bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased internalisation and degradation of GLT-1 glial glutamate transporter in a cell model for familial amyotrophic lateral sclerosis (ALS)
Authors: Vanoni Cristina , Massari Silvia , Losa Marco , Carrega Paolo , Perego Carla , Conforti Laura , Pietrini Grazia
Published: October 2004

It has been suggested that glutamate-induced excitotoxicity plays a central role in the development of motor neuron diseases such as amyotrophic lateral sclerosis (ALS). The GLT-1 isoform of the glutamate transporter gene family is the most important transporter involved in keeping extracellular glutamate concentration below neurotoxic levels. Its loss and an increase in extracellular glutamate has been documented in cases of sporadic and familial ALS, as well as in animal models expressing ALS-linked Cu2+-Zn2+ superoxide dismutase (SOD1) mutations, but the underlying molecular mechanisms are still unclear. We developed and characterised a cell model consisting of polarised epithelial Madin-Darby Canine Kidney (MDCK) cell lines stably expressing wild-type SOD1 or the ALS-linked SOD1 G93A mutant, and analysed the expression of glutamate transporters after transient transfection of the corresponding cDNAs. Like ALS patients and animal models of ALS, the G93A-expressing MDCK cell system showed reduced total glial GLT-1 expression, with no change in the expression of the neuronal EAAC1 glutamate transporter isoform. Morphological analysis revealed the intracellular redistribution of GLT-1 to acidic compartments, whereas the surface distribution of other glutamate transporters (neuronal EAAC1 and glial GLAST) was not affected. Moreover, mutant SOD1 affected the cytosolic tail of GLT-1 because reduced protein expression of EAAC-GLT but not GLT-EAAC chimeras was found in G93A-expressing cell lines. GLT-1 downregulation was greatly induced by inhibition of protein synthesis, and prevented by treatment with chloroquine aimed at inhibiting the activity of acidic degradative compartments. Negligible effect on the protein level or distribution of GLT-1 was observed in cells overexpressing wild-type SOD1. The specific decrease in the GLT-1 isoform of glutamate transporters is therefore recapitulated in G93A-expressing MDCK cell lines, thus suggesting an autonomous cell mechanism underlying the loss of GLT-1 in ALS. Our data indicate that the continuous expression of mutant SOD1 causes the downregulation of GLT-1 by increasing the internalisation and degradation of the surface transporter, and suggest that the cytosolic tail of GLT-1 is required to target the transporter to degradation.
The novel mouseconnexin39gene is expressed in developing striated muscle fibers
Authors: von Maltzahn Julia , Euwens Carsten , Willecke Klaus , Söhl Goran
Published: October 2004

The recently identified mouse connexin39 (mCx39) gene encodes a peptide of 364 amino acids that shows only 61% sequence similarity to its putative human orthologue connexin40.1 (hCx40.1). The coding regions of mCx39 and hCx40.1 are located on two different exons as described for murine and human connexin36. Northern blot and RT-PCR analyses revealed that mCx39 is expressed after embryonic day (ED) 13.5 up to birth and is absent from the adult stage. Polyclonal antibodies raised to a peptide corresponding to the 16 C-terminal amino acid residues detected a protein band of about 40 kDa apparent molecular mass in lysates of several embryonic tissues. In sections of ED14.5, ED16.5 and neonatal (P0) tissues, immunofluorescent signals were prominent between myotubes in the developing diaphragm, within the intercostal muscle, in the region around the occipital bone, as well as in muscles of the limb, tongue and connective tissue around the eye. These antibodies yielded punctate signals on apposed plasma membranes of HeLa cells transfected with Cx39 cDNA but did not react with wild-type cells. Furthermore, no intercellular permeation of microinjected neurobiotin and other tracers could be detected in Cx39 transfected HeLa cells. However, after microinjection of Alexa488 into myotubes of dissected neonatal diaphragm, we found spreading of this dye into neighbouring cells. As expression of no other known connexin could be verified in these cells, intercellular dye transfer might result from functional expression of Cx39 in developing striated muscle fibers.
Insulin but not PDGF relies on actin remodeling and on VAMP2 for GLUT4 translocation in myoblasts
Authors: Török Dòra , Patel Nish , JeBailey Lellean , Thong Farah S. L. , Randhawa Varinder K. , Klip Amira , Rudich Assaf
Published: October 2004

Insulin promotes the translocation of glucose transporter 4 (GLUT4) from intracellular pools to the surface of muscle and fat cells via a mechanism dependent on phosphatidylinositol (PtdIns) 3-kinase, actin cytoskeletal remodeling and the v-SNARE VAMP2. The growth factor PDGF-BB also robustly activates PtdIns 3-kinase and induces actin remodeling, raising the question of whether it uses similar mechanisms to insulin in mobilizing GLUT4. In L6 myoblasts stably expressing Myc-tagged GLUT4, neither stimulus affected the rate of GLUT4 endocytosis, confirming that they act primarily by enhancing exocytosis to increase GLUT4 at the cell surface. Although surface GLUT4myc in response to insulin peaked at 10 minutes and remained steady for 30 minutes, PDGF action was transient, peaking at 5 minutes and disappearing by 20 minutes. These GLUT4myc translocation time courses mirrored that of phosphorylation of Akt by the two stimuli. Interestingly, insulin and PDGF caused distinct manifestations of actin remodeling. Insulin induced discrete, long (>5 μm) dorsal actin structures at the cell periphery, whereas PDGF induced multiple short (<5 μm) dorsal structures throughout the cell, including above the nucleus. Latrunculin B, cytochalasin D and jasplakinolide, which disrupt actin dynamics, prevented insulin- and PDGF-induced actin remodeling but significantly inhibited GLUT4myc translocation only in response to insulin (75-85%, P<0.05), not to PDGF (20-30% inhibition). Moreover, transfection of tetanus toxin light chain, which cleaves the v-SNAREs VAMP2 and VAMP3, reduced insulin-induced GLUT4myc translocation by >70% but did not affect the PDGF response. These results suggest that insulin and PDGF rely differently on the actin cytoskeleton and on tetanus-toxin-sensitive VAMPs for mobilizing GLUT4.
General Motors Optimizes Its Scheduling of Cold-Weather Tests
Authors: Hsu Chih-Cheng , Blois Yvan de , Pyle Murray James
Published: October 2004

