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Biomedical subjects

K Alving

Publications and source records attributed to K Alving.

At least 73 records · Page 4Linked to original sources
PubMed1996

Elevated nitric oxide in the urinary bladder in infectious and noninfectious cystitis.

OBJECTIVES: A role for nitric oxide (NO) has been suggested in inflammation and host defense. At higher concentrations, this gas shows cytotoxic effects that may be directed against microorganisms, tumor cells as well as host cells. The aim of the present study was to study the relationship between bladder mucosal inflammation and local production of NO. METHODS: We measured NO directly in the urinary bladder in patients with infectious cystitis, interstitial cystitis, irradiation cystitis, and cystitis induced by antitumor treatment with bacillus Calmette-Guérin. NO-free air was introduced into the bladder during cystoscopy. The air was aspirated after 5 minutes of incubation and injected into a chemiluminescence NO analyzer. RESULTS: NO levels were 30 to 50 times higher in all varieties of cystitis as compared to controls. CONCLUSIONS: NO may contribute to host-defense mechanisms in the bladder during bacterial infection and antitumor treatment. Direct measurement of gaseous NO in the urinary bladder seems to be an attractive diagnostic method for detection of mucosal inflammation.

Aged↗
PubMed1996

Inhalation of nasally derived nitric oxide modulates pulmonary function in humans.

The vasodilator gas nitric oxide (NO) is produced in the paranasal sinuses and is excreted continuously into the nasal airways of humans. This NO will normally reach the lungs with inspiration, especially during nasal breathing. We wanted to investigate the possible effects of low-dose inhalation of NO from the nasal airways on pulmonary function. The effects of nasal and oral breathing on transcutaneous oxygen tension (tcPO2) were studied in healthy subjects. Furthermore, we also investigated whether restoring low-dose NO inhalation would influence pulmonary vascular resistance index (PVRI) and arterial oxygenation (PaO2) in intubated patients who are deprived of NO produced in the nasal airways. Thus, air derived from the patient's own nose was aspirated and led into the inhalation limb of the ventilator. In six out of eight healthy subjects tcPO2 was 10% higher during periods of nasal breathing when compared with periods of oral breathing. In six out of six long-term intubated patients PaO2 increased by 18% in response to the addition of nasal air samples. PVRI was reduced by 11% in four of 12 short-term intubated patients when nasal air was added to the inhaled air. The present study demonstrates that tcPO2 increases during nasal breathing compared with oral breathing in healthy subjects. Furthermore, in intubated patients, who are deprived of self-inhalation of endogenous NO. PaO2 increases and pulmonary vascular resistance may decrease by adding NO-containing air, derived from the patient's own nose, to the inspired air. The involvement of self-inhaled NO in the regulation of pulmonary function may represent a novel physiological principle, namely that of an enzymatically produced airborne messenger. Furthermore, our findings may help to explain one biological role of the human paranasal sinuses.

Administration, Inhalation↗
PubMed1996

Influence of endogenous cortisol on eosinophil function in sensitized pigs: direct measurements of eosinophil peroxidase.

BACKGROUND AND OBJECTIVES: Eosinophils are associated with bronchial asthma, but the role of the eosinophil is not fully understood. This study was initiated in order to study the influence of endogenous cortisol on eosinophil recruitment and activation in allergic inflammation in the lower airways in the pig. METHODS: Polyclonal and monoclonal antibodies against porcine eosinophil peroxidase (EPO) were raised. Detection of eosinophils in blood smears and lung biopsy specimens was achieved using the polyclonal antibody. For determination of porcine EPO in bronchoalveolar lavage (BAL) fluid, a sandwich enzyme-linked immunosorbent assay (ELISA) with a detection limit of 0.15 micrograms/L was developed. No cross-reactivity with porcine myeloperoxidase was found. Pigs that had been actively sensitized with repeated subcutaneous injections of Ascaris suum antigen were acutely challenged with antigen in the lower airways under pentobarbitone anaesthesia. RESULTS: Control animals with plasma cortisol levels of approximately 400 nM did not exhibit infiltration of eosinophils into lung parenchyma or EPO-release in the bronchial lumen within 8 h after challenge. However, in pigs treated with a cortisol-synthesis inhibitor (metyrapone), resulting in plasma cortisol levels of approximately 40 nM, there was a marked eosinophil infiltration into lung tissue at 8 h. Furthermore, EPO levels in BAL fluid were increased in some, although not all, low-cortisol animals. There was no infiltration of eosinophils into skin tissue in these animals. CONCLUSIONS: It is concluded that, after allergen challenge in the lower airways of metyrapone-treated pigs, newly recruited eosinophils infiltrate lung tissue specifically. Furthermore, a cortisol-sensitive release of the eosinophil-derived cationic protein EPO, into the bronchial lumen was established. This is, to our knowledge, the first description of direct measurements of the release of an eosinophil granule protein in a large animal model of allergy.

