Isolation and characterization of polymorphic microsatellite loci in muskrat, Ondatra zibethicus.

We describe the isolation and characterization of 12 highly polymorphic microsatellite loci for the muskrat, Ondatra zibethicus. Microsatellite markers from three other rodent species were cross-amplified in muskrat and one of them was polymorphic. We observed moderate to high levels of genetic variability in these 13 polymorphic loci (five to 22 alleles per locus) with observed heterozygosity ranging from 0.48 to 0.96. These markers will be useful for further studies on population genetic structure in muskrat and potentially in other rodent species.

Extubation after breathing trials with automatic tube compensation, T-tube, or pressure support ventilation.

BACKGROUND: Automatic tube compensation (ATC) is a new option to compensate for the pressure drop across the endotracheal or tracheostomy tube (ETT), especially during ventilator-assisted spontaneous breathing. While several benefits of this mode have so far been documented, ATC has not yet been used to predict whether the ETT could be safely removed at the end of weaning, from mechanical ventilation. METHODS: We undertook a systematic trial using a randomized block design. During a 2-year period, all eligible patients of a medical intensive care unit were treated with ATC, conventional pressure support ventilation (PSV, 5 cmH2O), or T-tube for 2-h. Tolerance of the breathing trial served as a basis for the decision to remove the endotracheal tube. Extubation failure was considered if reintubation was necessary or if the patient required non-invasive ventilatory assistance (both within 48 h). RESULTS AND CONCLUSIONS: After the inclusion of 90 patients (30 per group) we did not observe significant differences between the modes. Twelve patients failed the initial weaning trial. However, half of the patients who appeared to fail the spontaneous breathing trial on the T-tube, PSV, or both, were successfully extubated after a succeeding trial with ATC. Extubation was thus withheld from four and three of these patients while breathing with PSV or the T-tube, respectively, but to any patient breathing with ATC. It seems that ATC can be used as an alternative mode during the final phase of weaning from mechanical ventilation. Furthermore, this study may promote a larger multicenter trial on weaning with ATC compared with standard modes.

Identification of Cdc6 protein domains involved in interaction with Mcm2 protein and Cdc4 protein in budding yeast cells.

The Cdc6 protein (Cdc6p) has essential roles in regulating initiation of DNA replication. Cdc6p is recruited to origins of replication by the origin recognition complex (ORC) late in mitosis; Cdc6p in turn recruits minichromosome maintenance (Mcm) proteins to form the pre-replicative complex. Cdc6p is thought to interact with one or more Mcm proteins but this point has not yet been demonstrated. In the present study we observed that Cdc6p interacted significantly only with Mcm2p out of six Mcm proteins in yeast two-hybrid cells. Our results indicate that the interaction of Cdc6p with Mcm2p is specific, although we cannot exclude the possibility that the interaction might not be direct. In attempts to identify domains of Cdc6p important for interaction with Mcm2p, we tested interactions of various deleted versions of Cdc6p with Mcm2p and also with Cdc4p, which was previously known to interact with Cdc6p. The portion of Cdc6p from amino acid residues 51 to 394 was able to interact with Mcm2p. During the course of the studies we also discovered a previously undetected Cdc4p interaction domain between residues 51 and 394. Interestingly, when all six putative Cdc28 phosphorylation sites in Cdc6p were changed to alanine, a 6-7-fold increase in binding to Mcm2p was observed. This result suggests that unphosphorylated Cdc6p has higher affinity than phosphorylated Cdc6p for Mcm2p; this might partly explain the previous observation that Cdc6p failed to load Mcm proteins on replication origins during S phase when the cyclin-dependent protein kinase was active, thus helping to prevent the reinitiation of activated replicons.

Intensive care unit admission in patients with haematological disease: incidence, outcome and prognostic factors.

