Selectivity of auger decays to the local surface environment

The line shape of the Auger decay of adatoms is studied by a joint theoretical and experimental effort, the former within a DFT framework, and the latter with synchrotron radiation measurements. We investigate the KL(2,3)V Auger deexcitation of Na on Al(111), a system with different adsorption geometries. In particular, we study the (sqrt[3]xsqrt[3])R30 degrees phase at 1/3 ML (monolayer) and the more complex (2 x 2) structure at 1/2 ML coverage. From the comparison between theory and experiment, we unambiguously determine features that allow for the determination of the adsorption environment from the adatom Auger spectrum.

Subarachnoid anaesthesia in caesarean delivery: effects on alertness

AIM

Subjects in spinal anaesthesia have been reported to show a decrease in the level of alertness, even when they have not received any sedative drugs.

THE AIM

of this study is to verify, in caesarean delivery if the bupivacaine subarachnoid anaesthesia, with or without intrathecal fentanyl dose, produces a sedative effect, to define the entity and to identify the mechanism that most likely causes it.

METHODS

The clinical investigation is divided into Part I (non-randomized trial) and Part II (randomized trial) and is set in the University hospital's delivery-unit. Part I: 45 pregnant women were recruited and enrolled in 3 groups: women having natural delivery (n=15), women receiving caesarean delivery with subarachnoid anaesthesia (n=15) and with general anaesthesia (n=15). Self-rating depression scale (SDS), self-rating anxiety scale (SAS), state anxiety inventory (SAI) and trait anxiety inventory (TAI) psychometric tests were patient-completed for pre-delivery anxiety evaluation. Part II: 23 pregnant women undergoing caesarean delivery were single-blind randomized to receive subarachnoid anaesthesia with single 12.75 mg 0.5% hyperbaric bupivacaine (n=10) or with 12.75 microg 0.5% hyperbaric bupivacaine and 15 mg fentanyl (n=13). Bispectral index (BIS), observer's assessment of alertness/sedation (OAA/S) scale, self-sedation visual analogic scale (VAS) and mean arterial pressure (MAP) were perioperatively monitored.

RESULTS

Part I: it was found, using SAI, a higher level of state anxiety in the pregnant women undergoing caesarean delivery than those having natural delivery (p<0.05). Part II: pregnant women receiving subarachnoid anaesthesia for caesarean delivery had a decrease of the level of alertness from 10 to 70 min after the execution of lumbar puncture (p<0.05), with a sedative peak from 35 to 45 min (p<0.01), as measured by OAA/S scale and self-sedation VAS but not by BIS. Women who received bupivacaine-fentanyl spinal anaesthesia had a more consistent sedative effect from 35 to 70 min (p<0.05).

CONCLUSIONS

Pregnant women undergoing caesarean delivery had a more elevated level of state anxiety, assessed by SAI, as seen in Part I. Subarachnoid anaesthesia in caesarean delivery is associated with a reduction of alertness level. A double mechanism might cause a clinically valuable sedative effect, observed by OAA/S scale and self-sedation VAS: decrease of the afferent spinal inputs and an anxiolytic psychophysiologic effect, induced by good outcome of the birth and mother-baby contact. Intrathecal bupivacaine-fentanyl dose produces a larger alertness decrease than single bupivacaine, because the anaesthetic block density increases. BIS was not a sensitive measure to detect the light sedation occurring in Part II of this study.

Independent lung ventilation in patients with unilateral pulmonary contusion. Monitoring with compliance and EtCO(2)

OBJECTIVE

a) to describe a non-barotraumatic ventilatory setting for independent lung ventilation (ILV); b) to determine the utility of single lung end-tidal CO(2) (EtCO(2)) monitoring to evaluate the ventilation to perfusion (V/Q) matching in each lung during ILV and for ILV weaning.

DESIGN

prospective study.

SETTING

general intensive care unit in a university teaching hospital.

PATIENTS

twelve patients with unilateral thoracic trauma needing ILV.

