bluuebunny/crossref_metadata_2025 huggingface dataset:
Description and evaluation of an EBM curriculum using a block rotation
Authors: Thom David H , Haugen Julie , Sommers Peter S , Lovett Peter
Published: October 2004

Background

While previous authors have emphasized the importance of integrating and reinforcing evidence-based medicine (EBM) skills in residency, there are few published examples of such curricula. We designed an EBM curriculum to train family practice interns in essential EBM skills for information mastery using clinical questions generated by the family practice inpatient service. We sought to evaluate the impact of this curriculum on interns, residents, and faculty.

Methods

Interns (n = 13) were asked to self-assess their level of confidence in basic EBM skills before and after their 2-week EBM rotation. Residents (n = 21) and faculty (n = 12) were asked to assess how often the answers provided by the EBM intern to the inpatient service changed medical care. In addition, residents were asked to report how often they used their EBM skills and how often EBM concepts and tools were used in teaching by senior residents and faculty. Faculty were asked if the EBM curriculum had increased their use of EBM in practice and in teaching.

Results

Interns significantly increased their confidence over the course of the rotation. Residents and faculty felt that the answers provided by the EBM intern provided useful information and led to changes in patient care. Faculty reported incorporating EBM into their teaching (92%) and practice (75%). Residents reported applying the EBM skills they learned to patient care (86%) and that these skills were reinforced in the teaching they received outside of the rotation (81%). All residents and 11 of 12 faculty felt that the EBM curriculum had improved patient care.

Conclusions

To our knowledge, this is the first published EBM curriculum using an individual block rotation format. As such, it may provide an alternative model for teaching and incorporating EBM into a residency program.
Intracardiac echocardiography to guide transseptal catheterization for radiofrequency catheter ablation of left-sided accessory pathways: two case reports
Authors: Citro Rodolfo , Ducceschi Valentino , Salustri Alessandro , Santoro Michele , Salierno Michele , Gregorio Giovanni
Published: October 2004

Intracardiac echocardiography (ICE) is a useful tool for guiding transseptal puncture during electrophysiological mapping and ablation procedures. Left-sided accessory pathways (LSAP) can be ablated by using two different modalities: retrograde approach through the aortic valve and transseptal approach with puncture of the fossa ovalis. We shall report two cases of LSAP where transcatheter radiofrequency ablation (TCRFA) was firstly attempted via transaortic approach with ineffective results. Subsequently, a transseptal approach under ICE guidance has been performed. During atrial septal puncture ICE was able to locate the needle tip position precisely and provided a clear visualization of the "tenting effect" on the fossa ovalis. ICE allowed a better mapping of the mitral ring and a more effective catheter ablation manipulation and tip contact which resulted in a persistent and complete ablation of the accessory pathway with a shorter time of fluoroscopic exposure. ICE-guided transseptal approach might be a promising modality for TCRFA of LSAP.
Improved gene delivery to human saphenous vein cells and tissue using a peptide-modified adenoviral vector
Authors: Work Lorraine M , Reynolds Paul N , Baker Andrew H
Published: October 2004

The establishment of efficient gene delivery to target human tissue is a major obstacle for transition of gene therapy from the pre-clinical phases to the clinic. The poor long-term patency rates for coronary artery bypass grafting (CABG) is a major clinical problem that lacks an effective and proven pharmacological intervention. Late vein graft failure occurs due to neointima formation and accelerated atherosclerosis. Since CABG allows a clinical window of opportunity to genetically modify vein ex vivo prior to grafting it represents an ideal opportunity to develop gene-based therapies. Adenoviral vectors have been frequently used for gene delivery to vein ex vivo and pre-clinical studies have shown effective blockade in neointima development by overexpression of candidate therapeutic genes. However, high titers of adenovirus are required to achieve sufficient gene delivery to provide therapeutic benefit. Improvement in the uptake of adenovirus into the vessel wall would therefore be of benefit. Here we determined the ability of an adenovirus serotype 5 vector genetically-engineered with the RGD-4C integrin targeting peptide inserted into the HI loop (Ad-RGD) to improve the transduction of human saphenous vein smooth muscle cells (HSVSMC), endothelial cells (HSVEC) and intact saphenous vein compared to a non-modified virus (Ad-CTL). We exposed each cell type to virus for 10, 30 or 60 mins and measured transgene at 24 h post infection. For both HSVSMC and HSVEC Ad-RGD mediated increased transduction, with the largest increases observed in HSVSMC. When the experiments were repeated with intact human saphenous vein (the ultimate clinical target for gene therapy), again Ad-RGD mediated higher levels of transduction, at all clinically relevant exposures times (10, 30 and 60 mins tissue:virus exposure). Our study demonstrates the ability of peptide-modified Ad vectors to improve transduction to human vein graft cells and tissue and has important implications for gene therapy for CABG.
Multicenter Phase II Study of the Oral MEK Inhibitor, CI-1040, in Patients With Advanced Non-Small-Cell Lung, Breast, Colon, and Pancreatic Cancer
Authors: Rinehart John , Adjei Alex A. , LoRusso Patricia M. , Waterhouse David , Hecht J. Randolph , Natale Ronald B. , Hamid Oday , Varterasian Mary , Asbury Peggy , Kaldjian Eric P. , Gulyas Stephen , Mitchell David Y. , Herrera Roman , Sebolt-Leopold Judith S. , Meyer Mark B.
Published: October 2004

Purpose

This multicenter, open-label, phase II study was undertaken to assess the antitumor activity and safety of the oral mitogen-activated extracellular signal regulated kinase kinase (MEK) inhibitor, CI-1040, in breast cancer, colon cancer, non-small-cell lung cancer (NSCLC), and pancreatic cancer.

