bluuebunny/crossref_metadata_2025 huggingface dataset:
Myosin superfamily evolutionary history
Authors: Thompson Reid F. , Langford George M.
Published: October 2002

The superfamily of myosin proteins found in eukaryotic cells is known to contain at least 18 different classes. Members are classified based on the phylogenetic analysis of the head domains located at the amino terminus of the polypeptide. While phylogenetic relationships provide insights into the functional relatedness of myosins within and between families, the evolutionary history of the myosin superfamily is not revealed by such studies. In order to establish the evolutionary history of the superfamily, we analyzed the representation of myosin gene families in a range of organisms covering the taxonomic spectrum. The amino acid sequences of 232 myosin heavy chains, as well as 65 organisms representing the protist, plant, and animal kingdoms, were included in this study. A phylogenetic tree of organisms was constructed based on several complementary taxonomic classification schemes. The results of the analysis support an evolutionary hypothesis in which myosins II and I evolved the earliest of all the myosin groups. Myosins V and XI evolved from a common myosin II‐like ancestor, but the two families diverged to either the plant (XI) or animal (V) lineage. Class VII myosin appeared fourth among the families, and classes VI and IX appeared later during the early period of metazoan radiation. Myosins III, XV, and XVIII appeared after this group, and X appeared during the formative phases of vertebrate evolution. The remaining members of the myosin superfamily (IV, VI, XII, XIII, XIV, XVI, and XVII) are limited in distribution to one or more groups of organisms. The evolutionary data permits one to predict the likelihood that myosin genes absent from a given species are either missing (not found yet because of insufficient data) or lost due to a mutation that removed the gene from an organism's lineage. In conclusion, an analysis of the evolutionary history of the myosin superfamily suggests that early‐appearing myosin families function as generalists, carrying out a number of functions in a variety of cell types, while more recently evolved myosin families function as specialists and are limited to a few organisms or a few cell types within organisms. Anat Rec 268:276–289, 2002. © 2002 Wiley‐Liss, Inc.
Prevalence and clinical significance of lymphocytic foci in minor salivary glands of healthy volunteers
Authors: Radfar Lida , Kleiner David E. , Fox Philip C. , Pillemer Stanley R.
Published: October 2002

Objective

To determine the prevalence and severity of focal lymphocytic sialadenitis in minor salivary glands of healthy, asymptomatic individuals, in whom Sjögren's syndrome (SS) has been excluded.

Methods

Charts of 54 healthy volunteers who had salivary gland biopsies at the National Institutes of Health from January 1992 to August 1998 were reviewed. The healthy volunteers served as control subjects in various studies of salivary dysfunction. Significant medical conditions including SS were excluded. A biopsy with a focus score (FS) >1 was regarded as positive. Descriptive statistics were used to summarize the population's characteristics.

Results

The frequency of focal lymphocytic infiltration in the healthy volunteers was about 15% (8 of 54). None of these individuals had subjective xerostomia or dry eyes. The positive FS ranged from 2 to 6. FS did not correlate with age, smoking, serologic findings, or salivary flow in these patients.

Conclusion

Lymphocytic infiltration in minor salivary glands is not uncommon among individuals without a history of salivary gland dysfunction. This finding is in agreement with the result of a previous autopsy survey study, indicating that focal sialadenitis may occur in the absence of SS.
Comprehensive allelotyping of well‐differentiated human hepatocellular carcinoma with semiquantitative determination of chromosomal gain or loss
Authors: Nishimura Takafumi , Nishida Naoshi , Itoh Teruaki , Kuno Masato , Minata Mutsuko , Komeda Toshiki , Fukuda Yoshihiro , Ikai Iwao , Yamaoka Yoshio , Nakao Kazuwa
Published: October 2002

Allelic imbalance (AI), which represents certain chromosomal gains or losses, has been described in human hepatocellular carcinoma (HCC), but the impact of AI on the early stage of hepatocarcinogenesis has not been fully clarified. Moreover, no previous allelotype studies have identified the difference in chromosomal gain and loss that results in AI. To resolve these problems, we examined 18 well‐differentiated HCCs with comprehensive allelotyping by using 400 microsatellite markers with semiquantitative assessment of chromosomal gain or loss. To detect allelic gain effectively, the cutoff value of the allelic imbalance index was set at 0.70. Each allele showing imbalance was subjected to multiplex PCR with use of a retained allele as an internal control to determine whether the imbalance was the result of chromosomal gain or loss. High frequencies of chromosomal gains were detected at 1q (D1S196‐D1S2785, 56%), 5q (D5S647‐D5S2027, 44%), 6p (6pter‐D6S309, 33%), 7 (7pter‐D7S657, 22%), and 8q (D8S514‐qter, 44%), whereas chromosomal losses were frequently observed at 1p (1pter‐D1S234, 22%), 8p (8pter‐D8S549, 44%), and 17p (17pter‐D17S921, 28%). The extent of overall chromosomal aberration was closely related to the maximum tumor diameter (P = 0.002) and the presence of hepatitis B surface antigen (P = 0.03). Recurrent chromosomal losses at 1p and 8p and gains at 1q and 8q, even in HCCs with a minimal extent of aberrant chromosomes, indicate that these alterations were critical in the early stage of hepatocarcinogenesis. On the other hand, deletions of 13q and 16q were infrequent and were seen only in the most aberrant cases, which suggested that these were late events. © 2002 Wiley‐Liss, Inc.
Test‐retest reliability, validity, and sensitivity to change of the urogenital distress inventory and the incontinence impact questionnaire
Authors: Hagen Suzanne , Hanley Janet , Capewell Ann
Published: October 2002

Aims.

