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Biomedical subjects

J Kolbe

Publications and source records attributed to J Kolbe.

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

Quantification and identification of the main components of the Trichoderma cellulase complex with monoclonal antibodies using an enzyme-linked immunosorbent assay (ELISA).

An enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies has been developed to measure the concentration of three main cellulase components from Trichoderma reesei, cellobiohydrolase I (CBH I), cellobiohydrolase II (CBH II) and endoglucanase I (EG I), in both commercial enzyme preparations as well as in samples from laboratory fermentations. The sensitivity of the assay is 1-10 ng protein, depending on the type of cellulase. The coefficient of variability is between 10% and 20%. By a combination of two different domain-specific monoclonals against CBH I or II it is also possible to quantify the concentration of intact and truncated forms of these two enzymes, respectively. The use of the ELISA to quantify the formation of the three cellulase components under different cultivation conditions is described.

Antibodies, Monoclonal↗
PubMed1989

Exposure to 1 ppm ozone attenuates the immediate antigenic response of canine peripheral airways.

The effect of oxidant exposure on the immediate airway response to immunologic challenge is controversial. We investigated the response of canine peripheral airways to antigen aerosol, 1-3 h and 24 h after a 5-min exposure to 1 ppm ozone. In dogs that were natively sensitive to Ascaris suum antigen, resistance to flow through the collateral system (Rcs) was measured using the wedged bronchoscope technique. In eight dogs, four sublobar segments of each lung were wedged: two were exposed to ozone for 5 min and two (control) received air with 5% CO2. Ozone caused a mean ( +/- SE) increase in Rcs of 75 +/- 15%, which returned to baseline after 1-3 h. The increase in Rcs elicited by subsequent administration of antigen aerosol (25 microliters, 0.27 mg protein/ml) to the ozone-exposed segments (312.0 +/- 70.6%) was attenuated by 22% compared to controls (398.9 +/- 83.0%; p less than .05). In another series of experiments (n = 5), segments were exposed to ozone or air and challenged with antigen 24 h later and a significant attenuation (38%) of the antigen-induced increase in Rcs was detected compared to controls (178.5 +/- 57.9 vs 289.0 +/- 62.2; p less than .05). Cellular influx of polymorphonuclear leukocytes (PMNs) was not detected by bronchoalveolar lavage (BAL) 1-3 h after ozone, but was found after 24 h (19.8 vs. 4.7%; p less than .01). A significant increase in PMNs was detected in exposed subepithelial tissues 1-3 h after ozone compared to unexposed tissues. Tissue PMNs were not significantly different from unexposed tissues after 24 h, but a shift toward degranulation of mast cells was detected in ozone-exposed tissues at this time. These data suggest that the Rcs response to antigen is attenuated 1-3 h and 24 h after acute (5 min) exposure to 1 ppm ozone, and this effect occurs independently of PMNs in the airways.

Administration, Inhalation↗
PubMed1988

Rapid increase in mast cell numbers in canine central and peripheral airways.

In preliminary studies of antigen-induced airway inflammation, we noted an apparent increase in peribronchiolar mast cell number. Experiments were thus undertaken to investigate the nature of this migration of mast cells into the central and peripheral airway epithelium and to determine its time course. The tracheae and small airways of 10 anesthetized mongrel dogs were exposed via a bronchoscope to Ascaris suum antigen (Ag), fMet-Leu-Phe (fMLP), ovalbumin (OVA), and isotonic saline (SAL). In the central airways, all stimuli provoked a significant increase (P less than 0.05) in mast cell numbers at the base of the airway epithelium within 3 h. In the peripheral airways, only Ag aerosol stimulated a significant mast cell increase compared with unexposed tissue. In a second series of experiments, the trachea of seven dogs were exposed to 0.026, 0.26, and 2.6 micrograms of Ag. The tissue was collected at 1, 3, 6, and 10 h after exposure. In these experiments, there was a significant mast cell increase seen within 1 h but it was not dose dependent. By 6-10 h after exposure, mast cell counts were not significantly different from the unexposed condition, which is consistent with the idea that some of the cells either degranulated or migrated into the airway lumen. We conclude that mast cell migration is an acute response that can be demonstrated within 1 h of stimulation with Ag. The observation that nonimmunological stimuli may, in some cases, also stimulate mast cell movement affords the possibility that this process represents a generalized response to airway irritation.

Animals↗
PubMed1988

The role of mediators in the response of the canine peripheral lung to 1 ppm ozone.

