bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation of Rac-1, Rac-2, and Cdc42 by hemopoietic growth factors or cross-linking of the B-lymphocyte receptor for antigen
Authors: Grill Brock , Schrader John W.
Published: October 2002

Interleukin-3 (IL-3)–induced activation of endogenous Rac-1, Rac-2, and Cdc42. Rac-1 was also activated by colony-stimulating factor-1 (CSF-1), Steel locus factor (SLF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-5 or by cross-linking the B-lymphocyte receptor for antigen (BCR). The activation of Rac-1 induced by cross-linking the BCR or by IL-3 stimulation was blocked only partially by Ly294002, with about 25% to 30% of Rac-1 activation still occurring in the absence of detectable increases in phosphatidyl-inositol-3 kinase (PI-3K) activity. Overexpression of constitutively active mutants of H-Ras, N-Ras, or M-Ras resulted in activation of coexpressed Rac-1 through an Ly29402-resistant, PI-3K–independent mechanism. Overexpression of constitutively active mutants of p21 Ras, or Rac-1, but not of PI-3K, was sufficient for activation of p38 mitogen-activated protein kinase (MAPK) in cells of hemopoietic origin. Inhibition of increases in PI-3K activity by Ly294002 had no effect on the IL-3–induced activation of p38 MAPK. In contrast, Ly294002 partially inhibited the activation of p38 MAPK induced by cross-linking of the BCR, although some p38 MAPK activation occurred in the absence of increases in the activity of Rac-1 or PI-3K. The activation of Rac-1, Rac-2, and Cdc42 by IL-3 and other hemopoietic growth factors is likely to be an important component of their actions in promoting growth, survival, and function.
Genomic and proteomic analysis of the myeloid differentiation program: global analysis of gene expression during induced differentiation in the MPRO cell line
Authors: Lian Zheng , Kluger Yuval , Greenbaum Dov S. , Tuck David , Gerstein Mark , Berliner Nancy , Weissman Sherman M. , Newburger Peter E.
Published: October 2002

We have used an approach using 2-dimensional gel electrophoresis with mass spectrometry analysis combined with oligonucleotide chip hybridization for a comprehensive and quantitative study of the temporal patterns of protein and mRNA expression during myeloid development in the MPRO murine cell line. This global analysis detected 123 known proteins and 29 “new” proteins out of 220 protein spots identified by tandem mass spectroscopy, including proteins in 12 functional categories such as transcription factors and cytokines. Bioinformatic analysis of these proteins revealed clusters with functional importance to myeloid differentiation. Previous analyses have found that for a substantial number of genes the absolute amount of protein in the cell is not strongly correlated to the amount of mRNA. These conclusions were based on simultaneous measurement of mRNA and protein at just a single time point. Here, however, we are able to investigate the relationship between mRNA and protein in terms of simultaneous changes in their levels over multiple time points. This is the first time such a relationship has been studied, and we find that it gives a much stronger correlation, consistent with the hypothesis that a substantial proportion of protein change is a consequence of changed mRNA levels, rather than posttranscriptional effects. Cycloheximide inhibition also showed that most of the proteins detected by gel electrophoresis were relatively stable. Specific investigation of transcription factor mRNA representation showed considerable similarity to those of mature human neutrophils and highlighted several transcription factors and other functional nuclear proteins whose mRNA levels change prominently during MPRO differentiation but which have not been investigated previously in the context of myeloid development. Data are available online athttp://bioinfo.mbb.yale.edu/expression/myelopoiesis.
Phorbol ester stimulates a protein kinase C–mediated agatoxin-TK–sensitive calcium permeability pathway in human red blood cells
Authors: Andrews Dina A. , Yang Lu , Low Philip S.
Published: October 2002

Calcium entry into mature erythrocytes (red blood cells; RBCs) is associated with multiple changes in cell properties. At low intracellular Ca2+, efflux of potassium and water predominates, leading to changes in erythrocyte rheology. At higher Ca2+ content, activation of kinases and phosphatases, rupture of membrane-to-skeleton bridges, stimulation of a phospholipid scramblase and phospholipase C, and induction of transglutaminase-mediated protein cross-linking are also observed. Because the physiologic relevance of these latter responses depends partially on whether Ca2+ entry involves a regulated channel or nonspecific leak, we explored mechanisms that initiate controlled Ca2+ influx. Protein kinase C (PKC) was considered a prime candidate for the pathway regulator, and phorbol-12 myristate-13 acetate (PMA), a stimulator of PKC, was examined for its influence on erythrocyte Ca2+. PMA was found to stimulate a rapid, dose-dependent influx of calcium, as demonstrated by the increased fluorescence of an entrapped Ca2+-sensitive dye, Fluo-3/am. The PMA-induced entry was inhibited by staurosporine and the PKC-selective inhibitor chelerythrine chloride, but was activated by the phosphatase inhibitors okadaic acid and calyculin A. The PMA-promoted calcium influx was also inhibited by ω-agatoxin-TK, a calcium channel blocker specific for Cav2.1 channels. To confirm that a Cav2.1-like calcium channel exists in the mature erythrocyte membrane, RBC membrane preparations were immunoblotted with antiserum against the α1A subunit of the channel. A polypeptide of the expected molecular weight (190 kDa) was visualized. These studies indicate that an ω-agatoxin-TK–sensitive, Cav2.1-like calcium permeability pathway is present in the RBC membrane and that it may function under the control of kinases and phosphatases.
Dioxygen Activation by Copper Complexes. Mechanistic Insights into Copper Monooxygenases and Copper Oxidases
Authors: Itoh Shinobu , Fukuzumi Shunichi
Published: October 2002

