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Biomedical subjects

J Hebert

Publications and source records attributed to J Hebert.

At least 37 records · Page 2Linked to original sources
PubMed1994

Association Between Serial Measures of Systemic Blood Pressure and Early Coronary Arterial Perfusion Status Following Intravenous Thrombolytic Therapy.

Background: Systemic hypotension, at times transient while in other instances more prolonged, is common among patients with myocardial infarction (MI). It also is a characteristic feature for patients experiencing either advanced congestive heart failure or cardiogenic shock. In this group of patients, thrombolytic therapy has failed to exert. favorable impact on their high in-hospital mortality. Although it has been postulated that the success of thrombolytic therapy is directly linked to systemic blood pressure' there is little information available in human subjects. Methods and Results: In a University of Massachusetts Thrombolysis Data Bank Study, 127 patients with MI who were given intravenous thrombolytic therapy (tPA or streptokinase) within 6 hours from symptom onset (4.2 +/- 1.5 hours) had serial systemic blood pressure measurements (at the time of hospital arrival, treatment initiation, and every 30 minutes during the thrombolytic infusion) and underwent coronary angiography within 120 minutes of treatment initiation. All patients received intravenous heparin and oral aspirin. By univariate analysis, disastolic blood pressure below 80 mmHg at the time of treatment initiation was associated with a reduced angiographic coronary perfusion grade [Thrombolysis in Myocardial Infarction (TIMI) flow grade; p + 0.02]. A correlation analysis of tPA-treated patients indicated that a greater maximum change in diastolic blood pressure during treatment correlated inversely with coronary perfusion (r +.24, p < 0.05). By multivariate regression analysis, however, only shorter time to treatment (p + 0.001) and thrombolysis with tPA (p + 0.02) were independent predictors of coronary arterial perfusion grade. Conclusion: Systemic blood pressure (and presumably proximal coronary arterial perfusion pressure) in the ranges investigated in this study is not an independent predictor of coronary reperfusion following intravenous thrombolytic therapy with either tPA or streptokinase. It seems likely, therefore, that properties intrinsic to the ruptured plaque and occlusive thrombus, and potentially the local metabolic environment, either alone or acting synergistically with perfusion pressure, are determinants of thrombolytic success. Further investigation of factors influencing the efficacy of thrombolysis should be undertaken.

Journal Article↗
PubMed1994

Multicenter trial of fluticasone propionate aqueous nasal spray in ragweed allergic rhinitis.

A 4-week multicenter, double-blind, placebo-controlled, parallel-group trial was carried out with 416 adults with ragweed allergic rhinitis to compare 200 micrograms of fluticasone propionate once daily and 100 micrograms of fluticasone propionate twice daily with placebo. Compared with placebo, both groups receiving fluticasone propionate had greater number of symptom free days (P < .01), lower median symptom scores (P < .01), and greater number of days not requiring rescue medications (P < .001). No significant differences for individual symptoms were found between the two fluticasone propionate groups except that those taking the twice daily dosage used less antihistamine (P < .01) and had greater number of days free of rescue medications (P < .05). Adverse events were comparable between the three groups. These results indicate that topical intranasal fluticasone propionate 200 micrograms once daily and 100 micrograms twice daily are both efficacious and well tolerated.

Administration, Intranasal↗
PubMed1993

Evaluation of fluticasone propionate (500 micrograms day-1) administered either as dry powder via a Diskhaler inhaler or pressurized inhaler and compared with beclomethasone dipropionate (1000 micrograms day-1) administered by pressurized inhaler.

