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Biomedical subjects

D Barrett

Publications and source records attributed to D Barrett.

At least 73 records · Page 4Linked to original sources
PubMed1990

Effects of azatadine, terfenadine, and astemizole on allergen-induced nasal provocation.

Fifty-six patients with ragweed seasonal rhinitis were challenged intranasally with ragweed. A clinical score (0-12)--including measurements of rhinomanometry, secretions, and sneezes--was generated. Each patient then received either azatadine (A), terfenadine (T), astemizole (AS), or nothing (control), for 1 week. Repeat challenges revealed changes in clinical score with A 3.6 (P less than .01), AS 3.1 (P less than .02), and T 2.7 (P less than .05). All three antihistamines similarly inhibited the nasal provocation response to ragweed.

Adolescent↗
PubMed1989

New form of pseudohypoparathyroidism with abnormal catalytic adenylate cyclase.

Patients with pseudohypoparathyroidism type Ia have resistance to multiple hormones because of deficient activity of the stimulatory guanine nucleotide-binding protein (Gs) that couples membrane receptors to activation of adenylate cyclase. However, in a subset of patients with pseudohypoparathyroidism who have resistance to multiple hormones yet possess normal erythrocyte membrane Gs activity, the biochemical abnormality responsible for hormone resistance has remained undefined. Cultured skin fibroblasts were derived from a patient with this atypical form of pseudohypoparathyroidism. In the patient's fibroblast membranes, adenylate cyclase stimulation mediated by Gs after fluoride ion treatment produced only 52% of normal activity, yet fibroblast membrane Gs activity measured by cyc- complementation was normal. Activation of the catalytic unit of adenylate cyclase with manganese produced 49% of normal activity; manganese plus forskolin produced 54% of normal adenylate cyclase activity. beta-Adrenergic receptor coupling to Gs and phosphodiesterase activity were normal. A defect in the catalytic unit of adenylate cyclase can account for these results and may be a mechanism for clinical resistance to multiple hormones that act through adenylate cyclase.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1989

Isolation and preliminary characterization of immunoinhibitory factors from dog erythrocytes and liver.

Crude dog liver extract (DLE) inhibits proliferation of dog and human lymphocytes stimulated by phytohemagglutinin and alloantigens. While purifying this activity from dog liver, we observed that dog liver inhibitory factor (DLIF) shared properties with hemoglobin. DLIF migrated with hemoglobin during DEAE cellulose chromatography, and DLIF had oligomeric (61,900) and subunit (17,900 and 15,700) apparent molecular weights (AMW) similar to concurrently analyzed Sigma canine hemoglobin (61,100, 16,700 and 14,900). After separate cross linking, the proteins comigrated on sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) gels. We therefore isolated dog erythrocyte inhibitory factor (DEIF) from red blood cells to determine if DEIF was a hemoglobin derivative. DEIF, like DLIF, separated at an isoelectric point of 5.6. DEIF also had similar subunit AMW (17,600 and 15,300) by SDS PAGE, but DEIF had much lower lymphocyte inhibitory activity (LIA = 2.27) than DLIF (LIA = 100.00). We conclude that DLIF and DEIF are similar to each other and hemoglobin, but further studies are needed to determine the function and exact structure of DLIF and DEIF.

Animals↗
PubMed1989

Hypnotic susceptibility and dream characteristics.

This study examined the relationship of hypnotic susceptibility to a variety of dream characteristics and types of dream content. A Dream Questionnaire was constructed synthesizing Gibson's dream inventory and Hilgard's theoretical conceptions of hypnosis. Employing the Harvard Group Scale of Hypnotic Susceptibility and the Field Inventory for evaluating hypnotic response, several dream dimensions correlated significantly with hypnotizability. For subjects as a whole, the strongest correlates were the frequency of dreams which they believed to be precognitive and out-of-body dreams. Ability to dream on a chosen topic also correlated significantly with hypnotic susceptibility for both genders. For females only, there was a negative correlation of hypnotic susceptibility to flying dreams. Absorption correlated positively with dream recall, ability to dream on a chosen topic, reports of conflict resolution in dreams, creative ideas occurring in dreams, amount of color in dreams, pleasantness of dreams, bizarreness of dreams, flying dreams and precognitive dreams.