Reactions of copper(I) complexes with molecular oxygen have been examined using a series of N-alkyl-bis[2-(2-pyridyl)ethyl]amine tridentate ligands (R′Py2R) and N,N-dialkyl-2-(2-pyridyl)ethylamine didentate ligands (R′Py1R1,R2) at low temperature. The tridentate ligands predominantly provide (μ-η2 : η2-peroxo)dicopper(II) complexes (side-on type peroxo complex), while the didentate ligands enhance O–O bond homolysis of the peroxo species to produce bis(μ-oxo)dicopper(III) complexes. With the (μ-η2 : η2-peroxo)dicopper(II) complexes supported by the tridentate ligand, efficient oxygenation of phenolates to the corresponding catechols has been accomplished to provide a good model reaction of tyrosinase. The bis(μ-oxo)dicopper(III) complexes, on the other hand, undergo aliphatic ligand hydroxylation as well as oxygen atom transfer to sulfides to give the corresponding sulfoxides. In the reaction of bis(μ-oxo)dicopper(III) complex with 10-methyl-9,10-dihydroacridine (AcrH2) and 1,4-cyclohexadiene (CHD), a new active oxygen intermediate such as a (μ-oxo)(μ-oxyl radical)dicopper(III) or a tetranuclear copper-oxygen complex has been suggested to be involved as the real active oxygen species for the C–H bond activation of the external substrates. A mixed valence bis(μ3-oxo) trinuclear copper(II,II,III) complex has also been assessed using the didentate ligand with the smallest N-alkyl substituent (methyl). Mechanistic details of the above reactions as well as ligand effects on the copper(I)-dioxygen reactivity are discussed systematically.
Distribution of haptoglobin phenotypes in a Korean population, using the semi-automated PhastSystem
Authors: Yang Sung-Eun , Min Won-Ki , Park Hyosoon , Chun Sail , Nah Joon , Kim Jin Q
Published: October 2002

We have established a new phenotyping method for haptoglobin, based on sodium dodecyl sulphate-polyacrylamide gel electrophoresis using the PhastSystem (Pharmacia Biotech, Uppsala, Sweden), followed by immunoblotting for detection. We measured haptoglobin concentrations and determined the haptoglobin phenotypes of 316 healthy Koreans using this method: 31 (9·8%) were of Hp 1-1 type, 140 (44·3%) of Hp 2-1 type and 145 (45·9%) of Hp 2-2 type. The haptoglobin allele frequencies were calculated to be 0·32 for Hp1 and 0·68 for Hp2. We were able to visualize up to 12 bands from the human Hp 2-2 polymeric series, with molecular weights in the range 171·9 x 103 to 802·2 x 103. The reference range of serum haptoglobin concentrations obtained by the IFCC (International Federation of Clinical Chemistry) standard method was 0·27 - 2·14 g/L. The serum haptoglobin concentration in Koreans was similar to that of Caucasians, but the Hp1 allele frequency was lower in Koreans. Our method could be used in clinical laboratories as a simple and practical method of haptoglobin phenotyping. In addition, the Hp 2-2 polymeric series could be used as high molecular weight standards.
Screening for autoantibodies to SS-A/Ro by indirect immunofluorescence using HEp-2000TM cells
Authors: Bossuyt Xavier , Meurs Lisette , Mewis Alex , Mariën Godelieve , Blanckaert Norbert
Published: October 2002

We evaluated indirect immunofluorescence (IF) using HEp-2000TM slides, which are transfected with SS-A cDNA, for screening for anti-SS-A antibodies, by comparing it with counterimmunoelectrophoresis (CIE). A total of 2427 specimens were screened for IF reactivity and for SS-A precipitins, of which 1033 (43%) were negative on both IF and CIE. There were 1271 SS-A precipitin-negative specimens (52%) which were IF-positive but lacked the distinctive SS-A staining pattern. One precipitin-negative serum was IF-positive with the distinctive SS-A pattern in the HEp-2000 system. One hundred and twenty-two specimens (5%) were positive for anti-SS-A precipitins on CIE, 107 showed the distinctive SS-A fluorescence staining pattern, whereas 15 of these precipitin-positive samples (12%) were IF-positive but did not display the distinctive SS-A pattern on the transfected cells. Fourteen of the 15 samples in which the distinctive SS-A pattern was not observed displayed other significant antinuclear antibody (titre equal or > 1:320 patterns. In conclusion, the presence of the typical 'distinctive' SS-A pattern on IF using the HEp-2000 slides is highly specific for the presence of autoantibodies to SS-A and has a sensitivity of 88% for detecting these antibodies.
Thermodynamic considerations of arteriovenous gradients of hydrogen ion concentration and carbon dioxide tension
Authors: Rakitzis Emmanuel T
Published: October 2002