To evaluate two quality of life measures for urinary incontinence (UI) in Scottish females.

Methods.

Three groups with UI from two regions in Scotland were studied. Two groups were receiving treatment for incontinence; the third was not. Women completed the UDI and IIQ twice to allow assessment of test‐retest reliability and validity. Treatment groups completed the questionnaires again, postintervention, to assess ability of the measures to detect change. Other measures used to assess validity were the SF‐36, HADS, weight of urine leaked, and number of incontinence episodes. By design, the three subject groups differed significantly in their characteristics, ensuring a diverse sample of women.

Results.

Analysis of reliability showed a clinically trivial but statistically significant decrease in total UDI (mean, −6.1; 95% CI, −11.0 to −1.5) and IIQ (mean, −9.7; 95% CI, −15.5 to −3.9) scores between test and retest assessments, possibly due to a research effect. Most items of the UDI (18 of 19) and IIQ (28 of 30) performed very well on test‐retest. The UDI and IIQ were valid in that higher scores (indicating more bothersomeness of symptoms/impact on daily living) were associated with greater severity of UI. Additionally the IIQ showed the expected associations with measures of anxiety and health status.

Conclusions.

Both the UDI and IIQ detected changes in women's conditions due to intervention. The measures had good psychometric properties, including test‐retest reliability, across subject groups. Neurourol. Urodynam. 21:534–539, 2002. © 2002 Wiley‐Liss, Inc.
Unique biochemical and behavioral alterations in drosophilashibirets1 mutants imply a conformational state affecting dynamin subcellular distribution and synaptic vesicle cycling
Authors: Chen Mai‐Lei , Green David , Liu Lei , Lam Yung Carmen , Mukai Leona , Rao Sujata , Ramagiri Shobha , Krishnan K. S. , Engel Jeff E. , Lin Jim J.‐C. , Wu Chun‐Fang
Published: October 2002

ABSTRACT

Dynamin is a GTPase protein that is essential for clathrin‐mediated endocytosis of synaptic vesicle membranes. The Drosophila dynamin mutation shits1 changes a single residue (G273D) at the boundary of the GTPase domain. In cell fractionation of homogenized fly heads without monovalent cations, all dynamin was in pellet fractions and was minimally susceptible to Triton‐X extraction. Addition of Na+ or K+ can extract dynamin to the cytosolic (supernatant) fraction. The shits1 mutation reduced the sensitivity of dynamin to salt extraction compared with other temperature‐sensitive alleles or wild type. Sensitivity to salt extraction in shits1 was enhanced by GTP and nonhydrolyzable GTP‐γS. The shits1 mutation may therefore induce a conformational change, involving the GTP binding site, that affects dynamin aggregation. Temperature‐sensitive shibire mutations are known to arrest endocytosis at restrictive temperatures, with concomitant accumulation of presynaptic collared pits. Consistent with an effect upon dynamin aggregation, intact shits1 flies recovered much more slowly from heat‐induced paralysis than did other temperature‐sensitive shibire mutants. Moreover, a genetic mutation that lowers GTP abundance (awdmsf15), which reduces the paralytic temperature threshold of other temperature‐sensitive shibire mutations that lie closer to consensus GTPase motifs, did not reduce the paralytic threshold of shits1. Taken together, the results may link the GTPase domain to conformational shifts that influence aggregation in vitro and endocytosis in vivo, and provide an unexpected point of entry to link the biophysical properties of dynamin to physiological processes at synapses. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 319–329, 2002
Structural, kinetic and cytotoxicity aspects of 12–28 β‐amyloid protein fragment: a reappraisal
Authors: Rabanal Francesc , Tusell Josep M. , Sastre Lluis , Quintero M. Rosa , Cruz Montse , Grillo Dolors , Pons Miquel , Albericio Fernando , Serratosa Joan , Giralt Ernest
Published: October 2002

A chemical, structural and biological study on the β‐amyloid peptide β12–28 is reported which was carried out in order to assess the feasibility using this peptide fragment as a model of the natural β‐amyloid protein. The aggregation properties of β12–28 have been investigated by pulse field‐gradient NMR spectroscopy, Fourier transform infrared spectroscopy and transmission electron microscopy. The results obtained suggest that β12–28 behaviour is comparable to that of the natural β‐amyloid protein although kinetically slower. Translational diffusion coefficients obtained by NMR on an aged β12–28 solution suggest that the soluble peptide fraction is composed of oligomeric intermediates adopting an extended ellipsoidal assembly rather than a spherical one. The β12–28 peptide proved to be cytotoxic in PC12 cell cultures as monitored by the MTT assay, although a lack of reproducibility was observed in the dose‐response experiments. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd.
Longitudinal study of delayed reproductive success in a pair of white‐cheeked gibbons (Hylobates leucogenys)
Authors: Lukas Kristen E. , Barkauskas Rima T. , Maher Samantha A. , Jacobs Bonnie A. , Bauman Joan E. , Henderson Andrew J. , Calcagno James M.
Published: October 2002

