bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface radiation budget in an Alpine valley
Authors: Matzinger N. , Andretta M. , Gorsel E. Van , Vogt R. , Ohmura A. , Rotach M. W.
Published: March 2003

Surface radiation data were collected at seven sites in the Riviera Valley in southern Switzerland during the special observing period of the Mesoscale Alpine Programme's Riviera project from August until October 1999. During the daytime on selected ‘valley wind’ days, strong site contrasts occurred with respect to solar and downward long‐wave radiation fluxes. Site‐to‐site differences of incoming global radiation were caused by the different orientations of valley surfaces relative to the direct solar beam component and by shading from surrounding topography. Diurnal cycles of albedo, determined from horizontal and slope‐parallel measurements of reflected and incoming global radiation at three eastern side‐wall sites, show that reflection of the direct radiation component from the inclined surfaces is predominantly anisotropic diffuse radiation. Downward long‐wave radiation decreases with elevation in the valley because the higher sites have an increased angular exposure to the radiating sky (i.e. sky view factor). Contrasts between the valley‐floor and ridge‐top sites are largest on valley wind days but also occur on overcast days. Finally, strong site‐to‐site variations of the net all‐wave radiation occur during daytime due to variations in the received direct beam component of incoming global radiation. During night‐time, net outgoing all‐wave radiation increases with elevation, again because sky view fraction increases with elevation. On valley wind days, significant contrasts are found in mean diurnal cycles and daily sums of available radiation energy between south‐west and north‐east facing slopes. When the direct beam component is absent, inter‐site contrasts in radiation components are reduced, especially short‐wave radiation components.

A simple semi‐empirical method is described to estimate the net all‐wave radiation in a slope‐parallel frame of reference from measurements with horizontally exposed net radiometers. This method employs the theoretical ratio of short‐wave radiation on a slope to the horizontal equivalent. The method is tested successfully at one site where simultaneous measurements were made with inclined and horizontal sensors. Copyright © 2003 Royal Meteorological Society.
Gravity waves over the eastern Alps: A synopsis of the 25 October 1999 event (IOP 10) combining in situ and remote‐sensing measurements with a high‐resolution simulation
Authors: Volkert Hans , Keil Christian , Kiemle Christoph , Poberaj Gorazd , Chaboureau Jean‐pierre , Richard Evelyne
Published: March 2003

In situ and lidar data acquired during six repetitive flight legs across Grossglockner (3797 m, highest summit of the eastern Alps) reveal a coherent structure of the mountain‐wave field generated by a south‐westerly cross‐Alpine flow on 25 October 1999 during Intensive Observing Period (IOP) 10 of the Mesoscale Alpine Programme (MAP). The downward‐looking laser system sampling at 100 Hz provides distinct wave‐induced signatures in the layered clouds below the cruising altitude of about 11 km. Data obtained from three sondes dropped from the aircraft hint at mid‐tropospheric wave breaking in the lee of the main Alpine crest. The measurements are juxtaposed with results from a nested, non‐hydrostatic simulation (2 km horizontal resolution for the finest grid). Wave‐cloud signatures in satellite images (from Meteosat and the National Oceanic and Atmospheric Administration satellites) are used for comparisons with the simulation in a region away from the aircraft track. Sensitivity experiments reveal the regular wave response to be induced by the background profile and re‐enforced by the suitably spaced terrain. Copyright © 2003 Royal Meteorological Society.
Triple‐Doppler radar analysis of the heavy rain event observed in the Lago Maggiore region during MAP IOP 2b
Authors: Georgis Jean‐françois , Roux Frank , Chong Michel , Pradier Stephanie
Published: March 2003

This paper presents analyses of data collected with three ground‐based Doppler radars during the Mesoscale Alpine Programme (MAP) Intensive Observation Period (IOP) 2b from 1900 UTC 19 September until 1100 UTC 20 September 1999. During this period, the synoptic situation was characterized by the propagation of a deep upper‐tropospheric trough towards the Alps, as often observed when heavy precipitation occurs on the southern slopes of the Alpine massif. A frontal cloud system with embedded convective cells passed over northern Italy in association with the trough moving rapidly eastwards. Ahead of the advancing cold front, a strong south to south‐easterly low‐level flow impinged on the mountains near Lago Maggiore and produced copious amounts of rain (<200mm at several locations).