Patients and Methods

Patients with advanced colorectal, NSCLC, breast, or pancreatic cancer received oral CI-1040 continuously at 800 mg bid. All patients had measurable disease at baseline, a performance status of 2 or less, and adequate bone marrow, liver, and renal function. Expression of pERK, pAkt, and Ki-67 was assessed in archived tumor specimens by quantitative immunohistochemistry.

Results

Sixty-seven patients with breast (n = 14), colon (n = 20), NSCLC (n = 18), and pancreatic (n = 15) cancer received a total of 194 courses of treatment (median, 2.0 courses; range, one to 14 courses). No complete or partial responses were observed. Stable disease (SD) lasting a median of 4.4 months (range, 4 to 18 months) was confirmed in eight patients (one breast, two colon, two pancreas, and three NSCLC patients). Treatment was well tolerated, with 81% of patients experiencing toxicities of grade 2 or less severity. Most common toxicities included diarrhea, nausea, asthenia, and rash. A mild association (P < .055) between baseline pERK expression in archived tumor specimens and SD was observed.

Conclusion

CI-1040 was generally well tolerated but demonstrated insufficient antitumor activity to warrant further development in the four tumors tested. PD 0325901, a second generation MEK inhibitor, has recently entered clinical development and, with significantly improved pharmacologic and pharmaceutical properties compared with CI-1040, it may better test the therapeutic potential of MEK inhibition in cancer.
Prolonged Clinical and Molecular Remission in Patients With Low-Grade or Follicular Non-Hodgkin's Lymphoma Treated With Rituximab Plus CHOP Chemotherapy: 9-Year Follow-Up
Authors: Czuczman Myron S. , Weaver Robin , Alkuzweny Baha , Berlfein Judy , Grillo-López Antonio J.
Published: October 2004

Purpose

Long-term follow-up with updated time to disease progression (TTP) and duration of response (DR) data are presented from a multicenter, phase II trial of rituximab/cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) combination therapy in 40 patients with CD20+, B-cell, non-Hodgkin's lymphoma (NHL). Revised response rates based on International Workshop Response Criteria are also provided.

Patients and Methods

Enrollment began in April 1994 and consisted of patients with histologically confirmed, low-grade, B-cell lymphoma who had received no prior chemotherapy or who had no more than four prior standard therapies. Patients received six cycles of CHOP and six infusions of rituximab.

Results

Eight (21%) of the 38 treated patients were classified as International Working Formulation (IWF) A, 16 (42%) were IWF B, 13 (34%) were IWF C, and one (3%) was IWF D. Nine (24%) of 38 patients had received prior chemotherapy. Nine (24%) of 38 were considered poor risk according to the Follicular Lymphoma International Prognostic Index. Overall response rate was 100%; 87% of patients achieved a complete response or unconfirmed complete response. The median TTP and DR were 82.3 months and 83.5 months, respectively. Seven of eight patients who were bcl-2 positive at baseline converted to negative, and three of the seven patients have sustained the molecular remission.

Conclusion

Although a cure has not been found yet for follicular NHL, the R-CHOP combination provides a lengthy response duration in patients with relapsed or newly diagnosed indolent NHL.
Clinical Outcome of Lymphoma Patients After Idiotype Vaccination Is Correlated With Humoral Immune Response and Immunoglobulin G Fc Receptor Genotype
Authors: Weng Wen-Kai , Czerwinski Debra , Timmerman John , Hsu Frank J. , Levy Ronald
Published: October 2004

Purpose

The unique immunoglobulin idiotype (Id) expressed by each B-cell lymphoma is a target for immunotherapy. Vaccination with Id induces humoral and/or cellular anti-Id immune responses. However, the clinical impact of these anti-Id immune responses is unknown. We and others have previously reported that immunoglobulin G Fc receptor (FcγR) polymorphisms predict the clinical response of lymphoma patients to passive anti-CD20 antibody infusions. In this study, we tested whether anti-Id immune responses or FcγR polymorphisms associate with clinical outcome of patients who received Id vaccination.

Patients and Methods

We analyzed 136 patients with follicular lymphoma who had received Id vaccination. The anti-Id immune responses were measured and FcγRIIIa and FcγRIIa polymorphisms were determined and correlated with clinical outcome for these patients.

Results

Patients who mounted humoral immune responses had a longer progression-free survival (PFS) than those who did not (8.21 v 3.38 years; P = .018). Patients with FcγRIIIa 158 valine/valine (V/V) genotype also had a longer PFS than those with valine/phenylalanine (V/F) or phenylalanine/phenylalanine (F/F) genotypes (V/V, 8.21 v V/F, 3.38 years; P = .004; v F/F, 4.47 years; P = .035). Multivariate analysis using the Cox proportional hazards model showed that V/V genotype and humoral immune responses were independent positive predictors for PFS.

Conclusion

This study is the first to identify the predictive value of FcγR polymorphism on clinical outcome in patients who received active immunotherapy with tumor antigen vaccines. Our results imply that the antibodies induced against a tumor antigen are beneficial and that FcγR-bearing cells mediate an antitumor effect by killing antibody-coated tumor cells.
Phase I Clinical Trial of the Immunocytokine EMD 273063 in Melanoma Patients
Authors: King David M. , Albertini Mark R. , Schalch Heidi , Hank Jacquelyn A. , Gan Jacek , Surfus Jean , Mahvi David , Schiller Joan H. , Warner Thomas , Kim KyungMann , Eickhoff Jens , Kendra Kari , Reisfeld Ralph , Gillies Stephen D. , Sondel Paul
Published: October 2004

Purpose

To evaluate the safety, toxicity, in vivo immunologic activation, and maximum-tolerated dose (MTD) of EMD 273063 (hu14.18-IL-2) in patients with metastatic melanoma.

