Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung

<p>Abstract</p> <p>Background</p> <p>Repeated bronchoalveolar lavage (BAL) has been used in animals to induce surfactant depletion and to study therapeutical interventions of subsequent respiratory insufficiency. Intratracheal administration of surface active agents such as perfluorocarbons (PFC) can prevent the alveolar collapse in surfactant depleted lungs. However, it is not known how BAL or subsequent PFC administration affect the intracellular and intraalveolar surfactant pool.</p> <p>Methods</p> <p>Male wistar rats were surfactant depleted by BAL and treated for 1 hour by conventional mechanical ventilation (<it>Lavaged-Gas</it>, n = 5) or partial liquid ventilation with PF 5080 (<it>Lavaged-PF5080</it>, n = 5). For control, 10 healthy animals with gas (<it>Healthy-Gas</it>, n = 5) or PF5080 filled lungs (<it>Healthy-PF5080</it>, n = 5) were studied. A design-based stereological approach was used for quantification of lung parenchyma and the intracellular and intraalveolar surfactant pool at the light and electron microscopic level.</p> <p>Results</p> <p>Compared to <it>Healthy</it>-lungs, <it>Lavaged</it>-animals had more type II cells with lamellar bodies in the process of secretion and freshly secreted lamellar body-like surfactant forms in the alveoli. The fraction of alveolar epithelial surface area covered with surfactant and total intraalveolar surfactant content were significantly smaller in <it>Lavaged</it>-animals. Compared with <it>Gas</it>-filled lungs, both <it>PF5080</it>-groups had a significantly higher total lung volume, but no other differences.</p> <p>Conclusion</p> <p>After BAL-induced alveolar surfactant depletion the amount of intracellularly stored surfactant is about half as high as in healthy animals. In lavaged animals short time liquid ventilation with PF5080 did not alter intra- or extracellular surfactant content or subtype composition.</p

A survey of transcutaneous blood gas monitoring among European neonatal intensive care units

BACKGROUND: PCO(2 )and PO(2 )are important monitoring parameters in neonatal intensive care units (NICU). Compared to conventional blood gas measurements that cause significant blood loss in preterms, transcutaneous (tc) measurements allow continuous, non-invasive monitoring of blood gas levels. The aim of the study was to survey the usage and opinions among German speaking NICUs concerning tc blood gas monitoring. METHODS: A questionnaire was developed and sent to 56 head nurses of different NICUs in Germany, Switzerland and Austria. RESULTS: A completely answered questionnaire was obtained from 41 NICUs. In two of these units tc measurements are not performed. In most NICUs (77%), both P(tc)O(2 )and P(tc)CO(2 )are measured simultaneously. Most units change the sensors every 3 hours; however, the recommended temperature of 44°C is used in only 15% of units. In only 8% of units are arterial blood gases obtained to validate tc values. Large variations were found concerning the targeted level of oxygen saturation [median upper limit: 95% (range 80–100%); median lower limit: 86% (range 75–93%)] and PO(2 )[median upper limit: 70 mmHg (range 45–90 mmHg); median lower limit: 44 mmHg (range 30–60 mmHg)]. CONCLUSION: Our survey shows that the use of tc monitors remains widespread among German speaking NICUs, despite earlier data suggesting that their use had been abandoned in many NICUs worldwide. In addition, we suggest that the current method of monitoring oxygenation may not prevent hyperoxemia in preterm infants

Human Cytomegalovirus Reactivation during Lactation and Mother-to-Child Transmission in Preterm Infants