It is shown that, in a multicompartmental homeostatic system, the extent of interaction between any two compartments can be assessed by determination of the difference in free energy change of one particular reaction, or a series of coupled reactions, operative in both of the compartments under consideration. Hydrogen ion concentration and carbon dioxide tension have been used to determine free energy change difference relationships between the venous and arterial compartments (- G(a-v)) of the circulatory system. Data from the literature (from two studies of congestive heart failure and one study of experimentally induced cardiac arrest) are used to calculate - G(a-v). It was found that in control subjects - G(a-v) is close to zero, whereas in congestive heart failure or cardiac arrest, the value rises to 150 calmol-1 or more, whereas in blood, the approach towards equilibrium between hydrogen and bicarbonate ions and dissolved carbon dioxide (aqueous CO2) is known to be only moderately rapid. It is concluded that, in the system under study, and with respect to the reaction H+ + HCO3- = CO2 + H2O, a high value for the free energy change difference between the two compartments (high - G(a-v)) must be due to an insufficient blood circulation rate. Accordingly, - G(a-v) is probably a quantitative measure of cardiac insufficiency.
Auto-antibodies against oxidized LDL as a marker of coronary artery disease in patients with familial hypercholesterolaemia
Authors: Paiker J E , Raal F J , von Arb M
Published: October 2002

Auto-antibodies to oxidized low-density lipoprotein (ox-LDL) are thought to play a pivotal role in the pathogenesis of atherosclerosis. This study investigates the value of auto-antibodies to ox-LDL as a predictive marker of atherosclerosis in patients with both homozygous and heterozygous familial hypercholesterolaemia (FH), who are known to suffer from severe premature atherosclerosis. The influences of well-established risk factors for atherosclerosis such as age, LDL-cholesterol levels and smoking on the results were also determined. Auto-antibody titres to ox-LDL and fasting lipid profiles were measured in 26 homozygous FH patients, 20 heterozygous FH patients without documented coronary artery disease (CAD), 24 heterozygotes with overt CAD and 10 healthy normocholesterolaemic controls. Carotid intima-media thickness, used as an in vivo assessment of atherosclerosis, was also measured in the homozygous FH patients. Ox-LDL titres did not differ between the groups. There was also no association between ox-LDL titres and the LDL-cholesterol level ( P=0·14), presence or absence of CAD ( P=0·69), age ( P=0·50), carotid intima-media thickness ( P=0·51) or smoking ( P=1·0). In conclusion, antibody titres against ox-LDL cannot be used as a predictive marker of the presence or severity of atherosclerosis in patients with FH.
Simple high-performance liquid chromatographic method to monitor vigabatrin, and preliminary review of concentrations determined in epileptic patients
Authors: George S , Gill L , Braithwaite R A
Published: October 2002

SUMMARY. A simple and rapid high-performance liquid chromatographic method has been developed for the determination of vigabatrin concentrations in plasma or serum. The assay uses only 100 µL of specimen and has been found to be linear over a concentration range of 1 to 50 mg/L. The limit of detection has been determined as 1 mg/L, and the between-batch coefficient of variation for the two internal quality controls routinely analysed ( n=33) has been found to be less than 5%. There was no evidence of interferences in the assay from other commonly prescribed anti-epileptic drugs.

This method has been applied to routine clinical specimens to determine the concentration of vigabatrin in 47 patient specimens over a 12-month period. It was found that only 63% of the male group and 53% of the female group were within the proposed target concentration of 5 to 35 mg/L. In addition, it was found that 26% of the male group and 36% of the female group were found to have concentrations below 5 mg/L, which may indicate lack of compliance and/or lack of therapeutic efficacy of treatment.
Non-fasting reference intervals for the Abbott IMxTM homocysteine and AxSYMTM plasma folate assays: influence of the methylenetetrahydrofolate reductase 677 C→T mutation on homocysteine
Authors: Donnelly James G , Isotalo Phillip A
Published: October 2002

Plasma homocysteine comes under both genetic and nutritional control. B vitamins and particularly folate are important factors in homocysteine metabolism. We have obtained reference intervals for total plasma homocysteine and plasma folate. We have also determined the influence of methylenetetrahydrofolate reductase (MTHFR) genotype on plasma homocysteine concentrations in healthy individuals.

Reference intervals for Abbott IMxTM homocysteine and AxSYMTM plasma folate assays were established using 116 volunteers recruited from hospital staff. Exclusion criteria included cardiac, hepatic or renal disorders, and use of over-the-counter prescription medications. An exception was the inclusion of three women using oral contraceptives and one woman receiving post-menopausal oestrogen supplementation. Methylenetetrahydrofolate reductase 677C-T genotyping was performed on 101 of the volunteers to determine whether the MTHFR 677T allele influences homocysteine concentrations in healthy individuals. Reference intervals for homocysteine and folate were determined using the mean±2 standard deviations of the data. Folate/homocysteine ratios were sorted by MTHFR C677T genotype.

Homocysteine correlated negatively with plasma folate. Mean male homocysteine concentrations were significantly higher (9· μmol/L; P<0·05) than the mean value (7·1 μmol/L) obtained for females. Mean homocysteine values were significantly higher in subjects who were homozygous for the MTHFR 677T allele when compared with the 677CC genotype ( P<0·05). Ratios of folate/homocysteine were 20% and 7·44% lower in the male and female 677TT group than in the 677CC group, respectively. The mean homocysteine value of 43 volunteers who were taking multivitamins was not significantly different from that of 73 who were not vitamin supplemented. Conversely, the mean folate value was slightly greater, and statistically significant, in the group taking vitamin supplements. The mean folate values and reference intervals were not significantly different when grouped by sex or age.