OBJECTIVES: To examine incidence and outcome of intensive care unit (ICU) admission in patients with haematological malignancy and analyse prognostic factors associated with outcome. DESIGN: Retrospective cohort study in an intensive care unit of a tertiary referral center. PATIENTS: 78 patients with severe haematological malignancy were admitted 97 times between 1990-97 to the medical ICU for septic shock (18), respiratory failure (30), postoperative monitoring (19), cardiovascular (10) and central nervous complications (8) or for other reasons (12). Median age was 43 (4-73) years, average duration of ICU stay was 4 (1-43) days. Forty-two patients required mechanical ventilation, 46 vasopressors and 8 haemodialysis. RESULTS: Rates of ICU admission differed by treatment of the underlying disease. There were 18, 10 and 27 ICU admissions per 100 treatments in patients undergoing chemotherapy for acute leukaemia, autologous and allogeneic stem cell transplantation (p <0.005) respectively. Thirty-two of 78 patients died within 60 days of ICU admission. Organ failure, i.e. cardiovascular failure requiring vasopressors, respiratory failure requiring mechanical ventilation and renal failure, requiring haemodialysis, was most significantly associated with outcome. Mortality by day 60 after admission was 16%, 36%, 64%, and 83% (p <0.0002) for patients without organ failure, and for patients with 1, 2 or 3 failing organs. In a multivariate logistical regression model, only the organ failure score (p <0.0005) and evidence of liver damage, defined as ASAT or ALAT >100 IU/ L (p <0.007), but not age, sex, primary disease and treatment of the underlying disease predicted outcome. CONCLUSION: Multi-organ failure and evidence of liver damage but no other patient, disease, or treatment related factor predict outcome in patients with haematological disease admitted to the ICU.

Transplacental priming of the human immune system with environmental allergens can occur early in gestation.

BACKGROUND: Allergen-specific T cells play an important role in the allergic immune response to various environmental allergens. In vitro studies have shown that T-cell responses to these allergens do occur prenatally. Some allergens (milk proteins) appear to lead more often to fetal T-cell priming than others (house dust mite allergen, ovalbumin, and birch and grass pollen allergens). OBJECTIVE: We sought to determine the window of opportunity for prenatal T-cell priming with inhalant and nutritive allergens. METHODS: The T-cell reactivity of cord blood cells derived through cordocentesis from unborn (n = 62) and term babies (n = 114) in response to inhalant allergens (birch pollen major allergen, recombinant Bet v 1, and timothy grass major allergen, recombinant Phl p 1) was investigated. RESULTS: The results demonstrate that allergen-specific T-cell reactivity is as common in preterm as in term infants (Bet v 1, 8% and 5%, respectively; Phl p 1, 20% and 25%, respectively). CONCLUSIONS: Our data support the hypothesis that differential handling of the allergenic proteins by the feto-placental barrier and possibly by antigen-presenting cells may directly modulate the ensuing T-cell immune response.

[The aspiration and swallowing of foreign bodies. The management of the aspiration or swallowing of foreign bodies during dental treatment]. / Aspiration und Verschlucken von Fremdkörpern. Verhalten bei Aspiration oder Verschlucken von Fremdkörpern während der zahnärztlichen Behandlung.

The purpose of this article is to draw attention to the possible complications of foreign body ingestion or aspiration associated with dental treatment, especially oral implant treatment. A guide for the management of swallowed or inhaled objects is given. When the object cannot be coughed out, then it is mandatory to take frontal and lateral chest roentgenograms to identify the object's position in the intestinal system or in the tracheobronchial tree. In case of ingestion, attempts should be made to recover the foreign object by esophagoscopy. Aspirated foreign bodies should be removed within 24 hours. Acute obstruction can be life threatening and delaying the removal of foreign objects may make a bronchoscopy technically more difficult. The clinician must be aware of the complications involved in accidentally inhaling or ingesting foreign bodies during dental treatment. Patients at greater risk of swallowing or aspirating foreign objects need to be identified and extra preventive steps must be taken to avoid such complications.

Total versus tube-related additional work of breathing in ventilator-dependent patients.

