Sensory aspects of drinking water in contact with epoxy lined copper pipe.

Pipe relining via in situ epoxy lining is used to remediate corroded plumbing or distribution systems. This investigation examined the effects on odour, TOC, THM formation and disinfectant demand in water exposed to epoxy-lined copper pipes used for home plumbing. The study was conducted in accordance with the Utility Quick Test, a migration/leaching method for utilities to conduct sensory analysis of materials in contact with drinking water. The test was performed using water with no disinfectant and levels of chlorine and monochloramines representative of those found in the distribution system. Panelists repeatedly and consistently described a "plastic/adhesive/putty" odour in the water from the pipes. The odour intensity remained relatively constant for each of two subsequent flushes. Water samples stored in the epoxy-lined pipes showed a significant increase in the leaching of organic compounds (as TOC), and this TOC was demonstrated to react with free chlorine to form trichloromethane. Water stored in the pipes also showed a marked increase in disinfectant demand relative to the water stored in glass control flasks. A study conducted at a full scale installation at an apartment demonstrated that after installation and regular use, the epoxy lining did not yield detectable differences in water quality.

Physical-chemistry-based analysis of affymetrix microarray data.

We analyze publicly available data on Affymetrix microarray spike-in experiments on the human HGU133 chipset in which sequences are added in solution at known concentrations. The spike-in set contains sequences of bacterial, human, and artificial origin. Our analysis is based on a recently introduced molecular-based model (Carlon, E.; Heim, T. Physica A 2006, 362, 433) that takes into account both probe-target hybridization and target-target partial hybridization in solution. The hybridization free energies are obtained from the nearest-neighbor model with experimentally determined parameters. The molecular-based model suggests a rescaling that should result in a "collapse" of the data at different concentrations into a single universal curve. We indeed find such a collapse, with the same parameters as obtained previously for the older HGU95 chip set. The quality of the collapse varies according to the probe set considered. Artificial sequences, chosen by Affymetrix to be as different as possible from any other human genome sequence, generally show a much better collapse and thus a better agreement with the model than all other sequences. This suggests that the observed deviations from the predicted collapse are related to the choice of probes or have a biological origin rather than being a problem with the proposed model.

Comment on "Solving the riddle of the bright mismatches: labeling and effective binding in oligonucleotide arrays".

In a recent paper [Phys. Rev. E 68, 011906 (2003)], Naef and Magnasco suggested that the "bright" mismatches observed in Affymetrix microarray experiments are caused by the fluorescent molecules used to label RNA target sequences, which would impede target-probe hybridization. Their conclusion is based on the observation of "unexpected" asymmetries in the affinities obtained by fitting microarray data from publicly available experiments. We point out here that the observed asymmetry is due to the inequivalence of RNA and DNA, and that the reported affinities are consistent with stacking free energies obtained from melting experiments of unlabeled nucleic acids in solution. The conclusion of Naef and Magnasco is therefore based on an unjustified assumption.

Immaturity alters plasma lipoprotein composition of intravenously alimented newborn infants.

Plasma lipoprotein composition in infants receiving fat-free parenteral nutrition reflects the endogenous synthesis and metabolism of lipids. We studied the composition of plasma lipoproteins in 49 appropriate for gestational age newborn infants after surgery who received only glucose and amino acid solutions for 5.4 +/- 0.3 days (M +/- SE). Of the infants studied, 31 were fullterm (gestational age 39.5 +/- 0.2 weeks) and 18 premature (34.3 +/- 0.7 weeks). Plasma lipid levels (total lipids, triglycerides, free cholesterol, sterol, esters, phospholipids) did not differ between term and premature infants, but triglycerides and cholesterol were markedly lower than in young, fasting adults. The contribution of triglycerides to lipoprotein lipids was strikingly low in chylomicrons (21% vs. 90% in young fasting adults) and VLDL (34 vs 60%) and the infants had a consistently lower cholesterol content of HDL (21 mg/dl vs. 45-50 mg/dl in adults) and LDL (43 mg/dl vs. 100 mg/dl). All infantile lipoproteins were enriched with phospholipids. These results are comparable to those reported for cord plasma. In premature babies, VLDL were markedly reduced and contained less triglycerides, free and esterified cholesterol than in term infants. In contrast, HDL were increased in preterm infants and carried more phospholipids. VLDL contributed to al lesser and HDL to a greater extent to plasma lipid transport in premature infants. We conclude that in premature infants hepatic synthesis of triglycerides and cholesterol and their secretion as VLDL is reduced, which may be caused by low substrate availability or an immaturity of the synthetic pathway. In premature infants, HDL appears to play a major role in transporting plasma lipids to peripheral tissues.