MTHFR 677C T mutations influenced homocysteine values observed in our study of healthy volunteers, even though we did not observe outright folate-deficient individuals. Our random homocysteine values were similar to the fasting homocysteine values obtained in other studies.
Reference values of plasma lipoprotein (a) in newly classified apolipoprotein(a) phenotype groups in the Japanese population
Authors: Orisaka Michiko , Koyamada Kei , Saika Yasushi , Sakurabayashi Ikunosuke
Published: October 2002

We tried to establish the reference values of plasma lipoprotein (a) [Lp(a)] concentration in phenotype groups of apoliprotein(a) [apo A] classified by a new criterion. Lp(a) concentration was determined by latex agglutination immunoassay, and apo A was analysed by electrophoresis in sodium dodecyl sulphate-polyacrylamide gel and a Western blotting technique. According to the relative mobility to the apo B-100 band, apo A was classified into 11 isoforms, i.e. F, B, and S1-S9, and the phenotype was defined by their apparent combination. The frequency ratio of single-band versus double-band was approximately 2:1. In 382 cases of single-band, the most frequent phenotype was S5 (24·3%), followed by S4 (17·3% ), S6 (15·4% ) and S3 (14·4%). In 181 cases of double-band, S5/S6 phenotype was observed most frequently (12·2%), followed by S4/S5 (10·5%) and S3/S6 (7·2%). The reference value was determined between antilogs of the mean ± 1·96 standard deviation by logarithmic transformation of all observed values for individual phenotype cases. These results suggest that the reference values shown to be variable with apo A phenotypes should be useful for evaluating Lp(a) values in diagnosis of atherosclerosis.
Association between apolipoprotein B promotor haplotypes and cholesterol status
Authors: Hubacek Jaroslav A , Pistulková Helena , Škodová Zdena , Berg Kare , Poledne Rudolf
Published: October 2002

Association between apolipoprotein B (apo B) promoter haplotypes and cholesterol concentration was studied in two groups of children with low and high concentrations of cholesterol. Strong linkage equilibrium was demonstrated between I/D in the signal peptide of apo B and (C-516T) polymorphism in the promotor of apo B gene, and the I/I + allele T haplotype was associated with a low cholesterol concentration.
Effect of breast-feeding on concentration of nitric oxide in breast milk
Authors: Akçay Fatih , Aksoy Hülya , Memisogullari Ramazan
Published: October 2002

Background The effect of breast-feeding on the concentration of nitric oxide (NO) in milk was investigated in lactating mothers. Methods Breast milk specimens were obtained from 45 lactating women after normal delivery on postpartum days 1, 2, 3, 4 and 5. The subjects were divided into three groups: group 1, breast-feeding only; group 2, mixed feeding (breast milk by manual expression and additional formula feeds); and group 3, formula feeding only. Milk NO concentration was measured as the sum of nitrite and nitrate using the Griess reaction. Results The highest mean milk NO concentration was on day 4 in all groups, but the peak value in group 3 was significantly lower ( P < 0·0001) than in other groups. The milk NO concentrations of group 1 were significantly greater than those of groups 2 and 3. Conclusions We conclude that breast-feeding increases the concentration of NO in milk.
HDL-cholesterol and cardiac disease: which table to use?
Authors: Bayly Graham
Published: October 2002

Interventions to modify cardiovascular risk factors have the greatest benefit in individuals at greatest risk of a cardiovascular event, not necessarily those with the most extreme levels of any particular risk factor. Patients with vascular disease are readily identified, but risk calculation in those without disease provides a way of integrating several risk factors to identify individuals at greatest risk. Equations have been derived from different epidemiological studies (Framingham, PROCAM, etc.) to estimate the risk of different clinical end-points [coronary heart disease (CHD) or cardiovascular disease (CVD)]. Some algorithms have been adapted to produce risk 'charts' or 'tables'; others have been modified to incorporate additional risk factors. Current UK guidelines all endorse calculation of CHD risk using the Framingham algorithm. This predicts risk well for some North European populations but less reliably in low-risk populations. It does not incorporate some risk factors, including serum triglycerides, family history, C-reactive protein, or homocysteine. Risk calculation should not be used in those with evidence of vascular disease, genetic hyperlipidaemia or a strong family history of CHD, and should be interpreted with caution in non-Caucasians. Measurement of high-density lipoprotein (HDL)-cholesterol is essential for accurate risk calculation. This has significant cost and workload implications for the laboratory. The way a laboratory reports results should be designed in such a way as to facilitate simple and accurate risk calculation.
γ-Glutamyltransferase: value of its measurement in paediatrics
Authors: Cabrera-Abreu Jose C , Green Anne
Published: October 2002

γ-Glutamyltransferase (GGT) is a microsomal enzyme that is widely distributed in human tissues involved in secretory and absorptive processes, particularly the bile canaliculi. Serum GGT is elevated in liver diseases affecting the biliary system, such as extrahepatic biliary atresia, sclerosing cholangitis and progressive familial intrahepatic cholestasis (PFIC) type 3. Conversely, two other subtypes of PFIC have normal or low serum GGT activity, discordant with the degree of cholestasis. GGT is also useful in detecting cholestasis associated with parenteral nutrition and assessing the efficacy of ursodeoxycholic acid in its treatment. GGT may also help screening for biliary complications on patients that have undergone orthotopic liver transplantation. The reference range for GGT is age dependent. In normal full-term neonates the activity at birth is approximately six to seven times the upper limit of the adult reference range. The activity then declines, reaching adult levels by the age of 5-7 months.
Detection of serum M2 anti-mitochondrial antibodies by enzyme-linked immunosorbent assay is potentially less specific than by immunofluorescence
Authors: Patel D , Egner W , Gleeson D , Wild G , Ward A
Published: October 2002