Concern over a lack of breeding success in a pair of white‐cheeked gibbons (Hylobates leucogenys) prompted a four‐part study of gibbon behavior and physiology at the Lincoln Park Zoo. Data were collected to determine the female intermenstrual interval (IMI) and identify periods of peak receptivity. Subsequent behavioral data were gathered during both female menses and estrous periods to formulate a behavioral profile for each gibbon. The female experienced a species‐typical IMI of 21.6 days and exhibited heightened levels of behavioral receptivity toward the male during estrus. The male exhibited high levels of human‐directed behavior throughout the day. Closing the exhibit to visitors did not result in higher levels of social proximity or prosocial behavior between the pair, although it did eliminate the male's human‐directed behavior during the experimental condition only. The female exhibited higher levels of social grooming, solicitation of the male, and proximity to the male when the pair was locked indoors. Based on those findings, the pair was moved to an exclusively indoor exhibit. The female's visibility to the public decreased substantially in the alternate exhibit, but there were no other significant behavioral changes. Nearly one year after the exhibit change, the female gibbon was confirmed to be pregnant. Although the results of this study cannot be used to infer causal conditions that resulted in the pregnancy, they do support the notion that systematic documentation of animal behavior and physiology may be used as a tool for monitoring reproductive behavior and informing management decisions. Zoo Biol 21:413–434, 2002. © 2002 Wiley‐Liss, Inc.
The European Federation of Psychiatric Trainees (EFPT) - an integral part of the European harmonisation of psychiatric education and practise
Authors: Schulze Thomas G. , Treichel Kai C.
Published: October 2002

The European Federation of Psychiatric Trainees (EFPT) is the umbrella organisation for national European psychiatric trainees’ organisations. It primarily aims at advancing and harmonising the quality of psychiatric education and practise. As a permanent observer member of the European Board of Psychiatry and the European Board of Child and Adolescent Psychiatry, the EFPT actively participates both in the development of educational guidelines and in the evaluation of psychiatric training institutions in Europe. Through its annually held European Forum for all Psychiatric Trainees the EFPT provides a unique opportunity for the exchange of training-related experiences and opinions on current developments in psychiatry. This is the first comprehensive overview of the history, goals, and political work of the EFPT, depicting its evolution from an informal meeting of psychiatric trainees to a recognised organisation representing over 10 000 young psychiatrists throughout Europe.
Staphylococcus sciuri
Gene
erm
(33), Encoding Inducible Resistance to Macrolides, Lincosamides, and Streptogramin B Antibiotics, Is a Product of Recombination between
erm
(C) and
erm
(A)
Authors: Schwarz Stefan , Kehrenberg Corinna , Ojo Kayode K.
Published: October 2002

A gene which mediates inducible resistance to macrolides, lincosamides, and streptogramin B antibiotics, designated
erm
(33), was detected on the
Staphylococcus sciuri
plasmid pSCFS1. Analysis of the
erm
(33) reading frame suggested that this gene was the product of a recombination between an
erm
(C) gene and an
erm
(A) gene. Such a recombination event is a novel observation for
erm
genes.
Turbulent plumes of heat, moist heat, and carbon dioxide elicit upwind anemotaxis in tsetse fliesGlossina morsitans morsitansWestwood (Diptera: Glossinidae)
Authors: Evans W G , Gooding R H
Published: October 2002

The roles and interactions of turbulent plumes of heat, moist heat, and carbon dioxide in mediating upwind flight of adult tsetse flies (Glossina morsitans morsitans Westwood) were investigated using a wind tunnel in a constant-environment chamber. Heat fluctuations in the plume that were detected by a thermocouple and displayed as oscilloscope traces allowed direct visualization of the structures of the plumes. Significantly more flies flew upwind when exposed to plumes of (i) carbon dioxide (0.0051% above background) and air (58% relative humidity) compared with air alone; (ii) carbon dioxide and heated air (35% relative humidity and temperature fluctuating up to 0.09°C above background) compared with carbon dioxide and air; and (iii) carbon dioxide and moist (82% relative humidity) heated air (temperature fluctuating up to 0.05°C above background) compared with carbon dioxide and heated air. However, there were no significant differences in upwind flight of flies exposed to plumes of (i) air compared with humidified air (65% relative humidity); (ii) carbon dioxide and heated air compared with heated air alone; and (iii) carbon dioxide and moist heated air compared with moist heated air alone. Recorded temperature fluctuations in heat plumes transported downwind from a tethered steer in a pasture showed patterns similar to those produced in the wind-tunnel plumes. These results suggest that host emissions of carbon dioxide alone and combined heat and moisture carried downwind by low-velocity winds elicit upwind anemotaxis in tsetse flies, which distinguish these emissions from a background of lower atmospheric levels.
ON COMPUTATIONAL COMPLEXITY OF HIERARCHICAL OPTIMIZATION
Authors: JIA WEIJIA , SUN ZHIBIN
Published: October 2002

In this work, the computational complexity of a hierarchic optimization problem involving in several players is studied. Each player is assigned with a linear objective function. The set of variables is partitioned such that each subset corresponds to one player as its decision variables. All the players jointly make a decision on the values of these variables such that a set of linear constraints should be satisfied. One special player, called the leader, makes decision on its decision variables before of all the other players. The rest, after learnt of the decision of the leader, make their choices so that their decisions form a Nash Equilibrium for them, breaking tie by maximizing the objective function of player. We show that the exact complexity of the problem is FPNP-complete.
A FORMULA-DRIVEN MODULAR ATTACK ON STATE EXPLOSION
Authors: De Francesco Nicoletta , Santone Antonella
Published: October 2002