Five hundred and eighty-five patients with moderate asthma, currently receiving 400-1000 micrograms day-1 of an inhaled corticosteroid, were treated for 6 weeks in a double-blind, randomized, parallel group study with either 500 micrograms day-1 fluticasone propionate as a dry powder via a Diskhaler inhaler, 500 micrograms day-1 fluticasone propionate via a pressurized inhaler or 1000 micrograms day-1 beclomethasone dipropionate via a pressurized inhaler. For all three treatment groups, mean morning and evening peak expiratory flow rates (PEFRs) increased within 1 week of the start of treatment. There were also improvements in clinic lung function, daytime and night-time asthma symptoms and a reduction in daytime and night-time rescue bronchodilator medication in all three groups. There were no statistically significant differences between the two formulations of fluticasone propionate in any of the efficacy parameters. Fluticasone propionate via the Diskhaler was significantly more effective than beclomethasone dipropionate over the 6 week study period in reducing diurnal variation (mean difference--4 l min-1, 95% CI--8 to 0 l min-1: P = 0.03). Fluticasone propionate via the Diskhaler produced a statistically significant improvement in night-time symptoms when compared to beclomethasone dipropionate whereas, beclomethasone dipropionate 1000 micrograms day-1 was statistically significantly more effective than both formulations of fluticasone propionate in improving daytime symptoms (P < 0.05). However, these statistical differences must be viewed together with the fact that very few patients recorded a score of 2 or more for both daytime or night-time symptoms. There was a similarly low incidence of adverse events with all three treatments with no evidence of hypothalamic pituitary adrenal (HPA)-axis suppression. The results of the 6-week comparative study showed that 500 micrograms day-1 fluticasone propionate whether administered via pressurized inhaler or Diskhaler is as effective and as safe as 1000 micrograms day-1 beclomethasone dipropionate administered via a pressurized inhaler in the treatment of moderate asthma. Over 12 months fluticasone propionate 500 micrograms day-1 via a pressurized inhaler was at least as effective and as well tolerated as beclomethasone dipropionate 1000 micrograms day-1.

Adolescent↗
PubMed1993

Translocation t(3;22)(q27;q11) in non-Hodgkin's malignant lymphoma: chromosome painting and molecular studies.

Translocation t(3;22)(q27;q11) has recently been recognized as a recurrent abnormality in non-Hodgkin's malignant lymphoma (NHL). A new gene, LAZ3, has been shown to be involved in NHL with 3q27 rearrangement. Two patients with B-cell NHL were studied by chromosome painting and Southern blot analysis. Fluorescence in situ hybridization to metaphase chromosomes was shown to be an easy way to detect the chromosomal abnormality even in metaphase cells with poorly defined chromosomes. The gene LAZ3 was rearranged in one patient in the 'major translocation cluster region'. The comigration of rearranged LAZ3 and of IGL bands suggests that the translocation resulted in the juxtaposition of the two genes. This juxtaposition makes possible a potential deregulation of the LAZ3 gene expression, as previously shown for the MYC and BCL2 genes in Burkitt and follicular lymphoma translocations.

Aged↗
PubMed1992

Incorporation of different types of n-3 fatty acids into tissue lipids of poultry.

The objective of the present study was to compare the incorporation of different types of n-3 polyunsaturated fatty acids into thigh muscle lipids of poultry. Nine groups of broiler chicks were fed diets supplemented with three levels (1.0, 2.5, and 5.0%) of either corn, linseed, or menhaden oil. Birds supplemented with linseed oil, rich in linolenic acid (C18:3n-3), had significantly higher levels of n-3 fatty acids and higher n-3:n-6 ratios than those supplemented with the same level of menhaden oil, primarily due to an accumulation of C18:3n-3. Levels of eicosapentaenoic acid (C20:5n-3) were increased (P less than .05), compared with the controls fed the same level of corn oil, in the groups fed the two higher levels of linseed oil, and in all the groups fed menhaden oil. Linolenic acid is less susceptible to auto-oxidation, and is less likely to impart an off-flavor to the muscle. Thus, if it is desirable to increase the n-3:n-6 ratio in poultry, seed meals or oils with a high content of C18:3n-3 could be used in poultry feeds.

Animal Feed↗
PubMed1990

Increased morbidity in surgical patients undergoing secondary (incidental) cholecystectomy.