Aim To compare the predictive values of enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) techniques for the detection of M2 anti-mitochondrial antibodies. Methods Commercial ELISAs are widely available for the detection of antimitochondrial antibody subtypes in primary biliary cirrhosis (PBC). We compared the results from two ELISAs (one recombinant, one purified antigen) with those from two IIF methods in a well-defined cohort of PBC patients and in patients with systemic lupus erythematosus, Sjögren's syndrome, sicca syndrome, systemic sclerosis, rheumatoid arthritis and blood donor controls. Results There was good correlation between a rodent substrate IIF and ELISA A ( r = 0·9134), but poor correlation with ELISA B ( r = 0·5999), which produced many false-positive results in the control population. We show that rodent IIF alone or human epithelial cell (HEp-2000®) screening with confirmation by ELISA produce similar predictive values for PBC and require lesser degrees of skilled interpretation of IIF patterns. Conclusions We conclude that the specificities of IIF are greater than the ELISA methods (99% versus 85-97%), although the ELISAs are slightly more sensitive in biopsy-proven PBC. Careful in-house validation of all new ELISA technologies is mandatory for good laboratory practice, but IIF in experienced hands remains an effective and specific assay.
Sample matrix is critical in the evaluation of a dry-slide bromocresol green method for human albumin
Authors: Payn Michelle M , Lawrence David , Willis Roger , Lamb Edmund J
Published: October 2002

Background A dry-slide bromocresol green method for serum albumin consistently demonstrated negative bias in a proficiency testing scheme, particularly at low albumin concentrations. Methods and Results Albumin was measured using both a dry-slide method and an immunonephelometric method in patient serum samples and external quality assessment samples. Results obtained using the dry-slide method were lower than those obtained using immunonephelometry (mean bias - 1·0 g/L, P = 0·0039), but this difference was exaggerated in the quality assessment samples. In three other albumin preparations with assigned concentrations, recovery with the dry-slide method decreased upon dilution of the matrix. Conclusions Our results suggest that apparent under-recovery of albumin using this technology is probably due to the diffusive properties of the quality assessment sample matrix.
Immune complex transfer enzyme immunoassay for anti-ovalbumin IgA in serum
Authors: Hirota Kouichi , Kamashima Tomomi , Hashida Seiichi , Totani Masayuki
Published: October 2002

Background: An immune complex transfer enzyme immunoassay for antiovalbumin immunoglobulin A (IgA) was developed.

Methods: Serum-specific antibody was reacted simultaneously with 2,4-dinitrophenyl-bovine serum albumin-ovalbumin conjugate and ovalbumin- β-D-galactosidase conjugate. The complex formed from the three components was trapped onto polystyrene balls coated with anti-2,4-dinitrophenyl group immunoglobulin G, eluted with ε N-2,4-dinitrophenyl-L-lysine and transferred to polystyrene balls coated with anti-human IgA α-chain. Bound β-D-galactosidase activity was determined by fluorometry.

Results & Conclusions: The detection limit of this method for the measurement of specific anti-ovalbumin IgA was 9 fmol/tube, which was 20-fold lower than that of the enzyme-linked immunosorbent assay (ELISA). Because serum interference with this method was lower than that with the ELISA, the detection limit of this method was 300-fold lower than that by the ELISA. Anti-ovalbumin IgA was detected in 100% of healthy subjects, which was confirmed by pre-incubation with an excess amount of ovalbumin.
Interference in immunoassay is an underestimated problem
Authors: Ismail AAA , Walker PL , Cawood ML , Barth JH
Published: October 2002

The presence of antibodies in some patients' serum has long been known to be a potential source of interference in immunoassays, as shown by numerous case reports. These often appear after the introduction of a new analyte (e.g. troponin) and then decrease in number as the topic becomes exhausted. This highlights the persistent and intrinsic nature of this problem, despite attempts by the manufacturers to compensate for this source of error. However, an explanation of the immunoanalytical basis underpinning these assays could be more effective in raising awareness than intermittent case reports.

In this review we have outlined the use of antibodies as reagents, the factors determining how they bind to antigen(s), and the nature of the immune response in order to explain the insidious and unpredictable nature of this form of interference. Studies on the prevalence of interference have yielded values ranging from 0.05 to more than 2%. However, these figures are analyte- and assay-specific, influenced by the study design, and are not therefore generally applicable. It is also highly likely that figures on prevalence and incidence will worsen in the future because of the wider use of monoclonal antibodies as diagnostic and therapeutic tools.

