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M Griese

Publications and source records attributed to M Griese.

At least 73 records · Page 4Linked to original sources
PubMed1997

Cellular association of antiproteases in lavages from ventilated preterm human neonates.

Lung antiprotease activity is routinely assayed in the supernatant of bronchoalveolar lavage fluid (BALF). In this study the cellular fraction of lavages was also analyzed. Functionally active acid-resistant inhibitors with molecular masses characteristic of the mucus proteinase inhibitor (MPI, 14 kDa) and elastase-specific inhibitor (ESI, 7 kDa) were demonstrated by gel chromatography. Immunocytochemical studies of cells obtained at various postnatal time points from lavages of 10 premature infants with chronic lung disease showed that the inhibitors were confined to neutrophils and macrophages. At each time point, about 70% and 21% of these cells, respectively, stained positively. The polyclonal antibodies usually used to detect MPI did not distinguish between MPI and ESI. Because of this cross reactivity, it was not possible to differentiate between MPI and ESI. Analysis with reverse transcriptase-polymerase chain reaction (RT-PCR) of cells from lavages and of nucleated cells isolated from the peripheral blood showed the production of ESI only, but not of MPI. Nevertheless, MPI can associate with neutrophils and macrophages, as was shown in binding studies with the recombinant protein. These data suggest that when assaying bronchoalveolar lavages (BALs) for these antiproteases in the supernatant only, the total pool of inhibitors may be underestimated.

Bronchoalveolar Lavage Fluid↗
PubMed1997

Pulmonary surfactant in cystic fibrosis.

Cystic fibrosis (CF) leads to a chronic inflammation of the airways with significant air flow limitations developing early in the course of the disease. As a well-functioning pulmonary surfactant is necessary to keep the alveoli and the small conducting airways open during expiration, we hypothesized that the biochemical and biophysical properties of surfactant may be impaired in CF. Bronchoalveolar lavage fluid obtained during a clinically stable period was analysed from 20 CF patients (5.9-20 yrs) and 17 healthy children and adults. CF patients had significantly elevated total and polymorphonuclear neutrophil cell counts, whereas the concentrations of total protein and phospholipids did not differ from controls. The percentage of surface active phospholipids, phosphatidylcholine and phosphatidylglycerol, and the concentration of surfactant protein A were significantly reduced in CF patients. Surfactant protein B was unchanged. Although the relative proportion of large aggregates was higher in CF, their surface active properties were inferior, as assessed in the pulsating bubble surfactometer. Because the capacity of CF lavage fractions to inhibit surfactant function was the same as that of controls, impaired minimal surface tension was more likely to be due to the biochemical alterations detected, than to inhibition of a well-functioning surfactant. The impaired pulmonary surfactant system in clinically stable patients with cystic fibrosis is in agreement with the view that surfactant dysfunction may contribute to lung disease in cystic fibrosis.

Adolescent↗
PubMed1997

Nebulization of a bovine surfactant in cystic fibrosis: a pilot study.

Cystic fibrosis (CF) is a lethal disorder which results in excessive airway secretions and in chronic inflammation of the airways. In vitro and in vivo studies have shown that a lack of surfactant results in the closure of the small airways. In this pilot study, we aimed to determine whether surfactant administered by aerosol might improve lung function on a short-term basis in patients with CF. In a randomized, crossover double-blind pilot study, 120 mg of a lipid-extracted bovine surfactant (Alveofact) or placebo was aerosolized to five young adult patients with CF over a period of 30 min for five consecutive days. The sample size had the power of 90% to detect an increase in forced expiratory volume in one second (FEV1) of 15% (p < 0.05). Jet nebulization of surfactant produced particles of which more than 75% were the respirable range (< 5 microns). The inhalations were well tolerated. No changes in serum antibody titres against the surfactant proteins-B and -C (SP-B/SP-C) were observed. No differences in FEV1 and forced vital capacity were found before, and 30 or 90 min after, the inhalation. This pilot study shows no acute or short-term benefits of surfactant inhalation in young adults with cystic fibrosis. However, a beneficial effect of exogenous surfactant cannot be excluded before other reasons for a lack of effect, such as insufficient quantity delivered, inhomogeneous distribution or inhibition of the surfactant in the lungs, have been completely ruled out.

Administration, Inhalation↗
PubMed1996

Calcium, potassium, urea and total protein are not reliable dilutional markers of bronchoalveolar small volume-lavages in ventilated preterm human neonates.