An analysis of three‐dimensional radar‐derived wind and precipitation fields shows that the most intense precipitation occurred where and when the easterly component of the low‐ to mid‐level flow was the strongest with, however, a preferential location on the southern slopes of the Alps. This phenomenon can be explained by enhanced confluence between the main southerly flow and an intensifying easterly flow, and/or more favourable orientation of the moist inflow perpendicular to the mountain slopes. In addition, the propagation of convective cells from the Po Valley toward the Alps led to enhanced precipitation over the mountainous area.

Taking advantage of the approximately two‐dimensional character of the event, the different terms of the water budget are calculated for a series of 25 successive vertical cross‐sections to analyse the transformation of atmospheric moisture into surface rainfall. Copyright © 2003 Royal Meteorological Society.
Structure and dynamics of an Alpine potential‐vorticity banner
Authors: Schär Christoph , Sprenger Michael , Lüthi Daniel , Jiang Qingfang , Smith Ronald B. , Benoit Robert
Published: March 2003

A detailed analysis is undertaken of the primary Alpine shear zone that occurred on 1 October 1999 during the Mesoscale Alpine Programme. This shear zone emanates from the south‐western Alpine tip in north‐westerly flow conditions, develops in response to the Alpine‐scale flow splitting, and separates the northerly mistral wind to the south‐west of the Alps from the quasi‐stagnant air within the Alpine wake. The study is based on in situ flight‐level and dropsonde data from two research aircraft. The data are used for the construction of an objective analysis in a cross‐section perpendicular to the shear zone, and for diagnostic computations of the potential‐vorticity (PV) flux between vertically stacked flight legs. The observed flow structure is compared with simulation results of the Swiss Model and the non‐hydrostatic Canadian Mesoscale Compressible Community Model (MC2), operating at horizontal resolutions of 14 and 3 km, respectively.

Immediately downstream of the topography, the observed shear zone has a surprisingly quasi‐steady structure that becomes evident provided a slow westward migration is accounted for. Further downstream, the shear zone shows increased signs of transience. Near the surface, it has an overall width of ∼150 km, but narrows to about 25 km near the top of the mistral inversion at a height of ∼2 km. Detailed analysis shows that the shear zone has a complex substructure consisting of at least three positive and three negative PV filaments. These shear lines are characterized by a pronounced vertical coherence in the mixed layer and throughout most of the inversion layer. One of the banners is also evident in low‐level tracer constituents. Diagnostic computations of the PV flux along the banners using the generalized Bernoulli theorem reveal that most of the associated PV flux is due to vertically oriented vorticity within the inversion layer. Within the shear zone, there is a spanwise circulation of appreciable strength. It consists of a deformation flow with the axes of deformation oriented perpendicular to the shear zone. This deformation flow in effect squeezes the PV banners and thereby makes them resilient with respect to dissipation and barotropic instabilities.

Detailed intercomparison with numerical model results shows that models with a grid spacing below ∼15 km are able to capture the overall structure of the shear zone. The MC2 model in addition credibly replicates some of the finer‐scale sub‐structure of the shear zone, in particular at low levels. The high predictability and steadiness of the PV banners supports the idea that individual banners are generated by flow‐separation and/or gravity‐wave breaking events upstream. It is argued that the overall width of the shear zone is thus in effect determined by the geometry of the upstream topography and the dynamical processes that govern the downstream advection of the PV banners. Copyright © 2003 Royal Meteorological Society.
Runoff measurements and hydrological modelling for the estimation of rainfall volumes in an Alpine basin
Authors: Ranzi R. , Bacchi B. , Grossi G.
Published: March 2003

Streamflow data and water levels in reservoirs have been collected at 30 recording sites in the Toce river basin and its surroundings, upstream of Lago Maggiore, one of the target areas of the Mesoscale Alpine Programme (MAP) experiment. These data have been used for two purposes: firstly, the verification of a hydrological model, forced by rain‐gauge data and the output of a mesoscale meteorological model, for flood simulation and forecasting; secondly, to solve an inverse problem—to estimate rainfall volumes from the runoff data in mountain areas where the influence of orography and the limits of actual monitoring systems prevent accurate measurement of precipitation. The methods are illustrated for 19–20 September 1999, MAP Intensive Observing Period 2b, an event with a 4‐year return period for the Toce river basin. Uncertainties in the estimates of the areal rainfall volumes based on rain‐gauge data and via the inverse solution are assessed. Copyright © 2003 Royal Meteorological Society.
Clinical authorization: what is best for the patient?
Authors: le Roux C. W. , Bloom S. R.
Published: March 2003