Animals↗
PubMed1996

Effects of local and systemic budesonide on allergen-induced airway reactions in the pig.

1. In this study, an attempt was made to distinguish between local and systemic effects of low doses of the topical glucocorticoid, budesonide. The effect of aerosolized budesonide administered to the lower airways versus intravenously administered budesonide on the acute and late response to nebulized Ascaris suum extract in the lung, was evaluated in the minipig after active sensitization with purified A. suum antigen. Budesonide was administered once, 1 h prior to A. suum challenge and airway reactions and mediator release were observed for 8 h after allergen challenge. 2. In the budesonide aerosol group (n = 6), 10.2 +/- 1.2 micrograms kg-1 budesonide was given locally and in the budesonide infusion group (n = 5), 5 micrograms kg-1 was given intravenously. The area under the plasma concentration curve for budesonide during the experiment was 11.4 +/- 1.2 and 10.3 +/- 1.2 nM h in the budesonide aerosol and budesonide infusion group, respectively (no significant difference). The lung tissue content of budesonide in the two groups was 45.2 +/- 4.9 and 18.4 +/- 3.5 nmol kg-1 dry tissue, respectively, 8 h after allergen challenge (P < 0.05). For comparison, 6 pigs were given budesonide vehicle as an infusion prior to A. suum challenge. 3. Total lung resistance (RL) increased acutely (maximal response within 15 min) in the budesonide aerosol, budesonide infusion and budesonide vehicle groups (by 91 +/- 40, 150 +/- 86 and 80 +/- 27%, respectively). The acute reaction partially resolved at about 1 h and was followed by a late increase in RL in the budesonide infusion and budesonide vehicle groups (by 251 +/- 148 and 281 +/- 136% at 8 h, respectively). However, no late change in RL was seen in the budesonide aerosol group (7 +/- 24%). 4. Aerosolized budesonide had a protective effect in that it attenuated the late changes in arterial blood gas and pH as well as the late elevation of plasma catecholamines. Budesonide given as an infusion did not protect against the late changes in these parameters. However, budesonide aerosol or infusion did not inhibit the late vasodilation in the bronchial circulation. 5. Histamine and cysteinyl-leukotrienes were released during the acute reaction as measured by urinary concentration of methylhistamine and leukotriene E4 respectively. There was no release of histamine during the late reaction. A late increase in leukotriene E4 was observed in 2 of the budesonide infusion and 3 of the budesonide vehicle pigs, whereas no such increase was seen in any of the budesonide aerosol pigs. 6. Budesonide concentration in lung tissue, but not in plasma at 8 h correlated negatively with the late increase in RL (P < 0.05, r = -0.53, n = 10), whereas budesonide concentration in plasma but not in lung tissue correlated negatively with the late decrease in dynamic compliance (P < 0.05, r = -0.67, n = 12). 7. This study has shown that a single low dose of locally administered budesonide can inhibit the late allergic reaction in the pig lower airways. If budesonide was given as an intravenous infusion in a dose yielding a plasma concentration similar to that seen after the aerosol treatment, the protective effect of budesonide was poor. It may be suggested that the tissue-bound portion of budesonide affects local mechanisms involved in the development of late changes in the airways (RL), although it does not affect the late increase in bronchial blood flow. We conclude that the inhibitory effect of budesonide on the allergen-induced late reaction in the pig airways relates to tissue-bound steroid, and that the systemic component is of less importance.