In order to better understand the lung pathology in neonates, more information on basic parameters and their usefulness as dilutional markers in epithelial lining fluid (ELF) is desirable. In this study we determined the amounts of calcium (Ca++), potassium (K+), total protein, albumin and urea in specimens, obtained by small volume lavage, and also in serum from premature infants, who have and have not had surfactant treatment. None of the serum/lavage ratios of these parameters generally increased the correlation between the serum and lavage values of the other parameters and all were thus unreliable markers for the calculation of the dilution of lung ELF as recovered by the small volume lavage procedure. However, the consistently different magnitudes of these ratios appeared to allow gross estimates of the relative concentrations of these parameters between one another. On the basis of a serum/lavage ratio for urea of 1, K+ and Ca++ were concentrated in ELF by a factor of 2 in relation to serum, whereas the protein concentration was 2-3 times lower than in serum. Generally it appears most appropriate to express the results obtained in analyses of lavages either as the uncorrected concentrations per ml recovered lavage fluid or as the ratio of two parameters simultaneously determined in the lavage. In this study, except for marginally increased Ca++ concentrations during the first days of life in surfactant treated neonates, no differences were noted for K+, urea or protein between neonates treated with surfactant or without.

Biomarkers↗
PubMed1996

Respiratory support, surface activity and protein content during nosocomial infection in preterm neonates.

Small volume bronchoalveolar lavages from 10 infants (26.6 +/- 0.4 weeks gestational age) during postnatal nosocomial infection were fractioned by differential centrifugation into large (LA) and small (SA) surfactant aggregates. Before deterioration of the clinical status, the surface tension at minimum bubble radius (gamma min), as measured in a pulsating bubble surfactometer, was reduced to about 14 mN/m by LA and to about 22 mN/m by the corresponding SA. The gamma min of both LA and SA increased during clinical deterioration, was highest at the worst clinical state and returned during recovery to values in the range before deterioration. Respiratory support significantly correlated to gamma min at all times. In contrast, no correlation was observed for total protein or albumin content of the LA or SA fractions. The SA fraction was characterized by a 10-fold higher protein content than LA. These data demonstrate functional impairment of surfactant in subfractions during mechanical ventilation and nosocomial infection in preterm neonates that are not fully explained by inhibition with increasing amounts of total protein.

Adsorption↗
PubMed1996

Surfactant subfractions during nosocomial infection in ventilated preterm human neonates.

Long after resolution of the neonatal respiratory distress syndrome, deterioration of respiratory function in ventilated premature infants during severe nosocomial infections is commonly observed. Based on an increased oxygen demand and ventilatory support, impairment of the pulmonary surfactant system was hypothesized to occur. The clinical course of 10 premature neonates (764 +/- 57 g, 26.6 +/- 0.4 wk) with nosocomial infection mainly due to Staphylococcus epidermidis was divided into four periods in each individual patient: "before deterioration" (average 8 to 11 d of life), "deterioration" (11 to 17 d), "peak" (17 to 22 d), and "recovery" (22 to 24 d). A total of 810 airway specimens were obtained by small volume lavage (1 ml/kg bw), pooled to yield appropriate amounts for differential centrifugation into two distinct subfractions known as large surfactant aggregates (LA) and small surfactant aggregates (SA). "Before deterioration" the amount of phospholipids recovered was constant, and the two fractions were characterized by electron microscopic morphology and biochemical analysis. In the LA fraction lamellar body-like lipid structures were demonstrated, and the phospholipid composition was typical of pulmonary surfactant in premature neonates with a high content of phosphatidylcholine and phosphatidylinositol. With "deterioration" and "peak" the masses of total phospholipids and of phosphatidylcholine recovered were reduced (p < 0.05). At the same time the mass ratio of SA/LA for phosphatidylcholine decreased from 0.32 +/- 0.10 to 0.18 +/- 0.03, indicating a more pronounced decrease of the SA fraction (p < 0.05). The phospholipid composition in the LA fraction did not change during the course of nosocomial infection. In the SA fraction a decrease of phosphatidylcholine and a concomitant increase in lysophosphatidylcholine were observed at the "peak" of the infection. We concluded that, in ventilated premature neonates during nosocomial infection and respiratory deterioration, changes in phospholipid subfractions occur, possibly indicating impairment of pulmonary surfactant metabolism. These findings may be important when considering treatment of acute lung injury with nebulized exogenous surfactant.

Age Factors↗
PubMed1995

Pharmacokinetics of bovine surfactant in neonatal respiratory distress syndrome.