In this issue, Prinsloo and Gray report the results of a 137-laboratory audit on clinical authorization using the guidelines and standards from the Royal College of Pathologists. Only 33% of laboratories were found to be compliant with the standards, although many showed evidence of good practice. Clinical authorization is resource-hungry and the question raised by this study is whether adhering to the letter of the standards set by the Royal College of Pathologists is actually in the best interest of the patient and provides overall value for money, when the latter is key to optimizing the quality of service.
Wilson's disease: the importance of measuring serum caeruloplasmin non-immunologically
Authors: Walshe J. M.
Published: March 2003

Wilson's disease should be considered as a possible diagnosis in any child, adolescent or young adult with liver damage without other explanation, especially when haemolysis is present. However, it may also present in adolescents or young adults with neurological signs confined to the motor system. The first diagnostic screening test is the estimation of the serum caeruloplasmin and total serum copper concentrations, with calculation of the serum non-caeruloplasmin-bound ('free') copper. Serum caeruloplasmin, which contains copper, is best determined by measurement of its oxidase activity, as the immunonephelometric method measures both caeruloplasmin and the biologically inactive apo-form. Diagnosis may be confirmed by an elevated urinary copper excretion. All close relatives of an identified patient must be screened and, where doubt persists, investigation of the Wilson's gene at chromosome 13q14.3 can be employed. Lifelong follow-up studies are best conducted in a specialist centre. Compliance with chelating therapy (penicillamine or trientine) or administration of the metal antagonist tetrathiomolybdate or zinc is monitored by determination of the serum 'free' copper, which should be maintained at or near 1·6 µmol/L (10 µg/100 mL). Side-effects of therapy are detected by the estimation of urinary total protein, full blood count and erythrocyte sedimentation rate, clotting factors and liver function tests.
Cell-free nucleic acids in plasma, serum and urine: a new tool in molecular diagnosis
Authors: Chan Allen K. C. , Chiu Rossa W. K. , Lo Y. M. Dennis
Published: March 2003

There has recently been an upsurge of interest in the analysis of circulating nucleic acids (DNA and/or RNA) in blood plasma or serum as a clinical diagnostic tool. Occasional earlier reports suggested the existence of circulating nucleic acids, but the potential clinical implication was not realized until 1996, when DNA with tumour-specific characteristics was demonstrated in the plasma/serum of cancer patients. This finding opened up possibilities for non-invasive cancer diagnosis. Potential applications have been reported in cancer diagnosis, prenatal diagnosis, transplantation and traumatology. Some of the findings are on the verge of being translated into clinical use. DNA is also now being sought in other body fluids such as urine.
Why do general practitioners request rheumatoid factor? A study of symptoms, requesting patterns and patient outcome
Authors: Sinclair David , Hull Richard G.
Published: March 2003

Background: To investigate the reasons why general practitioners (GPs) request rheumatoid factor (RF) assays, we studied 200 consecutive requests for RF from general practice in 1995.

Method: By means of an audit questionnaire, we studied 100 negative, 50 positive and 50 borderline RF results and compared these with the presenting symptoms that prompted the request, the GPs' understanding of the significance of the result, the referral intention and behaviour of the GP, and finally, the patient outcome after 5 years.

Results: There was an 80% response rate. The presenting symptoms closely matched the American Rheumatism Association revised criteria for the classification of rheumatoid arthritis, indicating that the requests were made on valid clinical grounds, with polyarthralgia, morning stiffness and joint pain being the most common. Most GPs considered a negative or positive result to be meaningful, in that a positive RF meant that a referral was more likely than with a negative or borderline result, even in the presence of appropriate symptoms in all three groups. Seventeen to thirty per cent felt that the test excluded or confirmed RA. The result appeared to influence this decision to a greater extent than it should. A 5-year follow-up on these patients showed that 26/40 patients with positive RF were referred, and that 25 of them developed a rheumatic disease of some kind, with 17 patients eventually being diagnosed with RA. Only 17/80 patients with negative RF were referred, the remainder having no autoimmune problem evident after 5 years, 11 of them developing a rheumatic disease, and only three being diagnosed with RA.