Administration, Inhalation↗
PubMed1996

Exhaled nitric oxide in paediatric asthma and cystic fibrosis.

Nitric oxide (NO) is present in exhaled air of humans. This NO is mostly produced in the upper airways, whereas basal NO excretion in the lower airways is low. Children with Kartagener's syndrome have an almost total lack of NO in nasally derived air, whereas adult asthmatics have increased NO in orally exhaled air. NO excretion was measured in the nasal cavity and in orally exhaled air in 19 healthy children, in 36 age matched subjects with asthma, and in eight children with cystic fibrosis. NO levels in orally exhaled air were similar in controls and in children with cystic fibrosis, at 4.8 (SD 1.2) v 5.8 (0.8) parts per billion (ppb), but were increased in asthmatic children who were untreated or were being treated only with low doses of inhaled steroids (13.8 (2.5) ppb). Nasal NO levels were reduced by about 70% in children with cystic fibrosis compared to controls and asthmatics. Measurements of airway NO release in different parts of the airways may be useful in non-invasive diagnosis and monitoring of inflammatory airway diseases.

Adolescent↗
PubMed1996

Isolation and characterization of porcine cationic eosinophil granule proteins.

The allergic pig can be used as a large-animal model for studies of allergic reactions in the airways and the role of eosinophils in such reactions. To measure the activation of eosinophils, the release of eosinophil-derived cationic proteins can be used. The purpose of this study was to isolate and characterize cationic proteins derived from porcine eosinophils. Pigs were infested with live Ascaris suum eggs to induce eosinophilia (greater than or = 40% of leukocytes). Blood was collected and leukocytes were prepared by dextran sedimentation. Granules were obtained from the homogenized leukocytes by ultracentrifugation and cationic proteins were extracted and separated by gel filtration, cation exchange and zinc affinity chromatography. Using these methods, three cationic proteins were isolated from pig granulocytes, two of which were shown to originate from the eosinophil. The proteins were characterized according to molecular weight, amino acid composition, N-terminal sequence, isoelectric point, peroxidase and ribonuclease activity and antigenicity. One eosinophil protein was identified as eosinophil peroxidase and the other showed great similarities with human eosinophil cationic protein. The third protein was not specific for eosinophils, and had no obvious equivalent in human granulocytes. The eosinophil-derived proteins may be useful in the studies of eosinophil activation, e.g. in late-phase asthmatic reactions, where the pig represents a new candidate model for large-animal allergy research.

Amino Acid Sequence↗
PubMed1996

Calcium-independent and steroid-resistant nitric oxide synthase activity in human paranasal sinus mucosa.

Nitric oxide (NO) is present in the human nasal airways and originates primarily from the paranasal sinuses. Immunohistochemical studies and messenger ribonucleic acid (mRNA) in situ hybridization indicate that a type-2 NO synthase (NOS) is constitutively expressed in healthy sinus epithelium. We have further characterized sinus NOS activity by studying the enzymatic conversion of L-arginine to L-citrulline in biopsies from sinus mucosa. Maxillary sinus biopsies were obtained from nine healthy subjects during reconstructive facial surgery. In addition, nasal NO concentrations in nine controls were compared with those found in five patients treated with high systemic doses of glucocorticosteroids. Finally, the effects of i.v. L-arginine infusion on nasal cavity NO concentrations were studied in six healthy subjects. Ca(2+)-independent NOS activity was found in all biopsies and was five times higher than Ca(2+)-dependent activity (179 +/- 64 and 36 +/- 17 pmol.g-1.min, respectively). There was no difference in nasal NO levels between controls (344 +/- 21 parts per billion (ppb)) and steroid-treated patients (342 +/- 36 ppb). Nasal NO levels increased up to 35% following i.v. infusion of L-arginine. We conclude that NOS activity in healthy sinus mucosa is predominantly Ca(2+)-independent and this NOS is not downregulated by systemic steroids. Furthermore, L-arginine infusion increases nasal airway NO excretion in vivo, indicating that the substrate concentration is a rate-limiting factor under basal conditions. These findings further support the notion that sinus NOS is identical or very closely related to the type-2 NOS; however, the regulation of expression seems to be fundamentally different from that described previously for this NOS isoform.

