquire conditioned taste aversions to LiCl-paired flavors after AP lesions can be attributed to the absence of a significant 'illness' response in lesioned animals.

Animals↗
PubMed1992

Vasopressin deficiency abolishes a sexually dimorphic behavior in Brattleboro rats.

The role of vasopressin (VP) in a sexually dimorphic behavior, the extinction of a conditioned taste aversion, was investigated in male and female rats of three different genotypes. This behavior was examined with a two bottle test in the wild-type Long-Evans (LE) rats, and then in partially VP deficient heterozygous (HET-BB) and completely VP deficient homozygous (HO-BB) Brattleboro rats. In Experiment 1, non-deprived male and female LE rats were given aversions to a sucrose solution by pairing it with a LiCl injection. The rate of extinction of the aversion upon reexposure to ad lib sucrose solution was examined and observed to be sexually dimorphic. Female LE rats extinguished at a significantly more rapid rate than males. Experiment 2 compared HET-BB and HO-BB male and female rats using the same paradigm. Neither of these VP-deficient groups showed sexual dimorphism of the extinction behavior. The data suggest that intact VP levels are necessary to observe the expression of this sexually dimorphic behavior.

Animals↗
PubMed1992

Behavioral conditioned responses to contextual and odor stimuli paired with LiCl administration.

The present experiments examined whether behavioral conditioned responses (CRs) develop to LiCl-paired contextual and odor stimuli, and whether these CRs are similar to the behaviors observed following the administration of the drug. During conditioning, a novel context (Experiment 1) or a novel odor (Experiment 2) was paired with LiCl injections, and the CRs which developed to these stimuli were assessed during testing. Suppression of general activity occurred after LiCl exposure and after exposure to the lithium-paired context and odor. However, the actual behaviors which emerged as conditioned responses were distinctly different from those which were elicited by the drug itself. Lying on belly was the predominant unconditioned response to LiCl. Freezing was the predominant CR to the context, whereas gaping was the predominant CR to the odor. These outcomes are discussed and compared to previous results using a taste stimulus.

Animals↗
PubMed1992

Prevalence of dust mites in the homes of people with asthma living in eight different geographic areas of the United States.

The density and species prevalence of dust mites were determined at various times over a 5-year-period in 252 homes of dust mite sensitive people with asthma who lived in eight geographic areas of the United States (Cincinnati, Ohio; New Orleans, La.; Memphis, Tenn.; Galveston, Texas; Greenville, N.C.; Delray Beach, Fla.; San Diego and Los Angeles, Calif.). The most common dust mites found in the homes were Dermatophagoides farinae (DF), D. pteronyssinus (DP), Euroglyphus maynei (EM), and Blomia tropicalis. All homes in all locations contained Dermatophagoides spp. mites, but few homes were populated exclusively by either DF or DP alone. Most homes (81.7%) were coinhabitated by both DF and DP. In coinhabited homes one species was predominant and usually made up at least 75% of the total mite population. Prevalence of the dominant or only species present varied between homes within a geographic area. EM occurred in significant numbers in 35.7% of homes in New Orleans, Memphis, Galveston, Delray Beach, and San Diego. Blomia tropicalis occurred in these same cities but in low densities. For all dust samples, only 13 homes of the 252 sampled had 100 or fewer mites/gm dust, which is considered to be the threshold for sensitivity. Most homes had average mite densities of 500 or more mites/gm dust. The results of the present study suggest a significant and widespread occurrence of both DF and DP. Therefore extracts of both mite species should be considered for diagnostic tests and immunotherapy. Significant levels of EM were present in some areas. Thus sensitivity to EM should be considered in these areas.

Adolescent↗
PubMed1992

Evaluation of cutaneous responses and lung function from exposure to opiate compounds among ethical narcotics-manufacturing workers.