Lung pharmacokinetics of lipid-extracted natural bovine surfactants of different composition and currently used in neonatology were studied in 568 airway specimens from 23 consecutively admitted, small preterm neonates (gestational age, 26.7 +/- 0.3 wk) who were mechanically ventilated for 5 to 7 d in a tertiary care center. In six infants who were mechanically ventilated only, no changes in phospholipid quantity or composition were noted. The other infants were randomly assigned to two groups that received the natural surfactants Survanta or Alveofact, respectively. In the Survanta group (n = 6), exponential decreases were observed in the percentage of phosphatidylglycerol (PG) and sphingomyelin (Sph), while phosphatidylinositol (PI) remained low. In Alveofact-treated neonates (n = 8), PG also decreased exponentially, whereas PI increased linearly during the first week of life to values equivalent to those in infants not treated with surfactant. The exponential disappearance of PG and Sph from repetitive airway samples was utilized to calculate an apparent endogenous pool size, for the time before surfactant treatment, of about 20 mg phospholipids/kg body weight (n = 14). The apparent half-life of PG in the Alveofact group (43 +/- 11 h) was shorter than in the Survanta-treated infants (105 +/- 23 h, p < 0.01), and a similar value was obtained for Sph (97 +/- 21 h, n = 6). There was no correlation between PG or Sph half-life and the amount of surfactant applied. These data for human neonates show a dependence of surfactant clearance and metabolism on the type of bovine surfactant preparation administered.

Biological Products↗
PubMed1993

Signal-transduction mechanisms of ATP-stimulated phosphatidylcholine secretion in rat type II pneumocytes: interactions between ATP and other surfactant secretagogues.

ATP stimulates phosphatidylcholine secretion in type II cells, an effect that is mediated by both adenosine A2 receptors coupled to adenylate cyclase and P2 receptors coupled to phosphoinositide-specific phospholipase C. Activation of these effector enzymes leads to formation of cAMP, diacylglycerols and inositol trisphosphate (IP3). cAMP in turn activates cAMP-dependent protein kinase, diacylglycerols activate protein kinase C and IP3 promotes Ca2+ mobilization. To further investigate the signal-transduction mechanisms mediating the ATP effect, we examined its action in combination with that of other surfactant secretagogues: 5'(N-ethylcarboxyamido)adenosine (NECA), a A2 agonist that activates adenylate cyclase; TPA (12-O-tetradecanoylphorbol-13-acetate), a direct activator of protein kinase C; and ionomycin, an ionophore that increases intracellular Ca2+. The effects of NECA, TPA and ionomycin were additive and thus consistent with independent signaling mechanisms. However, the effects of all combinations of three or four secretagogues that contained ATP were 10-20% less than additive. This suggested that ATP and other secretagogues act via common mechanisms. Calmodulin antagonists decreased the effects of ionomycin and ATP by approx. 60% and 30%, respectively, but did not decrease the effects of NECA, terbutaline or TPA. Complete inhibition of the effect of ATP was achieved with a combination of a calmodulin antagonist, an A2 antagonist and a protein kinase C inhibitor. These and previous data suggest that the stimulatory effect of ATP on phosphatidylcholine secretion in type II cells is mediated by three signal-transduction mechanisms: activation of cAMP-dependent protein kinase; activation of protein kinase C; and a calmodulin-dependent mechanism.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1993

Potentiation of A2 purinoceptor-stimulated surfactant phospholipid secretion in primary cultures of rat type II pneumocytes.

Surfactant secretion is mediated by a number of different signal-transduction mechanisms. Positive and negative interactions between different signaling pathways can have an important influence on the overall regulation of secretion. To examine interactions between the adenosine A2 receptor-mediated pathway and those involving activation of protein kinase C and a Ca++/calmodulin-dependent system, we examined the effect of the A2 agonist 5'-(N-ethylcarboxyamido) adenosine (NECA) in combination with 2 activators of protein kinase C, 12-O-tetradecanoylphorbol-13-acetate (TPA) and dioctanoylglycerol, and the Ca++ ionophore ionomycin on phosphatidylcholine secretion in primary cultures of rat type II cells. The individual agonists increased secretion 3-5-fold over the rate in control cells. The stimulatory effects of NECA+TPA, NECA+dioctanoylglycoerol, and NECA+ionomycin were 44%, 20%, and 44% greater, respectively, than expected by addition of the effects of the individual agonists. NECA increased cAMP formation while the other agonists did not. However, the effect of NECA on cAMP formation was significantly enhanced by TPA and dioctanoylglycerol, while the duration of the increase in cAMP level was prolonged by dioctanoylglycerol and ionomycin. Although the possible involvement of other second messenger systems cannot be excluded, we speculate that the synergistic interaction between the agonists in stimulating phosphatidylcholine secretion is mediated by increased cAMP levels.

Adenosine↗
PubMed1993

Histamine release from basophils in childhood: age dependency and inhibition by pertussis infection and pertussis toxin.