Using computerized hospital discharge abstracts for all Vermont residents hospitalized during 1983 and 1984, we examined the question of whether increased morbidity occurs in patients undergoing secondary (incidental) cholecystectomy. Among a cohort of 4183 patients undergoing a primary surgical procedure in which secondary cholecystectomy might have been considered. 69 patients had a secondary cholecystectomy. The surgical wound infection rate was 8.7% in the secondary cholecystectomy group compared to 2.4% in the rest of the cohort (relative risk, 3.7, 95% C.I. 1.7, 8.1). Other postoperative complications occurred in 10.1% of those undergoing secondary cholecystectomy compared to 4.1% in those who did not (relative risk, 2.5, 95% C.I. 1.2, 5.1). The adjusted relative risk for wound infection was 3.3 (95% C.I. 1.4,8.0) and for other surgical complications was 1.7 (95% C.I. 0.8, 3.8). Postoperative length of hospital stay was longer for the secondary cholecystectomy group (mean, 13.8 days) than in the comparison group (mean 8.9 days, p = 0.001). These data suggest that patients undergoing a secondary cholecystectomy may have an increased risk of surgical wound infection and possibly other surgical complications.

Adolescent↗
PubMed1989

Efficacy and safety of loratadine (10 mg once daily), terfenadine (60 mg twice daily), and placebo in the treatment of seasonal allergic rhinitis.

A total of 317 patients received loratadine, 10 mg once daily, terfenadine 60 mg twice daily, or placebo in a 14-day, double-blind, randomized study in seasonal allergic rhinitis. Four nasal and four nonnasal symptoms were evaluated. At the end point evaluation, mean total scores of combined nasal and nonnasal symptoms decreased from baseline (improved) 46%, 44%, and 35%, respectively, for loratadine, terfenadine, and placebo. The difference between loratadine and placebo treatment was significant (p = 0.03). Loratadine was particularly effective compared with placebo in relieving nasal discharge, sneezing, and itching/burning eyes. Therapeutic response to treatment was good or excellent in 66 (64%) of 103 loratadine-treated patients, 58 (56%) of 104 terfenadine-treated patients, and 48 (47%) of 102 placebo-treated patients. Adverse experiences reported during the study were usually mild or moderate and were not significantly different among the three treatment groups. Sedation (somnolence) was reported by 10 loratadine-treated patients, seven terfenadine-treated patients, and eight placebo-treated patients. Loratadine, 10 mg once daily, was comparable to terfenadine, 60 mg twice daily, and significantly superior to placebo in the symptomatic relief of seasonal allergic rhinitis.

Adolescent↗
PubMed1989

Cellular reactions to polyester arterial prostheses impregnated with cross-linked albumin: in vivo studies in mice.

This study was designed to assess the possible immunological responses in mice against polyester prostheses coated with albumin and previously stabilized either with cross-linked glutaraldehyde (GA), at different concentrations, or with carbodiimide (CDI). Prosthetic discs were first implanted in the peritoneal cavities of mice, and T cells and T cell subsets (helper, suppressor, la-bearing T lymphocytes) were then quantified before implantation and at 1, 2, 3 and 4 weeks post-implantation. The percentages of T cells, subsets, and the helper/suppressor cell ratio, as well as the percentage of T cells with la receptors, were similar to the control in all experimental groups. No significant difference and no correlation were observed between the groups wherever tested. Virgin and albumin-coated grafts did not induce any quantitative changes in T cell subpopulations in mice.

Albumins↗
PubMed1988

Comparison of the efficacy and safety of loratadine, terfenadine, and placebo in the treatment of seasonal allergic rhinitis.

The efficacy and safety of loratadine, 40 mg once daily, were compared with terfenadine, 60 mg twice daily, and placebo in controlling symptoms of ragweed hay fever. The study was a randomized, multicentric, parallel-group, double-blind design involving 280 patients divided into three groups receiving either loratadine, terfenadine, or placebo for a period of 14 days in the autumn of 1984. Both loratadine and terfenadine demonstrated a statistically greater reduction in symptom score compared to placebo. They were not statistically different from each other, and there was no statistical difference in the incidence of side effects between the two drugs.

Adolescent↗
PubMed1988

Anti-idiotypic antibodies as probes for the determination of idiotopes shared by human and monoclonal murine antibodies.