Patients and Methods

Thirty-three patients were treated with EMD 273063, a humanized anti-GD2 monoclonal antibody (mAb) linked to interleukin-2 (IL-2). EMD 273063 was given as a 4-hour intravenous infusion on days 1, 2, and 3 of week 1. Patients with stabilization or regression of disease could receive a second course of treatment at week 5. Dose levels evaluated were 0.8, 1.6, 3.2, 4.8, 6.0, and 7.5 mg/m2/d.

Results

Nineteen of 33 patients completed course 1 with stable disease and went on to receive course 2. Eight patients had stable disease on completion of course 2. Grade 3 adverse events included hypophosphatemia (11 patients), hyperglycemia (three patients), hypotension (two patients), thrombocytopenia (one patient), hypoxia (three patients), elevated hepatic transaminases (two patients), and hyperbilirubinemia (one patient). Opioids were required for treatment-associated arthralgias and/or myalgias during 17 of 52 treatment courses. No grade 4 adverse events were observed. Dose-limiting toxicities at the MTD included hypoxia, hypotension, and elevations in AST/ALT. Grade 3 toxicities were anticipated based on prior studies of IL-2 or anti-GD2 mAbs, and all resolved. Immune activation was induced, as measured by lymphocytosis, increased peripheral-blood natural killer activity, and cell numbers, and increased serum levels of the soluble alpha chain of the IL-2 receptor complex.

Conclusion

Treatment with the immunocytokine EMD 273063 induced immune activation and was associated with reversible clinical toxicities at the MTD of 7.5 mg/m2/d in melanoma patients.
BRL1 and BRL3 are novel brassinosteroid receptors that function in vascular differentiation inArabidopsis
Authors: Caño-Delgado Ana , Yin Yanhai , Yu Cong , Vafeados Dionne , Mora-García Santiago , Cheng Jin-Chen , Nam Kyoung Hee , Li Jianming , Chory Joanne
Published: October 2004

Plant steroid hormones, brassinosteroids (BRs), are perceived by the plasma membrane-localized leucine-rich-repeat-receptor kinase BRI1. Based on sequence similarity, we have identified three members of the BRI1 family, named BRL1,BRL2 and BRL3. BRL1 and BRL3, but not BRL2, encode functional BR receptors that bind brassinolide, the most active BR, with high affinity. In agreement, only BRL1 and BRL3 can rescue bri1 mutants when expressed under the control of the BRI1 promoter. While BRI1 is ubiquitously expressed in growing cells, the expression of BRL1 and BRL3 is restricted to non-overlapping subsets of vascular cells. Loss-of-function of brl1 causes abnormal phloem:xylem differentiation ratios and enhances the vascular defects of a weak bri1 mutant. bri1 brl1 brl3 triple mutants enhance bri1 dwarfism and also exhibit abnormal vascular differentiation. Thus, Arabidopsis contains a small number of BR receptors that have specific functions in cell growth and vascular differentiation.
Primary Dental Care 1994–2004: The First Ten Years a Chronology
Authors: Renson Ted
Published: October 2004

The prime purpose of a professional journal is to keep its readers informed of changes of importance affecting the practise of that profession. That is the criterion that I have applied in producing this chronology of the papers that have been published in Primary Dental Care during the past decade.

The ambition which has guided me since I received the invitation to carry out this review is a simple one: to include as much as may generally be found useful by general dental practitioners (GDPs), who form the bulk of our readership.

In 1789 the English philosopher Jeremy Bentham extolled the virtues of utility for mankind when he declared that ‘the greatest happiness of the greatest number is the foundation of morals and legislation’. The contributors that I have included, by contrast, think of their utilitarianism as striving after the most practical. The principal purpose of this chronology is to achieve a summary, without weighing causes or consequences. From past experience, an outstanding virtue of such an aggregated record is that it can inspire fresh patterns of thought and thus encourage the submission of manuscripts as a result of those thoughts. I can think of scarcely any facet of the general practice of dentistry that has not been touched upon, for the most part authoritatively. I hope that these brief aide-memoires may persuade old readers to return to those articles of particular interest to them and that new readers will feel informed about past papers.

Every issue of the journal to date has been reviewed. Dates, volume and issue numbers and principal authors’ names are all included. With these identifying features any paper, to which reference is made, may be quickly found. It would be manifestly absurd to use precious space on a formal listing of more than 250 references and this listing has, therefore, been omitted.
The Clinical Innovations Conference
Authors: Eaton Kenneth A.
Published: October 2004

At the end of May, an impressive team of speakers from North America and the United Kingdom provided two days of lectures and hands-on sessions that updated delegates on practice management, team dentistry, fixed and removable prosthodontics, endodontics and implantology, with the emphasis on new materials and techniques.
An Interview with the Chief Dental Officer
Authors: Eaton Kenneth A
Published: October 2004

Some months ago, I mentioned to Professor Raman Bedi, the Chief Dental Officer (CDO) for England, that Primary Dental Care would be celebrating its tenth anniversary in October 2004. He kindly agreed to a special interview during which he would outline his vision for education, research and opportunities for career development in primary dental care in the future. The timing proved to be perfect as earlier on the day of the interview (16th July 2004), the Secretary of State for Health, John Reid, announced the Government's plans for NHS dentistry and NHS Dentistry: Delivering Change. Report from the Chief Dental Officer (England) 2004 was published.
Primary Dental Care 1994–2004: The First Ten Years Chronicles of a New Journal
Authors: Scott Julian P
Published: October 2004

