Prevention of respiratory complications after abdominal surgery: a randomised clinical trial

OBJECTIVE: To evaluate the prevention of respiratory complications after abdominal surgery by a comparison of a global policy of incentive spirometry with a regimen consisting of deep breathing exercises for low risk patients and incentive spirometry plus physiotherapy for high risk patients. DESIGN: Stratified randomised trial. SETTING: General surgical service of an urban teaching hospital. PATIENTS: 456 patients undergoing abdominal surgery. Patients less than 60 years of age with an American Society of Anesthesia classification of 1 were considered to be at low risk. OUTCOME MEASURES: Respiratory complications were defined as clinical features consistent with collapse or consolidation, a temperature above 38 degrees C, plus either confirmatory chest radiology or positive results on sputum microbiology. We also recorded the time that staff devoted to prophylactic respiratory therapy. RESULTS: There was good baseline equivalence between the groups. The incidence of respiratory complications was 15% (35/231) for patients in the incentive spirometry group and 12% (28/225) for patients in the mixed therapy group (P = 0.40; 95% confidence interval -3.6% to 9.0%). It required similar amounts of staff time to provide incentive spirometry and deep breathing exercises for low risk patients. The inclusion of physiotherapy for high risk patients, however, resulted in the utilisation of an extra 30 minutes of staff time per patient. CONCLUSIONS: When the use of resources is taken into account, the most efficient regimen of prophylaxis against respiratory complications after abdominal surgery is deep breathing exercises for low risk patients and incentive spirometry for high risk patients.     

Precipitated calcium carbonates as weathering enhancers and impact modifiers for rigid PVC siding and profiles

A study conducted to determine the suitability of calcium carbonate (CaCO₃) fillers in exterior PVC applications revealed that the surface-treated precipitated CaCO₃s of average particle sizes 0.5 micron and 0.07 micron, in fact, minimized the initial yellowing of PVC seen on weathering. It is hypothesized that these particle-size CaCO₃s, being optimum for light scattering, provide greater UV protection. Further, the high surface areas of these CaCO₃s increase the capacity to neutralize the HCl responsible for yellowing of the PVC. The optimum filler level is 5 to 10 phr. At this loading level, long-term impact strength is also retained.     

Surface modification of atmospheric plasma activated BOPP by immobilizing chitosan

Summary Chitosan was immobilized onto plasma activated biaxially oriented polypropylene (BOPP) films aimed at producing antimicrobially active barrier film for food packaging applications. 1% chitosan dissolved into 0.1 M acetic acid was mixed with 0.1% glutaraldehyde (cross-linking agent) and applied onto N₂-plasma + NH₃ activated BOPP film. Amount of immobilized chitosan was 1.8 g/m². Films had strong antimicrobial activity against both Bacillus subtilis and Escherichia coli and they reduced the oxygen transmission rate (OTR) measured in dry conditions from 1500 down to 27 cm³/(m²·24 h). Migration tests for determining the total amounts of substances migrating into food simulants (3% acetic acid, 95% ethanol and iso-octane) indicated, that chitosan coating was permanently immobilized onto BOPP without any leaching (total migration < 2 mg/dm²), thus it met the requirements stipulated in Directive 2002/72/EC relating to plastic materials and articles intended to come into contact with foodstuffs. The results suggest that chitosan treated BOPP films may be exploited in various food packaging applications requiring high oxygen barrier and/or antimicrobially active packaging materials.     

Aortic arch anomalies associated with long gap esophageal atresia and tracheoesophageal fistula

PURPOSE: The purpose of this study was to determine whether aortic arch anomalies are associated with long gap esophageal atresia and tracheoesophageal fistula (EA-TEF). METHODS: The authors performed a retrospective review of all infants who had EA-TEF from 1980 to 1996 at two pediatric surgery centers. Two hundred three infants who had EA-TEF were identified. RESULTS: Twelve infants were noted to have both long gap EA-TEF defined as a gap length greater than 3 cm and aortic arch anomalies. Of these 12, 7 had aberrant right subclavian arteries originating from the descending aorta. Four of the seven infants who had aberrant right subclavian artery (SCA) had gap lengths greater than 4 cm. All four had their fistulae divided initially through a right thoracotomy with primary repair performed at a later date. The remaining five infants who had long gap EA-TEF had right-sided aortic arch with aberrant left subclavian arteries. All five initially underwent exploration through the right chest. On discovery of the long gap EA and concurrent vascular anomaly, the thoracotomies were closed, and the infants underwent definitive repair of both their EA-TEF and their vascular anomaly through a left thoracotomy. CONCLUSIONS: The authors find that aortic arch anomalies are associated with long gap EA-TEF. Patients who have these two anomalies tend to have a long gap. Preoperative diagnosis of these anomalies may alter the timing and technique of surgical intervention. The embryogenesis of these vascular lesions may account for this more severe form of esophageal atresia.     