The influence of childhood pertussis infection and of purified pertussis toxin on histamine release from human basophil leucocytes was investigated. Three different stimuli, the peptide N-formyl-Met-Phe (NFMP), anti-IgE, and the calciumionophore A23187 were used to challenge the cells. When NFMP was the stimulus, histamine release in the control group (age 0.5-17 years) increased in an age-dependent fashion, whereas anti-IgE and A23187 stimulated release did not vary with age. During the convulsive state of pertussis infection there was a significant reduction of histamine release in response to 10 microM NFMP (from 9.5 +/- 1.4 [n = 21] to 6.7 +/- 1.5 [n = 19], P < 0.05) and in response to 800 and 80 U/ml anti-IgE (from 28.5 +/- 5 [n = 19] to 16.3 +/- 5 [n = 13], P < 0.05, and from 6.9 +/- 1.7 [n = 16] to 2 +/- 0.8 [n = 13], P < 0.01), whereas histamine release stimulated by A23187 was unchanged compared to release in control children. In vitro pretreatment of basophils from healthy children and adults with pertussis toxin also inhibited histamine release. When NFMP was the stimulus, release was completely blocked by pertussis toxin with an IC50 of about 11 ng/ml, whereas anti-IgE stimulated release was only inhibited by 20%-30% and release induced by A23187 was reduced to 40%-50% by toxin treatment. In conclusion we have demonstrated a functional impairment of histamine release during the convulsive state of pertussis and that this inhibition is likely to be mediated by pertussis toxin.

Adolescent↗
PubMed1992

Cibacron blue stimulation of surfactant secretion in rat type II pneumocytes.

1. The effect of cibacron blue, a selective P2y-purinoceptor antagonist in some systems, on the stimulatory effect of adenosine 5'-triphosphate (ATP) on [3H]-phosphatidylcholine secretion was examined in primary cultures of rat type II pneumocytes prelabelled by overnight culture with [3H]-choline. 2. Cibacron blue alone stimulated phosphatidylcholine secretion in a concentration-dependent manner in the range 10(-4)-10(-3) M. At a concentration of 10(-4) or lower, cibacron blue had no effect on ATP-induced phosphatidylcholine secretion but at 10(-4)-10(-3) M it increased the effect of ATP. Enhancement of the ATP effect was apparent whether cibacron blue was added before or together with ATP. Cibacron blue also increased ATP-induced secretion in the presence of the P1-purinoceptor antagonist, xanthine amine congener (10(-5) M). 3. The stimulatory effect of cibacron blue on phosphatidylcholine secretion was additive to those of 5' (N-ethylcarboxyamido) adenosine (NECA) and terbutaline but less than additive to that of ATP. 4. Cibacron blue alone had no effect on formation of cyclic AMP or inositol phosphate and when added simultaneously with ATP it did not affect the ATP-induced increase in these second messengers. Preincubation of the cells with cibacron blue before addition of ATP, however, resulted in antagonism of the ATP-induced increase in cyclic AMP and inositol phosphates. Preincubation with ATP had the same effect. The stimulatory effects of NECA and terbutaline on cyclic AMP formation were enhanced by preincubation with cibacron blue. 5. Thus, ATP-induced phosphatidylcholine secretion in type II cells is not diminished by the P2y-antagonist, cibacron blue.5. Thus, ATP-induced phosphatidylcholine secretion in type II cells is not diminished by the P2yantagonist, cibacron blue. On the contrary, cibacron blue stimulates phosphatidylcholine secretion. Cibacron blue may act as a P2-agonist in type II pneumocytes.

Adenosine↗
PubMed1992

Ontogeny of surfactant secretion in type II pneumocytes from fetal, newborn, and adult rats.

We measured phosphatidylcholine secretion and its response to surfactant secretagogues in type II cells from developing rats. Cells were isolated from fetal rats on day 21 of gestation by digestion with collagenase and trypsin and purification by differential adhesion. Cells were isolated from adult and postnatal rats on days 1, 7, 14, and 30 by elastase digestion and panning on immunoglobulin G-coated dishes. The basal rate of phosphatidylcholine secretion was the same at all ages but there were developmental changes in the response to secretagogues. The response to terbutaline and an adenosine A2 receptor agonist increased from fetal life until day 7 when it reached the level of adult cells. Adenosine deaminase did not increase the response of the cells to these agonists until day 30, suggesting that the adenosine A1 receptor inhibiting secretion does not become functional until that age. The response to 12-O-tetradecanoylphorbol 13-acetate was lower in the fetal cells but had reached the adult level by day 1. The developmental increase in the response of the cells to ATP was more prolonged with the maximum response not being attained until day 30. With the exception of day 30, when the response to most of the secretagogues was very high, the response to ionomycin was the same at the other ages. These data suggest differential maturation of the signal-transduction pathways mediating surfactant secretion in type II cells.