Metabolic consequences of increasing energy intake by adding lipid to parenteral nutrition in full-term infants.

The effect on energy metabolism and fuel utilization of increasing energy intake by adding intravenous lipid to a glucose and amino acid regimen was examined. Twenty fullterm, appropriate-for-gestational-age, intravenously fed neonates were entered into one of two groups: total energy intake was 261 kJ.kg-1 x d-1 (62 kcal.kg-1 x d-1) in group 1 and 355 kJ.kg-1 x d-1 (85 kcal.kg-1 x d-1) in group 2. Both groups received 2.8 g protein.kg-1 x d-1 and 14 g glucose.kg-1 x d-1. Group 2 received an additional 2 g lipid.kg-1 x d-1. Metabolic rate, respiratory gas exchange, and nonprotein substrate oxidation were similar in both groups. The addition of energy as lipid enhanced nitrogen retention (230 vs 306 mg.kg-1 x d-1; P < 0.02) and utilization (52.8% vs 66.5%; P < 0.03). Our data suggest that nitrogen utilization is improved in parenterally fed neonates by adding fat and increasing energy intake without change in metabolic rate, carbon dioxide production, oxygen consumption, and nonprotein substrate utilization. Energy expenditure does not necessarily increase with increasing energy intake independently of diet composition.

Value of magnetic resonance imaging in staging carcinomas of the oral cavity and oropharynx.

The value of magnetic resonance imaging (MRI) in preoperative tumor (T) staging was assessed prospectively in 46 patients with malignant carcinomas of the oropharynx and oral cavity. In each case, the MRI findings were compared with the preoperative clinical and postoperative histopathologic findings. MRI showed an accuracy of 89% in identifying the T stage, as compared with the histopathologic result. The accuracy of the clinical examination was 78%. Compared with the clinical examination, MRI is particularly suited for differentiating T3/T4 and the larger T2 tumors. MRI tends to overinterpret the T stage when the neighboring tissues are inflamed or edematous, as it allows no demarcation between inflamed or edematous tissue and tumor. Moreover, normal oropharyngeal mucous membrane and intrinsic tongue muscle both absorb contrast medium. In the clinical examination, the T stage is often underestimated, as the depth of infiltration and bone involvement cannot always be determined with certainty. The ability of MRI to give an axial, coronal, and sagittal image allows an exact preoperative view of tumor spread and assessment of infiltration into adjacent structures.

[Initial experiences with combined balloon angioplasty and rtPA thrombolysis in dialysis shunt failure]. / Erste Erfahrungen mit der kombinierten Ballonangioplastie und rtPA-Thrombolyse bei Dialyseshuntversagen.

The 23 interventions performed by us on 18 patients had a very high success rate both in intraarterial lysis therapy of obstructed haemodialysis shunts and in balloon angioplasty (19/23). Shunt failure had to be primarily treated by surgery in 3 cases only. The complications were confined to a rupture of a vessel that required surgical care. 14 shunts were found to be patent in a total of 18 patients (18 being of course as small patient group). Our experience leads us to believe that patients suffering from shunt insufficiency should always be primarily treated endoluminally if angiography confirms that intervention is possible. Surgical intervention is always advisable even if the result may occasionally be negative in a few rare cases.

[Magnetic resonance tomography and computerized tomography in tumor staging of mouth and oropharyngeal cancer]. / Magnetresonanztomographie und Computertomographie im Tumorstaging des Mundhöhlen-/Oropharynxkarzinoms.

30 patients with malignant tumours of the cavum oris and oropharynx were examined by MRI and CT to compare their accuracy for T-staging. There was histological information in all cases. Histological studies showed an accuracy in T-staging of 81% for MRI and 77% for CT. Differentiation between stages T2/T3 and T3/T4 is possible in 80% by CT and 84% by MRI. Tumours of the cavum oris and oropharynx of T1-stage are possible only in 1 of 3 cases. The use of T2-weighted sequences allows the best frequence of tumour representation in 89%. CT shows an earlier bone involvement than MRI. In addition, the ability to produce coronal and sagittal images by MRI makes it superior to CT in judging tumour extension.