BACKGROUND: In tracheally intubated or tracheostomized spontaneously breathing patients, tube resistance can highly increase the patient's work of breathing. In this study we focused upon the relationship between total (WOBtot) and tube-related additional inspiratory work of breathing (WOBadd) and compared different ventilatory modalities for proper tube compensation. METHODS: In ten tracheostomized spontaneously breathing patients we measured WOBtot and WOBadd in the continuous positive airway pressure (CPAP) mode, under inspiratory pressure support of 5, 10, and 15 cmH2O in the pressure support ventilation (PSV) mode, and under flow-adjusted pressure support in the automatic tube compensation (ATC) mode. WOBadd and WOBtot were calculated on the basis of measured tracheal pressure and esophageal pressure, respectively. Inspiratory peak tracheal pressure above PEEP was taken as an estimate of pressure support beyond mere tube compensation (i.e., overcompensation). RESULTS: The percentage of the tube-related WOBadd on WOBtot in the CPAP mode was 52%. It decreased with increasing pressure support in the PSV mode from 32% (PSV 5 cmH2O) to 17% (PSV 15 cmH2O). WOBadd was only 15% of WOBtot in the ATC mode. In contrast to the other ventilatory modes, reduction of WOBadd in the ATC mode was achieved with the smallest amount of overcompensation, i.e. with minimal pressure assist beyond mere tube compensation. CONCLUSION: In tracheally intubated or tracheostomized spontaneously breathing patients, adequate compensation of tube resistance (i.e. with minimal overcompensation and minimal undercompensation) is best done by the ATC mode.

Occupational exposure to inhalative irritants and methacholine responsiveness.

OBJECTIVES: Occupational exposures to inhalative irritants have been associated with an increased reporting of respiratory symptoms in previous studies. Methacholine responsiveness represents a continuous measure of airway responsiveness. As such, it may be less subject to recall bias and more sensitive to detecting effects of occupational exposure on airways. Such effects may be stronger among atopic persons. The objective of the study was to examine the relationship between self-reports of occupational exposure to dusts, gases, vapors, aerosols, and fumes and methacholine responsiveness. METHODS: A sample was studied of never smokers (N=3044) chosen randomly from 8 areas in Switzerland. Atopy was defined as any positive skin test to 8 inhalative allergens. Nonspecific bronchial reactivity was tested using methacholine chloride and quantified by calculating the slope of the dose-response. RESULTS: The methacholine slopes were 19% [95% confidence interval (95% CI) 6-32] higher for never smokers with exposure to dusts, fumes, vapors, gases, or aerosols than for the unexposed group. When only atopic never smokers were examined. the increase was larger (37%, 95% CI 7-75), and for persons with >2 positive skin prick tests the effect was still higher (42%, 95% CI -1.5-104). Exposure to vapors and aerosols was strongly associated with increased methacholine slopes among the atopic subjects. CONCLUSIONS: Occupational exposure, particularly to dusts and fumes, was associated with increased bronchial reactivity in never smokers in this study. The magnitude of the effect was larger among atopic subjects.

Takayasu disease with predominant pulmonary involvement.

We report a case of Takayasu's arteritis with predominant pulmonary involvement, which led eventually to complete obliteration of the right pulmonary artery. Subsequently, cavitation and chronic inflammation developed in the nonperfused right lung. A right pneumonectomy was performed to control the infectious process, leading to functional improvement and better control of the underlying immunologic disorder.

Phosphorylation controls timing of Cdc6p destruction: A biochemical analysis.