Conclusions: Although this is a locally based study, we believe the conclusions would be applicable to all laboratories and GPs undertaking these tests. RF requests are made on valid clinical grounds by GPs, but there may be an over-reliance on the results as regards referral behaviour. If patients were referred on clinical grounds, this would significantly lengthen consultants' waiting lists.
Immunoglobulins and immunoglobulin subclasses in the elderly
Authors: Lock R. J. , Unsworth D. J.
Published: March 2003

Background: Published data imply that adult concentrations are achieved for all Ig isotypes and plateau by 15--18 years of age. Recent data, however, suggest that these results are not applicable in the elderly. There are no equivalent data for IgG subclasses. We present reference range data for an elderly UK patient population, for IgG, IgA, IgM and IgG subclasses.

Methods: Serum immunoglobulins were reviewed on samples from 1146 patients > 60 years of age and 925 patients aged 18--60 years. Serum IgG subclasses were reviewed on samples from 498 patients >60 years and 484 patients aged 18--60 years. All Igs and subclasses were measured by nephelometry. Reference ranges were derived by probability plotting.

Results: Serum median IgG and IgM concentrations are reduced in the elderly (IgG female P < 0·001, IgG male P < 0·03; IgM female P < 0·001, IgM male P < 0·001). Serum IgA concentrations are maintained. Indeed, men showed a slight increase in serum IgA with age ( P = 0·03). Few differences dependent on gender were seen. Median IgM was lower in men in the younger age groups (18--60 years P < 0·001; 61--70 years P = 0·017). IgG2 is reduced in elderly men ( P = 0·002) and IgG, reduced in elderly women ( P = 0·009).

Conclusions: We advocate that centres offering these investigations provide local, method-dependent reference ranges, and suggest an approach as to how this might be achieved.
A survey of laboratory practice in the clinical authorization and reporting of results
Authors: Prinsloo P. J. J. , Gray T. A.
Published: March 2003

Background: The aim of this survey was to determine the practice of authorization and reporting of results in clinical biochemistry laboratories in the UK.

Method: Questionnaires were distributed to the heads of clinical biochemistry departments through the National Audit Committee of the Association of Clinical Biochemists. The standards surveyed were based on guidelines for the reporting of results produced by the Royal College of Pathologists and the relevant Clinical Pathology Accreditation standards.

Results: Completed questionnaires were received from 137 laboratories. Workload ranged from 15 000 to 750 000 requests per annum (median 276 883). Most laboratories (98%) release results electronically to at least some wards in real-time. Areas where difficulties were identified included identifying requests that had posed specific questions and access to clinical information at the authorization stage, recording clinical advice given, and ensuring comments remained attached to printed reports or were on the same screen on computer reports. All but six laboratories had consultant advice available, including out of hours, but only 17% had an arrangement for clinical authorization to occur out of hours.

Conclusion: Only 45 laboratories (33%) were able to achieve 100% compliance with the standards that currently exist, but many others showed evidence of good practice. The practical obstacles still to be overcome include limitations in the capabilities of laboratory computer systems, the lack of accessible electronic clinical records, the difficulties of covering work out of hours and insufficient appropriately trained staff.
Impact of European Society of Cardiology/American College of Cardiology guidelines on diagnostic classification of patients with suspected acute coronary syndromes
Authors: Collinson P. O. , Rao A. C. , Canepa-Anson R. , Joseph S.
Published: March 2003

Background: Assessment of the relative diagnostic accuracy of investigation strategies for patients with suspected acute coronary syndromes (ACS).

Methods: A prospective observational study followed two groups of patients over a 3-month period in a UK district general hospital. Group one: all admissions with suspected ACS ( n = 576); group two: non-cardiac in-patients who were suspected of developing ACS ( n = 87). Both were investigated by full clinical history, examination and serial electrocardiographs (ECGs). Conventional World Health Organization (WHO) criteria for myocardial damage were compared with diagnosis based on cardiac troponin T (cTnT). Clinical discharge diagnosis based on conventional WHO criteria was compared with the review diagnosis based on measurement of cTnT.