A common characteristic of the new distributed systems is the increasing complexity. Useful paradigms to cope with the complexity of systems are modularity and compositionality. In this paper we define a compositional method to attack the state explosion problem in model checking. The method, given a formula to be checked on a system composed of a set of parallel processes, allows syntactically reducing in a modular way the processes, in order to reduce the state space of their composition. The reduction is formula driven and is based on a notion of equivalence between processes, which is a congruence w.r.t. the parallel composition operator.
ISOBAR COMPONENTS AND MIRROR SYMMETRY BREAKING IN NUCLEI
Authors: BAKER T. , LASIUK B. , RANGACHARYULU C.
Published: October 2002

The possible role of isobar degrees of freedom in nuclear structure accounting for departures from the symmetry properties of mirror nuclei is investigated. Specifically for [Formula: see text] conjugate pairs, we evaluate the corresponding mirror Gamow-Teller beta decays. In a simple model description, admixtures of isobar components at the few percent level can accommodate the experimentally observed asymmetries in mirror pairs of masses A=13 and 17.
THEORETICAL HEAD SPIN ASSIGNMENTS OF YRAST BANDS FOR THREE ODD-ODD NUCLEI IN A = 160 REGION
Authors: ZHENG RENRONG , ZHU SHUNQUAN
Published: October 2002

The theoretical head spin assignments for Yrast bands of three odd-odd nuclei are predicted by using quasiparticles plus rotor model (QPRM) which have been shown to be successful in our previous calculations. The results indicate that the head spin I 0=8 is the best value of Yrast bands for both nuclei 156 Tb and 166 Lu while I 0=7 is the best spin for 158 Ho nucleus.
EXCLUSIVE AND INCLUSIVE ANTI-NEUTRINO REACTIONS IN 3He
Authors: MINTZ S. L. , GERSTNER G. M. , BARNETT M. A. , POURKAVIANI M.
Published: October 2002

Cross sections for the exclusive reactions, [Formula: see text], and [Formula: see text] are obtained from threshold to 1 GeV. We find the contributions of the individual form factors as well as all interference terms to the cross sections of both of these reactions. We find that the cross sections for these processes are relatively large making them possible candidates for experiments. We also obtain differential cross sections for suitable energies for these reactions and note the presence of sharp minima which might be observable with a well peaked neutrino flux. We also estimate the cross sections for the inclusive reactions [Formula: see text] and [Formula: see text] from threshold to a few hundred MeV.
PHASE-SHIFT ANALYSIS AND FIRST-ORDER EIKONAL CORRECTION TO OPTICAL POTENTIAL BY INVERSION FOR 16O+28SI ELASTIC SCATTERING AT Elab=1503 MEV
Authors: KIM YONG JOO , CHA MOON HOE
Published: October 2002

We analyze 16 O +28 Si elastic scattering at E lab =1503 MeV using a phase shift analysis based on McIntyre parametrization of S-matrix. The near- and far-side decompositions of elastic cross section have been also performed by following Fuller's formalism. By using the inversion procedure of McIntyre S-matrix, the optical potential is obtained and its result was compared with one of the optical model analysis. The first-order eikonal correction effect on the optical potential by inversion is discussed.
Identification of primary structural features that define the differential actions of IL-3 and GM-CSF receptors
Authors: Evans Caroline A. , Ariffin Shahrul , Pierce Andrew , Whetton Anthony D.
Published: October 2002

Activation of human interleukin 3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) receptors, ectopically expressed in FDCP-mix multipotent cells, stimulates self-renewal or myeloid differentiation, respectively. These receptors are composed of unique α subunits that interact with common βc subunits. A chimeric receptor (hGM/βc), comprising the extracellular domain of the hGM-CSF receptor α subunit (hGM Rα) fused to the intracellular domain of hβc, was generated to determine whether hβc activation is alone sufficient to promote differentiation. hGM-CSF activation of hGM/βc, expressed in the presence and absence of the hβc subunit, promoted maintenance of primitive phenotype. This indicates that the cytosolic domain of the hGM Rα chain is required for differentiation mediated by activation of the hGM Rα, βc receptor complex. We have previously demonstrated that the α cytosolic domain confers signal specificity for IL-3 and GM-CSF receptors. Bioinformatic analysis of the IL-3 Rα and GM Rα subunits identified a tripeptide sequence, adjacent to the conserved proline-rich domain, which was potentially a key difference between them. Cross-exchange of the equivalent tripeptides between the α subunits altered receptor function compared to the wild-type receptors. Both the mutant and the corresponding wild-type receptors promoted survival and proliferation in the short-term but had distinct effects on developmental outcome. The mutated hGM Rα promoted long-term proliferation and maintenance of primitive cell morphology, whereas cytokine activation of the corresponding hIL-3 Rα mutant promoted myeloid differentiation. We have thus identified a region of the α cytosolic domain that is of critical importance for defining receptor specificity.
Melatonin: reducing the toxicity and increasing the efficacy of drugs
Authors: Reiter Russel J , Tan Dun-xian , Sainz Rosa M , Mayo Juan C , Lopez-Burillo Silvia
Published: October 2002