Murine monoclonal antibodies (MAbs) against rye grass Group I (rye I) allergen were previously produced (290A-167, 348A-6 and 539A-6) and are further characterized herein. By competitive binding to polystyrene-bound allergen, it was shown that the three MAbs are directed against three different non-overlapping epitopes on rye I. Human rye I-specific IgG isolated from the serum of one rye grass sensitive patient could recognize the same or closely related epitopes than those recognized by MAbs. Antisera were then raised in rabbits against purified F(ab')2 fragments of human rye I-specific IgG and F(ab')2 fragments of 539A-6 MAb. The antisera were rendered idiotype specific by adsorption with insolubilized non-specific human IgG from the same donor, insolubilized normal murine immunoglobulins and finally with rye I. As shown by competitive binding to polystyrene-bound allergen, rabbit anti-idiotypic antibodies (anti-ID antibodies) produced against F(ab')2 fragments of human rye I specific IgG could inhibit the reaction between two MAbs (290A-167 and 539A-6) and the relevant allergen. Furthermore, human rye I specific IgG could inhibit the binding of 125I-labelled 539A-6 MAb to its specific anti-ID antibody to a significant degree. Human autoanti-idiotypic antibodies were also shown to inhibit the reaction between the three anti-rye I MAbs and the antigen. These observations suggest that cross-reactivity exists between idiotypic determinants of human rye I-specific IgG and the three murine MAbs, which implies structural similarity in the V genes coding for the variable region of the antibody from these two different species.

Allergens↗
PubMed1988

Isolation and characterization of Poa p I allergens of Kentucky bluegrass pollen with a murine monoclonal anti-Lol p I antibody.

The Poa p I allergens were isolated from the retentate fraction of a dialyzed preparation of an aqueous extract of Kentucky bluegrass pollen by means of a reverse immunosorbent prepared with a murine anti-Lol p I monoclonal antibody, Mab 290-A-167. By sodium dodecyl sulphate-polyacrylamide gel electrophoresis and preparative isoelectrofocusing, Poa p I was found to consist of a 35.8-kD component with an isoelectric point of 6.4 and a 33-kD component with one of 9.1 and designated as Poa p Ia (acidic) and Poa p Ib (basic), respectively. The relative protein content of these components was estimated from the intensity of the stained bands following sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Thus, Poa p Ia appeared to be the major protein constituent, and on Western immunoblot it also bound the monoclonal antibody to a greater extent than Poa p Ib. On the other hand, Poa p Ib was shown by Western immunoblot and autoradiographic analysis, to bind to a greater extent the IgE antibodies present in a pool of sera from grass-allergic individuals. Therefore, Poa p Ib was considered as the major allergenic component of Poa p I. By competitive inhibition of the radioallergosorbent test, it was demonstrated that the Mab inhibited the binding of Poa p I allergens to human IgE antibodies to the extent of 70%. Hence, it is suggested that Mab and human IgE antibodies recognize identical or closely related determinants of Poa p I allergens.

Allergens↗
PubMed1988

Comparison of alum-precipitated aqueous extracts and modified ragweed tyrosine adsorbate vaccine in the treatment of ragweed hay fever.

Thirty-five ragweed-sensitive patients received immunotherapy with either alum-precipitated aqueous extracts (AP) or modified ragweed tyrosine adsorbate vaccine (Pollinex-R). Symptoms decreased with AP therapy only. Immunologically, there was a blunted specific IgE response and little specific IgG increase associated with both groups. Alum-precipitated aqueous extracts appeared to be more efficacious than Pollinex-R.

Adsorption↗
PubMed1985

Studies on the release of leukotrienes and histamine by human lung parenchymal and bronchial fragments upon immunologic and nonimmunologic stimulation. Effects of nordihydroguaiaretic acid, aspirin, and sodium cromoglycate.