Adult↗
PubMed1996

Nitric oxide in exhaled air.

Much interest is now being focused on measurements of nitric oxide (NO) in exhaled air. In healthy subjects exhaled NO seems to originate mainly in the nasal airways, whereas the contribution from the lower respiratory tract is low. In certain inflammatory airway disorders, the excretion of NO into the airways is altered resulting in changes in the levels of NO in exhaled air. New techniques have been developed to measure NO release at different levels of the airways: asthmatics show increased orally-exhaled NO levels, whereas patients with cystic fibrosis or Kartagener's syndrome exhibit a marked reduction in nasal release of NO. It has been suggested that measurements of exhaled NO may be clinically useful in noninvasive diagnosis and monitoring of inflammatory airway diseases. To further evaluate the potential clinical usefulness of measurement of exhaled NO, it is vital to explore how airway NO production is normally regulated and what factors influence airway NO excretion.

Breath Tests↗
PubMed1996

Granulocyte function in the airways of allergen-challenged pigs: effects of inhaled and systemic budesonide.

BACKGROUND: Late airways obstruction and eosinophil infiltration after allergen challenge are often seen in human asthma and animal models of allergy. This inflammatory reaction, which may be a link between acute and chronic asthma, is blocked by glucocorticoid pretreatment. However, the role of eosinophils in late airways obstruction and the primary site of action of glucocorticoids, i.e. locally or systemically, have not been fully determined. OBJECTIVES: This study was initiated to find out the role of eosinophils and neutrophils in allergen-induced late airways obstruction in the pig. The effect of pretreatment with budesonide (BUD) given locally or systemically on cellular responses seen within 8 h after allergen challenge was also studied. METHODS: Twenty-five minipigs were actively sensitized with Ascaris suum antigen and challenged under anaesthesia with antigen in the lower airways. Pigs were given BUD as an aerosol (10 micrograms/kg) or an intravenous infusion (5 micrograms/kg) 1 h before allergen challenge. In one group, high doses of BUD (50 micrograms/kg) were infused twice with a 3-h interval before allergen challenge. As a positive control, one group was given the BUD vehicle as an infusion and as a negative control, one group not treated with BUD was given the irrelevant antigen ovalbumin. Eosinophils and neutrophils in lung tissue specimens were detected and levels of eosinophil peroxidase (EPO) and myeloperoxidase (MPO) in bronchoalveolar lavage (BAL) fluid were measured using specific antibodies against porcine EPO and MPO. RESULTS: The number of eosinophils in lung tissue and BAL fluid and the level of EPO in BAL fluid were significantly increased 8 h after A. suum challenge in pigs not treated with BUD. With regard to possible recruitment and activation of neutrophils the only significant finding was an increase in the number of cells in BAL fluid. The eosinophil numbers and the level of EPO in BAL fluid were shown to be decreased by all BUD treatments in all the compartments studied compared to the positive control. However, the number of eosinophils in lung tissue and EPO levels in BAL fluid did not correlate with the magnitude of the late airways obstruction. CONCLUSION: Although eosinophils are present in the bronchial wall and lumen and are apparently activated, a causative relationship between this granulocyte and the late bronchial obstruction could not be established in this model.

Administration, Inhalation↗
PubMed1995

High nitric oxide production in human paranasal sinuses.

Nitric oxide (NO) is present in air derived from the nasal airways. However, the precise origin and physiological role of airway-derived NO are unknown. We report that NO in humans is produced by epithelial cells in the paranasal sinuses and is present in sinus air in very high concentrations, close to the highest permissible atmospheric pollution levels. In immunohistochemical and mRNA in situ hybridization studies we show that an NO synthase most closely resembling the inducible isoform is constitutively expressed apically in sinus epithelium. In contrast, only weak NO synthase activity was found in the epithelium of the nasal cavity. Our findings, together with the well-known bacteriostatic effects of NO, suggest a role for NO in the maintenance of sterility in the human paranasal sinuses.