Melatonin (N-acetyl-5-methoxytryptamine) is a molecule with a very wide phylogenetic distribution from plants to man. In vertebrates, melatonin was initially thought to be exclusively of pineal origin; recent studies have shown, however, that melatonin synthesis may occur in a variety of cells and organs. The concentration of melatonin within body fluids and subcellular compartments varies widely, with blood levels of the indole being lower than those at many other sites. Thus, when defining what constitutes a physiological level of melatonin, it must be defined relative to a specific compartment. Melatonin has been shown to have a variety of functions, and research in the last decade has proven the indole to be both a direct free radical scavenger and indirect antioxidant. Because of these actions, and possibly others that remain to be defined, melatonin has been shown to reduce the toxicity and increase the efficacy of a large number of drugs whose side effects are well documented. Herein, we summarize the beneficial effects of melatonin when combined with the following drugs: doxorubicin, cisplatin, epirubicin, cytarabine, bleomycin, gentamicin, ciclosporin, indometacin, acetylsalicylic acid, ranitidine, omeprazole, isoniazid, iron and erythropoietin, pheno-barbital, carbamazepine, haloperidol, caposide-50, morphine, cyclophosphamide and l-cysteine. While the majority of these studies were conducted using animals, a number of the investigations also used man. Considering the low toxicity of melatonin and its ability to reduce the side effects and increase the efficacy of these drugs, its use as a combination therapy with these agents seems important and worthy of pursuit.
Endothelium-dependent vasorelaxation induced by L-carnitine in isolated aorta from normotensive and hypertensive rats
Authors: Herrera María Dolores , Bueno Rosario , de Sotomayor María Alvarez , Pérez-Guerrero Concepción , Vázquez Carmen M , Marhuenda Elisa
Published: October 2002

The aim of this work was to investigate the mechanism of the vasodilatory effect induced by L-carnitine. Relaxation produced by L-carnitine was studied in rat aortic rings with and without functional endothelium, pre-contracted with phenylephrine by adding cumulative doses of L-carnitine (10−7 to 10−3 M). The relaxation evoked by L-carnitine reached higher values in aortic rings from spontaneously hypertensive rats than those obtained in arteries from normotensive rats; no relaxation was produced in de-endothelialized arteries. However, in the presence of NG-nitro-L-arginine (3 × 10−5 M, a nitric oxide synthase inhibitor), Ro 68070 (10−4 M, a thromboxane synthetase inhibitor-thromboxane A2/prostaglandin H2 receptor antagonist) or ICI 192605 (10−5 M, a thromboxane A2 receptor antagonist) the relaxant response to L-carnitine was significantly inhibited. These results show that L-carnitine induced endothelium-dependent relaxation in the rat aorta and the mechanism of this relaxation appeared to be mostly mediated by endothelial production of nitric oxide but also could involve prevention of the action of cyclooxygenase endothelial products acting on the thromboxane A2/prostaglandin H2 receptor.
Fluorophotometric Determination of an Equilibrium Constant for the Formation of a Molecular Complex between Fluoranthene and Benzene in Solution
Authors: Enomoto Shigendo , Kumagai Ken-ichi , Hasegawa Miki , Kobayashi Michio , Hoshi Toshihiko
Published: October 2002

A fluorophotometric method was used to obtain equilibrium constants for the formation of a van der Waals molecular complex between fluoranthene and benzene in the ground state. The equilibrium constant for the above-mentioned complex formation is estimated to be 0.13 dm3 mol−1, which compares well with that (K = 0.15 dm3 mol−1) obtained from a traditional electronic absorption method.
Kinetics of the Oxidation of Heterocyclic Aldehydes by Quinolinium Dichromate
Authors: Chaubey Girija Shankar , Das Simi , Mahanti Mahendra Kumar
Published: October 2002

Quinolinium dichromate in sulfuric acid oxidizes heterocyclic aldehydes (2-furaldehyde, 2-pyrrolecarbaldehyde, 2-thiophenecarbaldehyde) to the corresponding acids in a 50% (v/v) acetic acid–water medium. The kinetic data on the rates of oxidation of the substrates have been discussed with reference to the aldehyde hydration equilibria. The kinetic results support a mechanistic pathway proceeding via a rate-determining oxidative decomposition of the chromate ester of the aldehyde hydrate.
Frontline ® immunochromatographic device for on-site urine testing of amphetamines: laboratory validation using authentic specimens
Authors: Beck O , Kraft M , Moeller M R , Smith B L , Schneider S , Wennig R
Published: October 2002

We evaluated a new test device for amphetamines and methamphetamines (Frontline ®, cut-off limit 300 ng/mL) using authentic clinical and forensic specimens. The device is based on immunochromatography and is dipped into urine and read visually by comparison with a colour scale after a few minutes. A total of 658 specimens were tested by comparing results of the screening procedure with established immunoassays. Discordant results were further investigated by gas chromatography- mass spectrometry or gas chromatography (with flame ionization detector). The Frontline device had a sensitivity of 93% and a specificity of 98%. When specimens were classified by urine amphetamine concentration, close agreement was obtained at concentrations below 150 ng/mL and above 1000 ng/mL. A small number of specimens with amphetamine concentrations between 300 and 1000 ng/mL tested negative in the Frontline test. This finding could to some extent be explained by the enantioselectivity of the antibodies in the Frontline test to d-amphetamine. We conclude that the performance of the Frontline test device for amphetamines is adequate for presumptive clinical and forensic screening.
Thyroid function tests: often justified in the acutely ill
Authors: Lamb E J , Martin J
Published: October 2002