We recently demonstrated morphine-6-hemisuccinate-human serum albumin conjugate (M-6-HS-HSA)-specific IgG in serum from ethic narcotics-manufacturing workers. In this article, we present results of epicutaneous tests to opiate compounds and lung-function studies in these same workers. Thirty-nine workers, exposed to opiates, were evaluated for possible work-related changes in lung function and were administered a questionnaire concerning opiate exposure and health history in February 1988. In December 1988, 33 employees with occupational exposure to opiates, six other workers (New Jersey referent) employed at the same factory with minimal exposure to opiate compounds, and 17 nonexposed individuals from Cincinnati, Ohio, were subjected to epicutaneous threshold testing with a panel of six opiate compounds and nine common aeroallergens. In opiate-exposed workers, significantly lower epicutaneous threshold concentrations were detected (compared to New Jersey referent and Cincinnati control subjects) for dihydrocodeine (p less than 0.01), hydrocodone (p less than 0.05), codeine (p less than 0.01), and morphine (p less than 0.05). Significant associates existed among epicutaneous threshold concentrations between the agents tested; that is, individuals with a positive morphine skin test would generally have a positive codeine skin test, etc. Atopic status (positive cutaneous test results to two or more of nine common aeroallergens) was not significantly associated (p greater than 0.05) with positive opiate skin sensitivity. Although the mean cross-shift decrements in FEV1 for all workers were nonsignificant, five opiate-exposed individuals demonstrated cross-shift decrements in FEV1 of greater than 10%. Daily maximum-minus-minimum changes in workweek PEFR (PEFRmax-min) were significantly reduced for Monday through Thursday (p less than 0.05) compared to PEFRmax-min changes during a nonwork, nonexposure 3-day weekend. Ten exposed workers demonstrated daily PEFRmax-min changes of greater than 20%, suggesting acute airway obstruction. Increased cutaneous reactivity to opiate compounds among opiate-exposed workers may reflect development of pharmacologic hyperresponsiveness to opiate compounds.

Adult↗
PubMed1992

Amiloride sensitivity of the chorda tympani response to sodium chloride in sodium-depleted Wistar rats.

Peripheral gustatory mechanisms that may contribute to the expression of sodium (Na) appetite have been a focus of interest for many years. Because amiloride-sensitive Na transport is involved in the generation of neural signals in response to NaCl stimulation, the present study assessed whether changes in amiloride sensitivity of the neural response to NaCl accompany the induction of a Na appetite in the rat. Na deprivation was achieved by acute depletion with the diuretic furosemide. The magnitude of the whole-nerve chorda tympani response to 0.5 M NaCl was reduced in Na-depleted, compared with Na-replete, rats, which provides qualified support for previous reports that the induction of a Na appetite is associated with reduced neural responses to NaCl. However, changes in sensitivity to the specific Na channel blocker amiloride hydrochloride as a result of Na depletion were not evident. These findings suggest that the behavioral and neural changes that occur after Na depletion are not based on changes in amiloride sensitivity in the taste bud.

Amiloride↗
PubMed1992

Sodium appetite after transection of the chorda tympani nerve in Wistar and Fischer 344 rats.

Acute sodium depletion in rats leads to dramatic increases in intake of hypertonic NaCl solutions, a behavior known as sodium appetite. The importance of signals conveyed by the chorda tympani (CT) nerve to the expression of sodium appetite is unclear. We examined the effects of bilateral CT transection on the short- and long-term response to sodium depletion in Wistar and Fischer 344 (F344) rat strains, because Wistar rats normally display a NaCl preference in the absence of need whereas F344 rats avoid NaCl. In both strains, sodium appetite after CT transection and treatment with the diuretic furosemide was delayed and blunted or eliminated. The results suggest that signals conveyed by the CT nerve are important in the expression of a sodium appetite. Effects on F344 rats are particularly interesting because CT transection surgery appears to have opposite effects on NaCl intake depending on whether F344 rats are sodium replete or deplete.

Animals↗
PubMed1992

The relationship between airway responsiveness measured before and after the allergen-induced late asthmatic response.