Clinical laboratories should be alert to assay interference from antibodies irrespective of its nature, as immunoassays will remain an indispensable analytical tool, unlikely to be replaced in the foreseeable future by a practical alternative.
Quarts out of pint pots - expanding the pint. Clinical budgeting in practice
Authors: Gray TA , Cooper RG , Galloway J , Marples J
Published: October 2002

Clinical budgeting is the process whereby clinical users are charged for the resources they use. A system for recharging users for the costs of tests was introduced at the Northern General Hospital, Sheffield, in 1995, and has been in operation since. The system has allowed pathology to maintain budgetary balance, has automatically compensated for workload increases, has allowed the introduction of new tests, and has encouraged clinical users to include pathology costs in their bids for funding for clinical developments. The system works according to rules agreed between pathology and its users at the outset, but once set up takes a minimal amount of work to operate and maintain.
Identification and typing of human papillomavirus (HPV) in squamous cell carcinoma of the oral cavity and oropharynx
Authors: Niv Alexander , Sion-Vardi Netta , Gatot Albert , Nash Michael , Fliss Dan. M.
Published: October 2002

Recent epidemiological research has raised the possibility of a connection between viral infection by the human papilloma virus (HPV) and the existence of squamous cell carcinoma of the oral cavity and oroharynx (SCCa). Some 60 subtypes have been identified to date, and specific subtypes are associated with lesions or infections at specific tissue sites. Twenty-three patients with SCCa of the oral cavity were studied for the presence of HPV in their tumours. HPV DNA (all type 16) was isolated from four specimens (17.3 per cent) using the Polymerase Chain Reaction (PCR) method. The four patients were all over age 50, and had advanced tumours (two T3 and two T4) that originated in the oropharynx. Our data supports other reports in the literature, demonstrating the presence of HPV DNA type 16 within cells from oropharyngeal SCCa. We conclude that the PCR method is a useful and reliable method for the detection of HPV DNA within tumour cells.
Fatal cerebral venous sinus thrombosis as major complication of metastatic cervical mass: computed tomography and magnetic resonance findings
Authors: López-Peláez Maria F. , Millán José M. , de Vergas Joaquin
Published: October 2002

Cerebral venous sinus thrombosis is an uncommon but potentially lethal condition, with mortality between 5.5–30 per cent. It was previously associated with infections of the orbit, mastoid or face, but, after the advent of antibiotics, the most common causes include neoplasms, dehydration, oral contraceptives, coagulopathies, collagen diseases, and pregnancy and the puerperium. We report a case of fatal cerebral venous sinus thrombosis in a 68-year-old patient with a metastatic cervical mass, who developed internal jugular vein thrombosis that progressed cranially to transverse and sagittal sinus thrombosis.
Chronic cerebrospinal fluid leak into skull base causing intramedullary osteolysis
Authors: Dutt Sunil , Salib Rami , Irving Richard , Chavda Swarupsinh
Published: October 2002

We present the rare case of a 74 – year – old woman with extensive intramedullary osteolysis of the petroclival skull base straddling both sides of the basi – occiput and basi – sphenoid. She presented with clinical features of recurrent spontaneous cerebrospinal fluid (CSF) otorrhoea despite three previous attempts at repair of the CSF leak. Recent advances in imaging techniques enable accurate radiological diagnosis of skull base lesions. We performed T1- and T2-weighted magnetic resonance (MR) images, a fluid attenuated inversion recovery (FLAIR) sequence MR, and a diffusion scan to study the characteristics of the skull base pathology. This revealed extensive osteolysis, with cystic spaces within the clivus and the petrous pyramid extending also to the basi – occiput. The leak was sealed using the technique of subtotal petrosectomy with obliteration of the eustachian tube and blind pit closure of the ear canal. The patient has been followed up for six months with no recurrence of symptoms.
Protective role of superoxide dismutase in rat eustachian tubal mucosa against acute otitis media induced by upper respiratory tract infection
Authors: Lee Eun-Soo , Woo Jeong-Soo , Hwang Soon-Jae , Lim Hyun-Ho , Suh Han-Kyu
Published: October 2002

Superoxide dismutase has been known to play a role as an anti – oxidative system against oxidative injury during acute inflammation. To investigate the role of superoxide dismutase in eustachian tubal mucosa during acute otitis media (AOM), an animal model was made. Sprague – Dawley rats were inoculated with Streptococcus pneumoniae through the nasal cavity following development of virus – induced upper respiratory infection. The animals were divided into three groups according to their tympanic cavity conditions following bacterial inoculation; inoculated animals with no resultant AOM (no – AOM), animals with resultant AOM (AOM) and animals with resolving otitis media (recovery). The changes of superoxide dismutase in each tubal mucosa were compared with that of the normal control using immunohistochemistry and immunoblotting methods. On Western blot, there were little changes of optical density and surface area in no-AOM (213.5. ± .22.4, 13.2. ± .0.8.mm2) and recovery group (219.3. ± .18.7, 14.8. ± .0.7 mm2) compared to the normal control (223.5 ± 26.2, 16.7 ± 0.4 mm2). However, a marked decrease was found in the AOM model (167.6. ± .19.3, 6.5. ± .0.9 mm2). These findings suggest that superoxide dismutase may play a role in protecting tubal mucosa from free radical injury during AOM.
Vagus nerve stimulation: quality control in thyroid and parathyroid surgery
Authors: Lambert A. W. , Cosgrove C. , Barwell J. , Oxenham S. , Wilkins D. C.
Published: October 2002

This paper describes the use of the Neurosign 100 Nerve Monitor and vagus nerve stimulation in the identification and assessment of the integrity of the recurrent laryngeal nerve (RLN) during thyroid and parathyroid surgery.

Vocal fold function was assessed pre- and post-operatively in all patients undergoing thyroid and parathyroid surgery. The nerve monitor, used in association with endotracheal electrodes, was used to confirm correct RLN identification and demonstrate its integrity at the completion of surgery.

There were 21 unilateral and 19 bilateral neck explorations. In these 40 patients, 57 of 59 RLNs were identified. The nerve monitor demonstrated RLN continuity in all but one case (equipment failure: electrode misplacement) after initial identification. Vagus nerve stimulation was performed in 21 patients without adverse sequelae. Damage to the RLN was identified in one of these patients, in whom direct RLN stimulation close to the larynx had failed to indicate discontinuity. Post-operatively this patient had a transient unilateral vocal fold palsy.