We tested the hypothesis that the in vivo response of the canine peripheral lung to 1 ppm ozone is mediated, in part, by histamine and cyclooxygenase and lipoxygenase products of arachidonic acid metabolism. Ozone was delivered for 5 min to lobar segments through a wedged bronchoscope and resulted in a mean (+/- 1 SE) increase in collateral system resistance (Rcs) of 220.7 +/- 13.8% immediately after exposure. Four 5-min exposures of ozone to the same segments over a 3-h period yielded reproducible Rcs responses, i.e., tolerance to the exposure regimen was not exhibited. Analyses of bronchoalveolar lavage fluid obtained from the isolated segment 1 min after a single exposure to ozone indicated significant increases, compared with control, in mean concentrations of PGD2 (135.3 +/- 33.3 pg/ml versus 47.8 +/- 16.0; p less than 0.025) and histamine (1.43 +/- 0.19 ng/ml versus 1.18 +/- 0.17; p less than 0.05). Additionally, a molecule that exhibited high reactivity with LTB4 antibody was found in greater concentrations in ozone-exposed segments compared to controls (821.5 +/- 206.7 pg/ml versus 437.5 +/- 78.8; p less than 0.05). In contrast, the concentration of TxB2 was not significantly greater in ozone-exposed segments compared to controls (37.2 +/- 6.6 pg/ml versus 33.7 +/- 10.3; p less than 0.05). Cyclooxygenase inhibition (indomethacin, 5 mg/kg, IV) significantly inhibited the Rcs response by 32% (p less than 0.05) and histamine H1-receptor blockade (chlorpheniramine maleate, 5 mg/kg, IV) reduced the response by 30% (p less than 0.05). However, blockade of thromboxane synthetase (UK-37,248, 3 mg/kg, IV) had no significant effect on the ozone-induced response.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Thromboxane contributes to the immediate antigenic response of canine peripheral airways.

The actions of specific humoral mediators in the immediate response of the canine peripheral airways to antigen challenge are not well understood. Using a method which allows localized exposure of the peripheral lung to antigen, we investigated the role of locally released thromboxane A2 (TxA2) in the immediate response of collateral airways to aerosolized antigen. In dogs with native sensitivity to Ascaris suum antigen, resistance to flow through the collateral system (Rcs) was measured using a wedged bronchoscope technique. Local administration of antigen aerosol (25 microliters, 1:10,000 dilution) produced a gradual increase in Rcs which reached a maximum of 365% of base line in 4-8 min. Analysis of bronchoalveolar lavage fluid obtained from the exposed segment at the peak of the response demonstrated significantly more TxB2 compared with control lavage samples (41.8 +/- 7.8 pg/ml vs. 27.9 +/- 8.3; P less than 0.025). After inhibition of thromboxane synthase with UK-37,248 (3 mg/kg iv) or OKY-046 (5 mg/kg iv), the increase in Rcs was significantly reduced at 40 s (P less than 0.001) and 2 min (P less than 0.01) after antigen delivery, and the maximal increase was attenuated by 41% (P less than 0.005). In contrast, the magnitude and time course of the airway response to aerosols of a stable thromboxane analog (U-46619) were not affected by blockade. Despite a similar attenuation (42%) of the maximal increase in Rcs by sodium meclofenamate (3 mg/kg iv), this cyclooxygenase inhibitor had no effect on the time course of the antigenic response.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1987

Hypocapnia-induced constriction of the canine peripheral airways exhibits tachyphylaxis.

Hypocapnia-induced constriction of peripheral airways may be important in regulating the distribution of ventilation in pathological conditions. We studied the response of the peripheral lung to hypocapnia in anesthetized, paralyzed, mechanically ventilated dogs using the wedged bronchoscope technique to measure resistance of the collateral system (Rcs). A 5-min hypocapnic challenge produced a 161 +/- 19% (mean +/- SE) increase in Rcs. The magnitude of this response was not diminished with repeated challenge or by atropine sulfate (1 mg base/kg iv), chlorpheniramine maleate (5 mg base/kg iv), or indomethacin (5 mg/kg iv). The response was reduced by 75% by isoproterenol (5 micrograms/kg iv) (P less than 0.01) and reduced by 80% by nifedipine (20 micrograms/kg iv) (P less than 0.05). During 30-min exposure to hypocapnia the maximum constrictor response occurred at 4-5 min, after which the response attenuated to approximately 50% of the maximum response (mean = 53%, range 34-69%). Further 30-min challenges with hypocapnia resulted in significantly decreased peak responses, the third response being 50% of the first (P less than 0.001). The inability of indomethacin or propranolol to affect the tachyphylaxis or attenuation of the response suggests that neither cyclooxygenase products nor beta-adrenergic activity was involved. Hence, hypocapnia caused a prompt and marked constrictor response in the peripheral lung not associated with cholinergic mechanisms or those involving histamine H1-receptors or prostaglandins. With prolonged exposure to hypocapnia there was gradual attentuation of the constrictor response with continued exposure and tachyphylaxis to repeated exposure both of which would tend to diminish any compensatory effect of hypocapnic airway constriction on the distribution of ventilation.

Airway Resistance↗
PubMed1986

Bronchial blood flow affects recovery from constriction in dog lung periphery.