The General Motors Cold Weather Development Center is responsible for performing vehicle road tests under excessively cold weather conditions; each vehicle must undergo a specified number of tests under various temperatures in specified sequences. The center usually completes a vehicle's tests over several weeks based on such factors as the number of days cold enough to provide meaningful results. The center prepares a master test schedule daily with the goals of maximizing overall efficiency, assigning enough tests to each vehicle, and respecting operating constraints. To address this scheduling problem, we developed a decision-support tool with a specialized heuristic. Implementing the tool improved throughput by more than 100 percent and saved millions of dollars in vehicle warranty cost.
The Daniel H. Wagner Prize for Excellence in Operations Research Practice
Authors: Discenza Joseph H.
Published: October 2004

The author introduces the winners of the 2003 Daniel H. Wagner Prize for Excellence in Operations Research Practice.
Improving Volunteer Scheduling for the Edmonton Folk Festival
Authors: Gordon Lynn , Erkut Erhan
Published: October 2004

The annual Edmonton Folk Music Festival is run almost entirely by its 1,800 volunteers. While people are usually enticed into volunteering for the folk fest by perks, such as free access to the entertainment, gourmet meals, and T-shirts, their willingness to return year after year depends on an intangible degree of satisfaction. In spring 2003, a crew coordinator sought to automate the scheduling process for his crew of about 35 volunteers to save time and to accommodate volunteers' preferences when possible. We developed a spreadsheet-based decision-support tool that generated shift times, scheduled volunteers according to various constraints and preferences, and produced master and individual schedules.
Taste and Smell Disturbance with the α-Adrenoceptor Agonist Midodrine
Authors: Young Tim M , Mathias Christopher J
Published: October 2004

OBJECTIVE

To report a case of a disturbance of taste and smell associated with the α-adrenoceptor agonist midodrine.

CASE SUMMARY

A 64-year-old white man with autonomic failure was started on midodrine 5 mg/day as treatment for orthostatic hypotension. After 3 months, the dose was increased to 12.5 mg/day, whereupon he noted a new onset of taste and smell disturbance. These symptoms made eating so unpleasant that the man greatly reduced his food intake, leading to significant weight loss. In addition, he experienced well-recognized adverse effects of midodrine, such as scalp pruritus, after the dose increase. All symptoms resolved with a dose reduction of midodrine (to 5 mg/day), and the patient increased his food intake, resulting in a return to his initial body weight.

DISCUSSION

Midodrine is commonly associated with dose-dependent adverse effects, such as scalp pruritus and cutis anserina. Disorders of taste and smell have not been previously reported with midodrine, although it has been suggested that other sympathomimetic drugs may have effects on the olfactory threshold. Severe disorders of taste and smell may impact not only on a patient's quality of life, but also on their physical well-being, with significant weight loss being reported in this case. According to the Naranjo probability scale, this patient's taste and smell disturbance was probably associated with midodrine.

CONCLUSIONS

The use of midodrine may be associated with taste and smell disturbance. This case suggests that such an association is likely to be dose dependent.
Probable Vancomycin-Induced Neutropenia
Authors: Segarra-Newnham Marisel , Tagoff Shari S
Published: October 2004

OBJECTIVE

To report a case of vancomycin-induced neutropenia and provide a review of the literature.

CASE SUMMARY

A 64-year-old white man was treated with intravenous vancomycin 1.5 g/day for finger osteomyelitis. He developed neutropenia after 21 days of vancomycin therapy. The absolute neutrophil count reached a nadir of 418 cells/mm3 during vancomycin use and returned to normal 7 days after its discontinuation. The eosinophil count was also elevated during the neutropenic episode and probably related to vancomycin. Based on the Naranjo probability scale, the reaction was probably related to vancomycin use.

DISCUSSION

Articles describing cases of vancomycin-induced neutropenia were identified. All patients developed neutropenia as a result of vancomycin therapy 12 days. Neutrophil counts generally increased following discontinuation of vancomycin. One article reported successful resolution of neutropenia and infection by switching the patient's therapy to the structurally related antibiotic agent teicoplanin. Other patients were continued on vancomycin therapy, and neutropenia was treated with moderate to good success with filgrastim. Rechallenge was not generally attempted. The mechanism of neutropenia caused by vancomycin is unclear, but appears to be immune-mediated.

CONCLUSIONS

Vancomycin therapy should not be prolonged unless absolutely necessary, and therapy should be reserved for patients with clear indications for the drug, such as infections due to gram-positive organisms resistant to other therapies. Patients should have periodic assessment of white blood cell and neutrophil counts with consideration to discontinue vancomycin if neutropenia develops.
Probable Codeine Phosphate–Induced Seizures
Authors: Kuo Shih-Chen , Lin Ya-Chu , Kao Shu-Min , Yang Yea-Huei Kao
Published: October 2004

OBJECTIVE

To report a case of seizure activity associated with oral codeine phosphate administered for analgesia in an elderly woman with end-stage renal disease.