Adolescent↗
PubMed1995

Sympathetic vascular control of the laryngeo-tracheal, bronchial and pulmonary circulation in the pig: evidence for non-adrenergic mechanisms involving neuropeptide Y.

Neuropeptide Y (NPY) and noradrenaline (NA) are co-stored in sympathetic perivascular nerves of the airway mucosa and lung. THe superior laryngeal, bronchial and pulmonary vascular responses were therefore studied in anaesthetized pigs after systemic injections of NPY and NA and after stimulation (2 or 10 Hz, 15 V, 5 ms) of the cranial and caudal portions of hte cervical sympathetic trunk or the stellate ganglia. NPY and NA increased vascular resistance, suggesting vasoconstriction in all three vascular beds. Stimulation of the cervical sympathetic trunk in the cranial direction caused clear-cut vasoconstriction and a decrease in the superficial blood flow in the laryngeal and tracheal circulation supplied by the superior laryngeal artery. This vascular response may be related to release of NA at 2 Hz and possibly also NPY at 10 Hz, since a remaining vasoconstrictor response at 10 Hz was present in reserpinized preganglionically transected pigs when tissue content of NA but not NPY was depleted. The decrease in superficial blood flow in the tracheal mucosa on sympathetic stimulation was absent after reserpine, however. Stimulation of the cervical sympathetic trunk in caudal direction provoked vasoconstriction in the bronchial and pulmonary vascular beds in control pigs. The basal tone of these two vascular beds was not influenced on electrical stimulation after reserpine pretreatment, however, suggesting involvement of NA and possibly aslo NPY, which were both depleted by reserpine. Electrical stimulation of the stellate ganglia also evoked reserpine-sensitive vasoconstriction in both the bronchial and pulmonary vascular beds. The left stellate ganglion dominated the vasomotor response in the bronchial circulation, whereas the right side mainly influenced the pulmonary circulation and the heart.

Animals↗
PubMed1995

Allergen-induced late-phase airways obstruction in the pig: mediator release and eosinophil recruitment.

The aim of this study was to develop a novel model for studies of mediator mechanisms involved in the late asthmatic reaction in the lower airways, by using the sensitized pig. The release of histamine and cysteinyl-containing leukotrienes (cys-LTs), as well as the levels of inflammatory cells in blood and bronchoalveolar lavage fluid, were determined and their relationship to plasma cortisol levels and pulmonary airways obstruction was noted. Specific-pathogen free pigs were actively sensitized with Ascaris suum allergen, and one group of animals was treated with a cortisol-synthesis inhibitor (metyrapone) by constant intravenous infusion. Ascaris suum allergen was nebulized into the lower airways and total lung resistance, blood leucocyte count and urinary levels of methylhistamine and leukotriene E4 (LTE4) were followed for 8 h, whereafter bronchoalveolar lavage was performed for analysis of leucocytes. An increase in urinary methylhistamine and LTE4 was seen during the acute allergic reaction in both groups of pigs. Metyrapone treatment prolonged the acute release of histamine, and this was seen together with a prolonged acute bronchoconstrictor response. In metyrapone-treated pigs, a continuous release over 8 h was seen for cys-LTs, but not for histamine. A late blood eosinophilia was also seen in metyrapone-treated animals, starting 4-6 h after allergen challenge. Late cys-LT release and eosinophilia were absent in non-metyrapone-treated animals. These results suggest that allergen-induced late release of cys-LTs as well as blood eosinophilia occur simultaneously with late-phase airways obstruction in the pig, and that all these reactions are prevented by high levels of endogenous cortisol.

Allergens↗
PubMed1995

Allergen-induced late-phase airways obstruction in the pig: the role of endogenous cortisol.