In a clinical trial, the incidence of cytomegalovirus reactivation in breastfeeding mothers and transmission to their preterm infants were studied. Breast milk from 73 mothers as well as urine and tracheal and pharyngeal aspirates from their 89 infants were screened weekly for human cytomegalovirus (HCMV) DNA during the first 2 months after delivery. Of the 73 mothers, 48 (66%) were positive for HCMV DNA in the lactating breast. HCMV reactivation could be confirmed for 19 of 20 (95%) immunoglobulin G-positive mothers. Of the eight immunoglobulin G-negative mothers one was positive for HCMV DNA in breast milk. In only 2 out of 13 seropositive mothers with HCMV DNA in breast milk could viral DNA be detected in the peripheral blood. HCMV mother-to-child transmission was concluded for 20 of the 48 (42%) mothers positive for DNA or 7 of 19 (37%) seropositive for HCMV and positive for HCMV DNA in breast milk and one of one mother seronegative for HCMV but positive for HCMV DNA in breast milk. One mother transmitted the virus to her twins. In addition, one infant acquired postnatal HCMV infection despite the mother's being negative for HCMV DNA in breast milk; altogether, we found 22 infants with HCMV infection. In 13 of these 22 infants, virus infection occurred definitively postnatally; two of them developed severe symptomatic HCMV infection. HCMV-infected infants demonstrated higher incidences of amniotic infection, respiratory distress syndrome, bronchopulmonary dysplasia, and retinopathia praenatalis than noninfected infants, however, the differences were not statistically significant. In summary, our study confirmed a very high incidence of HCMV reactivation in mothers during lactation and a significant risk of transmission to preterm infants with the possibility of severe disease in these babies

Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung-2

<p><b>Copyright information:</b></p><p>Taken from "Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung"</p><p>http://respiratory-research.com/content/8/1/40</p><p>Respiratory Research 2007;8(1):40-40.</p><p>Published online 5 Jun 2007</p><p>PMCID:PMC1892019.</p><p></p>ular myelin with its characteristic lattice-like structure in the healthy animals is exemplarly shown in (A). Multi- and unilamellar surfactant forms are shown in (B). Tubular myelin was only extremely rarely seen in the lavaged animals where multi- and unilamellar forms (C) and numerous lamellar body-like forms (D) were present

Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung-1

<p><b>Copyright information:</b></p><p>Taken from "Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung"</p><p>http://respiratory-research.com/content/8/1/40</p><p>Respiratory Research 2007;8(1):40-40.</p><p>Published online 5 Jun 2007</p><p>PMCID:PMC1892019.</p><p></p>ies appear normal in number in the Healthy-Gas (A) and Healthy-PF5080 (B) groups, while the type II cells seem to be smaller in size and contain less lamellar bodies in the Lavaged-Gas (C) and Lavaged-PF5080 (D) groups. Lamellar bodies in the process of secretion were seen more frequently in the lavaged animals (exemplarly shown in D)

Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung-4

<p><b>Copyright information:</b></p><p>Taken from "Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung"</p><p>http://respiratory-research.com/content/8/1/40</p><p>Respiratory Research 2007;8(1):40-40.</p><p>Published online 5 Jun 2007</p><p>PMCID:PMC1892019.</p><p></p>iment. Values in the PF5080 group are significantly higher than in gas ventilated animals (* p < 0.0001)

Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung-3

<p><b>Copyright information:</b></p><p>Taken from "Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung"</p><p>http://respiratory-research.com/content/8/1/40</p><p>Respiratory Research 2007;8(1):40-40.</p><p>Published online 5 Jun 2007</p><p>PMCID:PMC1892019.</p><p></p>ile all four different intraalveolar surfactant subtypes (lamellar body-like forms = lbl, tubular myelin = tm, multilamellar vesicles = mv, unilamellar vesicles = uv) were present in healthy animals, there were no measurable amounts of tubular myelin and decreased fractions of unilamellar vesicles in lavaged animals. This was counterbalanced by increased fractions of lamellar body-like forms and multilamellar vesicles in the lavaged groups, indicating a relative increase in freshly secreted surfactant material in the alveoli

Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung-0

<p><b>Copyright information:</b></p><p>Taken from "Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung"</p><p>http://respiratory-research.com/content/8/1/40</p><p>Respiratory Research 2007;8(1):40-40.</p><p>Published online 5 Jun 2007</p><p>PMCID:PMC1892019.</p><p></p>iment. Values in the PF5080 group are significantly higher than in gas ventilated animals (* p < 0.0001)