It is claimed that inappropriate requesting of thyroid function tests (TFTs) is common in acutely ill patients. Consecutive inpatient TFTs ( n=129) were assessed in relation to clinical history and common symptoms and signs of thyroid disease. Requests were justified in 69% of cases, most commonly on the basis of atrial fibrillation and/or tachycardia. There were no clear reasons for requesting TFTs in the remaining cases, although the yield of abnormal results in these patients was similar to that in those with justified requests. Thyroid stimulating hormone (TSH) concentration was increased (median 7·5 mU/L, range 4·8-38·6 mU/L) in 22 patients, six of whom had biochemical and/or clinical evidence of hypothyroidism (previously undiagnosed) and five of whom had pre-existing hypothyroidism. Of the remaining 11 patients with increased TSH levels, three were confirmed to have compensated hypothyroidism; non-thyroidal illness (NTI) (including the effect of drugs) accounted for four cases. In four patients (one of whom died during the admission) follow-up was not possible. Of six patients with reduced TSH concentration (range < 0·05-0·35 mU/L), one was thyrotoxic on carbimazole, one was receiving thyroxine for hypothyroidism, one had NTI and three were lost to follow-up (two of whom died during their admission). Manifestations of thyroid disease are protean and often subtle, and TFTs are thus clinically justified in many unwell inpatients. Although NTI contributes to some cases of abnormal TSH levels, a significant number of TFT abnormalities are consistent with underlying thyroid abnormality requiring investigation/treatment.
Radioimmunoassay for the measurement of thrombospondin in plasma and breast cyst fluid: validation and clinical application
Authors: Ayden Katharine H , Tetlow Lesley , Byrne Ged , Bundred Nigel
Published: October 2002

Thrombospondin is an adhesive protein that has been implicated in malignancy, specifically in tumour progression and angiogenesis. We developed a radioimmunoassay for the measurement of thrombospondin in plasma and breast cyst fluid. The assay exhibited high accuracy, with recoveries of 102-136% and acceptable imprecision, with an intra-assay coefficient of variation (CV) of < 7·5% across the analytical range 30-1000 ng/mL and inter-assay CV of 4·4% and 7·7% at 152 and 224 ng/mL, respectively. Thrombospondin measured in the breast cyst fluid of patients with gross cystic disease of the breast showed that patients with type II (Na+) cysts had significantly higher concentrations than type I (K+) cysts. The plasma thrombospondin reference range was determined as 131-274 ng/mL. Patients with breast cancer had significantly higher plasma thrombospondin concentrations than normal individuals or patients with benign breast disease. Plasma thrombospondin was higher in breast cancer patients with lymph node involvement.
Assessment of iron status in cystic fibrosis patients
Authors: Keevil B , Rowlands D , Burton I , Webb A K
Published: October 2002

We investigated the use of soluble transferrin receptor (sTfR), together with more traditional measurements such as iron, transferrin and ferritin, to assess iron status in 70 adult cystic fibrosis patients. sTfR concentration was measured using particle-enhanced immunonephelometry. We found that 69% of subjects as determined by transferrin saturation had iron deficiency, but only 29% as determined by sTfR and 11% as determined by ferritin. We found a significant correlation between C-reactive protein (CRP) and both ferritin ( r=0·38, P=0·0001) and transferrin saturation ( r = -0·54, P<0·0001). In addition, because the CRP concentration was elevated in 64% of subjects, we feel that the transferrin saturation was overestimating, and the ferritin underestimating, iron deficiency in these patients. The sTfR concentration, on the other hand, is unaffected by the acutephase response and was therefore thought to be the most useful test for detecting iron deficiency in this group of patients.
Direct polymerase chain reaction from whole blood without DNA isolation
Authors: Nishimura Naoyuki , Nakayama Tomoko , Tonoike Hiroshi , Kojima Kouichi , Kato Shingo
Published: October 2002

Blood and other animal fluids contain a variety of substances that inhibit the polymerase chain reaction (PCR), so that isolation of DNA is generally necessary prior to PCR. We have developed a novel reagent cocktail that effectively suppresses these inhibitory substances and makes DNA isolation from blood unnecessary for PCR. When this reagent was included in the PCR mixture, DNA fragments of the-globin gene could be efficiently amplified directly from human blood samples treated with various anticoagulants or PCR-inhibitory substances. We confirmed the usefulness of this cocktail by examining a large number of blood samples with various PCR primer sets. In addition to fresh blood, this method enabled PCR amplification from blood samples stored at 4 C, -20 C or -80 C for a minimum of 1 year.
Moderately low vitamin B12 does not compromise transmethylation in adults on a free diet: implications for assessment of vitamin B12 status
Authors: Patel N , Briddon A
Published: October 2002

Lower reference limits for vitamin B12 are often defined solely in relation to haematological criteria. This may be misleading and there is evidence indicating that biochemical anomalies should also be considered. In 50 patients we measured creatine, as the major product of B12-mediated remethylation, to see if this helps the definition of the B12 reference interval and to investigate the possible effect of low B12 on essential transmethylation. Vitamin B12 values were grouped into six fractiles covering the range 50-500 ng/L; the corresponding creatine results were assessed by analysis of variance giving F=0·94 and a significance of 0·466. Although no correlation between B12 and creatine was found, and therefore no obvious effect on transmethylation of low B12 concentration, this must be interpreted with respect to methionine availability. Other factors indicate that biochemical perturbations should be taken into account when defining vitamin B12 reference intervals.
Differences in circulating concentrations of total, free and bound leptin relate to gender and body composition in adult humans
Authors: McConway M G , Johnson D , Kelly A , Griffin D , Smith J , Wallace A M
Published: October 2002