Results: Diagnosis based on WHO criteria missed 58 patients (8·7%) admitted with suspected ACS who had high risk unstable angina. Thirty-three patients (5% of all admissions) who were diagnosed as non-Q wave acute myocardial infarction (AMI) were found to have normal troponin values and to have been incorrectly classified as AMI.

Conclusions: Diagnostic strategies based on WHO criteria are inaccurate. The measurement of cTnT in all patients with suspected ACS would have increased the number of those with a diagnosis of AMI by 58 (8·7%), while avoiding inaccurate diagnosis in 33 (5%), therefore producing an absolute increase of 25/663 (3·8%) but a relative increase of 58/138 (42%). In patients with a primary diagnosis of suspected ACS, the overall increase in patients with a diagnosis of AMI will be 55 (9·5%), a relative increase of 55/118 (46·6%) but an absolute increase of 36/576 (6·3%).
The role of transferrin saturation as a screening test for hereditary haemochromatosis in an Irish population seeking medical care
Authors: O'Hara R. , Cavanagh N. , Cassidy M. , Cullina M.
Published: March 2003

Background: Genetic studies have indicated a high prevalence of mutations for hereditary haemochromatosis (HH) in Irish populations. Given the high cost of genetic screening and the ethical implications thereof, we assessed the role of transferrin saturation (TS) as a primary screening test for HH in an Irish population seeking medical care.

Methods: TS and ferritin were measured on 330 consecutive blood specimens received in the laboratory for routine screening. Patients with TS > 45% were genetically screened for the C282Y and H63D mutations.

Results: Twenty-six patients had TS values > 45%. Of these, specimens were available for genetic screening on 20 patients. Three previously undiagnosed patients were found to be C282Y homozygotes and one a compound heterozygote (C282Y/H63D). The prevalence of C282Y homozygotes was 0·93%, which is similar to the reported prevalence found in Irish populations by genetic screening.

Conclusion: Given the number of positive findings in this study, we conclude that, in the absence of a national programme, TS could be used as part of a health-screening panel in the Irish setting. Patients expressing iron overload would be detected before organ damage occurred, leading to less severe clinical disease and better patient prognosis.
Measurement of serum 'free' or 'easily dissociable' insulin-like growth factor-1
Authors: Roch M. , Williams J. , Clark P. M.
Published: March 2003

Background: Serum insulin-like growth factor-1 (IGF-1) exists as ternary and binary complexes, and as the free hormone. An immunometric assay for 'free IGF-1' or 'easily dissociable IGF-1' has been described, although its use has not been widely assessed.

Methods: The assay was assessed using the serum concentration/dilution test and by determining the relationship of the measured free hormone to the total hormone/binding protein ratio.

Results: In six serum pools the measured free IGF-1 did not remain constant on concentration/dilution of the sample. However there was a significant correlation between the measured free IGF-1 and total IGF-1 ( P < 0·001) and between total IGF-1/IGF binding protein-3 ratio ( P < 0·001).

Discussion: Although the assay failed the serum concentration/dilution test, there was still a significant relationship to the total hormone/binding protein ratio. It is possible that the serum dilution test is inappropriate to such a complex system or that the assay does not measure the free fraction. It is suggested that, though more cumbersome, it should be referred to as 'easily dissociable' IGF-1 as suggested by the manufacturers.
Field-testing and validation in a primary care setting of a point-of-care test for C-reactive protein
Authors: Seamark David A. , Backhouse Susan N. , Powell Roy
Published: March 2003

Background: Use of point-of-care testing (POCT) in primary care has increased. There is a need for high-quality field evaluation of POCT before deployment can be considered.

Method: A POCT system for C-reactive protein was evaluated in a routine general practice setting. The standard laboratory method was a dry slide method based in a routine hospital laboratory.

Results: Scatterplots for both venous and capillary blood POCT system results versus the standard laboratory assay produced correlation coefficients of greater than 0·96. Bland-Altman plots indicated that 95% of venous and capillary POCT results fell within ±10 mg/L of the mean value with no clinically significant difference from laboratory results.