[Feasibility of the differential diagnostic imaging of neck lymphomas]. / Möglichkeiten der bildgebenden Differentialdiagnostik der Halslymphome.

In 51 patients with cervical swellings, pretherapeutic examinations by ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) were carried out for the confirmation of exclusion of cervical lymph node metastases. By use of the M/Q ratio and morphological criteria, it is possible with ultrasound to differentiate between relatively enlarged lymph modes and lymph node metastasis with a certainly of > 90%. This was only possible in CT after administration of contrast media and the success rate was lower (72%). Both by use of the M/Q ratio and contrast medium administration, MRI is able to distinguish between lymph node metastases and reactively altered lymph nodes. Differentiation between Hodgkin/non-Hodgkin lymphomas of the neck and reactively enlarged lymph nodes is also possible with the aid of the M/Q ratio. In such cases, sonography and MRI are superior to CT. A certain differentiation between lymph node metastases and Hodgkin/non-Hodgkin lymphomas is only possible in some cases. However, there are indicative criteria for differential diagnosis. A delineation between specific lymph node inflammations and glomus carotid tumors is also possible because of the differing take-up of contrast medium in CT and MRI and via doppler sonographic criteria.

[The value of magnetic resonance tomography and computed tomography in the tumor staging of laryngeal and hypopharyngeal carcinomas]. / Wertigkeit von Magnetresonanztomographie und Computertomographie im Tumorstaging des Larynx-/Hypopharynxkarzinoms.

43 patients with malignant tumours of the larynx or hypopharynx were examined by MRT and CT to compare their accuracy for T-staging. There was histological confirmation in all cases. Histological studies showed an accuracy in T-staging of 90% for MRT and 82% for CT. Differentiation between stages T2/T3 and T3/T4 is possible in most cases by either method. A source of error is the difficulty of differentiating oedema or inflammatory changes from tumour. This led to occasional overinterpretation of the T4 stage. Demonstration of cartilage involvement was easier with MRT (88%) than with CT (84%). The use of Gd-DTPA with T1 weighted and proton weighted sequences allows earlier diagnosis of cartilage invasion. Early cartilage involvement may be missed by CT when it is seen on MRT. In addition, the ability to produce coronal and sagittal images by MRT makes this superior to CT in judging tumour extension.

Contrast-enhanced transcranial Doppler US with a new transpulmonary echo contrast agent based on saccharide microparticles.

The purpose of this first patient study (phase II) was to evaluate the clinical usefulness of a new echo contrast agent at transcranial Doppler ultrasonography (US). Twenty patients were selected from a group of 242 patients undergoing conventional transcranial Doppler US who had low (n = 18) or absent (n = 2) Doppler signals from the middle cerebral artery (MCA). The extent and duration of Doppler signal increase was measured in 30 MCAs and in 14 basilar arteries following the intravenous injection of a transpulmonary galactose microparticle suspension (SH U 508 A) at three concentrations (200, 300, and 400 mg/mL). Doppler waveform analysis became possible in 93% (28 of 30) of the MCAs following injection. The maximal increase in average Doppler signal intensity (11 dB at 200 mg/mL, 15 dB at 300 mg/mL, and 17 dB at 400 mg/mL) and the increase in average duration of the signal enhancement (163 seconds at 200 mg/mL, 219 seconds at 300 mg/mL, and 240 seconds at 400 mg/mL) depended on contrast agent concentration. Doppler waveform analysis became possible in 79% (11 of 14) of the basilar arteries. The intravenous injection of this new echo contrast agent markedly increases Doppler signal intensity in patients with nondiagnostic results at conventional Doppler US.

[The magnetic resonance tomographic differential diagnosis between reactively enlarged lymph nodes and cervical lymph node metastases]. / Magnetresonanztomographische Differentialdiagnostik zwischen reaktiv vergrösserten Lymphknoten und Halslymphknotenmetastasen.

A prospective study was carried out involving 27 patients to determine whether MRT can distinguish between lymph node metastases and reactive lymph node enlargement. The results of MRT were compared with the pathological findings. Using T1 and T2 weighted sequences and proton density sequences it was not possible to differentiate between reactively enlarged lymph nodes and lymph node metastases. Following the administration of Gd-DTPA the observation of central hypo-intensity with marginal hyper-intensity is a reliable sign of a lymph node metastasis. Using the criterion of length greater than 10 mm for lymph node metastases results in a specificity of 32% and sensitivity of 75%. The use of the sonographic maximal/cross measurement quotient > 2 in the axial/coronary/sagittal dimension improves specificity and sensitivity to 94%.