CASE SUMMARY

A 73-year-old Taiwanese woman with end-stage renal disease received oral codeine phosphate 30 mg 4 times daily for her back and rib pain without adjustment of her dosage regimen. Seven days after starting codeine therapy, the woman became stuporous and developed tonic–clonic seizures. After phenytoin initiation, codeine discontinuation, and naloxone administration, the seizures did not recur.

DISCUSSION

Codeine is a frequently used opioid analgesic, especially when pain control with acetaminophen or nonsteroidal antiinflammatory drugs fails. Although seizures associated with codeine have been reported, pertinent data are very limited and the exact mechanism is unknown. An objective causality assessment indicated the seizure to be a probable drug-related event in this patient.

CONCLUSIONS

Elderly patients with end-stage renal disease may be predisposed to seizures with higher doses of codeine phosphate. It is imperative to adjust the codeine dosage regimen based on patients’ renal function to avoid the potential toxicity with overdose.
Evaluation of the Iron Status of the Newborn by Soluble Transferrin Receptors in Serum
Authors: Kuiper-Kramer Ellen P. A. , Baerts Wim , Bakker Reinout , van Eyck Jim , van Raan Jan , van Eijk Henk G.
Published: October 2004

The concentration of soluble transferrin receptors in serum has proven to be a reliable predictor of iron status in adults. Its high sensitivity for iron deficiency combined with a small sample size (10 μl) makes it an interesting parameter for the assessment of iron stores in newborn infants.

In the present study we investigated the usefulness of the concentration of soluble transferrin receptors in serum in the assessment of iron metabolism in the newborn. Infants born after an uncomplicated labour were compared to infants in the intensive care unit. The concentration of soluble transferrin receptors in serum was found to be elevated compared to normal adults and independently of iron metabolism. The concentration of soluble transferrin receptors did not correlate with serum iron and ferritin concentrations. In contrast to what was found in other studies, no relationship could be demonstrated between soluble transferrin receptors and birth weight or gestational age. The results of this study have shown that care has to be taken in the interpretation of the concentration of soluble transferrin receptors in serum in newborn infants. It seems to be a parameter which is independent of iron metabolism at least during the first days of life.
Quantitation of IgG and IgM Human Anti-Mouse Antibodies (HAMA) Interference in CA 125 Measurements Using Affinity Chromatography
Authors: Koper Norbert P. , Thomas Chris M. G. , Massuger Leon F. A. G. , Segers Martin F. G. , Olthaar André J. , Verbeek André L. M.
Published: October 2004

Currently no available immunoassay system offers complete protection against spuriously elevated or lowered results due to interference by Human Anti-Mouse Antibodies (HAMA). Although routine use of chromatography procedures is not an acceptable option because of the extra cost and workload involved, such a procedure would be highly desirable to ensure accurate immunoassay results. The present report describes a relatively simple affinity chromatography procedure using a HiTrap Protein G column to isolate immunoglobulin G (IgG) HAMA, followed by a HiTrap N-hydroxy-succinimide(NHS)-activated column coupled to goat-anti human immunoglobulin M (IgM) to bind IgM HAMA. To examine the usefulness of this purification procedure we determined CA 125 in forty serum samples prior to and following chromatography. Pre- and post-injection samples were obtained from 20 patients injected with 1 mg of 111In-Iabelled murine OC 125 F(ab′)2 fragments in an immunoscintigraphy study.

It is shown that this analytical procedure provides a technique to determine the extent and the nature of the existing HAMA interference in samples of patients after in vivo use of monoclonal antibodies for diagnostic or therapeutic purposes. The procedure can also contribute to the clarification of clinically discordant CA 125 results. Finally, the availability of such a procedure in the clinical laboratory provides an opportunity to test the robustness of newly developed immunoassay systems towards HAMA interference.
Objectives, Design and Recruitment of a Familial and Longitudinal Cohort for Studying Gene-Environment Interactions in the Field of Cardiovascular Risk: The Stanislas Cohort
Authors: Siest Gérard , Visvikis Sophie , Herbeth Bernard , Gueguen René , Vincent-Viry Monique , Sass Catherine , Beaud Brigitte , Lecomte Edith , Steinmetz Josiane , Locuty Jean , Chevrier Philippe
Published: October 2004

The main objective of the Stanislas cohort is to study the role and the contribution of genetic and environmental factors to cardiovascular status. We plan:

a)

to describe the degree of association of a large number of cardiovascular risk indicators with cardiovascular endpoints,

b)

to evaluate the contribution of genetic and that of environmental factors to this association,

c)

to follow the evolution of these risk indicators during a period of at least ten years,

d)

to search for the determinants influencing this evolution.

The principal variables studied are:

a)

to describe the degree of association of a large number of cardiovascular risk indicators with cardiovascular endpoints,

b)

to evaluate the contribution of genetic and that of environmental factors to this association,

c)

to follow the evolution of these risk indicators during a period of at least ten years,

d)

to search for the determinants influencing this evolution.

a)

blood pressure, cardiac mass, and wall thickness of carotid and femoral arteries,

b)

obesity and fat mass,

c)

indicators of lipid metabolism,

d)

genetic polymorphisms of several cardiovascular risk candidate genes,

e)

food, tobacco and alcohol consumption,

f)

consumption of drugs and anti-oxidant vitamins.