Fragments of human lung parenchyma or bronchi were studied by high performance liquid chromatography, gas chromatography-mass spectrometry, and bioassay for the biosynthesis of 5-lipoxygenase metabolites of arachidonic acid, and by radioenzymatic assay for the release of histamine, upon immunologic and nonimmunologic stimulation. Human lung parenchyma were passively sensitized with serum from timothy-positive allergic patients (radioallergosorbent test, 30-40%) and challenged with 0.5 microgram/ml of timothy allergen. Analysis of the incubation media showed the presence of LTB4, LTC4, LTD4, LTE4, and histamine. Maximum release of LTB4 and LTD4 was observed after 15 min of challenge (92.8 +/- 21, and 67.8 +/- 14 pmol/g tissue wet weight, respectively; mean +/- SEM) whereas maximum release of LTC4 was observed after 5 min of challenge (25 +/- 7.1 pmol). In parallel to leukotriene formation, histamine was released rapidly and reached a maximum after approximately 15 min of challenge (2.85 +/- 0.76 nmol/g tissue). When fragments of human lung parenchyma were stimulated with ionophore A23187 (4 microM), we observed a profile of leukotriene and histamine release similar to that seen in response to the allergen. Ionophore A23187 stimulated the release of two- to fivefold greater amounts of leukotrienes and histamine than did the allergen. Release of LTC4 and histamine was maximal after 5 min of stimulation (83 +/- 22.2 and 5.2 +/- 0.95 nmol/g tissue, respectively), whereas LTB4 and LTD4 release reached a maximum after 15 min (438 +/- 66.6 and 205 +/- 68 nmol/g tissue, respectively). In addition, human lung parenchyma metabolized LTB4 into omega-OH-LTB4 and omega-COOH-LTB4. This tissue also released 5-hydroxy-eicosatetraenoic acid (5-Hete), 12-Hete, and 15-Hete. Fragments of human lung bronchi also released a similar profile of leukotrienes (except LTC4) and histamine when challenged with the allergen or ionophore A23187. Maximum release of LTB4 and LTD4 by allergen or ionophore stimulation was observed after approximately 15 min (40 +/- 7.5 and 21 +/- 8 pmol/g tissue, respectively, upon allergen challenge; 100 +/- 13 and 47 +/- 10.6 pmol/g tissue, respectively, upon ionophore stimulation). The maximum release of histamine by bronchi was observed after approximately 15 min of allergen challenge and 5 min of ionophore stimulation (2.25 +/- 0.65 and 3.15 +/- 0.9 nmol/g tissue, respectively). The release of leukotrienes but not of histamine by human lung parenchyma upon both allergen and ionophore challenge was inhibited by nordihydroguaiaretic acid (NDGA) (ID50, 2 X 10(-6)M).(ABSTRACT TRUNCATED AT 400 WORDS)

Adjuvants, Immunologic↗
PubMed1984

Abnormal bronchoalveolar lavage in asymptomatic dairy farmers. Study of lymphocytes.

Bronchoalveolar lavage (BAL) was performed on 24 asymptomatic dairy farmers. Thirteen had serum precipitins to Micropolyspora faeni (MF) antigens (Group 1), and 11 were seronegative control subjects (Group 2). All were nonsmokers and had no history of previous lung disease. Thirteen of 24 subjects (9 in Group 1 and 4 in Group 2) had a high percentage of lymphocytes (greater than or equal to 20%) in their BAL. The T-lymphocyte subpopulations as estimated by OKT3, OKT4, and OKT8 monoclonal antibody reactivity were measured in peripheral blood lymphocytes; OKT3 = 58.5 +/- 15.6% for Group 1, and 58.5 +/- 8.7% for Group 2; OKT4 = 40.6 +/- 10.7% and 39.9 +/- 10.0%; OKT8 = 21.5 +/- 10.6% and 22.4 +/- 8.0%, respectively (p = NS). These lymphocyte characteristics were also similar when subjects with a high percentage of lymphocytes in BAL were compared to those with a normal percentage. Specific (MF-coated) chicken erythrocyte lymphocytotoxicity (Group 1, 45.2 +/- 29.5%, Group 2, 49.2 +/- 23.4%), and nonspecific lymphocytotoxicity (Group 1, 43.9 +/- 28.6%, Group 2, 37.9 +/- 18.0%) were also similar. We conclude that a large number of asymptomatic dairy farmers have an increased percentage of lymphocytes in their BAL ("alveolitis") and that peripheral blood lymphocytes in these subjects have normal subpopulations, as assessed by monoclonal antibodies, and normal lymphocytotoxicity.

Adult↗