The replication initiation protein Cdc6p forms a tight complex with Cdc28p, specifically with forms of the kinase that are competent to promote replication initiation. We now show that potential sites of Cdc28 phosphorylation in Cdc6p are required for the regulated destruction of Cdc6p that has been shown to occur during the Saccharomyces cerevisiae cell cycle. Analysis of Cdc6p phosphorylation site mutants and of the requirement for Cdc28p in an in vitro ubiquitination system suggests that targeting of Cdc6p for degradation is more complex than previously proposed. First, phosphorylation of N-terminal sites targets Cdc6p for polyubiquitination probably, as expected, through promoting interaction with Cdc4p, an F box protein involved in substrate recognition by the Skp1-Cdc53-F-box protein (SCF) ubiquitin ligase. However, in addition, mutation of a single, C-terminal site stabilizes Cdc6p in G2 phase cells without affecting substrate recognition by SCF in vitro, demonstrating a second and novel requirement for specific phosphorylation in degradation of Cdc6p. SCF-Cdc4p- and N-terminal phosphorylation site-dependent ubiquitination appears to be mediated preferentially by Clbp/Cdc28p complexes rather than by Clnp/Cdc28ps, suggesting a way in which phosphorylation of Cdc6p might control the timing of its degradation at then end of G1 phase of the cell cycle. The stable cdc6 mutants show no apparent replication defects in wild-type strains. However, stabilization through mutation of three N-terminal phosphorylation sites or of the single C-terminal phosphorylation site leads to dominant lethality when combined with certain mutations in the anaphase-promoting complex.

Adjunctive drug treatment in severe hypoxic respiratory failure.

This article reviews the pharmacological treatment of severely hypoxaemic critically ill patients, notably those with acute respiratory distress syndrome (ARDS), acute lung injury or the sepsis syndrome. Haemodynamic support in hypotensive patients often initially requires aggressive fluid resuscitation with crystalloids or colloids, combined with vasopressors to maintain adequate end-organ perfusion. The catecholamine of choice in severe hypotension with low systemic resistance is norepinephrine (noradrenaline); dopamine is often used in mild hypotension. Once haemodynamic stabilisation is achieved, loop diuretics such as furosemide (frusemide) are used to obtain the lowest volaemia that guarantees adequate perfusion. If the fraction of inspired oxygen necessary to achieve the satisfactory haemoglobin oxygen saturation of 90% approaches 1, a trial of nitric oxide with or without almitrine is justified. Oxygen consumption can be lowered by treating fever with paracetamol (acetaminophen) and physical cooling. Occasionally, deep sedation using a combination of an opioid (most often morphine or fentanyl) and a benzodiazepine (lorazepam or midazolam) is necessary; in the presence of renal or hepatic insufficiency, propofol is a valid, although expensive, alternative. Paralysis with pancuronium or vecuronium has been associated with critical illness polyneuropathy and is used only as a last resort. Corticosteroids may be indicated in the subacute (fibroproliferative) phase of ARDS. Other anti-inflammatory treatments (such as cytokine antagonists, cyclo-oxygenase inhibitors, antioxidants or monoclonal anti-endotoxin antibodies), as well as surfactant supplementation, have failed to improve prognosis in randomised trials.

Cord blood leucocytes/basophils produce and release sulfidoleucotrienes in response to allergen stimulation.

BACKGROUND: Leucocyte-derived sulfidoleucotrienes (SLT) from children and adults can be detected in vitro in response to specific allergen stimulation, a mechanism thought to require the presence of allergen-specific immunoglobulin (Ig)E antibodies on the surface of basophils. It is unknown whether this mechanism is functional in cord blood basophils. OBJECTIVE: We studied the in vitro SLT-release of leucocytes in response to allergen and anti-IgE stimulation in term newborns and children with allergic diseases. METHODS: Cord blood from randomly selected term newborns were analysed for total IgE-antibodies and in vitro SLT-release in response to allergen and anti-IgE stimulation. Children from an allergy outpatient clinic were used as the control group. The Cellular Allergen Stimulation Test (CAST) was used as read-out system. Allergen stimulation was performed with an allergen-mix containing 21 nutritive and inhalant allergens. RESULTS: Peripheral blood leucocytes/basophils derived from allergic children (n = 56; median SLT release 1049 pg/mL) were more responsive to anti-IgE stimulation as cord blood leucocytes/basophils (n = 104; median 419 pg/mL P < 0.0001). In response to stimulation with an allergen-mix, the two groups did not differ significantly from each other. Only SLT-releasability in response to anti-IgE showed a correlation with cord blood IgE. CONCLUSIONS: Sulfidoleucotriene-release of cord blood basophils is functional in response to allergens. It appears possible that cord blood basophils are armed with allergen-specific IgE-antibodies though not detectable in serum. Therefore, cord blood SLT-release may indirectly reflect prenatal priming with allergens with subsequent production of allergen-specific IgE.