Between September 1993 and August 1995, 1006 families consisting of the two biological parents with at least two children were recruited totalling 4295 individuals. This cohort will be followed up until 2004. There will be two health examinations five and ten years after the initial examination. A bank of blood samples (serum and plasma) in liquid nitrogen and DNA (−80 °C) has been established.
Total Carbon Dioxide Measured by the Vitros Enzymatic Method
Authors: Frezzotti Annarita , Margarucci Gambini Anna Maria , Coppa Gilberto , De Sio Giuseppina
Published: October 2004

We evaluated the performance of an enzymatic method using dry chemistry for serum total carbon dioxide (tCO2) determination using a Vitros 500 analyser. Imprecision results were acceptable and the linearity was verified for concentrations within a range of 5.5–39.2 mmol/l, i.e. ymeasured = 0.93 xcalculated +1.32, r = 0.99. The Vitros tCO2 method was unaffected by haemoglobin at all concentrations tested. Significant interference was caused by bilirubin at concentrations higher than 30 μmol/l; the addition of bilirubin lowered the apparent values for tCO2 dose-dependently. Serum tCO2 results were practically the same as those for plasma. The reference interval for venous tCO2 concentrations in a healthy population was: 22.4–34.2 mmol/l (mean: 28.3 mmol/l). Comparison of venous serum tCO2 results assayed using the Vitros method with bicarbonate (HCO3
−) values calculated by blood gas determination of pCO2 and pH in arterial blood samples gave poor agreement, r = 0.58. The data revealed a mean difference of 5.48 ± 3.09 mmol/l between the tCO2 measurements and calculated bicarbonate. This was statistically (p = 0.01) and clinically significant. We conclude that the Vitros method provides reliable tCO2 results in venous serum but this method must not be used as an interchangeable alternative to calculated arterial bicarbonate in order to avoid confusion, misinterpretation of results and erroneous therapeutic decisions.
Evaluation of Glucocard Memory 2 and Accutrend® Sensor Blood Glucose Meters
Authors: Arens Sofie , Moons Veronique , Meuleman Paul , Struyf Frank , Zaman Zahur
Published: October 2004

The performance and practicability of 2 blood glucose meters (Glucocard Memory 2 and Accutrendr sensor) were evaluated. Both glucose meters produced acceptably precise results in the hyper- and normoglycaemic concentration ranges. In the hypoglycaemic concentration range, the imprecision of Accutrend® sensor was much higher than recommended by the American Diabetes Association. Within-run coefficients of variation for Glucocard Memory 2 were 6.3 %, 3.9 % and 2.4 % at glucose concentrations of 1.7 mmol/l, 5.8 mmol/l and 11.7 mmol/l, respectively; for Accutrend® sensor these were 15.2 %, 5.0 % and 1.2% at respective concentrations of 0.9 mmol/l, 4.2 mmol/l and 19.6 mmol/l. Between-day coefficients of variation for Glucocard Memory 2 were 4.8 % and 3.5 % at glucose concentrations of 3.9 mmol/l and 17.2 mmol/l, respectively and for Accutrend® sensor they were 3.8 % and 2.9 % at glucose concentrations of 3.8 mmol/land 18.7 mmol/l, respectively. Results were linear over a range of 1.6 mmol/l–29.7 mmol/l for Glucocard Memory 2 and 1.6 mmol/l–33.3 mmol/l for Accutrend® sensor. Results of both blood glucose meters correlated closely with the hexokinase/glucose-6-phosphate dehydrogenase laboratory method. Ninety-eight percent of both Glucocard Memory 2 and Accutrend® sensor results were within 20 % of the comparison method values. Ninety-three percent of the Glucocard Memory 2 and 96 % of the Accutrend® sensor results were within 15 % of the comparison method results. An inverse relation between the glucose readings and haematocrit values was observed for both blood glucose meters in the hyperglycaemic range and this effect was more pronounced for Accutrend r sensor. In the normo- and hypoglycaemic ranges the effect was insignificant and absent, respectively. Minimum sample volume for Glucocard Memory 2 was 3 μl and for Accutrend® sensor it was 9 μl. Lower sample volumes gave erroneous results. Presenting more than the required volume had no effect on results.
Evaluation of Circulating Type I Procollagen Propeptides in Patients with Paget's Disease of Bone
Authors: Bonnin Maria R. , Moragues Carmen , M. Nolla Juan , Lirón Francisco J. , Roig-Escofet Daniel , Navarro Miguel A.
Published: October 2004

We evaluated circulating aminoterminal and carboxyterminal propeptides of type I procollagen and total alkaline phosphatase levels in eighty consecutive patients affected by Paget's disease of bone. We compared the biochemical data with the extent of bone disease calculated on the basis of the bone scintigraphic indices.

Serum aminoterminal propeptide of type I procollagen levels were high in 77% of patients, serum carboxyterminal propeptide of type I procollagen levels in 22% and serum total alkaline phosphatase levels in 76%. We found significant correlations between the three markers studied. The three biochemical markers correlated significantly with the bone scintigraphic activity indices, but the highest correlation coefficient was between the aminoterminal propeptide and total alkaline phosphatase.

