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Biomedical subjects

J V Collins

Publications and source records attributed to J V Collins.

At least 37 records · Page 2Linked to original sources
PubMed1991

A comparison of several agents with two delivery systems for the prevention of airway narrowing induced by nebulised pentamidine isethionate.

Bronchial narrowing is the major side effect of inhaled nebulised pentamidine isethionate, used for the prophylaxis and treatment of Pneumocystis carinii pneumonia. Several agents and delivery systems were assessed for prophylaxis of bronchial narrowing in HIV-positive males receiving regular nebulised pentamidine isethionate. In a previous study we found the mean maximum fall in FEV1 with nebulised pentamidine alone to be 21%. FEV1 was measured before and after inhaling nebulised pentamidine, preceded by one of the following bronchodilator/immunoregulatory agents: Terbutaline metered dose inhaler (500 micrograms), nebulised salbutamol (5 mg), nebulised ipratropium bromide (500 micrograms), nebulised sodium cromoglycate (20 mg), and nedocromil sodium metered dose inhaler (4 mg). Each agent was administered once only to ten different subjects. Nebulised salbutamol gave most effective prophylaxis against bronchial narrowing induced by nebulised pentamidine (mean maximum fall in FEV1 = 5% vs. 21%, P less than 0.001). Terbutaline given by metered dose inhaler was significantly less effective than high dose terbutaline (10 mg) given by nebuliser, demonstrated in the previous study (mean maximum fall in FEV1 = 14% vs. 6%, P less than 0.05). Mean maximum falls in FEV1 for ipratropium bromide, sodium cromoglycate and nedocromil sodium were 16, 17 and 16%, respectively. High dose beta 2-agonists administered by nebuliser give more effective prophylaxis against nebulised pentamidine-induced bronchial narrowing than either lower doses given by metered dose inhaler, anticholinergics or immunoregulatory drugs.

Adult↗
PubMed1991

Effect of terbutaline on bronchoconstriction induced by nebulised pentamidine.

The severity, duration, and reversibility of pentamidine induced bronchial narrowing was studied with and without pretreatment with nebulised terbutaline 10 mg in an open study of 40 patients seropositive for the human immunodeficiency virus (HIV). All subjects received pentamidine 300 mg in 5 ml water via an Acorn System 22 jet nebuliser. The forced expiratory volume in one second (FEV1) fell in all 20 patients given pentamidine alone, the mean maximum fall being 20.6%. In the 20 patients given pentamidine preceded by nebulised terbutaline the mean maximum fall in FEV1 was 4%; three subjects had a fall in FEV1 of more than 10%.

Administration, Inhalation↗
PubMed1991

Recovery of the human immunodeficiency virus from fibreoptic bronchoscopes.

Ten bronchoscopes that had been used on patients with the acquired immunodeficiency syndrome were sampled to determine the nature and extent of microbial contamination. Samples were taken by irrigating the suction biopsy channel with modified viral transport medium and by swabbing the insertion tube. Sampling was repeated after they had been cleaned in detergent and after two minutes' disinfection in 2% alkaline glutaraldehyde. Before being cleaned the seven bronchoscopes tested by polymerase chain reaction were contaminated with the human immunodeficiency virus, though infectivity and antigen assays gave negative results. Other organisms identified were hepatitis B virus (1), commensal bacteria (9), and Pneumocystis carinii (4). Mean bacterial contamination was 2.27 log colony forming organisms per millilitre. Cleaning the bronchoscope before disinfection removed all detectable contaminants with a reduction in bacterial growth of up to 8 log colony forming units/ml.

Bronchoscopes↗
PubMed1991

Interleukin-5 mRNA in mucosal bronchial biopsies from asthmatic subjects.

Using in situ hybridization, we have investigated the expression of interleukin-5 (IL-5) mRNA in bronchial biopsies from asthmatics (n = 10) and controls (n = 9). The number of IL-5-nRNA-positive cells were compared with the number of CD25+ and EG2+ cells and total eosinophil counts. Specific hybridization signals for IL-5 mRNA were demonstrated in 6 out of the 10 asthmatic subjects but in none of the controls. The 6 IL-5-mRNA-positive asthmatics tended to have more severe disease and showed a significant increase in the degree of infiltration of the bronchial mucosa by activated T lymphocytes and eosinophils.

Asthma↗
PubMed1991

Expression of mRNA for interleukin-5 in mucosal bronchial biopsies from asthma.