We describe a radioimmunoassay (RIA) for total leptin and a gel filtration procedure for the separation of free and bound leptin in human serum. The RIA, based on a locally prepared antibody, has a minimum detection limit of 0·9 ng/mL, a working range (CV< 10%) of 2·5-50 ng/mL, inter-assay precision of 10·2, 7·2 and 8·9%CV at 7·9, 15·4 and 30·0 ng/mL, respectively, 94% recovery of exogenous leptin (range 81·1-120·6%), exhibited parallelism and demonstrated no significant cross-reactivity or interferences. A difference plot of results from this method and those from a commercially available kit (Linco Research) demonstrated satisfactory agreement up to concentrations of 50 ng/mL total leptin, with no significant bias. A gender-dependent correlation was obtained between body mass index (BMI) and total leptin ( r=0·91, P<0·001, n=75 for men; r=0·79, P<0·001, n=72 for women), with women having higher leptin concentrations than men for any given BMI. Gel filtration studies (inter-assay precision: 4·7%CV, n=18) demonstrated that a variable fraction (between 10% and 40%) of total leptin in serum was bound with high affinity ( Keq=1·0-1·45x109 L/mol) to a non-albumin, non-lipid macromolecule. Binding affinities were found to be similar irrespective of gender or fat mass. A significant positive correlation between free or bound leptin concentrations and BMI was obtained for both men and women ( r=0·87-0·94); free and bound leptin concentrations were also significantly higher in women ( P < 0·01) than in men for any given BMI, and higher in obese ( P<0·01) than in lean individuals. We conclude that leptin 'resistance' associated with obesity cannot be accounted for by reduced free leptin concentrations in serum and that the methods described are suitable for the investigation of total, free and bound leptin for both clinical and research purposes.
Molecular determination of RhD phenotype by DNA typing: clinical applications
Authors: Cotorruelo Carlos , Biondi Claudia , Borrás Silvia Garcia , Galizzi Silvina , Di Mónaco René , Racca Amelia
Published: October 2002

Rhesus D (RhD) typing is performed by agglutination methods; however, in clinical situations where these techniques cannot be performed, RhD DNA typing is an alternative approach. The Rh antigens are encoded by the RHD and RHCE genes. In RhD-negative individuals the RHD gene is absent or grossly deleted, but variations in the arrangement of the RH locus in different populations are emerging. The aim of this study was to analyse the gross organization of the RH genes in our population using a previously described multiplex polymerase chain reaction (PCR) method with some modifications. We studied 253 DNA samples from Argentinian blood donors, 15 samples with a reduced expression of the D antigen and 1 Dc- phenotype. We evaluated the clinical utility of this method to ascertain the RhD antigen in 10 patients with warm-type autoimmune haemolytic anaemia (AIHA) and 14 samples of amniotic fluids. All Rh phenotypes were properly characterized and no discrepancies with serological typing were found. Analyses performed in the Dc- phenotype suggest the presence of a hybrid RHCE- RHD gene. DNA typing confirmed the RhD-negative type of one AIHA sample in which serological tests were inconclusive. Foetal DNA typing correctly indicated the RhD in every foetus. VNTR (variable number of tandem repeats) and STR (short tandem repeats) analysis detected maternal contamination in two amniocentesis samples and confirmed the foetal origin of 12. This multiplex PCR strategy is suitable for RhD determination in clinical situations in which serological typing cannot be accomplished with its usual ease.
Prevalence of macroamylasaemia using polyethylene glycol precipitation as a screening method
Authors: Lawson Graham J
Published: October 2002

Four hundred and fifty-four subjects with hyperamylasaemia were screened for the presence of macroamylase using polyethylene glycol precipitation (PEG) and the Beckman automated amylase assay based on the hydrolysis of maltotetraose. Twenty-five subjects (5·5%) exhibited PEG precipitation values suggestive of macroamylasaemia (MA) (> 52% loss of original amylase activity). Macroamylasaemia was confirmed by gel filtration chromatography (GFC) in 21/25 subjects, using albumin as a molecular weight marker. Biochemical and clinical details of the 21 subjects identified are presented and discussed. It is recommended that serum exhibiting more than 57% precipitation of the original amylase activity by PEG should be examined by GFC to confirm or exclude MA.
Improved immunoturbidimetric assay for cystatin C
Authors: Lewis A V , James T J , McGuire J B J , Taylor R P
Published: October 2002

An immunoturbidimetric assay for cystatin C was optimized with respect to assay imprecision. After investigating the optimum pH, polyethylene glycol concentration and specimen volume, two modifications were introduced: an increase in specimen volume to 25 µL; and an extension of the pre-incubation period to 240s. These modifications produced an assay with between-batch imprecision (coefficient of variation, n=10 or 11) ranging from 3·9% at 0·72mg/L to 1·3% at 5·29mg/L. The assay was susceptible to interference from lipaemia and haemolysis but not bilirubinaemia in both the original and modified protocol. Extending the preincubation to 240s improved tolerance to common interferences and retained assay applicability in the routine clinical setting.
Correction formula for carbamylated haemoglobin in diabetic uraemic patients
Authors: Hammouda A M A , Mady G E
Published: October 2002