Conclusions: The POCT system performed reliably in a routine general practice setting with satisfactory performance against an accepted laboratory method.
A survey of laboratory 'critical (alert) limits' in the UK
Authors: Tillman J. , Barth J. H.
Published: March 2003

Introduction: Critical or alert limits are the values of laboratory measurements that are regarded as requiring urgent clinical action and should be communicated to a clinician urgently. Despite this, there has been little evaluation of these values in the UK.

Methods: We have conducted a survey of hospital biochemistry laboratories in the UK.

Results: Ninety-four laboratories responded to the questionnaire; the response rate was not recorded. Twenty-three laboratories had derived their action limits locally from a consensus with their clinicians, experience over many years, and the literature. Only two laboratories quoted literature to support their values. Seven laboratories did not submit actual critical values. There was considerable variance in the values defined as critical by the responding laboratories.

Discussion: Each laboratory needs to evaluate its own list of acutely important critical values and aim for a small number of analytes that are always communicated to the doctor, so that clinical needs are met without raising the risk of information overload.
Comparison of simple acid-ethanol precipitation with gel exclusion chromatography for measuring leptin binding in serum of normal subjects and cancer patients
Authors: Jamieson Nigel B. , McMillan Donald C. , Brown Duncan J. F. , Wallace A. Michael
Published: March 2003

Background: In humans, leptin circulates in a free form and is also bound to macromolecules. The aim of the present study was to compare a rapid acid-ethanol precipitation (AEP) method of measuring bound leptin with the more laborious gel exclusion chromatography (GEC) reference procedure. Serum samples collected from healthy subjects and cancer patients were used in this comparison.

Methods: AEP and GEC methods for measuring leptin binding in serum (from 14 healthy volunteers and 14 patients with advanced non-small cell lung cancer) were adapted from previously published procedures.

Results: Intra- and inter-assay precision of the AEP method were 6% ( n = 10) and 8% ( n = 10), respectively. Bland-Altman analysis of results obtained from the AEP and GEC methods indicated no significant difference in healthy controls. However, significantly higher results were obtained by the AEP method in the cancer patients.

Conclusions: Evaluation of the AEP method revealed that on examination of normal subjects the method was less precise than had previously been reported. Moreover, the method gave differing results in the cancer patients when compared with the GEC method. This study indicates that careful evaluation of any new method for measuring leptin binding requires comparison with a GEC method using the sample matrix of interest.
Effect of a protease inhibitor on in vitro stability of intact parathyroid hormone
Authors: Anderson N. R. , Nicholas J. , Holland M. R. , Gama R.
Published: March 2003

Background: We investigated whether increased protease activity explains the increased in vitro degradation of intact parathyroid hormone (iPTH) observed in serum when compared to EDTA plasma.

Methods: Pre-dialysis blood samples for iPTH were taken from 11 patients with chronic renal failure and collected into plain glass tubes, tubes containing 200 KIU/mL aprotinin (a protease inhibitor) and EDTA tubes. All sample aliquots were separated at 20 min, 1 h, 2 h, 4 h, 8 h and 24 h post collection.

Results: Over 24 h, iPTH concentrations remained unchanged in EDTA tubes. iPTH concentrations were significantly lower in both plain tubes ( P < 0·01) and aprotinin tubes ( P < 0·001) at 24 h when compared to the baseline sample (20 min). At 24 h, iPTH concentrations in EDTA tubes were higher than in plain tubes ( P < 0·001) and aprotinin tubes ( P < 0·01). The addition of aprotinin to plain tubes significantly reduced the degradation of iPTH ( P < 0·05) at 24 h.

Conclusion: Aprotinin significantly reduces the in vitro degradation of iPTH in plain tubes at 24 h from 24·7% to 9·6%. We suggest that increased protease activity contributes to the decline in serum iPTH over time. As this is observed in serum and not plasma it suggests that the increased protease activity may be due to the clotting process.
Stability of parathyroid hormone ex vivo in haemodialysis patients
Authors: Teal T. K. , Reed M. , Stevens P. E. , Lamb E. J.
Published: March 2003

Background: The stability of parathyroid hormone (PTH) in blood ex vivo is a significant practical problem for laboratories and clinicians. Several studies have suggested that PTH is more stable in blood collected into a potassium edetate (EDTA) preservative.