INTERVENTIONS AND RESULTS

ILV was started with each lung ventilated with the same tidal volume (Vt): plateau airway pressure (Pplat) was 34.2+/-3.2 cmH2O in diseased lungs (DL) and 18.1+/-1.9 cmH2O in normal lungs (NL) ( P<0.01). Static compliance (Cst) was 9.9+/-1.1 ml/cmH(2)O in DL and 19.3+/-1.7 ml/cmH(2)O in NL ( P<0.01). EtCO2 was 22.5+/-2.2 mmHg in DL and 36.6+/-1.9 mmHg in NL ( P<0.01). PaO(2)/FiO(2) was at 151+/-20. PEEP was applied on the DL and each lung was ventilated with a Vt that developed Pplat < or =26 cmH2O. With this setting, Vt given to the NL was unchanged, whereas it was reduced in the DL (238+/-30 ml vs 350+/-31 ml; P<0.01). Cst and EtCO2 were still significantly lower in the DL ( P<0.01, respectively), while the PaO(2)/FiO(2) ratio remained unchanged. Vt was then progressively increased in the DL as Pplat decreased, but remained unchanged in the NL. ILV was discontinued when Vt, Cst and EtCO(2) were the same in each lung. PaO(2)/FiO(2) ratio had then increased to 295+/-18.

CONCLUSIONS

a) during ILV, adequate oxygenation and a reduction in V/Q mismatch can be obtained by setting Vt and PEEP to keep Pplat below a safe threshold for barotrauma; b) measurement of single lung EtCO2 can be useful to evaluate progressive V/Q matching.

Uroplakin expression in the urothelial tumors of cows

Expression of uroplakins (UPs) was investigated in 20 bladder tumors from cows that had been suffering from chronic enzootic hematuria for several years. In dysplastic urothelium and papillomatous proliferations, UP expression was evident both as luminal and intercellular staining. UPs appeared to clearly define the plasma membrane of luminal cells and the borders of cells placed in deeper layers, whether or not these intermediate cells were adjacent to superficial ones. Occasionally, some intermediate cells showed a remarkable cytoplasmic immunoreactivity. The pattern of UPs in grade I tumors was characterized by an evident discontinuity of luminal staining and by the presence of numerous intermediate cells showing a diffuse intracytoplasmic positivity for UPs. In grade II tumors, there was a decrease of luminal and intermediate cells showing UP expression and an apparent increase of clusters of intermediate cells with intracytoplasmic reactivity for UPs. In grade III tumors, immunoreactivity was heterogeneously distributed and a severe loss of UP-positive luminal and intermediate cells could be seen. Focally, superficial and deeper cells showed strong membraneous immunoreactivity that marked and delimited single cells, with complete circumferential peripheral staining clearly evident. UP expression in bladder tumors of cows reported in this study is similar to the UP pattern of some urothelial tumors in humans. Although UP expression is remarkably changed in bladder carcinogenesis of cattle, the UP gene(s) remains expressed during cell transformation and tumor progression.

[Indications for the surgical treatment of abdominal aortic aneurysms]

BACKGROUND

On the basis of a literature review and of personal experience, the authors analyze the main indications and the best strategy for elective surgical repair of infrarenal abdominal aortic aneurysm (AAA).

METHODS

Personal experience concerning elective surgical treatment of 110 patients with infrarenal AAA, is presented.

RESULTS

No operative deaths have been observed and the postoperative recovery was regular in 108 patients. Two early complications (colon ischemia) and ten late postoperative complications (5 pseudoaneurysms, 5 sexual dysfunctions) occurred.

CONCLUSIONS

The main therapeutic guidelines concerning the management of AAA should follow specific indications (aneurysm dimensions and growth rates). Indications for operative repair of aneurysms obviously should be judged in relation to the presence or absence of associated risk factors or concomitant medical conditions. In most cases, aneurysm repair can be performed safely, despite associated medical risks, by careful preoperative evaluation and preparation.