In developing a novel model for studies of the allergen-induced late-phase airways obstruction, by using the pig, the importance of endogenous cortisol levels was examined by the use of metyrapone, a cortisol-synthesis inhibitor. Specific-pathogen free pigs were actively sensitized with Ascaris suum allergen. One group of pigs was treated with a constant infusion of metyrapone in order to maintain low levels of plasma cortisol. Ascaris suum allergen was nebulized into the lower airways and plasma cortisol and catecholamine levels, total lung resistance and dynamic compliance, blood gases and pH, and blood flow in the bronchial circulation were continuously recorded for 8 h. At the time of allergen challenge, the plasma cortisol levels in sensitized pigs were 455 +/- 37 nM and 40.1 +/- 3.8 nM in non-metyrapone-treated and metyrapone-treated pigs, respectively. No difference was seen between the magnitude of the acute bronchoconstrictor response in the two groups. A late airways obstruction, starting at about 4 h, developed only in pigs with low cortisol levels, whereas a late increase in blood flow in the bronchial circulation was seen in both groups, even if a late airways obstruction was absent. Plasma adrenaline did not seem to influence the late-phase reaction. These results suggest that endogenous cortisol levels, but not adrenaline, modify the late response to allergen in the pig. Furthermore, it is suggested that the pig is a suitable model for studies of allergic reactions in the airways, if metyrapone is used to keep plasma cortisol levels within a normal range.

Airway Obstruction↗
PubMed1994

Greatly increased luminal nitric oxide in ulcerative colitis.

A role for nitric oxide (NO) in ulcerative colitis has been suggested because mucosal NO synthase activity, measured by indirect assays, is increased in this disorder. We directly measured luminal NO in the colons of twelve controls and six patients with active ulcerative colitis. During colonoscopy, gas was aspirated from different parts of the colon and immediately analysed by a chemiluminescence technique. NO concentrations were more than 100 times higher in the patients than in the controls. Luminal NO is rapidly and easily measurable and may be used to monitor inflammatory bowel disease.

Adult↗
PubMed1994

Intragastric nitric oxide production in humans: measurements in expelled air.

High values (800-6000 parts per billion) of nitric oxide (NO) in expelled air from the stomach were shown in humans by chemiluminescence technique. These NO values were more than 100 times higher than those found in orally exhaled air. Intragastric NO production is probably non-enzymatic, requiring an acidic environment, as NO in expelled air was reduced by 95% after pretreatment with the proton pump inhibitor omeprazole. Furthermore, large amounts of NO were formed in vitro from lettuce and saliva when placed in hydrogen chloride (pH < 2). In conclusion, large amounts of NO are formed intragastrically in humans and this source of NO may be of importance for the integrity of the gastric mucosa in health and disease. Measurements of NO in expelled air might be of value as a non-invasive method for estimation of gastric acidity.

Adult↗
PubMed1994

Primarily nasal origin of exhaled nitric oxide and absence in Kartagener's syndrome.

The exact origin of nitric oxide (NO) in exhaled air is not known. We wanted to further investigate at what site exhaled NO is produced and to determine whether children with Kartagener's syndrome exhibited altered levels of exhaled NO. NO was measured by chemiluminescence technique in air sampled directly from the nose and in normally exhaled air of four children (2.5-13 years old) with Kartagener's syndrome, 20 healthy children, four healthy adults, and four conscious tracheostomized adults. NO was almost absent (98% reduced) in air sampled directly from the nose in four children with Kartagener's syndrome (4 +/- 1 parts per billion (ppb)), compared to age-matched controls (221 +/- 14 (ppb)). Tracheostomized adult subjects had considerably higher NO values in nasally (22 +/- 3 ppb) and orally (14 +/- 2 ppb) exhaled air, compared to levels in air exhaled through the tracheostomy (2 +/- 0 ppb). Treatment with intranasal corticosteroids for 14 days, or with antibiotics for 1 week, did not affect exhaled NO. These results clearly show that, basically, all NO in exhaled air of healthy subjects originates from the upper respiratory tract, with only a minor contribution from the lower airways. Furthermore, the absence of nasal NO in children with Kartagener's syndrome could be of use as a simple noninvasive diagnostic test.

Adolescent↗