The first Editor, Julian Scott (1992–96), writes of the establishment and early years of the journal.
Generalised Hypercementosis: A Case Report
Authors: Seed Rachel , Nixon Paul P
Published: October 2004

The following case report describes the clinical and radiographical presentation of a female who attended a general dental practice as a new patient. The patient was diagnosed with generalised hyper-cementosis, possibly attributable to oral neglect. Hypercementosis is associated with a number of aetiological factors, which may be local or systemic in nature. It is important that the general dental practitioner is aware of these factors and is able to distinguish presentation due to a local cause from that of a systemic disease process. The aims of this paper are to illustrate an unusual presentation of hypercementosis and to discuss the radiographic differentiation that led to diagnosis.
Development of Molecular Genetics
Authors: Tahvanainen Esa
Published: October 2004

Human genetics has rapidly evolved from vague impression that descendants resemble their parents, to science which is now of utmost importance to the development of new principles and practice in medicine. It was only in the beginning of this century when it was suggested that chromosomes might carry genetic information. During the two last decades researchers have developed amazing methods to study and manipulate genes. This has created new possibilities to diagnose and cure diseases, but also raised ethical and legal questions. These developments are outlined in the present paper.
The Changing Face of Clinical Laboratories
Authors: Plebani Mario
Published: October 2004

Laboratory medicine has undergone a sea change, and medical laboratories must now adapt to, and meet new, customer-supplier needs springing from shifts in the patterns of disease prevalence, medical practice, and demographics. Managed care and other cost-containment processes have forced those involved in health care to cooperate to develop a full picture of patient care, and this has affected clinical laboratory objectives, the main focus now being on improvement in medical outcomes. More recently, the resource shortages in health care and results of cost/effectiveness analysis have demonstrated that the value of a laboratory test must be ascertained not only on the basis of its chemical or clinical performance characteristics, but also by its impact on patient management, the only true assessment of the quality of testing being quality of patient outcomes. The time is ripe for changing the vision of laboratory medicine, and some of the reasons for this are the availability of results in real-time, the introduction of more specific tests, and the trend to prevent diseases rather than cure them. The information from laboratory tests designed to evaluate biochemical or genetic risk and/or prognostic factors cannot be replaced either by physical examination and/or the assessment of symptoms. Today, the importance of laboratory scientists must be proven in three broad areas: a) guaranteeing the quality of tests, irrespective of where they are performed; b) improving the quality of the service; c) maximizing the impact of laboratory information on patient management.
Analysis of the Gly40Ser Polymorphism in the Glucagon Receptor Gene in a German Non-Insulin-Dependent Diabetes Mellitus Population
Authors: Ambrosch Andreas , Lobmann Ralf , Dierkes Jutta , König Wolfgang , Luley Claus , Lehnert Hendrik
Published: October 2004

A heterozygous polymorphism changing GGT40 (Gly) to AGT40 (Ser) in the glucagon receptor gene (GCG-R) was reported to be associated with non-insulin-dependent diabetes mellitus (NIDDM). A possible involvement of this polymorphism in impaired glucose tolerance was also suggested in a French population. However, the prevalence of this polymorphism differs markedly among different ethnic groups, whereby the results in German populations were found to be contradictory. We thus investigated the association of this mutation with NIDDM and healthy subjects in 508 German subjects (196 NIDDM, and 312 controls).

None of the control subjects, but one of the NIDDM patients demonstrated the Gly40Ser polymorphism. Since no first-degree relative of the index patient had this genetic variance, a de novo mutation is suggested. Although the frequency of the Gly40Ser polymorphism in NIDDM observed in France is not confirmed in our population, this genetic variance is also evident in Germany.
A Relationship between K-ras Gene Mutations and Some Clinical and Histologic Variables in Patients with Primary Colorectal Carcinoma
Authors: Beránek Martin , Bureš Jan , Palička Vladimír , Jandík Pavel , Langr František , Nejedlá Eliška
Published: October 2004

Mutations in the Kirsten ras 2 (K-ras) gene were described as early events in the process of colorectal carcinogenesis. The aim of this study was to find a possible relationship between the presence of K-ras mutation in samples of primary colorectal carcinomas and the clinico-pathological data of the investigated patients. Mutation in codon 12 of the K-ras gene was determined in 18 of 53 colorectal carcinomas (34 %) in our group of patients. The presence of K-ras gene mutations was not related to gender, age of subject at diagnosis, staging or cancer location (p > 0.05). Sixteen of the 42 (38 %) moderately differentiated carcinomas, and two of the eight (25 %) well differentiated carcinomas contained K-ras mutation in codon 12, but none of the three poorly differentiated carcinomas contained the mutation. Moderately differentiated tumours contained an aspartate code GAT (in eight cases), a valine code GTT (in six cases), an alanine code GCT (in one case) and a serine code AGT (in one case) in codon 12. Well differentiated tumours contained only the valine code GTT (two cases).