[Short-term effects of prone positioning on the oxygenation of pediatric patients submitted to mechanical ventilation]

OBJECTIVE: To analyze the short-term effects of prone positioning on the oxygenation of mechanically-ventilated children suffering from severe hypoxemia. MATERIALS AND METHODS: A prospective, nonrandomized trial (each patient as his/her own control) was conducted between July 1998 and July 1999. Mechanically-ventilated children with peak inspiratory pressure greater than or equal to 30 cm H(2)O, FiO(2) greater than or equal to 0.5, and PaO(2)/FiO(2) ratio less than or equal to 200 were included in the study. Each patient was kept in the prone position for two hours, returning to the supine position after this period. Oxygenation was assessed by means of PaO(2)/FiO(2) in the supine position (one hour before prone positioning), one hour after prone positioning, and one hour after returning to the supine position. Patients who presented an increase of at least 20 in PaO(2)/FiO(2) were considered responsive. The results were compared by Student t-test, Friedman test, chi-square test, Fishers exact test, and confidence interval. RESULTS: Eighteen children (10 males), whose mean age was 11.5 -/+11.5 months, with initial PaO(2)/FiO(2) of 96.06 -/+ 41.78, participated in the study. After one hour in the prone position, 27.7% of the patients (5/18) improved their PaO(2)/FiO(2) ratio (P=0.045). Six of these patients presented reduced lung compliance (four of them had acute respiratory distress syndrome); and twelve patients showed increased airway resistance (six of them presented bronchiolitis). No significant difference was observed between these two groups (reduced lung compliance x increased airway resistance) in terms of age, sex, duration of ventilation prior to change in position, peak inspiratory pressure, FiO(2), severity of hypoxemia, and outcome. CONCLUSION: Prone positioning during mechanical ventilation of children with severe hypoxemia may improve the PaO(2)/FiO(2) ratio in the first hour.

Liquid chromatographic/mass spectrometric determination of desmedipham and phenmedipham and their metabolites in soil

A simple method is described for the simultaneous determination of residues of 2 carbamate herbicides (phenmedipham and desmedipham) and related metabolites (m-aminophenol, aniline, and m-toluidine) in soil. The analytes are extracted from spiked soils with methanol. The solvent/soil suspension is centrifuged, and the supernatant is directly injected, without any further cleanup, into a reversed-phase liquid chromatography/mass spectrometry apparatus equipped with a TurbolonSpray interface. The method was tested on 5 soils having different physicochemical properties. Recoveries from the soil types, spiked over the range of 50-200 ppb, were essentially quantitative for each analyte. The detection limits of the method are < or = 25 ng/g.

Solid-phase extraction followed by liquid chromatography-mass spectrometry for trace determination of beta-lactam antibiotics in bovine milk

A confirmatory assay able to unambiguously identify and quantify 10 approved-for-use beta-lactam antibiotics in milk below stipulated U.S. and EU tolerance levels is presented. beta-Lactams are extracted from 10 mL of intact milk by a Carbograph 4 cartridge. After solvent removal, residue reconstitution, and filtration, a completely transparent and uncolored extract is injected into a liquid chromatography -mass spectrometry (LC-MS) instrument equipped with an electrospray (ES) ion source and a single quadrupole. During the chromatographic run, the ES/MS system is operated first in the positive-ion mode (PI) and then in the negative-ion (NI) mode. This is done to circumvent matrix interferences resulting in remarkable signal weakening of the last-eluted analytes, when detecting them as [M+H]+ adduct ions. MS data acquisition is performed by a time-scheduled three-ion selected ion monitoring program. At the 5 ng/mL level, recoveries of the beta-lactams are between 70 (nafcillin) and 108% (cephalin), with relative standard deviations ranging between 5 (oxacillin) and 11% (amoxicillin and ceftiofur). The response of the ES/MS detector is linearly related to injected amounts up to 500 ng, irrespective of the chemical characteristics of the beta-lactams and the acquisition mode selected (PI or NI modes). Limits of quantification, based on a minimal value of the signal-to-noise ratio of 10, were estimated to be within 0.4 (cephalin) and 3 ng/mL (dicloxacillin). Analyses of milk samples taken after intramammary application of amoxicillin showed that 1.2 ng/mL of this penicillin was still present 6 days after treatment. At this concentration level, the identification power of the method is not weakened, as signals of the three product ions of amoxicillin are still well distinguishable from the background noise.