[The value of nuclear magnetic resonance tomography in tumor staging of laryngeal-/hypopharyngeal cancer]. / Wertigkeit der Kernspintomographie im Tumorstaging des Larynx-/Hypopharynxkarzinoms.

Twenty-four patients with tumors of the larynx and hypopharynx were examined with magnetic resonance imaging (MRI) and laryngoscopy. The results of MRI and laryngoscopy were then correlated with the pathology reports. Diagnostic findings of 84% of the MRI studies correlated with the pathology report, while laryngoscopy provided exact classification in 79%. MRI tended to overestimate tumor size because edema or inflammatory reactions of surrounding tissues simulated tumors. However, normal mucosa also enhanced contrast medium, restricting the value of this technique. Laryngoscopy tended to underestimate tumor size, because deep extensions of tumor and cartilage involvement were difficult to detect. Nonetheless, the utility of MRI in obtaining axial, coronal and sagittal slices was found to facilitate the preoperative staging of tumor extensions.

[The differential diagnosis of liver metastasis and regional fatty liver: a comparison of CT and MRT]. / Zur Differentialdiagnostik von Lebermetastasierung und regionaler Leberverfettung: Vergleich von CT und MRT.

Differentiation between liver metastases and local fat deposition may be difficult when using CT; the value of MRI was therefore investigated in 18 patients with metastases and ten patients with fat deposits. CT shows both lesions as similar hypodense areas. MRI, however, produces different appearances: T1- and 2-weighted images show marked differences in the signal arising from metastases, whereas local fat collections in both sequences differ little in their signal from normal liver. Quantitative MRI signal intensity of the two types of lesion were also different. Where the differentiation by CT may be difficult, it may be made with certainty by means of MRI.

Partition of energy metabolism in the surgical newborn.

Variations in energy expenditure (EE) and substrate utilization were investigated in 12 surgical neonates (body weight, 2.81 +/- 0.15 kg) receiving total parenteral nutrition (TPN) at an energy intake of 66.34 +/- 2.16 kcal/kg/d in a thermoneutral environment of 32 degrees C to 34 degrees C. Respiratory gas exchange was continuously recorded for 12 hours by a computerized, open-circuit indirect calorimeter. Physical activity was monitored on a modified Freymond scale. Urine was collected over 3 days, including the time of the calorimetry study to determine the urinary nitrogen excretion rate. Oxygen consumption, carbon dioxide production, nonprotein respiratory quotient, and EE were calculated according to the principles of indirect calorimetry for each 30-minute period and for the entire 12 hours. During the indirect calorimetry study the patients were receiving a fat-free TPN mixture consisting of 10% glucose and 2% amino acids (GL/AA) for 8 hours. The fat-free TPN was interrupted by an isocaloric and isovolemic infusion of intralipid 10% (IL) for 4 hours. The effect of physical activity on EE was evaluated separately according to the macronutrient intake (GL/AA for 8 hours v IL for 4 hours) and then combined throughout the 12 hours of intravenous alimentation. The neonates were resting during 80% of the 12-hour study time (range, 38% to 90%). The partition of EE expressed as mean +/- SEM in kcal/kg/d was: total EE 48.5 +/- 2.1; resting EE 43.9 +/- 1.6; energy cost of activity 4.6 +/- 1.3.(ABSTRACT TRUNCATED AT 250 WORDS)

[Quantification of capsular sack forces after intraocular lens implantation]. / Quantifizierung der im Kapselsack wirkenden Kräfte nach Implantation von intraokularen Linsen.

In order to quantify the force acting in the capsular bag following implantation of an intraocular lens (IOL), 58 J- and C-loop lenses obtained from four different manufactures were implanted into the capsular bag in porcine eyes. The cornea and iris were removed before implantation. Photographs of the capsular bag before and after implantation, with a measuring rod for comparison, were taken under a microscope. In this way, the compression of the haptics could be measured (mean 1.7 mm, standard deviation 0.6 mm). Afterwards one haptic of each lens was fixed in a special mount placed on a high precision scale and the opposite haptic was compressed by 2 mm using a special micrometer-screw. After 5 min compression time, differences of 300% between the different manufacturers and lens types were measured. To find out whether the differences measured have an influence on the deformation of the capsular bag, a graph was plotted with force measured and values for elongation of the capsular bag along the axes. In this way a correlation of the elongation and the force could be shown. The results show that besides shaping the haptics of IOLs, the force necessary to compress the haptics also has an influence on the final form of the capsular bag.