Our results show that the frequency of mutations in the K-ras gene in carcinomas in Central Europe is not different from the frequencies found in other parts of the world. The homogeneous incidence of K-ras mutation does not seem to be related to ethnic factors, dietary habits, or the composition of the diet.
Particle Counting Immunoassay for Urinary Cotinine. Comparison with Chromatography, Enzyme-linked Immunoassay and Fluorescence Polarization Immunoassay
Authors: Galanti Laurence M. , Dell'Omo Juliette , Vanbeckbergen Danielle , Dubois Pierre , Masson Pierre L. , Cambiaso César L.
Published: October 2004

Urinary cotinine was measured according to its inhibitory activity on the agglutination of cotinine-coated latex particles by anti-cotinine antibodies, the agglutination being measured by optical counting of the remaining non-agglutinated particles (particle counting, PaC). The detection limit was 0.03 μg/ml and the practical range extended from 0.03 to 3.9 μg/ml. The correlation results of 320 urine samples with those of high pressure liquid chromatography, enzyme-linked (Coti-Tracq EIA, Serex Inc., Maywood, NJ, USA), and fluorescence polarization immunoassay (TDX instrument, Abbott, Abbott Park, IL, USA) were r = 0.90, r = 0.69, r = 0.87, respectively, whereas the correlation coefficients between the assays other than particle counting ranged from 0.62 to 0.88. PaC does not require any separation step and can thus be easily automated.
Identification of IgG-specific Oligoclonal Banding in Serum and Cerebrospinal Fluid by Isoelectric Focusing: Description of a Simplified Method for the Diagnosis of Neurological Disorders
Authors: Marchetti P. , Gutierrez J. , Velia P. , Faucompré J.-L. , Onraed B. , Formstecher P. , Hennache B.
Published: October 2004

Clinical laboratory procedures using cerebrospinal fluid (CSF) to assist in the diagnosis of multiple sclerosis (MS) are based essentially on the determination of oligoclonal bands (OB) in CSF and not in serum. To date, the techniques using isoelectric focusing (IEF) have represented one of the most efficient methods for detecting supernumerary bands in CSF but unfortunately were not always compatible with a routine use. Here, we describe a revised method of IEF suitable for the diagnosis of neurological disorders. The kit-based technique was simplified and the present procedure allowed an easier execution, reduced the overall analysis time and permitted an uncomplicated intepretation of oligoclonal profiles. Moreover, the technique developed was very sensitive and specific for the diagnosis of MS diagnosis. In conclusion, the IEF protocol described in this report is suitable for OB detection in any laboratory.
Low Bone Mineral Density after Total Gastrectomy in Males: a Preliminary Report Emphasizing the Possible Significance of Urinary Net Acid Excretion, Serum Gastrin and Phosphorus
Authors: Schmiedl Angelika , Schwille Paul Otto , Stühler Christine , Göhl Jonas , Rümenapf Gerhard
Published: October 2004

The bone mineral density (BMD) and the associated extracellular status of mineral and acid-base metabolism were evaluated in 11 males, 3–18 years after total gastrectomy (GX). In the lumbar spine, but not in the femoral neck, BMD was decreased in seven, normal in three, and falsely high in one individual. Relative to the limits of normalcy, fasting serum levels of gastrin were low, but normal for calcium, phosphorus, parathyroid hormone, calcitonin and vitamin D, while the level of total alkaline phosphatase was elevated; fasting urine pH and calcium were low, while phosphorus and net acid were high. Regression analyses revealed serum gastrin and phosphorus, and urinary net acid as possible predictors of BMD. It was concluded that over the long-term GX evokes low BMD, but not hyperparathyroidism and deranged vitamin D metabolites. Future studies may focus on gastrin, parathyroid hormone-independent hyperphosphaturia and disturbed acid-base metabolism as indicators of a new extra-cellular equilibrium of minerals.
Characterization of the Isoenzyme Profile of β-N-Acetylhexosaminidase in the Urine of Newborns
Authors: Pérez Luis F. , Martínez M. Isabel , Ribeiro Helena M. , Pinto Rui A. , Miranda M. Clara Sá , Tutor J. Carlos
Published: October 2004

The urinary isoenzymes of β-N-acetylhexosaminidase (Hex) in newborn infants were characterised by chromatography, electrophoresis, thermodynamic analysis and through substrate specificity. No qualitative difference was found for the major Hex A and Hex B isoenzymes between full-term or premature newborns and adults, although in the latter group the relative proportion of Hex B is much lower (18.5 ± 2.7 % vs. 36.3 ± 1.0 %). An additional minor enzyme form was found in some premature newborns, which eluted from the DEAE-cellulose column at a higher concentration of NaCl than Hex A and, like this isoenzyme, is able to hydrolyse 4-methylumbellipheryl-2-acetamido-2-deoxy-β-D-glucopyranoside-6-sulphate, which would suggest that it has α subunits in its molecule. These results do not confirm the hypothesis of other authors about the existence of a unique fetal Hex isoenzyme in neonatal urine which eluted before the application of the NaCl gradient, similarly to the Hex B.
Oxidized Low Density Lipoprotein: Atherogenic and Proinflammatory Characteristics during Macrophage Foam Cell Formation. An Inhibitory Role for Nutritional Antioxidants and Serum Paraoxonase
Authors: Kaplan Marielle , Aviram Michael
Published: October 2004