Response of severe HIV-associated thrombocytopenia to highly active antiretroviral therapy including protease inhibitors

OBJECTIVE

To investigate the response of HIV-associated severe thrombocytopenia (STP) to highly active antiretroviral therapy (HAART) including protease-inhibitors.

METHODS

In this retrospective study, 15 patients with HIV-associated STP (platelet count < 50 x 10(9)/l mostly antiretroviral experienced (13/15), underwent HAART for at least 6 months (median 21; range 6-41 months) during which the platelet (PLT) count and plasmatic HIV-RNA were monitored. The PLT response was compared to that observed in 19 patients previously treated with zidovudine (AZT) monotherapy.

RESULTS

HAART induced a significant increase in the PLT count (chi(2)=10.53, P=0.01) within the third month which was sustained up to the sixth month of therapy. No STP relapse was observed among eight PLT responders followed for longer than 6 months (median 27; range 7-41 months). The PLT increase after HAART was similar to that observed with AZT monotherapy, but a greater number of HAART patients were antiretroviral-experienced. HAART determined a PLT response in 10/13 subjects whose thrombocytopenia had not improved after previous AZT monotherapy. After 6 months of HAART, a complete platelet response occurred more frequently in patients with undetectable plasma HIV-RNA levels (P=0.01).

CONCLUSIONS

HAART induces a sustained PLT response in HIV-associated STP, even in antiretroviral-experienced subjects and in those with AZT-resistant thrombocytopenia. An undetectable plasma HIV viraemia induced by HAART is necessary for STP recovery.

Atomically resolved images from near node photoelectron holography experiments on Al(111)

Szöke's concept for electron holography is hampered by forward scattering that dominates electron diffraction from electron point sources below the surface top layer. Forward scattering was proposed to be suppressed if the anisotropic nature of the electron source wave is exploited [T. Greber and J. Osterwalder, Chem. Phys. Lett. 256, 653 (1996)]. Experiments show a strong suppression of forward scattering in Al(111) if Al 2s photoelectrons (E(kin) = 952 eV) are measured near the nodal plane of the outgoing p wave. The holographic reconstruction from such diffraction data provides three dimensional images of atomic sites in unit cells with a size of more than 10 A.

[Exogenous surfactant treatment for severe acute viral bronchiolitis: case report]

OBJECTIVE: To describe the possible clinical and laboratory effects of exogenous surfactant instillation into the tracheal tube of a child with severe acute bronchiolitis undergoing mechanical ventilation. CASE REPORT: a 2-month-old girl with clinical diagnosis of acute viral bronchiolitis underwent mechanical ventilation. She required high positive inspiratory peak pressure (35 to 45 cmH(2)O) and high inspiratory fraction of oxygen (FiO(2) = 0.9), but showed no clinical response or improvement in the arterial blood gas analysis. An exogenous surfactant (Exosurf(R), Glaxo - 50 mg/kg) was used to facilitate the use of a less aggressive ventilatory strategy. RESULTS: Four hours after surfactant administration, it was possible to reduce the positive peak inspiratory pressure (PIP) from 35 to 30 cmH(2)O, and FiO(2) from 0.9 to 0.6; and to increase the positive end-expiratory pressure (PEEP) from 6 to 9 cmH(2)O. During this period the paO(2)/FiO(2) ratio increased from 120 to 266. At the end of 24 hours, FiO(2) could be reduced to 0.4. DISCUSSION: Surfactant inactivation may be a decisive factor in the unfavorable evolution of some severe cases of acute bronchiolitis. The tracheal instillation of exogenous surfactant, in these cases, allows us to adopt less aggressive ventilatory strategies, and promotes rapid clinical responses.