Single blind allergen (Ag) and saline solution bronchial challenges were performed on two successive study days in ten asthmatic subjects. Histamine challenges were performed before, at approximately 2 h (or after resolution of the immediate bronchial response [IR]), and 24 h after saline solution or Ag inhalation. Specific airway conductance (SGaw) was measured after delivery of challenge agents until a 50 percent fall in SGaw was observed. The SGaw was monitored over 8 h for immediate and late asthmatic responses (LAR). Results were expressed as provocative concentrations eliciting a 50 percent decrease in SGaw (SGawPC50HIS). No significant changes from baseline SGaw or SGawPC50HIS were demonstrated after saline solution. Eight subjects (dual reactors) exhibited both an IR and LAR after Ag and two had isolated IRs. Of the eight dual reactors, five had greater than 50 percent decreases in SGawPC50HIS immediately after resolution of the IR and six exhibited such decrements 24 h after Ag provocation. Mean baseline SGawPC50HIS (N = 10) on the Ag challenge day was 3.2 +/- 4.59 mg/ml and decreased to 0.92 +/- 4.56 mg/ml at 102 to 187 minutes after Ag (p = 0.0009) and was significantly decreased from baseline at 1.47 +/- 3.8 mg/ml 24 h after Ag (p = 0.0004). One of the two patients with isolated IR also showed an early onset increase in airway responsiveness (EOR). There was a significant correlation between the percentage of fall from baseline in SGawPC50HIS immediately after the IR and that at 24 h after Ag (r = 0.811, p = 0.005). There was no significant correlation between the decrease in SGawPC50HIS after the IR and the magnitude of the LAR. These data suggest that (1) the early events occurring prior to the LAR may determine changes in airway responsiveness observed at 24 h after Ag challenge, and (2) the EAR to histamine is not exclusively associated with the LAR.

Airway Resistance↗
PubMed1992

Angioneurotic edema with acquired C1- inhibitor deficiency and autoantibody to C1- inhibitor: response to plasmapheresis and cytotoxic therapy.

A patient with severe acquired angioneurotic edema had essentially no C1- inhibitor activity in his serum and nearly died of cardiopulmonary arrest during an acute episode of facial, oral, and pharyngeal edema. This patient had an antibody directed against C1- inhibitor and C1- inhibitor-anti-C1- inhibitor complexes in his serum. The antibody required a normal residue (Arg) in the reactive center of the inhibitor for its optimal interaction with the inhibitor. Plasmapheresis with 5% human serum albumin replacement relieved him of his antibody load and the edema; additional treatment with pulsed cyclophosphamide has provided a sustained remission. The 5% albumin solution that was used contained functional C1- inhibitor; other lots that were tested contained only traces or none. No underlying disease has yet been identified. During this acute episode of edema, the C1- inhibitor in the patient's plasma was a 92 kd component, and on recovery, a 105 kd component reappeared. C1- inhibitor isolated from the patient's plasma, which was obtained before pheresis, was mainly in lower molecular weight forms (56 kd and 45 kd). The antibody in the patient's serum appeared to render C1- inhibitor susceptible to proteolysis, for when purified antibody was added to normal serum, a cleaved form of C1- inhibitor was generated.

Angioedema↗
PubMed1992

Pemirolast, a new oral nonbronchodilator drug for chronic asthma.

Pemirolast is a new oral, nonbronchodilator antiallergy medication that is being evaluated for the therapy of asthma. In this multicenter, double-blind, randomized study, 96 patients with mild asthma received pemirolast, 50 mg (n = 34); pemirolast, 25 mg (n = 31); or placebo (n = 31) BID for 6 weeks. Patients were evaluated weekly at the research centers; they maintained daily symptom diaries and measured peak expiratory flow rates twice a day. Methacholine challenge was performed at the start and end of the study. Results with pemirolast, 50 mg BID, showed statistically significant decrease in nocturnal symptoms (P = .02), in composite symptom scores (P = .02) and in bronchodilator use (P = .05) when compared with placebo. There were no statistically significant differences between treatments in pulmonary function tests or in methacholine challenge sensitivity. Pemirolast, 25 mg BID, did not differ from placebo. There were no significant adverse effects. Pemirolast, 50 mg BID, demonstrated sufficient antiasthma activity to warrant further studies in patients with more severe asthma and with higher doses.

Administration, Oral↗
PubMed1991

Reversal of the sodium chloride aversion of Fischer 344 rats by chorda tympani nerve transection.

Fischer 344 (F344) rats are atypical in their lack of preference for any concentration of NaCl solution over water. It was hypothesized that abnormal signals mediated by the chorda tympani nerve (CT) could be causally involved in NaCl avoidance by F344 rats. This study assessed whether CT transection would normalize the salt preference of F344 rats. Preference for NaCl solutions (0.6%, 0.8%, and 1.0%) versus water was assessed using two-bottle preference tests. At all concentrations tested, CT-transected animals preferred NaCl solutions to water. This preference differed dramatically from the avoidance of these solutions by controls. These findings are striking, particularly because CT transections have generally failed to significantly affect NaCl preference in other rat strains. The results are consistent with the hypothesis that in F344 rats the avoidance of the taste of NaCl stems from input mediated by the CT.