The use of the Neurosign 100 Nerve Monitor is no substitute for meticulous surgery. Stimulation of the vagus nerve may be a more sensitive means of assessing RLN integrity during thyroid and parathyroid surgery than stimulation of the RLN itself. Confirmation of RLN integrity allows the surgeon to proceed with confidence to the contralateral side of the neck during hazardous bilateral explorations.
Ectopic thymic cyst in the neck
Authors: Terzakis Georgios , Louverdis Dionisios , Vlachou Stamatia , Anastasopoulos Georgios , Dokianakis Georgios , Tsikou-Papafragou A.
Published: October 2002

Ectopic thymic tissue in the neck is rarely reported in medical literature. This paper presents the case of a young female, who presented with a soft, fluctuating mass in the left side of her neck. Surgical excision revealed an ectopic thymic cyst. Ectopic thymic tissue may be an infrequent finding, but it should be included in the differential diagnosis of neck masses, especially in children. This case report is accompanied by a short review of the relative literature.
Laryngeal granuloma: characteristics of the covering epithelium
Authors: Luzar Boŝtjan , Gale Nina , Klopĉiĉ Ulrika , Fischinger Janez
Published: October 2002

The purpose of the present study was to evaluate the biological behaviour of the marginal epithelium, that proliferates and eventually covers laryngeal granulomas, and to reveal the applicability of the recently re-introduced Ljubljana classification when reporting reactive epithelial hyperplastic lesions.

A retrospective clinical and histomorphological analysis was performed on 149 laryngeal granuloma biopsies. Epithelial changes were classified according to the Ljubljana classification into normal epithelium; simple, abnormal, or atypical hyperplasia; and carinoma in situ. Atrophic epithelium, not evaluated separately in the Ljubljana classification, was additionally assessed. Simple hyperplasia was found in 98 cases (65.8 per cent), abnormal hyperplasia in seven (4.7 per cent), atrophic epithelium in 24 (16.1 per cent), and normal squamous epithelium in 20 (13.4 per cent). Atypical hyperplasia and carcinoma in situ were not observed.

The results of our study clearly showed that the proliferation of the covering epithelium mostly in the form of simple hyperplasia, is entirely reactive and therefore reversible. No epithelial hyperplastic lesions were found that were previously described to be associated with an increased risk of malignant alteration, namely atypical hyperplasia and carcinoma in situ. However, since an initial growth of an invasive malignant neoplasm might macroscopically imitate the appearance of laryngeal granuloma, a histological examination in all aetiological forms of laryngeal granulomas is required. By clearly discerning the benign nature of epithelial changes in laryngeal granulomas, the recently re-evaluated and further formulated Ljubljana classification may also influence the clinical handling of patients.
Narrow internal auditory canal syndrome: parasaggital reconstruction
Authors: Cho Yang-Sun , Na Dong Gyu , Jung Jae Yun , Hong Sung Hwa
Published: October 2002

Narrow internal auditory canal (IAC) syndrome is a malformation of the temporal bone, that is defined as an IAC diameter of only 1–2 mm on high-resolution computed tomographic scans (HRCT). This syndrome is known to be caused by the absence (aplasia or hypoplasia) of the vestibulocochlear nerve. We present a case of unilateral narrow IAC syndrome which was diagnosed by HRCT. The aplasia of the vestibulocochlear nerve was confirmed using parasigittal reconstruction magnetic resonance image (MRI). The IAC was composed of two separate canals, one of which contained a facial nerve and the other was empty with aplasia of the vestibulocochlear nerve.
The arcuate eminence is not a protrusion of the superior semi-circular canal but a trace of sulcus on the temporal lobe
Authors: Tsunoda Atsunobu , Kimura Yurika , Sumi Takuro , Komatsuzaki Atsushi , Sato Tatsuo
Published: October 2002

Thirteen cadavers (26 temporal bones) were examined to show the arcuate eminence, especially its correspondence to the superior semicircular canal and inferior surface of the temporal lobe. Arc-like eminences on the petrous bone were observed in 92 per cent of specimens, however, they did not exactly correspond to the superior semi-circular canal. Some eminences corresponded to sulci of the temporal lobe of which most were traces of the occipitotemporal sulcus.

On the other hand, a dull, smooth and even domed eminence existed in nine temporal bones independently of the arc-like eminence. Those eminences corresponded to each superior semi-circular canal in only three out of nine specimens.

The arcuate eminence was listed as an important landmark in the middle cranial fossa approach. However, in order to drill out the internal auditory canal safely, surgeons should rely on other landmarks or apply other methods from our data.
Transcervical foreign body
Authors: Ahmad Rauf , Pampori Rafiq Ahmad , Wani Asef Ahmad , Qazi Sajjad Majid , Ahad Sheikh Abdul
Published: October 2002

The uncommon occurrence of acute retropharyngeal abscess in adults can be the result of a retained foreign body. A large piece of wood impacted in the neck in a road traffic accident and presenting as retropharyngeal
and bilateral parapharyngeal abscesses is reported for its rarity and clinical interest.
Burow’s solution in the treatment of active mucosal chronic suppurative otitis media: determining an effective dilution
Authors: Thorp M. A. , Gardiner I. B. , Prescott C. A. J.
Published: October 2002