Method development for measuring trace levels of penicillins in aqueous environmental samples

A method based on liquid chromatography/mass spectrometry with an electrospray ion source and a single quadrupole instrument (LC/ES-MS) has been developed for determining trace levels of eight widely used penicillins in aqueous environmental samples. Analyte extraction was performed from 4 L tap water, 2 L groundwater, 1 L river water, 0.2 L treated sewage and 0.1 L raw sewage, by using a Carbograph 4 cartridge. During removal of the solvent, penicillins were purposely allowed to convert into their penicilloyl methyl esters. This 'in situ' derivatization step resulted in a dramatic enhancement of the response of the ES-MS system for non-amphoteric penicillins. Analyte recoveries were better than 80% irrespective of the type of aqueous sample, with the exception of amoxicillin (76%) and ampicillin (77%) in tap water. At the level of 50 ng/L of each analyte in ground water, the within-day precision was in the range 6-10%. Calibration curves were linear for injected amounts up to 800 ng, with R(2) in the range 0.9952-0.9995. When injecting large equivalent volumes of the aqueous samples, the electrospray matrix effect altered in-source collision-induced dissociation (CID) spectra of the analytes by severely weakening signals for fragment ions, as compared to spectra of reference standards. Remedies to obviate this anomalous unwelcome effect are suggested. On the basis of a signal-to-noise ratio of 10, limits of quantification were estimated to range between 2 (cloxacillin) and 24 ng/L (amoxicillin) in river water.

Compensation for increase in respiratory workload during mechanical ventilation. Pressure-support versus proportional-assist ventilation

Variation in respiratory impedance may occur in mechanically ventilated patients. During pressure-targeted ventilatory support, this may lead to patient-ventilator asynchrony. We assessed the hypothesis that during pressure-support ventilation (PSV), preservation of minute ventilation (V E) consequent to added mechanical loads would result in an increase in respiratory rate (RR) due to the large reduction in tidal volume (VT). WITH proportional-assist ventilation (PAV), preservation of V E would occur through the preservation of VT, with a smaller effect on RR. We anticipated that this compensatory strategy would result in greater patient comfort and a reduce work of breathing. An increase in respiratory impedance was obtained by chest and abdominal binding in 10 patients during weaning from mechanical ventilation. V E remained constant in both ventilatory modes after chest and abdominal compression. During PSV, this maintenance of VE was obtained through a 58 +/- 3% increase in RR that compensated for a 29 +/- 2% reduction in VT. The magnitudes of the reduction in VT (10 +/- 3%) and of the increase in RR (14 +/- 2%) were smaller (p < 0. 001) during PAV. During both PSV and PAV, chest and abdominal compression caused increases in both the pressure-time product (PTP) of the diaphragm per minute (142.9 +/- 26.9 cm H(2)O. s/min, PSV, and 117.6 +/- 16.4 cm H(2)O. s/min, PAV) and per liter (13.4 +/- 2.5 cm H(2)O. s/L, PSV, and 9.6 +/- 0.7 cm H(2)O. s/L, PAV). These increments were greater (p < 0.001) during PSV than during PAV. The capability of keeping VT and V E constant through increases in inspiratory effort after increases in mechanical loads is relatively preserved only during PAV. The ventilatory response to an added respiratory load during PSV required greater muscle effort than during PAV.

Fat distribution evaluated by computed tomography and metabolic abnormalities in patients undergoing antiretroviral therapy: preliminary results of the LIPOCO study

BACKGROUND

Fat distribution abnormalities have been reported in patients treated with various antiretroviral drug regimens. The LIPOCO study is an ongoing observational study of unselected HIV-infected patients which aims to better characterize such disorders and their metabolic correlations.

METHODS

Cross-sectional analysis of data collected at baseline in the first 154 male patients included. Investigators divided patients into four predetermined clinical categories of fat distribution: lipoatrophy, obesity, mixed condition and normal. Body composition (tetrapolar bioelectrical impedance analysis and skinfold thickness), fat distribution [computed tomography (CT) scan], plasma glucose and insulin concentrations both fasting and during an oral glucose tolerance test and endocrine and lipid profile were measured and compared between the four groups.