Long-term ambient air pollution and respiratory symptoms in adults (SAPALDIA study). The SAPALDIA Team.

The association between long-term exposure to ambient air pollution and respiratory symptoms was investigated in a cross-sectional study in random population samples of adults (aged 18 to 60 yr, n = 9,651) at eight study sites in Switzerland. Information on respiratory symptoms was obtained with an extended version of the European Community Respiratory Health Survey questionnaire. The impact of annual mean concentrations of air pollutants was analyzed separately for never-, former, and current smokers. After controlling for age, body mass index, gender, parental asthma, parental atopy, low education, and foreign citizenship, we found positive associations between annual mean concentrations of NO2, total suspended particulates, and particulates of less than 10 micrometers in aerodynamic diameter (PM10) and reported prevalences of chronic phlegm production, chronic cough or phlegm production, breathlessness at rest during the day, breathlessness during the day or at night, and dyspnea on exertion. We found no associations with wheezing without cold, current asthma, chest tightness, or chronic cough. Among never-smokers, the odds ratio (95% confidence interval) for a 10 micrograms/ m3 increase in the annual mean concentration of PM10 was 1. 35 (1.11 to 1.65) for chronic phlegm production, 1.27 (1.08 to 1.50) for chronic cough or phlegm production, 1.48 (1.23 to 1.78) for breathlessness during the day, 1.33 (1.14 to 1.55) for breathlessness during the day or at night, and 1.32 (1.18 to 1.46) for dyspnea on exertion. No associations were found with annual mean concentrations of O3. Similar associations were also found for former and current smokers, except for chronic phlegm production. The observed associations remained stable when further control was applied for environmental tobacco smoke exposure, past and current occupational exposures, atopy, and early childhood respiratory infections when restricting the analysis to long-term residents and to non- alpine areas, and when excluding subjects with physician-diagnosed asthma. The high correlation between the pollutants makes it difficult to sort out the effect of one single pollutant. This study provides further evidence that long-term exposure to air pollution of rather low levels is associated with higher prevalences of respiratory symptoms in adults.

Lung function and long term exposure to air pollutants in Switzerland. Study on Air Pollution and Lung Diseases in Adults (SAPALDIA) Team.

The effect of long-term exposure to air pollutants was studied in a cross-sectional population-based sample of adults (aged 18 to 60 yr; n = 9,651) residing in eight different areas in Switzerland. Standardized medical examination included questionnaire data, lung function tests, skin-prick testing, and end-expiratory CO concentration. The impact of annual means of air pollutants on FVC and FEV1 was tested (controlling for age and age squared, sex, height, weight, educational level, nationality, and workplace exposure). Analyses were done separately for healthy never-smokers, ex-smokers (controlling for pack-yr), for current smokers (controlling for cigarettes per day and pack-yr smoked), and for the whole population. Significant and consistent effects on FVC and FEV1 were found for NO2, SO2, and particulate matter < 10 microm (PM10) in all subgroups and in the total population, with PM10 showing the most consistent effect of a 3.4% change in FVC per 10 microg/m3. Results for ozone were less consistent. Atopy did not influence this relationship. The limited number of study areas and high intercorrelation between the pollutants make it difficult to assess the effect of one single pollutant. Our conclusion is that air pollution from fossil fuel combustion, which is the main source of air pollution with SO2, NO2, and PM10 in Switzerland, is associated with decrements in lung function parameters in this study.

Interaction between yeast Cdc6 protein and B-type cyclin/Cdc28 kinases.