DNA copy number amplifications in human neoplasms: review of comparative genomic hybridization studies

This review summarizes reports of recurrent DNA sequence copy number amplifications in human neoplasms detected by comparative genomic hybridization. Some of the chromosomal areas with recurrent DNA copy number amplifications (amplicons) of 1p22-p31, 1p32-p36, 1q, 2p13-p16, 2p23-p25, 2q31-q33, 3q, 5p, 6p12-pter, 7p12-p13, 7q11.2, 7q21-q22, 8p11-p12, 8q, 11q13-q14, 12p, 12q13-q21, 13q14, 13q22-qter, 14q13-q21, 15q24-qter, 17p11.2-p12, 17q12-q21, 17q22-qter, 18q, 19p13.2-pter, 19cen-q13.3, 20p11.2-p12, 20q, Xp11.2-p21, and Xp11-q13 and genes therein are presented in more detail. The paper with more than 150 references and two tables can be accessed from our web site http://www.helsinki.fi/lglvwww/CMG.html. The data will be updated biannually until the year 2001.     

Estimation of the wavelength-dependent effective refractive index of spherical plastic pigments in a liquid matrix

Refractive-index data are important for the prediction of light scattering from spherical pigments. Reflectance from a slurry that contains plastic pigments was studied with the aid of a reflectometer. The effective refractive index of spherical plastic pigments in a slurry was determined by use of reflectance data and a phase-retrieval procedure based on the maximum-entropy method. This method provides a simple way to estimate the effective refractive index of pigments in a liquid matrix.     

Use of trout liver slices to enhance mechanistic interpretation of estrogen receptor binding for cost-effective prioritization of chemicals within large inventories

The cost of testing chemicals as reproductive toxicants precludes the possibility of evaluating large chemical inventories without a robust strategyfor prioritizing chemicals to test. The use of quantitative structure-activity relationships in early hazard identification is a cost-effective prioritization tool, but in the absence of systematic collection of interpretable test data upon which models are formulated, these techniques fall short of their intended use. An approach is presented for narrowing the focus of candidate ED chemicals using two in vitro assays: one optimized to measure the potential of chemicals to bind rainbow trout estrogen receptors (rtER), and a second to enhance interpretation of receptor binding data in a relevant biological system (i.e., fish liver tissue). Results of rtER competitive binding assays for 16 chemicals yielded calculable relative binding affinities (RBA) from 179 to 0.0006% for 13 chemicals and partial or no binding for an additional 3 chemicals. Eleven lower to no affinity chemicals (RBA < 0.1%) were further tested in trout liver slices to measure induction of rtER-dependent vitellogenin (VTG) mRNA in the presence of chemical passive partitioning (from media to multiple hepatocyte layers in the slice) and liver xenobiotic metabolism. VTG induction in slices was observed in a concentration-dependent manner for eight chemicals tested that had produced complete displacement curves in binding assays, including the lowest affinity binder with an RBA of 0.0006%. Two chemicals with only partial binding curves up to their solubility limit did not induce VTG. The monohydroxy metabolite of methoxychlor was the only chemical tested that apparently bound rtER but did not induce VTG mRNA. Data are presented illustrating the utility of the two assays in combination for interpreting the role of metabolism in VTG induction, as well as the sensitivity of the assays for measuring enantiomer selective binding and ER-mediated induction. The combined approach appears particularly useful in interpreting the potential relevance of extremely low affinity chemical binding to fish receptors (RBA = 0.01-0.0001%) within a defined toxicity pathway as a basis for prioritizing within large chemical inventories of environmental concern.     

Photosensitivity from chlorophyll-derived pigments

The photosensitisation of young albino rats fed diets containing specially prepared lucerne leaf protein concentrates (LPC) or purified pigments has been investigated. Signs of intense photosensitivity including death occurred after a few hours of illumination in animals fed a diet containing 20% LPC prepared by holding lucerne juice at 70 °C for 55 min. However a sample prepared by briefly heating juice to 90 °C was not active. Mixed chlorophyllides and purified pheophorbide a were strongly photosensitising whereas pheophorbide b was much less active and pheophytin a was inactive. Where strong photosensitisation occurred pigments derived from chlorophyll could be extracted from blood plasma and livers. Examination of stomach and intestine contents showed that dietary chlorophyllides and chlorophylls were converted to pheophorbides and pheophytins in the gut. The photosensitising potential of a diet can be related principally to the combined content of pheophorbide a and chlorophyllide a.     