The measurement of carbamylated haemoglobin is a useful indicator of uraemic state during the preceding few weeks in patients with renal failure. In diabetic uraemic patients with hyperglycaemia, glycation of haemoglobin may interfere with its carbamylation, as both reactions involve the free amino groups of the protein. The aim of this study was to investigate the carbamylation of haemoglobin in the presence of hyperglycaemia. The study included 29 patients with chronic renal failure on regular haemodialysis, 14 diabetic and 15 non-diabetic patients, and 10 healthy controls. We found a significant correlation between the degree of haemoglobin carbamylation and mean blood urea concentration in both uraemic and control subjects. Carbamylation of haemoglobin was higher in both diabetic and non-diabetic chronic renal failure patients, but there were no significant differences between the groups regarding mean blood urea concentration or level of haemoglobin carbamylation. Carbamylated haemoglobin per unit of blood urea concentration was lower in the diabetic patients. Using a correction formula to account for the degree of haemoglobin glycation, there was no longer a significant difference in carbamylation per unit of blood urea concentration. In vitro incubation of red blood cells from six healthy and six diabetic non-uraemic patients in 70mmol/L urea showed a significantly lower carbamylation in the diabetic patients, but there was no significant difference when using corrected carbamylated haemoglobin values. We conclude that glycation of haemoglobin affects its carbamylation and that monitoring of uraemia in a diabetic patient necessitates the use of carbamylated haemoglobin value corrected for the degree of glycation.
Decreased longevity in Japanese men, associated with low-molecular-weight apolipoprotein(a) phenotypes
Authors: Matsubara Miyao , Akita Harukuni , Shibuya Hitoshi , Chiba Hitoshi
Published: October 2002

Lipoprotein(a) [Lp(a)] is an established risk factor for atherosclerosis. High plasma Lp(a) concentrations are associated with low-molecular-weight (LMW) apolipoprotein(a) (apo a) phenotypes, which raises the question of whether LMW apo a phenotypes occur less frequently in the elderly. To assess this possibility, we studied apo A phenotype and allele frequencies in Japanese subjects ≥80 years old (men:women=40:34) in comparison with those <80 years old (men:women= 221:296). Significantly fewer LMW phenotypes and LMW alleles were observed in ≥80 year old men compared with those <80 years old: 2·5% versus 16·1% for the LMW phenotype frequency and 1·3% versus 9·7% for the LMW allele frequency ( P<0·05, Fisher's exact probability test). Similar differences were not found in the women. Consistent with this, plasma Lp(a) concentrations were significantly lower in the men ≥80 years old than in the younger group. These results indicate that LMW apo a phenotypes are associated with a shorter lifespan in men but not in women, possibly reflecting the higher susceptibility of men to atherosclerosis.
Effect of lipoprotein lipase on binding of chylomicrons to LDL receptor-deficient Chinese hamster ovary cells
Authors: Kobayashi Junji , Tashiro Jun , Bujo Hideaki , Morisaki Nobuhiro
Published: October 2002

The authors investigated the binding of human plasma 125I-labelled chylomicrons to Chinese hamster ovary (CHO) cells, i.e. native CHO cells are mutant ldl-A7 cells lacking the low-density lipoproteins receptor, in the absence and presence of exogenous bovine milk lipoprotein lipase (LPL) in the culture medium. Only a small amount of binding to either cell was observed in the absence of added LPL. Exogenously added LPL increased the specific binding of chylomicrons to ldlA7 cells, as well as to native CHO cells. The enhanced binding of chylomicrons to ldl-A7 cells or native CHO cells by LPL was inhibited by heparinase and a monoclonal antibody against LPL (5D2) which recognizes the carboxyl terminal of LPL. However, the enhanced binding was not inhibited by 1M NaCl, which abolishes the enzymatic activity of LPL in either ldl-A7 cell or native CHO cells. These results suggest that LPL enhances the binding of chylomicrons to heparan sulphate proteoglycans of CHO cells, and that it is the carboxyl terminal of LPL but not the enzymatic activity of LPL that is essential for LPL to mediate the binding of chylomicrons to CHO cells.
3-Hydroxyanthranilic acid, an L-tryptophan metabolite, induces apoptosis in monocyte-derived cells stimulated by interferon- γ
Authors: Morita Toshiko , Saito Kuniaki , Takemura Masao , Maekawa Naoya , Fujigaki Suwako , Fujii Hidehiko , Wada Hisayasu , Takeuchi Shoji , Noma Akio , Seishima Mitsuru
Published: October 2002

3-Hydroxyanthranilic acid (3-HAA), a metabolite of L-tryptophan, accumulates in monocyte-derived cells (THP-1),but not in other celllines tested(MRC9, H4, U373MG, Wil-NS), following immune stimulation that induces indoleamine 2,3-dioxygenase (IDO), a rate-limiting enzyme in the L-tryptophan-kynurenine pathway. We examined whether metabolites of the L-tryptophan-kynurenine pathway act to induce apoptosis in monocytes/macrophages. Of the L-tryptophan metabolites tested, only 3-HAA at a concentration of 200µmol/L was found to induce apoptosis in THP-1 and U937 cells. The addition of ferrous or manganese ions further enhanced apoptosis and free radical formation by 3-HAA in these two types of cells. The apoptotic response induced by 3-HAA was significantly attenuated by the addition of antioxidant, α-tocopherol or Trolox (a water-soluble analogue of vitamin E), and the xanthine oxidase inhibitor, allopurinol. In addition, the 3-HAA-induced apoptotic response was slightly attenuated by catalase, but not by superoxide dismutase (SOD), indicating that generation of hydrogen peroxide is involved in this response. Interferon-γ (IFN-γ), an inducer of IDO, potently induced apoptosis in THP-1 cells, but not in U937 cells, in the presence of ferrous or manganese ions. This different susceptibility to apoptosis inducer between THP-1 and U937 cells may depend on the capacity of the cells for 3-HAA synthesis following IDO induction by IFN-γ. Furthermore, apoptosis was suppressed by cycloheximide in THP-1 cells, suggesting that newly synthesized proteins may be essential for apoptotic events. These results suggest that 3-HAA induces apoptosis in monocytes/macrophages under inflammatory or other pathophysiological conditions.