We conclude that there is a discrepancy between serum levels of the propeptides studied in relation to Paget's disease of bone. The sensitivity of the carboxyterminal propeptide of type I procollagen in this disease is low. In contrast the aminoterminal propeptide may be as sensitive a marker for the evaluation of this disorder as total alkaline phosphatase, and in addition may be more specific.
Genetic Approach for Insulin-Independent Diabetes Mellitus in Clinical Practice
Authors: Danze Pierre-Marie , Penet Sylvie , Fajardy Isabelle
Published: October 2004

Insulin-independent diabetes mellitus (IDDM) is a polygenic disease with an environmental component. Technological advances and large collection families allowed genetic factors understanding. On clinical practice, two questions could be asked. First, will the genetic markers be of interest in disease prediction either in family studies or in the main population? Secondly, will the genetic approach explain the physiopathological process of the disease? Initially, the gene candidate approach led to the identification of two important loci: Linkage with the human leukocyte antigen (HLA) locus showed the importance of the autoimmune part. Linkage of insulin-independent diabetes mellitus with insulin locus gave a mechanistic answer for disease susceptibility. These two loci can be used as prediction markers, but only in family studies. Since 1993, a whole genome approach has been performed and has led to the identification of other susceptibility loci. These initial results are in progress and should have important implications for public health strategies.
An Enzymatic Method for the Determination of Free Fatty Acids in Serum/Plasma
Authors: Kızıltunç Ahmet , Akçay Fatih
Published: October 2004

Estimation of serum free fatty acids (FFA) in serum based on the formation of inorganic phosphate has been simplified by eliminating complex stages. The principle of the present method is based on breakdown of pyrophosphate, formed by thioesterification of free fatty acids with ATP and CoA with the aid of acyl-CoA synthetase (EC 6.2.1.3) to inorganic phosphate. This is measured using the reaction with molybdate. The reaction equations are as follows:

The recovery of free fatty acids was 96 %. The interferences of citrate, phosphatidylserine, succinate, ascorbic acid and lecithin were between 0.5 and 2 %. The correlation between the new enzymatic and the classic enzymatic method was 0.966. The lower detection limit was 0.018 mmol/I. The method was linear between 0.02 and 2.0 mmol/I. The within-assay and between-assay imprecision (CV) of control sera was 5.5 % and 8 %, respectively.
Specificity of Cardiac Troponins I and T in Renal Disease
Authors: Willging Stefan , Keller Frieder , Steinbach Gerald
Published: October 2004

We investigated and compared serum levels of cardiac troponins I(cTnI) and cardiac troponin T (cTnT) in 85 renal patients (chronic renal impairment n = 23, continuous ambulatory peritoneal dialysis n = 20, hemodialysis n = 42). Patients with the following conditions were excluded: myocardial infarction, angina pectoris, liver disease, malignant neoplasms, enforced physical activity, skeletal muscle trauma, myositis, rhabdomyolysis and seizures. Troponin T was measured by the second generation cTnT-ELISA with a cutoff value = 0.1 μg/l. Troponin I was measured by a cTnI immunoassay analyser with a cut-off value = 2.0 μg/l. Additionally, creatine kinase (CK), CK-MB activity, CKMB mass concentration and myoglobin levels were measured. Specificity was determined as the fraction of true-negative cases compared to the total number of false-positive and true-negative cases. Specificity for cTnT was 96 % [78–100] in patients with renal impairment (creatinine > 150 μmol/l), 95 % [75–100] in continuous ambulatory peritoneal dialysis patients, but in hemodialysis patients it was 75 % [53–92] for short-term hemodialysis (< 1 year) and 46 % [24–68] for long-term hemodialysis (> 1 year). There was a weak correlation between cTnT levels and duration of hemodialysis therapy (r = 0.35, n = 34, p < 0.04). Specificity for cTnI in renal impairment patients was 96 % [78–100] and 100 % [84–100] in continuous ambulatory peritoneal dialysis and all hemodialysis patients. None of the studied markers showed higher specificity than cTnI. Only myoglobin was less specific than cTnT in hemodialysis patients. Different clearances of the troponins during dialysis (investigated by pre-hemodialysis and post-hemodialysis levels) cannot explain the discordant results of cTnT and cTnI.

Conclusion: Cardiac troponin I exhibits higher specificity than cardiac troponin T in hemodialysis patients. Uremic myopathy could explain falsely elevated troponin T levels in hemodialysis patients.
Fucosylation and Galactosylation of IgG Heavy Chains Differ between Acute and Remission Phases of Juvenile Chronic Arthritis
Authors: Flögel Mirna , Lauc Gordan , Gornik Ivan , Maček Boris
Published: October 2004

Oligosaccharide structures are attached to nearly all membrane and serum proteins, and their composition changes significantly in many diseases. We have analysed glycosylation of IgG heavy chains in 34 patients with juvenile chronic arthritis and 13 control individuals. IgG was purified from 0.7 ml of serum, separated by electrophoresis and transferred on to polyvinylidene difluoride (PVDF) membrane. Ricinus communis agglutinin (RCA I) and Bandeirea simplicifolia (BSA II) and Ulex europaeus (UEA I) lectins were used to measure galactose, N-acetylglucosamine and fucose, respectively. While there was no significant difference in average levels of galactose and N-acetylglucosamine, patients with juvenile chronic arthritis had 2.4 times more fucose attached to IgG heavy chains than control individuals. A different picture emerged when patients were divided into those with acute disease and those in remission. Patients in whom juvenile chronic arthritis was currently active had significantly lower levels of galactose than those in remission, in whom galactose levels were comparable to the control group. Fucose levels in both groups of patients were significantly higher than in the control group. These results show that whereas de-galactosylation is a good test to detect and measure the activity of juvenile chronic arthritis, increased fucosylation is a much more reliable measure for diagnosis of the disease itself.
Analytical Evaluation of an Improved Procedure for Measuring Thyrotropin
Authors: González-de-la-Presa Bernardino , Palacios Gonzalo , Bonnin Rosa , Martinez Jose M. , Navarro Miguel A.
Published: October 2004