Physical aspects of total-body irradiation at the Middlesex Hospital (UCL group of hospitals), London 1988-1993: II. In vivo planning and dosimetry

Part II of this paper gives the results of applying the TBI methods described in part I, to in vivo patient planning and dosimetry. Patients are planned on nine CT based body slices, five of which pass through the lungs. Planned doses are verified with ten silicon diodes applied bi-laterally to five body sites, at each treatment. LiF TLDs are applied to seven other body sites at the first treatment only. For 84 patients and at least 1016 measurements per body site with the diodes, the mean measured total doses agreed with planned doses within at most 2% except at lung levels, where the mean measured dose was 3% too low. Standard deviations of the measurements about the mean were between 2.4 and 3.1%. For the LiF TLDs, the mean measured doses for all seven body sites were with in +/- 5% of planned doses. A separate assessment of measured entrance and transmitted doses showed that the former agreed well with planned doses, but that the latter tended to be low, especially over the lungs, and that they had a wider dispersion. Possible reasons for this are discussed. These results show measurement uncertainties similar to those for non-TBI treatments of Nilsson et al, Leunens et al and Essers et al. An analysis of the treatment plans showed a mean dose inhomogeneity in the body (75 patients, nine slices) of 19 +/- 6.0% (1 s.d.) and in the lungs (40 patients, five slices) of 9.2 +/- 2.85% (1 s.d.). The conclusions are that, overall, the methods are reasonably satisfactory but that, with an extra effort, even closer agreement between measured and planned doses and a further limited reduction in the body dose inhomogeneity could be obtained. However, if it were thought desirable to make a substantial reduction in the dose inhomogeneity in the body and lungs, this could only be achieved with the available equipment by changing from lateral to anterior-posterior irradiation and any potential advantages of this change would have to be balanced against a likely deterioration in patient comfort and an increase in treatment set-up times.     

Evaluation of Collections 4 and 5 of the MODIS Gross Primary Productivity product and algorithm improvement at a tropical savanna site in northern Australia

In this study, we assessed the accuracy of the MODIS (Moderate Resolution Imaging Spectroradiometer) GPP (gross primary productivity) Collections 4.5, 4.8 and 5 along with Leaf Area Index (LAI), fraction of absorbed Photosynthetically Active Radiation (fPAR), light use efficiency (LUE) and meteorological variables that are used to estimate GPP for a northern Australian savanna site. Results of this study indicated that the MODIS products captured the seasonal variation in GPP, LAI and fPAR well. Using the index of agreement (IOA), it was found that Collections 4.5 and 4.8 (IOA 0.89 respectively) agreed reasonably well with flux tower measurements between 2001 and 2006. It was also found that MODIS Collection 4.5 predicted the dry season GPP well (Relative Predictive Error (RPE) 4.17%, IOA 0.72 and Root Mean Square Error (RMSE) of 1.05 g C m^− 2 day^− 1), whilst Collection 4.8 performed better in capturing wet season dynamics (RPE 1.11%, IOA 0.80 and RMSE of 0.91 g C m^− 2 day^− 1). Although the wet season magnitude of GPP was predicted well by Collection 4.8, an examination of the inputs to the GPP algorithm revealed that MODIS fPAR was too high, but this was compensated by PAR and LUE that was too low. Although LAI and fPAR estimated by Collection 5 were more accurate, GPP for this Collection resulted in a much lower value (RPE 25%) due to errors in other factors. Recalculation of MODIS GPP using site specific input parameters indicated that MODIS fPAR was the main reason for the differences between MODIS and tower derived GPP followed by LUE and meteorological inputs. GPP calculated using all site specific values agreed very well with tower data on an annual basis (IOA 0.94, RPE 6.06% and RMSE 0.83 g C m^− 2 day^− 1) but the early initiation of the growing season calculated by the MODIS algorithm was improved when the vapor pressure deficit (VPD) function was replaced with a soil water deficit function. The results of this study however, reinforce previous findings in water limited regions, like Australia, and incorporation of soil moisture in a LUE model is needed to accurately estimate the productivity.