Adolescent↗
PubMed1988

Thymosin and the spontaneously diabetic BB rat.

The biological basis for autoimmunity and immunoincompetence in the BB rat has yet to be localized. In spite of normal thymic histology, thymocyte subsets and blastogenesis, thymus gland products (thymosins) have yet to be studied. In the present report, thymus gland function was studied by measuring thymosin alpha 1 levels at one time point in the BB rat compared with control rates, and BB rat responses to exogenous thymosin (Thymosin fraction 5) were observed. At five months of age, BB rats had thymosin alpha 1 levels comparable to Lewis and Wistar furth rats. Thymosin fraction 5 increased the ratio of peripheral blood W3/25 positive to OX8 positive cells, but otherwise had no effect on the BB rats' T-cell immunodeficiency, or frequencies of tissue autoantibodies or insulin-dependent diabetes. Although B-lymphocyte counts were normal in BB rats, splenocyte responses to B-lymphocyte mitogens were depressed. However, thymosin fraction 5 improved the BB rat B-lymphocyte blastogenesis to near normal for Mycoplasma neurolyticum. Coupled with our previous work, our results suggest that the immune derangement in the BB rat resides outside the thymus.

Animals↗
PubMed1987

Preclinical toxicology studies of 4-ipomeanol: a novel candidate for clinical evaluation in lung cancer.

4-Ipomeanol (ipomeanol) is being developed as a potential antitumor agent to treat lung cancer. Ipomeanol produced a dose-related toxicity in CD2F1 mice, Fischer 344 rats, and beagle dogs. The LD50 in mice after a single iv dose of ipomeanol was 35 mg/kg in males and 26 mg/kg in females. Minimal cumulative toxicity occurred in mice after seven doses; LD50 was 30 mg/kg/day in males and 21 mg/kg/day in females. In rats, iv doses greater than or equal to 15 mg/kg were lethal. Labored respiration, terminal bronchiolar epithelial necrosis, interstitial inflammation, and alveolar edema were present in rats dosed with ipomeanol at greater than or equal to 9 mg/kg. In addition to pulmonary lesions, splenic and thymic lymphocyte depletion and/or necrosis was present. Ipomeanol had little cumulative toxicity in rats given seven daily doses. In dogs, iv doses greater than 12 mg/kg were lethal. Dogs treated with lethal doses of ipomeanol showed rapid, shallow respiration and pulmonary edema prior to death; diffuse pulmonary congestion or hemorrhage and diffuse renal congestion were present at necropsy. Pulmonary microscopic changes caused by nonlethal doses of ipomeanol included subacute interstitial inflammation and necrosis of respiratory bronchiolar and alveolar duct epithelium. In contrast to rodents, seven daily doses of ipomeanol were cumulatively toxic in dogs. The nonlethal pulmonary effects of ipomeanol were reversible in all three species. Tolerance to lethal doses of ipomeanol occurred in animals of all three species pretreated with multiple nontoxic doses of the drug. The LD50 of ipomeanol in male and female mice increased 2.4- and 4.5-fold, respectively, in tolerant mice. In rats and dogs, previously lethal doses of 48 and 24 mg/kg were nonlethal after tolerance was induced by pretreatment with seven daily doses of ipomeanol.

Animals↗
PubMed1985

Sequence structures of a mouse major urinary protein gene and pseudogene compared.

Laboratory mouse strains carry approximately 35 major urinary protein (MUP) genes per haploid genome, tightly clustered together on chromosome 4. Most belong to two main groups (Groups 1 and 2). The available evidence strongly suggests that the Group 1 genes are active while the Group 2 genes are pseudogenes. Here we present the complete sequence of a Group 1 gene and a Group 2 gene and 700 bp of flanking sequence. The sequence of the Group 1 gene is consistent with its being active. The Group 2 gene contains two stop codons and a frame-shift mutation in the reading frame defined by the Group 1 gene, and would code for a signal peptide 25 rather than 19 amino acids long. The Group 2 gene differs from the Group 1 gene in other ways: a deletion upstream of the TATA box and another in intron 3, a base change in the TATA box itself, a 2 bp duplication at the splice acceptor boundary of intron 6, an altered poly(A) addition signal and a 1-base deletion 5' to the initiation codon. Some of these differences may explain the 10- to 20-fold higher level of Group 1 mRNA in mouse liver, and the fact that Group 1 and Group 2 transcripts are mainly spliced differently. The presence of the stop codon means that the Group 2 gene is a pseudogene in the context of the Group 1 gene. However, there is some evidence that the mature hexapeptide that it would code for may have biological activity. The 12 acceptor splice sites of the two genes all contain the identical sequence ACAG at the exon boundary.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Measurement of antigen-specific IgE in nasal secretions of patients with perennial rhinitis.