RESULTS

Patients in the lipoatrophy group had significantly decreased abdominal and mid-thigh subcutaneous fat area values and elevated levels of plasma triglycerides. Patients in the obese and mixed groups had significantly increased intra-abdominal fat area values and elevated levels of plasma insulin and C-peptide. The CT scans identified some patients with isolated subcutaneous fat accumulation but no other alterations in fat distribution and no insulin resistance. Visceral adipose tissue measured by CT scan was positively correlated with fasting insulin and the sum of insulin levels (P < 0.0001). Fasting insulin as well as the sum of insulin levels were negatively correlated with the delta HIV-RNA (log(10)). In a multivariate logistic regression model, the use of stavudine significantly correlated with fat wasting in both nucleoside reverse transcriptase inhibitor and protease inhibitor groups: odds ratio (OR), 413 [95% confidence interval (CI), 5.2-999; P = 0.0068] and OR, 2.08 (95% CI, 0.92-7.0; P = 0.058) respectively, when compared with the use of zidovudine. Neither lamivudine or didanosine use, nor the use of protease inhibitors were significantly associated with fat distribution abnormalities or fat wasting.

CONCLUSIONS

These preliminary results suggest that three major types of fat distribution abnormalities may occur in isolation or in association in HIV-infected patients undergoing active antiretroviral therapy: a fat depletion or 'lipoatrophy' syndrome which might be related to the use of stavudine; a mixed or fat redistribution syndrome related to an unusual side-product of effective virus control; and a subcutaneous adiposity syndrome reflecting increase in caloric intake.

A syndrome of peripheral fat wasting (lipodystrophy) in patients receiving long-term nucleoside analogue therapy

OBJECTIVE

To compare body composition, body fat distribution and insulin secretion in patients taking nucleoside reverse transcriptase inhibitor (NRTI) therapy.

DESIGN AND SETTING

Cross-sectional study in three French AIDS clinical centres.

PATIENTS

Forty-three HIV-infected patients on long-term NRTI therapy including stavudine (n = 27) or zidovudine (n = 16) and 15 therapy-naive HIV-infected patients (control group).

MAIN OUTCOME MEASURES

Fat wasting was assessed by physical examination and body composition by bioelectrical impedance. Regional fat distribution was estimated using caliper measurements of skinfold thickness at four sites and evaluated by computed tomography at abdominal and mid-thigh level. Fasting glucose, insulin, C-peptide, triglyceride, cholesterol, free fatty acid, testosterone, follicle stimulating hormone, luteinizing hormone, cortisol levels, CD4 cell count and HIV viral load were determined. Daily total caloric and nutrient intake were evaluated.

RESULTS

The zidovudine group and the control group had similar body composition and regional fat distribution. Stavudine therapy was associated with a significantly lower percentage of body fat (12.9% versus 15.2% in the zidovudine group; P < 0.05), markedly decreased subcutaneous to visceral fat ratio (0.90 +/- 0.63 versus 1.92 +/- 1.34, P < 0.01) and higher mean intake of fat and cholesterol (P < 0.01). Fasting plasma glucose, insulin and C-peptide levels were similar among the three groups. Triglyceride levels were significantly higher in the stavudine group than in the controls (P < 0.05), but did not differ between the stavudine and the zidovudine group or between the zidovudine and the control group. Free fatty acids tended to be higher in the stavudine group but the difference did not reach statistical significance. Lipodystrophy was observed clinically in 17 (63%) patients taking stavudine, and in three (18.75%) patients taking zidovudine after a median time of 14 months. The relative risk of developing fat wasting was 1.95 in the stavudine group as compared with the zidovudine group (95% confidence interval, 1.18-3.22). Five out of 12 patients had a major or mild improvement in their lipodystrophy after stavudine was discontinued.

CONCLUSION

Lipodystrophy may be related to long-term NRTI therapy, particularly that including stavudine.

Effect of mechanical ventilation on inflammatory mediators in patients with acute respiratory distress syndrome: a randomized controlled trial

CONTEXT

Studies have shown that an inflammatory response may be elicited by mechanical ventilation used for recruitment or derecruitment of collapsed lung units or to overdistend alveolar regions, and that a lung-protective strategy may reduce this response.

OBJECTIVE

To test the hypothesis that mechanical ventilation induces a pulmonary and systemic cytokine response that can be minimized by limiting recruitment or derecruitment and overdistention.