During purification of recombinant Cdc6 expressed in yeast, we found that Cdc6 interacts with the critical cell cycle, cyclin-dependent protein kinase Cdc28. Cdc6 and Cdc28 can be coimmunoprecipitated from extracts, Cdc6 is retained on the Cdc28-binding matrix p13-agarose, and Cdc28 is retained on an affinity column charged with bacterially produced Cdc6. Cdc6, which is a phosphoprotein in vivo, contains five Cdc28 consensus sites and is a substrate of the Cdc28 kinase in vitro. Cdc6 also inhibits Cdc28 histone H1 kinase activity. Strikingly, Cdc6 interacts preferentially with B-type cyclin/Cdc28 complexes and not Cln/Cdc28 in log-phase cells. However, Cdc6 does not associate with Cdc28 when cells are blocked at the restrictive temperature in a cdc34 mutant, a point in the cell cycle when the B-type cyclin/Cdc28 inhibitor p40Sic1 accumulates and purified p40Sic1 inhibits the Cdc6/Cdc28 interaction. Deletion of the Cdc28 interaction domain from Cdc6 yields a protein that cannot support growth. However, when overproduced, the mutant protein can support growth. Furthermore, whereas overproduction of wild-type Cdc6 leads to growth inhibition and bud hyperpolarization, overproduction of the mutant protein supports growth at normal rates with normal morphology. Thus, the interaction may have a role in the essential function of Cdc6 in initiation and in restraining mitosis until replication is complete.

Metaproterenol responsiveness after methacholine- and histamine-induced bronchoconstriction.

We investigated whether the bronchodilator response to a beta-adrenergic agonist is influenced by the mechanism of induced bronchoconstriction. Normal subjects and asymptomatic asthmatics inhaled a dry aerosol (mass median aerodynamic diameter, 1.5 microns) with increasing concentrations of methacholine or histamine to produce a 35% decrease in specific airway conductance (SGaw), followed by a single inhalation of a metaproterenol aerosol. By studying normal subjects and asthmatics, we were able to compare metaproterenol responsiveness after widely divergent doses of the bronchoprovocative agents but the same degree of bronchoconstriction. Airway deposition of methacholine, histamine, and metaproterenol was measured using a quinine fluorescence technique. Mean baseline SGaw, metaproterenol responsiveness, and metaproterenol mass deposited were similar in normal subjects and asthmatics. Likewise, mean SGaw after completion of methacholine and histamine challenge, and the subsequently deposited metaproterenol mass were similar in the two groups. After methacholine challenge (mean +/- SD provocative drug mass causing a 35% decrease in SGaw, PM35: 8.94 +/- 5.96 mumol in normal subject and 0.30 +/- 0.29 mumol in asthmatics), metaproterenol increased mean SGaw by 89 +/- 33% in normal subjects and by 190 +/- 55% in asthmatics (p < 0.05, two-way analysis of variance). After histamine challenge (PM35, 2.92 +/- 2.49 mumol in normal subjects and 0.17 +/- 0.29 mumol in asthmatics), metaproterenol increased mean SGaw by 111 +/- 38% in normal subjects and 113 +/- 69% in asthmatics (p = not significant). Thus, for the same degree of bronchoconstriction, metaproterenol responsiveness was influenced by the dose of methacholine but not the dose of histamine. The differential metaproterenol response could be related to a functional antagonism between muscarinic and beta-adrenergic agonists.

[Dysphagia, cavernous changes of the lungs and subarachnoid hemorrhage following kidney transplantation]. / Dysphagie, kavernöse Lungenveränderungen und Subarachnoidalblutung nach Nierentransplantation.

A 54-year-old patient with polycystic kidney disease developed relapsing urinary-tract infections after renal transplantation. In the post-transplantation period he underwent two rejection episodes. The general condition worsened without obvious reason. Six months after transplantation the patient was hospitalized due to gram-negative sepsis. Despite adequate antimicrobial treatment he continued to lose weight and complained of dysphagia. Chest X-ray and computer tomogram of the thorax showed multiple cavitating infiltrations of the lung. A few days later the patient died from an extended subarachnoidal hemorrhage.