Oxidative stress and inflammatory processes are of major importance in atherogenesis because they stimulate oxidized LDL (Ox-LDL)-induced macrophage cholesterol accumulation and foam cell formation, the hallmark of early atherosclerosis. Under oxidative stress, both blood monocytes and plasma lipoproteins invade the arterial wall, where they are exposed to atherogenic modifications. Oxidative stress stimulates endothelial secretion of monocyte chemoattractant protein 1 (MCP-1) and of macrophage colony stimulating factor (M-CSF), leading to monocyte adhesion and differentiation, respectively. LDL binds to extracellular matrix (ECM secreted by endothelial cells, smooth muscle cells and macrophages) proteoglycans, in a process that contributes to the enhanced susceptibility of the lipoprotein to oxidation by arterial wall macrophages. ECM-retained Ox-LDL is taken up by activated macrophages via their scavenger receptors. This leads to cellular cholesterol accumulation and enhanced atherogenesis. Protection of LDL against oxidation by antioxidants that can act directly on the LDL, or indirectly on the cellular oxidative machinery, or conversion of Ox-LDL to a non-atherogenic particle by HDL-associated paraoxonase (PON-1), can contribute to attenuation of atherosclerosis.
Molecular Aspects and Natural Source of Procalcitonin
Authors: Russwurm Stefan , Wiederhold Matthias , Oberhoffer Mathias , Stonans Ilmars , Zipfel Peter F. , Reinhart Konrad
Published: October 2004

The search for sensitive and specific markers of systemic infection has shown that procalcitonin levels are increased in sepsis, and, consequently, this plasma protein has come into the focus of clinical research. Human procalcitonin is encoded by theCalc-Igene, which gives rise to two alternatively spliced transcripts. Despite systemic investigation of theCalc-Igene and mechanisms of the tissue-specific regulation and alternative splicing, little is known about the biology of procalcitonin and the cells which express this protein during inflammation. Here we focus on the molecular and biochemical properties of the molecule and summarize the known biological functions of procalcitonin. We report on the structure of theCalc-Igene, the amino acid conservation of procalcitonin in different species, and the consensus sequences of the protein with regard to sites relevant for posttranslational modification, spatial distribution, and homologies to other cytokines. We discuss aspects of intracellular location of procalcitonin and demonstrate that it has the characteristics of a secreted protein.
Rat Tissue Collagen Modified by Advanced Glycation: Correlation with Duration of Diabetes and Glycemic Control
Authors: Turk Zdenka , Mišur Irena , Turk Nikša , Benko Bojan
Published: October 2004

Collagenous proteins are especially prone to nonenzymatic glycation, because they contain several dibasic amino acid residues with free amino groups, have a very slow turnover rate, and are exposed to ambient levels of glucose. The aim of this study was to determine the time-dependent course of advanced glycation process in diabetic rats in relation to glycemic control and duration of diabetes, compared to age-matched controls. Immunochemical assay with antibodies to advanced glycation end products (AGE) was first developed to qualitatively detect and quantify the AGE formed in rat tendon and aortic collagen. Individual collagen samples were extracted by extensive pepsin and collagenase digestion. The amount of AGE was measured by competitive ELISA and results were expressed as AGE U/mg collagen. Diabetic rats showed a significant increase in AGE content in aortic collagen at 20 weeks (n=6, 206.6 ± 16.7 U/mg collagen) compared with that measured at 4 and 12 weeks (n=6, 110 ± 12.8 U/mg collagen, and n=13, 184.9 ± 12.3 U/mg collagen at 4 and 12 weeks, respectively; p < 0.001 between 20 weeks and 4 weeks; p < 0.01 between 20 weeks and 12 weeks). The amount of AGE in tendon collagen of diabetic rats increased from 1.9 ± 0.38 U/mg at 4 weeks to 11.2 ± 6.1 U/mg collagen at 20 weeks, p < 0.001. Considerable disparity was observed in the intensity of glycation between aortic and tendon collagen. AGE-content per mg of aortic collagen was several-fold to that found in tendon collagen (p < 0.001). To investigate the effect of glycemic control on the advanced glycation process, total aortic AGE-collagen content was compared between untreated diabetic rats (D; n=13, 184.9 ± 12.3 U/mg) and diabetic rats treated for 12 weeks with insulin (DI; n=6, 133.9 ± 10.7 U/mg), or phlorizin (DP; n=6, 132.4 ± 8.9 U/mg), or by a combination of insulin/phlorizin (DIP; n=6, 124.3 ± 6.5 U/mg). In spite of therapy used, all groups of diabetic animals had a significantly higher aortic AGE-collagen content than those in the nondiabetic control group (C: n=8, 104.6 ± 14.9 U/mg) of the same age (D, DI, DP, DIP vs. C, p < 0.001). Comparison between the mean levels of glycated hemoglobin (D: 5.62 ± 0.38 % vs.C: 1.7 ± 0.05 %) and mean AGE levels in the studied group of animals yielded a very good exponential correlation (r = 0.89, p < 0.001). Glycation-derived late-stage collagen modification was detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and by immunoblotting confirmed to contain (an) AGE-structure(s). Our study provides strong immunochemical evidence of AGE formation in vivo during hyperglycemia, and of their temporal association with structural alterations of extracellular matrix proteins. The advanced glycation process is retarded and reduced in intensity, but not completely abolished, by glycemia regulation with, or independently of, insulin.
Reference Values for a Homogeneous Ferritin Assay and Traceability to the 3rd International Recombinant Standard for Ferritin (NIBSC Code 94/572)
Authors: Lotz Johannes , Hafner Gerd , Prellwitz Winfried
Published: October 2004