The analytical characteristics of the AxSYM Ultrasensitive hTSH-II (Abbott Laboratories) procedure for quantitation of serum thyrotropin (TSH) concentration were evaluated. Within- and between-run imprecisions, functional sensitivity, analytical interval and relative inaccuracy with respect to the Enzymum-Test TSH (Boehringer Mannheim) were studied. In all cases, the within-run and between-run of coefficients variation were lower than 6.69 % and 8.12 % respectively. The measurement range was tested with serial dilutions of a serum with a high thyrotropin concentration, and the procedure was found to be linear up to at least 87.0 mIU/l. The functional sensitivity was 0.018 mIU/l. The relative inaccuracy study (Passing-Bablok non-parametric linear regression) produced the following linear equation:

(AxSYM) = 1.02. (ES-700)−0.03 mIU/l, with 95 % confidence intervals of a(−0.05; −0.01); b(0.98; 1.06).
Acute Exogenous Elevation of Plasma Free Fatty Acids Does Not Influence the Plasma Magnesium Concentration
Authors: de Valk Harold W. , Bianchi Rutgert , van Rijn Herman J.M. , Erkelens D. Willem
Published: October 2004

Objective: Plasma non-esterified (free) fatty acid concentrations rise as a consequence of stimulated endogenous lipolysis and are inversely related to the plasma magnesium concentration when plasma adrenaline concentration is increased. The aim of the study was to test whether high plasma non-esterified fatty acid concentration after infusion of non-esterified fatty acids decreases plasma magnesium concentration.

Methods: Twelve healthy subjects received 500 ml Intralipid or saline in a randomised, cross-over, double-blind design. Infusion of Intralipid results in an isolated elevation of plasma non-esterified fatty acid concentration. Plasma magnesium concentration was determined at baseline and every 30 minutes; plasma nonesterified fatty acid and triglyceride concentrations at baseline and after 120 minutes.

Results: Initial plasma magnesium, non-esterified fatty acid, and triglyceride concentrations were similar in both groups. A significant increase in plasma non-esterified fatty acids (2.42 ± 0.96 mmol/l vs 0.58 ± 0.23 mmol/l, p = 0.00013) and triglyceride (median and 95th percentile 5.36 (7.35) mmol/l vs 1.18 (1.92) mmol/l, p = 0.003) concentrations was seen with Intralipid. Plasma magnesium concentration increased significantly after Intralipid (0.89 ± 0.09 mmol/l vs 0.81 ± 0.06 mmol/l, p = 0.007). No significant changes were seen with saline. A positive association was found between the change in plasma magnesium and triglyceride concentrations (r = 0.85, p = 0.001).

Conclusion: Acute infusion of non-esterified fatty acids from an exogenous source does not result in a fall in plasma magnesium concentration, indicating that the circulating non-esterified fatty acids play no part in a decrease in plasma magnesium concentration. The high circulating non-esterified fatty acid levels and the fall in plasma magnesium concentration are both a consequence of intracellular lipolysis.
Teaching and Training Laboratory Professionals for the 21st Century
Authors: Dominiczak Marek H.
Published: October 2004

Educational activities are a background to research and to a dynamic, developing discipline. The principles now being applied in undergraduate curricula are applicable to teaching and training in laboratory medicine. A fresh look at the education and training and an implementation of new educational techniques is necessary to prepare a cadre of individuals who will be developing laboratory medicine in the 21st century.
The Effect of Ascorbic Acid Ingestion on the Biochemical and Physicochemical Risk Factors Associated with Calcium Oxalate Kidney Stone Formation
Authors: Auer Bronwyn Leigh , Auer Derek , Lawrence Rodgers Allen
Published: October 2004

The present study was undertaken to determine the effect of ingestion of large doses of vitamin C on urinary oxalate excretion and on a number of other biochemical and physicochemical risk factors associated with calcium oxalate urolithiasis. A further objective was to determine urinary ascorbate excretion and to relate it qualitatively to ingested levels of the vitamin and oxalate excretion. Ten healthy males participated in a protocol in which 4 g ascorbic acid was ingested for 5 days. Urines (24 h) were collected prior to, during and after the protocol. The urine collection procedure was designed to allow for the analysis of oxalate in the presence and absence of an EDTA preservative and for the analysis of ascorbic acid by manual titration using 2,6 dichlorophenolindophenol. Physicochemical risk factors such as the calcium oxalate relative supersaturation and Tiselius risk index were calculated from urine composition. The results showed that erroneously high analytical oxalate levels occur in the asence of preservative. In the preserved samples there was no significant increase in oxalate excretion at any stage of the protocol. Ascorbate excretion increased when vitamin C ingestion commenced but levelled out after 24 hours suggesting that saturation of the metabolic pool is reached within 24 hours after which ingested ascorbic acid is excreted unmetabolized in the urine. While transient statistically significant changes occurred in some of the biochemical risk factors, they were not regarded as being clinically significant. There were no changes in either the calcium oxalate relative supersaturation or Tiselius risk index. It is concluded that ingestion of large doses of ascorbic acid does not affect the principal risk factors associated with calcium oxalate kidney stone formation.
Development of an HPLC Assay to Study the Effect of Endogenous and Exogenous Substances on Heat-Induced Aggregation of Human Serum Albumin
Authors: Saso Luciano , Casini Maria Luisa , Valentini Giovanni , Mattei Eleonora , Panzironi Claudio , Silvestrini Bruno
Published: October 2004

The mechanism of action of non-steroidal anti-inflammatory drugs which are used in high doses in chronic inflammatory conditions is not clearly understood. Their known protein-stabilizing properties could play a significant role. The inhibition of cyclooxygenase may not be essential for their anti-rheumatic activity, since compounds with strong anti-denaturant properties and devoid of anti-inflammatory activity were shown to be effective in an experimental model of rheumatoid arthritis. Hence, to develop new anti-rheumatic drugs it is essential that a simple in vitro method to evaluate the anti-denaturant activity of endogenous and exogenous compounds is available.