Burow’s solution (13 per cent aluminium acetate) has been found to inhibit in vitro the growth of most commonly occurring bacteria found in the discharging ear. An in vitro study has shown that the minimum inhibitory concentration of Burow’s solution for these organisms lies between a 1:80 and a 1:160 dilution. This paper reports on a clinical trial that incorporated 67 discharging ears to establish the most effective strength of aluminium acetate solution. There was no statistical difference in the effectiveness of full strength Burow’s solution compared to 3.25 per cent aluminium acetate solution (a quarter strength Burow’s solution). Response rates of 80.8 per cent and 75 per cent respectively following a two-week treatment period were achieved using these two solutions. A 1.3 per cent aluminium acetate solution (1/10 strength Burow’s solution) was found to be markedly inferior. Bacteriological and audiological profiles were recorded for each patient.
Unusual cause of subglottic stenosis in an adult
Authors: D’Souza A. R. , Fenton J. E. , Russell J. D.
Published: October 2002

Subglottic foreign bodies presenting, as chronic subglottic stenosis is extremely rare in adults. A high index of suspicion and a careful history is of paramount importance in the diagnosis of a subglottic foreign body. Laser should not be used to excise granulation tissue to expose the foreign body because of the danger and potential of a fire particularly when the nature of the foreign body is not known. Rigid bronchoscopes are more beneficial than flexible ones in the removal of foreign bodies especially in long-standing cases.
Rosai-Dorfman disease of the larynx
Authors: Aluffi P. , Prestinari A. , Ramponi A. , Castri M. , Pia F.
Published: October 2002

We present a case of an 81-year-old man with a history of worsening dysphonia of six months duration. A year before a sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) was diagnosed on a submandibular lymph node biopsy. On presentation the patient showed a mass in the left subglottic area with a modest reduction in the airway space. The patient underwent an endoscopic CO2 laser excision of the mass, without post-operative complications. Histopathological examination and electron microscope images confirmed the previous diagnosis of Rosai-Dorfman disease. The clinical and pathological features of this entity are discussed.
Effect of packing on nasal mucosa of sheep
Authors: Shaw Chi-kee Leslie , Dymock Robert B. , Cowin Allison , Wormald Peter-John
Published: October 2002

The effects of packing with ribbon gauze and neuropatties on the nasal mucosa was assessed using sheep as an animal model. Fourteen sheep either underwent ribbon gauze or neuropattie nasal packing. Trauma to nasal mucosa caused by ribbon gauze and neuropatties was compared to mucosa on the lateral aspect of the middle turbinate which was not in contact with any packing. This tissue was used as a control. Ribbon gauze packing resulted in significant loss of 68 per cent of the ciliated surface of the mucosa when compared with the control group with a 15 per cent loss of ciliated surface (p < 0.005). Neuropattie packing also resulted in significant loss of 50 per cent of the ciliated surface of the mucosa when compared with the control group (p < 0.005). There was no significant difference in loss of ciliated mucosa in the specimens packed with ribbon gauze or neuropatties (p = 0.25).

Nasal packing results in a significant mucosal injury with loss of cilia. This may influence the mucociliary clearance of the nose in the post-operative healing phase. Pre-operative nasal packing should be used circumspectly and if possible avoided.
Omission of polysomnography in treatment of snoring: common reasons and medico-legal implications
Authors: Goh Y. H. , Choy D. K. S.
Published: October 2002

Although polysomnography (PSG) is an important investigation in the treatment of snorers, it was observed that a large number of patients did not have pre-operative PSG assessment in a tertiary hospital in Singapore. Of the 118 Asian patients who underwent surgery for snoring from January 1997 to December 1998, 36 (30.5 per cent) of patients did not have pre-operative PSG and only 21 (17.8 per cent) of patients had post-operative PSG. In this cohort, 43 (36.4 per cent) patients presented with snoring as their only complaint and not associated with symptoms indicative of obstructive sleep apnoea syndrome (OSAS). Thirty-one of these ‘simple snorers’ underwent sleep studies with the following outcome: two (6.5 per cent) true simple snorers, two (6.5 per cent) upper airway resistance syndrome, nine (29 per cent) mild OSAS, seven (22.6 per cent) moderate OSAS and 11 (35.5 per cent) severe OSAS. Our study showed that without the aid of PSG, it would be difficult to predict the severity of sleep apnoea based on clinical history alone. In an increasingly litigation-conscious society such as Singapore, there is therefore little justification in omitting PSG in the treatment of snoring. The common reasons for omission of preoperative PSG and the medico-legal implications are also discussed.
Predominant role of the chorda tympani nerve in the maintenance of the taste pores: the influence of gustatory denervation in ear surgery
Authors: Ohishi Yoshimichi , Komiyama Sohtaro , D.D.S Yoshiki Shiba
Published: October 2002

The effect on the taste pores of denervation of the chorda tympani nerve in the middle-ear cavity was studied comparing confocal laser microscopy with lingual nerve resection. Taste pore cells were stained for actin with rhodamine-phalloidin and positive fluorescence was observed as a ring shape at the transverse cross sections. Within three days after chorda tympani nerve resection the ring reaction disappeared, although the pore morphology remained intact as seen by scanning electron microscopy. On the other hand, lingual nerve resection did not induce such rapid disappearance of the ring reaction. These results suggest that the chorda tympani nerve plays a predominant role in the maintenance of actin filaments in taste pore cells.