Reference values for two ferritin assays (Tina-quant®a Ferritin, Enzymun®, both Roche Diagnostics, Mannheim, Germany) were established (136 males and 139 females). To rule out inflammation as well as iron deficiency in the reference population, subjects with the C-reactive protein concentration < 5 mg/l, and zinc protoporphyrin < 40 µmol/mol heme and the soluble transferrin receptor < 3 mg/l were selected. Taking into account latent iron deficiency as well as hereditary hemochromatosis the 5–95 percentile range was as follows: male, 27–365 μg/l; female, 13–148 μg/l for Tina-quant®a and 12–151 μg/l for Enzymun®. The Tinaquant® a Ferritin assay showed a very good correlation (r≧0.990) to Enzymun® ferritin, Ferritin Abbott® (Abbott Diagnostics, Delkenheim, Germany), N Latex Ferritin® (Dade Behring, Marburg, Germany) and the Ferritin Chiron® (Chiron Diagnostics, Fernwald, Germany). However, the slopes of the standard principal component method analysis were calculated to be between 1.03 (Enzymun®) and 1.41 (N Latex Ferritin®). For four assays the median recovery of the 3rd International Recombinant Ferritin Standard (NIBSC 94/572) measured by serial dilution was 89–109 %. The N Latex Ferritin® assay recovered half of the target values. Because of the good correlation with other assays, a matrix effect is likely. The question arises whether the manufacturers' agreement on the recombinant
Neural Networks for the Biochemical Prediction of Bone Mass Loss
Authors: Queraltó Josep M. , Torres Josep , Guinot Misericordia
Published: October 2004

Neural networks are specialized artificial intelligence techniques that have shown high efficiency in dealing with complex problems. Paradigms such as backpropagation have been successfully applied in a number of biomedical applications, but not in attempts to identify women at risk of postmenopausal osteoporotic complications. In this paper, several neural networks were trained using different combinations of biochemical variables as inputs. Bone densitometric measurements in Ward's triangle and in the spinal column were used as separate classification criteria (outputs) between slow and fast bone mass losers. The most parsimonious model with the best performance included plasma concentrations of estrone, estradiol, osteocalcin, parathyrin and urine concentrations of calcium and hydroxyproline (expressed as ratio to creatinine excretion) as input neurons; ten neurons in a single hidden layer; and one neuron in the output layer. Diagnostic efficiency was 76 % in Ward's triangle and 74 % in the spinal column; sensitivity was 70 and 81 %, and specificity was 77 and 65 %, respectively. Linear discriminant analysis showed a diagnostic efficiency of 66 % in Ward's triangle and 64 % in the spinal column, sensitivity was 55 and 86 %, and specificity was 75 and 13 %, respectively. We conclude that performance of the stepwise discriminant analysis was not superior to the neural networks.
Mitochondrial Disorders. A Diagnostic Challenge in Clinical Chemistry
Authors: Bauer Matthias F. , Gempel Klaus , Hofmann Sabine , Jaksch Michaela , Philbrook Christine , Gerbitz Klaus-Dieter
Published: October 2004

Mitochondria play a pivotal role in cellular metabolism and in energy production in particular. Defects in structure or function of mitochondria, mainly involving the oxidative phosphorylation (OXPHOS), mitochondrial biogenesis and other metabolic pathways, have been shown to be associated with a wide spectrum of clinical phenotypes. The ubiquitous nature of mitochondria and their unique genetic features contribute to the clinical, biochemical and genetic heterogeneity of mitochondrial diseases. We will focus on the recent advances in the field of mitochondrial disorders and their consequences for an advanced clinical and genetic diagnostics. In addition, an overview on recently identified genetic defects and their pathogenic molecular mechanisms will be given.
Enrichment of Mutant Alleles by Chromatographic Removal of Wild Type Alleles: a New Principle for the Detection of Alleles with Unknown Point Mutations at Excess of Wild Type Alleles
Authors: Nollau Peter , Fischer Carsten , Tschentscher Peter , Wagener Christoph
Published: October 2004

In human carcinomas, mutations that alter tumour genes such as the KRAS, P53, or APC genes, are mostly point mutations. The detection of mutant alleles of tumour genes in specimens such as urine, pancreatic juice, sputum, and stool holds great promise for an early diagnosis of cancer. In addition, the detection of mutant tumour genes in tissue samples, such as lymph nodes or resection margins, may allow a sensitive diagnosis of residual malignant disease. However, the reliable detection of mutant alleles in excess of wild type alleles remains an unresolved analytical problem when the mutations are not known a priori. In the present communication, a new approach is described which makes possible the detection of unknown point mutations in tumour genes at excess of wild type alleles. The method is based on the removal of wild type alleles by hybridisation to immobilised complementary oligonucleotides. Using this approach, an enrichment of mutant KRAS, P53 and APC alleles of one mutant in up to 103 normal alleles has been achieved. Parallel miniaturised separation units with oligonucleotides complementary to defined sequences of a wild type allele should allow the detection of unknown point mutations as well as small insertions or deletions which occur in the sequence range covered by the oligonucleotides.
Quantitative Differences between Aberrant Transcripts Which Occur as Common Isoforms and due to Mutation-based Exon Skipping of the Mismatch Repair Gene hMLH1
Authors: Plaschke Jens , Bulitta Clemens , Saeger Hans D. , Schackert Hans K.
Published: October 2004

About one-third of hereditary non-polyposis colorectal cancer-related mutations in the mismatch repair gene hMLH1 result in the loss of entire exons from the wild type transcripts. Here we describe quantitative differences of hMLH1 transcripts without exon 15, exon 16 or exon 17 in several members of a family with hereditary non-polyposis colorectal cancer. The transcript lacking exon 15 is caused by a G to A transition affecting the last nucleotide of the respective exon and results in a truncated protein. The transcripts lacking exon 16 or exon 17, which are in-frame deletions, were also found in all tested samples of a normal population and represent common isoforms. Reverse transcription-polymerase chain reaction-based relative quantification revealed about 50 % signal intensity for the mutation-based transcript, but less than 10 % for the common isoforms, if compared to the wild type. All aberrant transcripts were detected from blood-derived cDNAs but not from samples of normal colon epithelium. Although the biological significance of the common isoforms is unknown, they might lead to false risk assessment in hereditary non-polyposis colorectal cancer cases.
Analytical and Clinical Performance of Two Cardiac Troponin I Immunoassays
Authors: Zaman Zahur , De Spiegeleer Sandy , Gerits Mathieu , Blanckaert Norbert
Published: October 2004