Multiple slice FLASH imaging: an improved pulse sequence for contrast enhanced MR brain studies.

A multisclice gradient echo sequence (FLASH) was compared with a conventional spin-echo (SE) technique with regard to its value for contrast enhanced brain studies. In 50 patients with contrast enhancing intracranial lesions, MR studies (0.5 Tesla MR tomograph) were performed with SE images (SE 400/30; four images/3.4 min) and FLASH scans (FLASH 315/14, 90 degrees; 15 images/1.4 min) before and after Gd-DTPA. Based on visual and quantitative assessment diagnostic results of postcontrast SE- and FLASH images were equivalent with respect to contrast enhancement, lesion/brain-contrast, lesion/edema-contrast, and lesion delineation. Although image quality generally was excellent on postcontrast FLASH images, susceptibility artifacts were more severe on FLASH scans than on SE images. However, with the exception of postoperative patients with artifacts due to metal remains, diagnostic information was not decreased by artifacts on postcontrast FLASH images. In conclusion, because of the clearly higher efficiency of the multisclice FLASH technique, this pulse sequence offers the opportunity to speed up contrast enhanced brain imaging.

Analysis of energy and macronutrient balance in the postoperative infant.

The purpose of this study was to better define the energy and macronutrient balance of infants after major surgery. Forty studies were conducted in 29 full-term surgical infants (mean weight, 3.27 +/- 0.19 kg; mean days postsurgery, 8 +/- 1). Nineteen infants were receiving total parenteral nutrition, 13 were orally fed, and eight received a combination of intravenous and oral nutrition (mean caloric intake, 84 +/- 4 kcal/kg/d). Each study was comprised of a three-day nutritional balance measuring energy intake and energy losses in excreta. Metabolizable energy intake (MEI) was determined by subtracting losses from gross intake. Energy expenditure and macronutrient oxidation were determined on the second day of the balance using continuous open-circuit indirect calorimetry in combination with timed urinary nitrogen excretion. Energy and macronutrient storage were calculated by subtracting oxidation and losses from measured intake. The mean global energy expenditure was 57 +/- 1 kcal/kg/d. Linear regression analysis of the nutritional balance data allowed estimates of energy, fat, and protein storage at various MEI. The data suggest that in the surgical infant, protein balance is maintained, even during hypocaloric nutritional regimens. In infants receiving adequate calories to maintain energy balance, maintenance metabolism is supported by the oxidation of endogenous fat. Net fat deposition will predictably only occur at metabolizable intakes of greater than 71 kcal/kg/d.

Resting energy expenditure is increased in infants and children with extrahepatic biliary atresia.

To determine if liver dysfunction in children affects energy and macronutrient homeostasis, we performed 13 metabolic studies in 11 patients (age, 17.8 +/- 5.9 months [mean +/- SEM]) with extrahepatic biliary atresia (EHBA). Nutritional balance, indirect calorimetry, anthropometry, and biochemical liver function tests were utilised. Sixty-four percent of the energy losses were in the form of stool fat. Energy expenditure (68 kcal/kg/d) was 29% higher than normal (P less than 0.0025). Only one third of the metabolisable energy intake (37 kcal/kg/d) was stored in the body for new tissue synthesis. In spite of the bountiful protein intake for age, the increased protein oxidation (2g/kg/d) resulted in a virtually zero mean nitrogen balance. In addition, four patients oxidised endogenous protein as well. The respiratory quotient was 0.96, and did not change significantly between pre- and post-meal measurements, suggesting a predominant utilisation of carbohydrate for energy metabolism. Net lipid oxidation was severely diminished. We found that the higher the serum aspartate aminotransferase level (previously named SGOT), the lower the net fat oxidation, and the higher the conversion of glucose to fat. These data suggest that markedly increased energy expenditure contributes to the malnutrition of patients with EHBA. We characterised for the first time how severe liver disease in infants and children affects carbohydrate, fat, and protein metabolism, thus inducing protein-energy malnutrition.