We developed a new assay, using gel permeation high performance liquid chromatography, to study the effect of endogenous and exogenous compounds on heat-induced aggregation of human serum albumin in conditions in which protein precipitation does not occur. Non-steroidal anti-inflammatory drugs like diclofenac, ibuprofen and naproxen inhibited the aggregation of albumin at low concentrations (EC50 10−4–10−5 mol/l) comparable to those active in a classical turbidimetric method, whereas the effect of weak stabilizers, like sodium cloride and formic, fumaric, maleic, malonic, and succinic acid (EC50 10−1–10−2 mol/l in the Mizushima test) was not detectable.

Furthermore, the HPLC assay allowed the examination of a number of coloured substances, including bilirubin, which appeared to be a strong stabilizer of its physiological carrier, albumin.

These data could be clinically relevant, since the drugs examined are used at very high doses in rheumatoid arthritis and related conditions, with plasma levels that could cause significant stabilization of serum albumin and perhaps other proteins.
The Predictive Value of Several Markers in the Progression to Acquired Immunodeficiency Syndrome
Authors: Planella Teresa , Cortés Mariano , Martínez-Brú Cecília , Barrio Josep , Sambeat Ma Antònia , González-Sastre Francesc
Published: October 2004

Serum β2-microglobulin, neopterin, immunoglobulins A, G and M, adenosine deaminase and CD4+ lymphocyte count were evaluated as predictors of progression of HIV-1 infection to AIDS. A population of HIV-1 seropositive, initially asymptomatic men (n=213) and women (n=101) was followed up quarterly.

We estimated the AIDS-free time using the actuarial method (median survival time 47.2 months). Cox proportional hazard analysis revealed that all markers studied were significant (p<0.05) in relation to progression to AIDS. The best markers for predicting progression to AIDS were, in descending order, CD4+ lymphocyte count, β2-microglobulin, IgA, neopterin, IgG, IgM and adenosine deaminase. On stratifying population into four groups (devided at percentiles 25, 50 and 75—from group 1, with values nearest to reference ranges, to group 4, with most abnormal values) we observed statistically significant differences (p<0.05) for all markers except for adenosine deaminase. The relative risk from the Cox proportional hazards model were used to quantify the effects of the best markers and compared to the risk obtained in group 1.

CD4+ lymphocyte count was the best predictor of progression to AIDS. When considering β2-microglobulin and CD4+ together, the relative risk in the group with lowest CD4+ cell count (group 4) ranged from 25.6% (with lower β2-microglobulin values) to 41.1% (with higher β2-microglobulin values). Similar results were obtained when considering neopterin and CD4+ together. The addition of β2-microglobulin or neopterin values to CD4+ lymphocyte count improved the predictive value of CD4+ lymphocyte count.
The Increase of Plasma Homocysteine Concentrations with Age Is Partly due to the Deterioration of Renal Function as Determined by Plasma Cystatin C
Authors: Norlund Lena , Grubb Anders , Fex Göran , Leksell Håkan , Nilsson Jan-Erik , Schenck Henning , Hultberg Björn
Published: October 2004

One of the main determinants of plasma homocysteine in healthy subjects is serum creatinine. In the present study, we therefore investigated the relation between plasma homocysteine concentration, serum creatinine and a new marker for glomerular filtration rate, plasma cystatin C concentration. Cystatin C reflects the glomerular filtration better than serum creatinine and is not related to the muscle mass and formation of creatinine. The study group consisted of 255 healthy subjects from a well-defined area in the southern part of Sweden.

The concentration of plasma homocysteine was increased in men compared to women. This difference disappeared when men and women were stratified by serum creatinine values. Statistically significant correlations were noted between plasma homocysteine and age, plasma cystatin C and serum creatinine. It is shown that plasma homocysteine is not only correlated to serum creatinine as a result of renal function but also as a result of the relationship between homocysteine production and creatine-creatinine synthesis. Using linear regression we were able to show that plasma cystatin C had a higher explanatory value than age. Serum creatinine showed a lower explanatory power than age. The findings in the present study might suggest that the increase of plasma homocysteine concentration with age could be partly due to the deterioration of renal function. Study
Serum CA 242: The Search for a Valid Marker of Pancreatic Cancer
Authors: Ventrucci Maurizio , Ubalducci Giuseppina Margaret , Cipolla Antonio , Panella Maria Antonietta , Ligabue Amedeo
Published: October 2004