Cardiac troponin I assays for Axsym (Abbott Diagnostics, Abbott Park, IL, USA) and Immuno 1 (Bayer Corporation, Tarrytown, NY, USA) analysers were evaluated. Heparin plasma or serum could be used for both assays. Samples were stable for 24 h at ambient temperature, 3 days at 4–8 ℃ and 3 months at −20 °C. After 10 months' storage at −80 °C, the recoveries were well above 100 % by both assays. Total coefficients of variation for Axsym assay were 9.0 %, 5.8 % and 5.3 % at concentrations of 2.6 μg/l, 9.83 μg/l and 34.3 μg/l respectively; for Immuno 1 these were 4.4 %, 1.6 % and 1.8 % at 2.3 μg/l,6.27 μg/l and 44.35 μg/l respectively. It was ≥ 20 % at concentration of ≤ 0.5 μg/l for Axysm assay and ≤ 0.15 μg/l for Immuno 1 assay. Recoveries were ≤ 90 % at ≤ 0.22 μg/l on Axsym and at ≤ 1.47 μg/l on Immuno 1. Neither method showed significant interference with haemoglobin, bilirubin, triglycerides or rheumatoid factor. Correlation between the two methods was excellent (r = 0.997, Y (Axsym) = 4.2X (Immuno 1) + 3.2). The highest concentrations detected in 50 healthy subjects were 0.3 μg/l and 0.1 μg/l by Axsym and Immuno 1 methods, respectively. Twelve out of 43 renal failure patients had troponin I 0.13–0.9 μg/l using Axsym method and 4 had levels of 0.07–0.13 μg/l using Immuno 1. In muscle trauma patients, troponin I was undetectable.
Development of an Automated Immunoturbidimetric Ferritin Assay
Authors: Borque Luis , Rus Antonio , Bellod Laura , Seco Ma Luisa
Published: October 2004

We have developed a new procedure for turbidimetric measurement of ferritin concentration in human serum, based on latex microparticle agglutination technology. The procedure has been automated using the Falcor 300 analyzer. Carboxilated latex particles (336 nm in diameter) were covalently coupled with immunopurified F(ab′)2 fragments of anti-ferritin IgG antibodies. Coated microparticles were automatically mixed with undiluted sample and the resulting absorbance due to agglutination was measured at 550 nm. The procedure generated a calibration curve with a measuring range of 0 to 558 μg/l, showing a day-today imprecision lower than 5.7 %. The detection limit was 4 μg/l. There were no interferences from bilirubin, hemoglobin or rheumatoid factors. Turbid and lipemic samples caused an important interference which could be avoided by pretreating those samples prior to measurement. A prozone effect was provisionally obtained with ferritin concentrations over 1800 μg/l. The results suggested a hook-like effect due to a rapid microparticle precipitation in the reaction media, that could be avoided by increasing the reaction medium density by adding sucrose to the buffer, up to 150 g/l concentration. This sucrose addition resulted in a displacement of the Heidelberger curve with a prozone phenomenon occuring at concentration higher than 3000 μg/l of ferritin. Results obtained with the present procedure correlated well with those obtained by a nephelometric procedure and with those obtained by an RIA. We conclude that this latex turbidimetric immunochemical procedure is simple, rapid, has a good analytical and operational performance on the Falcor 300 analyzer and is well suited for the measurement of ferritin concentration in human serum.
Does the Uncertainty of Commonly Performed Glucose Measurements Allow Identification of Individuals at High Risk for Diabetes?
Authors: Kallner Anders , Waldenström Johan
Published: October 2004

Revised recommendations for diagnosis of diabetes introduce the intermediary risk group of impaired fasting glucose (IFG), defined as individuals with a fasting blood-glucose concentration between 5.6 and 6.0 mmol/l. We apply the concept of uncertainty to identifiable steps of sampling and measuring blood-glucose. Since many instruments in primary health care measure plasma-glucose and report results as blood-glucose and vice versa, factors affecting the transformation are also considered. The study identifies the measurement procedure as the major source of uncertainty, closely followed by preanalytical sources. The estimated uncertainties indicate that the presently available procedures do not allow identification of IFG by a single investigation. The approach to establish an uncertainty budget can be used to evaluate the clinical usefulness of measurements.
Autoantibodies against Oxidized LDL in the First Phase of Life
Authors: Steinerová Alexandra , Racek Jaroslav , Stožický František , Tatzber Franz , Lapin Alexander
Published: October 2004

The study presents a comparison of data concerning lipid metabolism and lipid oxidation (oxidative stress) in children at the time of their birth and 3 months later, as well as of their mothers at the time of delivery, compared to a control group of non-pregnant women of the same age. The data confirm that labour represents an oxidative stress for both mother and child; it is expressed as a significant increase of malondialdehyde concentration in mothers immediately after delivery in comparison with non-pregnant women (p < 0.001). Its concentration in newborns was even higher than in their mothers (p < 0.005). Concentration of antibodies against oxidized LDL (oxLDLAb) was comparable in mothers and newborns due to their transplacental transport. During the first three months of life these autoantibodies increased almost two-fold. The importance of this unique observation is discussed with respect to possible early atherogenesis.