Animals↗
PubMed1991

TNF-induced anorexia and learned food aversions are attenuated by area postrema lesions.

Tumor necrosis factor (TNF) or cachectin has been proposed as an important mediator of cancer anorexia and cachexia. The present studies examined the extent to which TNF administration generates symptoms similar to those produced by tumor growth. Like the growth of certain tumors, TNF administration was found to be associated with the development of strong aversions to a novel diet. Area postrema lesions were found to significantly attenuate the effects of TNF on intake of a novel diet, a finding previously reported for tumor anorexia. In addition, the anorexic effects of TNF differed considerably as a function of the novelty of the diet. When the available diet was novel, effects of TNF in lowering food intake were substantial, whereas more modest effects were seen when the diet was familiar. These findings provide evidence for parallels between TNF- and tumor-induced anorexias. Nonetheless, these studies also confirm previous observations of the rapid development of tolerance to the anorexic effects of TNF, a finding that is not consistent with a role for TNF as a critical mediator of tumor anorexia.

Animals↗
PubMed1991

Amiloride sensitivity of chorda tympani response to NaCl in Fischer 344 and Wistar rats.

Fischer 344 (F-344) rats fail to prefer NaCl solutions to water at any concentration and avoid NaCl solutions preferred by other strains, including Wistar rats. Behavioral and electrophysiological responses of the mammalian gustatory system to NaCl have been shown to depend on a sodium transport system that is specifically blocked by lingual application of the sodium-transport blocker amiloride. The present study examined whether strain differences exist between F-344 and Wistar rats in the amiloride sensitivity of the chorda tympani (CT) electrophysiological response to NaCl. Whole nerve CT recordings were obtained from adult F-344 and Wistar rats during chemical stimulation of the anterior tongue. Responses to NaCl solutions ranging from 0.01 to 1.0 M were examined both before and after pretreatment with amiloride hydrochloride. Integrated whole nerve responses to NaCl solutions were expressed relative to the response to 0.5 M NH4Cl. Strain differences in the response to NaCl solutions emerged, with F-344 animals showing a significantly larger amplitude of the tonic response to NaCl, relative to NH4Cl, than Wistars. F-344 rats were also more sensitive to the sodium-channel blocker amiloride. These results suggest that strain differences in amiloride sensitive signals mediated by the CT nerve may contribute to the NaCl aversion displayed by F-344 rats.

Amiloride↗
PubMed1979

Preferential synthesis of IgE reaginic antibodies in rats immunized with alum-adsorbed antigens.

The reaginic antibody response to alum-precipitated ovalbumin (OA) and the dialyzed water-soluble extracts of ragweed (DWSR) and Alternaria tenuis (DWST) in several strains of rats appeared to be wholly an IgE response. There was no evidence of a heat-stable (IgGa) antibody to OA, DWSR and DWST in the sera of the rats immunized with these antigens suspended in alum. Wistar-Furth and Lew inbred and hooded outbred rats produced comparable amounts of reaginic antibody after immunization with DWST, but BN inbred rats failed to generate a reaginic response to this antigen. The amount of antigen-induced histamine release from rat peritoneal mast cells did not always correlate with the level of circulating IgE-specific antibody.

Adsorption↗
PubMed1979

Studies on Alternaria allergens. I. Isolation of allergens from Alternaria tenuis and Alternaria solani.

Extracts of Alternaria tenuis and Alternaria solani were separated into dialyzable (molecular weight less than 10,000) and non-dialyzable forms. The latter was further fractionated by gel filtration through Sephadex G-100 followed by ion-exchange chromatography on DEAE-cellulose. The dialyzable material was fractionated by gel filtration through Sephadex G-50. The allergenic activities of the fractions obtained from the A. tenuis extract was measured in vitro by the radioallergosorbent test assay and the allergenic potency was measured by radioallergosorbent test inhibition assay. Allergenic activity was detected in most of the non-dialyzable fractions, the majority of the activity being in the last G-100 fraction (MW approximately 20,000) which was predominantly protein in nature. The same component may be responsible for the activity found in the dialyzate and its first G-50 fraction since the immunodiffusion studies indicated that the last G-100 fraction has antigenic components in common with those of the first G-50 fraction. In addition, cross-reactions between A. tenuis and A. solani extracts show that the two species share common antigenic determinants.

Allergens↗