DESIGN AND SETTING

Randomized controlled trial in the intensive care units of 2 European hospitals from November 1995 to February 1998, with a 28-day follow-up.

PATIENTS

Forty-four patients (mean [SD] age, 50 [18] years) with acute respiratory distress syndrome were enrolled, 7 of whom were withdrawn due to adverse events.

INTERVENTIONS

After admission, volume-pressure curves were measured and bronchoalveolar lavage and blood samples were obtained. Patients were randomized to either the control group (n = 19): tidal volume to obtain normal values of arterial carbon dioxide tension (35-40 mm Hg) and positive end-expiratory pressure (PEEP) producing the greatest improvement in arterial oxygen saturation without worsening hemodynamics; or the lung-protective strategy group (n = 18): tidal volume and PEEP based on the volume-pressure curve. Measurements were repeated 24 to 30 and 36 to 40 hours after randomization.

MAIN OUTCOME MEASURES

Pulmonary and systemic concentrations of inflammatory mediators approximately 36 hours after randomization.

RESULTS

Physiological characteristics and cytokine concentrations were similar in both groups at randomization. There were significant differences (mean [SD]) between the control and lung-protective strategy groups in tidal volume (11.1 [1.3] vs 7.6 [1.1] mL/kg), end-inspiratory plateau pressures (31.0 [4.5] vs 24.6 [2.4] cm H2O), and PEEP (6.5 [1.7] vs 14.8 [2.7] cm H2O) (P<.001). Patients in the control group had an increase in bronchoalveolar lavage concentrations of interleukin (IL) 1beta, IL-6, and IL-1 receptor agonist and in both bronchoalveolar lavage and plasma concentrations of tumor necrosis factor (TNF) alpha, IL-6, and TNF-alpha, receptors over 36 hours (P<.05 for all). Patients in the lung-protective strategy group had a reduction in bronchoalveolar lavage concentrations of polymorphonuclear cells, TNF-alpha, IL-1beta, soluble TNF-alpha receptor 55, and IL-8, and in plasma and bronchoalveolar lavage concentrations of IL-6, soluble TNF-alpha receptor 75, and IL-1 receptor antagonist (P<.05). The concentration of the inflammatory mediators 36 hours after randomization was significantly lower in the lung-protective strategy group than in the control group (P<.05).

CONCLUSIONS

Mechanical ventilation can induce a cytokine response that may be attenuated by a strategy to minimize overdistention and recruitment/derecruitment of the lung. Whether these physiological improvements are associated with improvements in clinical end points should be determined in future studies.

Atypical cilia in the tracheal epithelium of healthy water buffaloes (Bubalus bubalis)

Samples of tracheal mucosa were obtained from 10 healthy adult water buffaloes and 50 000 cilia were examined ultrastructurally. Ciliary abnormalities were found in all 10 subjects. Atypical cilia occurred as compound cilia (up to 1.5%), intracytoplasmic cilia (0.07%) and swollen cilia (0.05%). The microtubular pattern was determined in 5000 cross-sectioned cilia, with about 7% showing axonemal abnormalities in which peripheral defects prevailed. Some electron-dense plugs appeared inside the cylinder lumen of 2.5% of basal bodies. Freeze-fracture studies revealed a ciliary necklace composed of up to eight rows of intramembranous particles. This fine detail appeared to differ from that of other small and large ruminants.

Primary cilium expression in cells from normal and pathological caprine skin

Primary cilia were detected in keratinocytes and fibroblasts, from the skin of two healthy and five Saanen goats suffering from a severe papillomatosis of the udder, respectively. Single cilia were detected in very few normal and neoplastic keratinocytes; rare biciliated keratinocytes were also seen. A remarkable number of dermal fibroblasts from healthy goats showed single cilia. Similarly, primary cilia were found in fibroblasts from the tumour stroma in all five goats. These data seem to strengthen the statement that ciliation is a peculiar ultrastructural aspect of fibroblasts, which is of interest in the light of the emerging role of fibroblasts in many physiopathological processes.