Adenosine↗
PubMed1992

[Pulmonary surfactant and the immune system].

Natural surfactant, a mixture of lipids and proteins is potentially immunogenic. Frequent therapeutic and prophylactic use of exogenous lung surfactants necessitates a review of the data on its influence and relation to the immune system. Detection of circulating surfactant-antisurfactant immune complexes in the serum of newborn with respiratory distress syndrome and sporadically of free antisurfactant antibodies was not associated with any other specific symptoms during short term survey. Several studies were unable to detect formation of specific surfactant protein B or C antibodies in response to treatment with bovine surfactants. However further and long term follow up of these neonates especially during newly acquired lung diseases is desirable. In addition to its antigenicity, surfactant participates in a complex manner in the local immune response of the lung. Due to its direct bactericidal effects for some bacteria and various interactions with alveolar macrophages, lymphocytes and monocytes, surfactant is specifically involved in the defense of pulmonary pathogens. Furthermore there is evidence for a modulation and suppression of immune responses in the terminal alveoli by surfactant. These immunological aspects of lung surfactant need further study.

Antigen-Antibody Complex↗
PubMed1991

Adenosine A2-receptor-mediated phosphatidylcholine secretion in type II pneumocytes.

Adenosine and its analogues stimulate phosphatidylcholine secretion in cultured rat type II pneumocytes. There is evidence that this effect is mediated by A2 receptors. We have now employed the radioligand 5'(N-ethylcarboxyamido)adenosine (NECA) in an attempt to study the adenosine receptor in a membrane fraction of type II cells. Specific binding of [3H]-NECA was saturable with a total binding capacity (Bmax) of 4.91 pmol/mg protein and a dissociation constant (Kd) of 240 nM. The Kd was similar to the concentration of NECA which half-maximally stimulated phosphatidylcholine secretion (EC50, 150 nM). Although the relative potency of adenosine analogues in displacing bound [3H]NECA was consistent with that expected at an A2 receptor, there were discrepancies between binding and function with respect to some agonists as well as the antagonist xanthine amine congener (XAC). This together with the unusually high Bmax suggests that the NECA binding site is not the adenosine receptor mediating phosphatidylcholine secretion. The receptor was further characterized functionally by measuring its antagonist dissociation constant (Kb). KbS for XAC inhibition of the effects of NECA, N6-(L-2-phenylisopropyl)adenosine, and adenosine on phosphatidylcholine secretion were 19 +/- 8, 24 +/- 11, and 6 +/- 12 nM, respectively, suggesting that all three agonists act at the same receptor. The Kb value allowed comparison of the receptor in type II cells with that in other tissues and revealed that it was similar to the A2 receptor previously described in human platelets. These functional data further characterize and are consistent with a physiological role for the adenosine A2 receptor in the regulation of lung surfactant secretion.

Adenosine↗
PubMed1991

ATP-stimulated inositol phospholipid metabolism and surfactant secretion in rat type II pneumocytes.

Extracellular ATP (10(-3) M) stimulated [3H]phosphatidylcholine secretion approximately 3.4-fold in rat type II pneumocytes prelabeled overnight with [3H]choline. The same concentration of ATP caused a rapid increase in [3H]inositol trisphosphate (IP3) and a decrease in [3H]phosphatidylinositol bisphosphate (PIP2) in [3H]inositol-prelabeled cells. ATP also caused a biphasic increase in 1,2-[3H]diacylglycerol in cells prelabeled with [3H]arachidonic acid: a rapid increase that peaked at 10 s followed by a larger increase that peaked at 5-10 min. The first peak in diacylglycerol and the increase in IP3 are consistent with phospholipase C action on PIP2 and generation of second messengers that promote mobilization of intracellular Ca2+ and activation of protein kinase C. However, at the level of phosphatidylcholine secretion the stimulatory effects of ATP and of direct activators of protein kinase C, 12-O-tetradecanoylphorbol-13-acetate (TPA) and 1,2-dioctanoyl-sn-glycerol, were at least additive, suggesting that activation of protein kinase C may not be the major signal transduction mechanism in ATP action or alternatively that ATP activates a different isoform of protein kinase C. Pretreatment of type II cells with TPA for 30 min led to a subsequent 40% diminution in the stimulatory effects of ATP on both phosphatidylcholine secretion and IP3 generation.

Adenosine Triphosphate↗