Many efforts have been made to find valuable serum tumour markers which help the diagnosis of pancreatic cancer. In the present study we investigated the diagnostic value of CA 242 in comparison with two other routinely used tumour markers (CA 19–9 and CA 50). Two-hundred and seventy six subjects were enrolled in this study: 46 patients with pancreatic cancer preoperatively, 53 with chronic pancreatitis, 28 with acute pancreatitis, 49 with other malignancies, 50 with miscellaneous non-neoplastic digestive diseases, and 50 healthy subjects. CA 242 was determined in serum by means of a two-step fluoroimmunometric assay. Sensitivities of CA 242, CA 19–9 and CA 50 for pancreatic cancer when all patients were considered were 41.3%, 54.3% and 47.8%, respectively (95% specificity level). No significant improvement was achieved by combination of CA 242 with CA 19–9 and/or CA 50. Cholestasis affected serum levels of CA 242 in patients without pancreatic cancer, but not in those with this tumour. The metastatic stage of pancreatic cancer appeared to influence the levels of CA 242. In conclusion, CA 242 serum assay does not seem to improve diagnostic accuracy for pancreatic cancer compared to CA 19–9 and CA 50.
Glass Facade Assessment
Authors: Schwartz TA
Published: October 2004

Glass is the most widely used building facade material. No other material matches its combination of optical clarity, durability, economy, and ability to control light and heat transfer. Despite these attractive properties, the inherent brittleness and potentially dangerous fracture characteristics of glass will continue to challenge cladding designers and building owners. Since glass makes up such a substantial portion of contemporary building facades, the economic consequences of poor glass performance are significant.

This paper presents a brief review of glass in facade architecture, its strengths and weaknesses, and in situ condition assessment techniques. Issues include glass surface assessment, evaluating glass breakage characteristics, and insulating glass (IG) unit durability and performance.
The Technical Foundations of a Unified Adjusted Reference Temperature for RPV Fracture Toughness
Authors: Lott RG , Rosinski ST , Server WL
Published: October 2004

The use of a reference temperature to define the transition from ductile-to-brittle behavior is a well-established practice in reactor pressure vessel integrity analysis. Current procedures for analysis of irradiated pressure vessel steels use an Adjusted Reference Temperature (ART or RTPTS) that shift the unirradiated RTDNT value based on Charpy data and apply additional margins. The recent adoption of an ASTM Standard Test Method for Determination of Reference Temperature, To, for Ferritic Steels in the Transition Range (E 1921) has made direct determinations of fracture toughness reference temperature in irradiated materials using Master Curve feasible. ASME Code Case N629 recognizes the potential of this new technology as an alternative means of determining an ART value for use in reactor pressure vessel integrity analysis. This alternative approach has been used in recent plant specific submittals to the NRC. ASTM sub-committee E10.02 is currently considering adopting a standard to provide a unified definition of the Adjusted Reference Temperature. This unified definition would provide consistent procedures for using either RTNDT or Master Curve based definitions of ART. This unified definition would provide common margins for the two approaches and assure a consistent level of confidence in the analysis. The statistical basis of the Master Curve makes it possible to establish a more rational basis for the margins applied in both approaches.
Fatigue Response and Life Prediction of Selected Reactor Materials
Authors: Li M , Stubbins JF
Published: October 2004

This paper analyzes experimental fatigue response for selected unirradiated and irradiated reactor materials: AISI 316 stainless steel, ferritic/martensitic MANET and HT9 steels. Available tensile test results on the same or similar materials are used to predict changes in fatigue response using the Universal Slopes method. The predictions are compared with the experimental data to assess the potential for using tensile data to predict reactor component fatigue response. It was found that the effect of irradiation on fatigue life was less severe than on tensile properties. However, tensile properties are useful for qualitative predictions of fatigue response.
Effect of Heat Treatment and Tantalum on Microstructure and Mechanical Properties of Fe-9Cr-2W-0.25V Steel
Authors: Klueh RL , Hashimoto N , Sokolov MA
Published: October 2004

An Fe-9Cr-2W-0.25V-0.07Ta-0.1C (9Cr-2WVTa) steel has a smaller prior-austenite grain size than this same composition without tantalum (9Cr-2WV) when the steels are given a similar heat treatment. Except for prior-austenite grain size, the microstructures of the steels are similar before irradiation, and they develop similar changes in microstructure during irradiation. Nevertheless, the 9Cr-2WVTa shows less effect of irradiation on the Charpy behavior. To determine the effect of grain size on the Charpy properties of the 9Cr-2WV and 9Cr-2WVTa, specimens of the two steels were given various normalization heat treatments to produce different prior austenite grain sizes, and the tensile and impact properties were determined. For the smaller prior-austenite grain sizes, the 9Cr-2WV steel had impact properties similar to or better than those of the 9Cr-2WVTa steel. Differences in the microstructures of the steels were used to explain the observations and what they mean for developing steels with improved properties.
Flowable Fill Using Flue Gas Desulfurization Material
Authors: Butalia TS , Wolfe WE , Zand B , Lee JW
Published: October 2004

Flowable fills are an effective and practical alternative to commonly used compacted earth backfills. Flowable fill is a cementious material, commonly a blend of cement, fly ash, sand, and water, that does not require compaction, may be self-leveling at time of placement, may harden quickly within a few hours, and can be excavated in the future if need be. Many flue gas desulfurization (FGD) materials have low unit weight and good shear strength characteristics and thus hold promise for flowable fill applications. This paper focuses on the potential of using two types of FGD materials (spray dryer and wet fixated FGD material) in flowable fill as a replacement for conventional fly ash. Several design mixes were considered. The design mixes consisted of varying amounts of FGD material, cement, lime, and water. The mixes were tested in the laboratory for flowability, unit weight, moisture content, unconfined compressive strength, erodibility, set-time, penetration, and long-term strength characteristics. Tests were conducted for up to 90 d of curing. Without any additives, the FGD material was observed to be as good as a regular (normal set) flowable fill in terms of placeability, unconfined compressive strength, and diggability. FGD material flowable fill with additives and admixtures compares favorably with the characteristics of conventional quick set flowable fills.