We have attempted to identify mRNA for IL-5 in endobronchial mucosal biopsies from asthmatics and controls, using the technique of in situ hybridization. Bronchial biopsies were obtained from 10 asthmatics and 9 nonatopic normal controls. A radio-labeled cRNA probe was prepared from an IL-5 cDNA and hybridized to permeabilized sections. These were washed extensively before processing for autoradiography. An IL-5-producing T cell clone derived from a patient with the hyper-IgE syndrome was used as a positive control. As a negative control, sections were also treated with a "sense" IL-5 probe. Specific hybridization signals for IL-5 mRNA were demonstrated within the bronchial mucosa in 6 out of the 10 asthmatic subjects. Cells exhibiting hybridization signals were located beneath the epithelial basement membrane. In contrast, there was no hybridization in the control group. No hybridization was observed with the sense probe. The six IL-5 mRNA-positive asthmatics tended to have more severe disease than the negative asthmatics, as assessed by symptoms and lung function, and showed a significant increase in the degree of infiltration of the bronchial mucosa by secreting (EG2+) eosinophils and activated (CD25+) T lymphocytes. Within the subjects who showed positive IL-5 mRNA, there was a correlation between IL-5 mRNA expression and the number of CD25+ and EG2+ cells and total eosinophil count. This study provides evidence for the cellular localization of IL-5 mRNA in the bronchial mucosa of asthmatics and supports the concept that this cytokine regulates eosinophil function in bronchial asthma.

Adult↗
PubMed1990

Elimination of high titre HIV from fibreoptic endoscopes.

Concern about contamination of fibreoptic endoscopes with human immunodeficiency virus (HIV) has generated a variety of disruptive and possibly unnecessary infection control practices in endoscopy units. Current recommendations on the cleaning and disinfection of endoscopes have been formulated without applied experimental evidence of the effective removal of HIV from endoscopes. To study the kinetics of elimination of HIV from endoscope surfaces, we artificially contaminated the suction-biopsy channels of five Olympus GIF XQ20 endoscopes with high titre HIV in serum. The air and water channels of two instruments were similarly contaminated. Contamination was measured by irrigating channels with viral culture medium and collecting 3 ml at the distal end for antigen immunoassay. Endoscopes were then cleaned manually in neutral detergent according to the manufacturer's recommendations and disinfected in 2% alkaline glutaraldehyde (Cidex, Surgikos) for two, four, and ten minutes. Contamination with HIV antigens was measured before and after cleaning and after each period of disinfection. Initial contamination comprised 4.8 x 10(4) to 3.5 x 10(6) pg HIV antigen/ml. Cleaning in detergent achieved a reduction to 165 pg/ml (99.93%) on one endoscope and to undetectable levels (100%) on four. After two minutes in alkaline glutaraldehyde all samples were negative and remained negative after the longer disinfection times. Air and water channels, where contaminated, were tested after 10 minutes' disinfection and were negative. These findings underline the importance of cleaning in removing HIV from endoscope and indicate that the use of dedicated equipment and long disinfection times are unnecessary.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Effects of inhaled PAF in humans on circulating and bronchoalveolar lavage fluid neutrophils. Relationship to bronchoconstriction and changes in airway responsiveness.

We have compared the effect of inhaled platelet activating factor (PAF) on circulating neutrophils with its ability to induce bronchoconstriction and bronchial hyperresponsiveness in humans. Human volunteers inhaled PAF, given as six successive inhalations 15 min apart, followed by bronchoalveolar lavage (BAL) 4 h later. The mean density and volume of circulating neutrophils were measured by metrizamide gradients and flow cytometry, respectively. PAF caused a decrease in Vp20 of 38.2 +/- 4.5% at 5 min after the first inhalation (p less than 0.001). This was associated with a fall in the peripheral blood neutrophil count from 3.15 +/- 0.3 to 1.1 +/- 0.3 x 10(6) per ml (p less than 0.001), followed by a rebound neutrophilia (p less than 0.01). The mean density of peripheral blood neutrophils fell significantly at 15 min (p less than 0.02), with a return to baseline values despite further PAF inhalations; this was associated with an increase in neutrophil volume (n = 4; p less than 0.05). The numbers of neutrophils (x 10(5] in BAL fluid after PAF were significantly greater than after inhalation of lyso-PAF: 7.1 +/- 1.4 (n = 7) versus 1.3 +/- 0.3 (n = 5, p less than 0.01); eosinophil counts did not change significantly. The PC40 (the concentration of methacholine needed to cause a fall in Vp30) decreased from 17.1 (GSEM 1.40) to 8.7 (1.44) mg/ml (n = 12, p less than 0.02) 3 days after PAF. Inhaled lyso-PAF was inactive in all these respects.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1990

Identification of activated T lymphocytes and eosinophils in bronchial biopsies in stable atopic asthma.