Sixteen of 53 patients with rhinitis had positive skin tests corresponding with serum-specific IgE (RAST). Concomitant positive nasal secretion (NS) RAST was found in 10/16. Four patients with both negative skin tests and serum RAST had positive NS RAST. In a subset of patients with perennial rhinitis, specific IgE may be detected only in NS. Further studies are necessary to document the clinical relevance of such NS IgE antibodies.

Absorption↗
PubMed1984

Hospital boards and adaptability to competitive environments.

The characteristics of a hospital's board vis-a-vis its environment is a critical strategic factor in determining success. Those institutions that are successful in competitive versus noncompetitive environments will have boards that exhibit certain readily definable--and different--characteristics.

Data Collection↗
PubMed1984

Anaerobic testing using the Wingate and Evans-Quinney protocols with and without toe stirrups.

Recently, considerable attention has been focused on the measurement of maximal anaerobic power. The Evans-Quinney (1981) protocol which considers leg volume as well as body weight in establishing optimal load settings on the bicycle ergometer has been shown to result in significantly higher anaerobic power outputs than the body weight-relative Wingate protocol. The purpose of this investigation was to compare the anaerobic power outputs during bicycle ergometer work using the Wingate and Evans-Quinney protocols with and without toe stirrups. Fifty male physical education and varsity athletes (average age 22.6 years) volunteered to participate in this experiment. All subjects performed a total of four maximal 30-second anaerobic power tests utilizing the force settings established by the Wingate (load [L] = 0.075 kp/kg body weight) and Evans-Quinney (L = -0.4914-0.2151 (weight, kg) + 2.1124 (leg volume, litre) protocol. The subjects were randomly assigned to one of four counterbalanced orders of test administration. Analysis of data indicated significant differences (P less than or equal to .05) among the variables of: 5-second peak power (W), 30-second anaerobic capacity (W) and percent fatigue as a function of test protocol. Significantly higher values were obtained for all variables under the Evans-Quinney test procedure using toe stirrups while the Wingate test procedure without toe stirrups showed significantly lower values for all variables. It was concluded that the Evans-Quinney load setting protocol with toe stirrups resulted in significantly higher power measures than any of the other treatments tested.

Adult↗
PubMed1983

Venom immunotherapy--a critical evaluation of in vitro techniques.

An immunological evaluation of 62 Hymenoptera sensitive patients, including 13 treated with venom, was undertaken. Skin testing was more sensitive than serum specific IgE and total IgE was not helpful. Specific IgE did not decrease on therapy. Changes in specific IgG occurred in bee but not in mixed vespid treated patients.

Antigen-Antibody Complex↗
PubMed1982

Chronic urticaria and angioedema.

Of 231 patients evaluated for chronic urticaria and angioedema (CUA), 192 were diagnosed as having an idiopathic condition. The roles of serum IgE, complement (CH50), and immune complexes (IC) were investigated in 112 patients with idiopathic CUA. Immediate skin tests were not helpful, but total IgE was elevated in 13%, equally divided between dermographic (D) and non-dermographic (ND) patients. Depressed haemolytic complement (CH50) was noted in 10% of CUA, all of whom were D. Serum IC were elevated in 38% equally divided between D and ND patients. There was no relationship between depressed CH50 and elevated IC. Skin biopsies, evaluated by both light and immunofluorescent techniques, were negative for all specimens tested. The pathophysiology of idiopathic CUA is multifactorial, with a variety of immunological mechanisms involving serum IgE, CH50, and IC. . The relationship between depressed CH50 and dermographism was noted but unexplained by serum or tissue studies.

Adenocarcinoma↗