We investigated the effect of eliminating the bronchial circulation on recovery time from intravenous histamine challenge in canine lung periphery. Results from animals with intact bronchial circulations were compared with a second group in which the left lower lobe was isolated in situ. The pulmonary artery to this lobe was perfused and a bronchoscope was wedged in a small airway, which provided an index of resistance to airflow through the collateral system. The lobe was challenged with intravenous histamine, and the time constant of recovery (tau) from bronchoconstriction was measured. With or without pulmonary blood flow, elimination of the bronchial circulation increased tau 44.4 and 48.5%, respectively. This increase was similar to that found by stopping pulmonary blood flow alone (56.5%). Histamine challenges were also performed in sympathectomized or vagotomized animals with intact bronchial circulations. Neither of these conditions increased tau. We conclude that blood flow through the bronchial circulation affects the recovery time from intravenous histamine challenge in the lung periphery to a degree similar to that of the pulmonary circulation.

Animals↗
PubMed1986

Central role of cyclooxygenase in the response of canine peripheral airways to antigen.

We studied the effects of antigen aerosol challenge on the airways of the canine peripheral lung and examined the roles of cyclooxygenase products, histamine, and cholinergic activity in the responses. One-minute deliveries of 1:10,000 or 1:100,000 concentrations of Ascaris suum antigen aerosol through a wedged bronchoscope resulted in mean maximal increases in collateral system resistance (Rcs) of 415 and 177%, respectively, after 4-8 min. Repeated antigen challenge (1:100,000) resulted in significantly decreased responsiveness to antigen after the initial exposure (P less than 0.005). Bronchoalveolar lavage fluid obtained from the isolated, challenged segment had a significant increase in mean (+/- SE) prostaglandin D2 (PGD2) concentration vs. control (222.0 +/- 65.3 vs. 72.7 +/- 19.5 pg/ml; P less than 0.05); histamine concentrations were variable and not significantly different (4.1 +/- 2.6 vs. 1.2 +/- 0.2 ng/ml; P greater than 0.05). In nine experiments, cyclooxygenase inhibition significantly attenuated the antigen-induced increase in Rcs by 53.4% (P less than 0.001), and the concentration of PGD2 in lavage fluid was reduced by 96.0% (P less than 0.01). Blockade of histamine H1-receptors (n = 8) or cholinergic receptors (n = 7) did not significantly affect the airway response (P greater than 0.05). These data indicate that the canine peripheral lung responds in a dose-dependent manner to antigen aerosol challenge and exhibits characteristics of antigen tachyphylaxis. Results also suggest that cyclooxygenase products play a central role in the acute bronchoconstrictive response of the lung periphery.

Aerosols↗
PubMed1986

[Is the PACS feasible for a large radiological department? Reflections on the image data volume of the Medical Radiation Institute of the University of Tübingen in 1983. Picture Archiving and Communication System].

Picture Archiving and Communication Systems (PACS) are getting more and more important for departments of radiology with the increasing spread of digital imaging methods. To determine the demands made on such systems, we calculated the digital image data volume for all examinations carried out in 1983 at the Department of Medical Radiology of the University of Tübingen. 20.37% of all examinations were performed with digitalised equipment. Plain radiography takes the lion's share among the total number of image data. If digitalisation is based on a spatial resolution of 8 Lp/mm, the share is 98.4% of the total image data volume of 7 123 GByte. This figure is far in excess of the estimates stated in literature. The possibilities of image data reduction and feasibility of a major PACS are discussed.

Academic Medical Centers↗
PubMed1984

Thoracic empyema due to Streptococcus milleri: four cases.

Four cases of Streptococcus milleri empyema occurring over a six month period are reported. Empyema was post-pneumonic in three patients and followed blunt abdominal and chest trauma in one patient. There was an absence of serious underlying disease in these patients and management consisted of tube drainage, lavage of the pleural space and prolonged intrapleural and systemically administered antibiotic therapy. Complete recovery was achieved in three patients and a satisfactory result in the other without surgical intervention. The clinical and microbiological features of this group of patients are reviewed.

Administration, Oral↗
PubMedDate not supplied

Asthma education, action plans, psychosocial issues and adherence.

This article deals with four separate but not disparate topics. The first section discusses asthma education, reviews the current literature and attempts to challenge some of the dogma that is associated with this area. Knowledge alone does not guarantee appropriate behaviour, due to a variety of adverse socioeconomic and psychological factors that need to be considered for each patient. Action plans and peak flow monitoring have both been disappointing in terms of reducing asthma morbidity; the former needs to be individualized, and the latter may be useful in specific situations. Space precludes an in-depth discussion of psychological issues and adherence, but an attempt has been made to address salient issues, particularly related to the first two topics. Psychological factors, especially anxiety, play an important role in asthma outcome. Adherence to medication prescriptions and other management strategies need to be taken into account when an individual's treatment program is planned.

Asthma↗