We have used immunohistochemistry and monoclonal antibodies to analyze the phenotypic composition and activation status of the cellular infiltrate of bronchial biopsies obtained by fiber optic bronchoscopy of 11 atopic asthmatic subjects (FEV1% predicted range 78 to 114), 9 atopic nonasthmatic control subjects, and 10 normal healthy subjects. Examination of mucosal biopsies obtained from both central (level I) and subsegmental (level II) bronchi showed that the highest number of CD45-, DC3-, DC4-, and CD8-positive cells were found in the group with asthma. There was a significant increase in the number of interleukin-2 receptor (CD25)-positive cells (a marker of lymphocyte activation) at airway level I in the asthmatic group compared with both nonasthmatic atopic (p less than 0.05) and normal control subjects (p less than 0.01). Eosinophil numbers were significantly increased in asthma at both airway levels and at airway level II in the nonasthmatic atopic group when compared with normal healthy control subjects (p less than 0.05). EG2-positive cells (an index of secretion of eosinophil cationic protein following activation) were found at both airway levels in the asthmatic group and at level I in the nonasthmatic atopic control group (p less than 0.05). When asthmatic subjects were compared with normal healthy subjects, there was a reduction in the number of neutrophil elastase-positive cells in the asthmatic subjects which, as a percentage of leukocytes, was significant (p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Sputum induction for diagnosis of Pneumocystis carinii pneumonia.

51 patients infected with the human immunodeficiency virus (HIV) and with suspected Pneumocystis carinii pneumonia underwent sputum induction. Sputum specimens from 18 patients were positive for P carinii and patients were treated appropriately 25 of the 33 patients with negative specimens underwent bronchoscopy and bronchoalveolar lavage within 4 days of sputum induction, only 1 of whom had evidence of Pneumocystis infection. For diagnosis of Pneumocystis carinii pneumonia, sputum induction according to a strict protocol had a sensitivity of 94.7% and a negative predictive value of 96%, compared with bronchoalveolar lavage.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Contamination of endoscopes used in AIDS patients.

Contamination of twenty endoscopes used in patients with AIDS was assessed. The suction-biopsy, air, and water channels and the insertion tube were sampled after use, after washing in detergent, and after disinfection for 2 min in 2% alkaline glutaraldehyde. The polymerase chain reaction with Southern blotting, cell cultures, and antigen immunoassay were used to detect human immunodeficiency virus (HIV). Samples were also examined for cytomegalovirus, adenoviruses, enteroviruses, herpes simplex virus, myxoviruses, hepatitis B surface antigen, fungi, and bacteria. Seven of twenty unwashed endoscopes were contaminated by HIV. Commensal bacteria were found in all endoscopes, Candida albicans in six, Staphylococcus aureus in five, and Pseudomonas aeruginosa in five. Washing alone removed all detectable organisms from 66 of 68 contaminated sites; Neisseria spp were recovered from two air channels after washing but not after disinfection. Washing achieved a mean reduction of 4.93 (95% confidence interval 3.69-6.17) colony forming units per ml.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Chemical inactivation of HIV on surfaces.

To assess whether alcohol and glutaraldehyde are effective disinfectants against dried HIV the virucidal effects of 70% alcohol (ethanol and industrial methylated spirit) and 1% and 2% alkaline glutaraldehyde were tested against cell associated and cell free HIV dried on to a surface. Virus stock (100 microliters) or 10,000 cultured C8166 T lymphocytes infected with HIV were dried onto sterile coverslips and immersed in 2% and 1% alkaline glutaraldehyde and 70% ethanol for 30 seconds and one, two, four, and 10 minutes, there being an additional time point of 20 minutes for cell free virus disinfected with 70% industrial methylated spirit. In addition, virus stock in neat serum was tested with 1% and 2% alkaline glutaraldehyde to see whether the fixative properties of glutaraldehyde impair its virucidal properties. Virus activity after disinfection was tested by incubating the coverslips (cell associated virus) or the coverslips and sonicated cell free virus with C8166 T lymphocytes. The lymphocytes were examined for the formation of syncytia and HIV antigens were assayed in the culture fluid. Both 2% and 1% alkaline glutaraldehyde inactivated cell free HIV within one minute; 2% alkaline glutaraldehyde also inactivated cell free virus in serum within two minutes, but a 1% solution was ineffective after 15 minutes' immersion. Cell associated HIV was inactivated by 2% alkaline glutaraldehyde within two minutes. Seventy per cent industrial methylated spirit failed to inactivate cell free and cell associated HIV within 20 and 15 minutes, respectively, and 70% ethanol did not inactivate cell free virus within 10 minutes. Seventy per cent industrial methylated spirit and ethanol are not suitable for surface disinfection of HIV. Fresh 2% solutions of alkaline glutaraldehyde are effective, but care should be taken that they are not too dilute or have not become stale when used for disinfecting HIV associated with organic matter.

Acquired Immunodeficiency Syndrome↗