Methods: To confirm that this was applicable to renal dialysis patients using our assay (Nichols chemiluminescence), we examined PTH stability in 13 patients with end-stage renal failure using three different blood collection tubes.

Results: PTH remained stable in EDTA plasma for up to 48 h at room temperature. PTH was significantly reduced in serum collected into plain tubes after 2 h, and after 4 h in serum collected into serum separator tubes, at room temperature.

Conclusion: In the assessment of renal osteodystrophy, the use of EDTA plasma can confer significant benefit, especially in busy laboratories where rapid frozen separation of blood may be hard to achieve.
Canal wall down tympanoplasty with canal reconstruction for middle-ear cholesteatoma: post-operative hearing, cholesteatoma recurrence, and status of re-aeration of reconstructed middle-ear cavity
Authors: Ikeda Minoru , Yoshida Shinya , Ikui Akihiro , Shigihara Shuntaro
Published: March 2003

The post-operative outcome of hearing, the reconstructed external auditory canal, and the state of the reconstructed middle-ear cavity after canal wall down tympanoplasty with canal and attico-antrum reconstruction was studied in 103 ears with middle-ear cholesteatoma. The reconstructed mastoid cavity was re-aerated in 36.5 per cent of the cases, which was significantly lower than for the epitympanum (63.5 per cent) and tympanic cavity (82.4 per cent). Tympanoplasty was successful in terms of hearing results in 68.9 per cent of all subjects and in 75.4 per cent of the ears having a re-aerated tympanic cavity, which was significantly better than the 38.5 per cent for ears in which the tympanic cavity was not re-aerated. The findings of recurrent cholesteatoma, tympanic atelectasis, and tympanic effusion were observed with significantly (p<0.03) high incidence in ears with no re-aerated space in their reconstructed mastoid cavities. It was revealed that the post-operative outcome of this surgical technique was significantly related to the state of re-aeration of the reconstructed middle-ear cavity.
Retrospective case study of carbon dioxide laser stapedotomy with lens-based and mirror-based micromanipulators
Authors: Lescanne Emmanuel , Moriniere Sylvain , Gohler Catherine , Manceau Aurélia , Beutter Patrice , Robier Alain
Published: March 2003

Most clinical studies on carbon dioxide (CO2) (λ = 10.6.mm) laser stapedotomy have been carried out with the laser guided by a conventional lens-based micromanipulator, with the attendant risks of correct aiming (HeNe) and surgical (CO2) beam misalignment. Hence, engineering advances have attempted to improve laser targeting as well as the spot size focus. The development of the mirror-based micromanipulator was a response to this need but no data concerning its use in stapes surgery is available. We performed a retrospective case-series review of patients treated for otosclerosis between 1992 and 2000. Primary laser stapedotomy was performed in 218 consecutive patients. In the first 78 procedures, the aiming beam (HeNe, λ = 632 nm) and surgical beam (CO2) were guided with a conventional lens-based micromanipulator whereas in the subsequent 140 procedures, they were guided by using a mirror-based micromanipulator. Hearing was tested at six and 12 months. The mean (SD) air-bone gap was 5 dB (4.5) and 4.5 dB (3.9). The mean closure was 15 dB (9.9) and 14.4 dB (9.4). The mean change in the high-tone bone-conduction level was 5.5 dB (7.3) and 7.8 dB (7.5). Overheating of the facial canal produced transient facial paralysis in one case and was due to misalignment of the beams with the lens-based micromanipulator. Use of the mirror-based micromanipulator obviated the need to verify alignment. The light-weight and superior optical yield of this system made it possible to reduce the number of impacts on the footplate by the integral restitution of the energy source. This study demonstrated that the CO2 laser is an effective method for performing stapedotomy. In addition, microtrauma to the labyrinth is reduced by its ability to perform calibrated footplate fenestration without mechanical or vibrational injury to the inner ear. The optical reflection micromanipulator simplified beam alignment and enhanced surgical comfort.
Effect of stapedectomy on subjective tinnitus
Authors: Szymański Marcin , Gołąbek Wiesław , Mills Robert
Published: March 2003

A series of 149 patients, who had tinnitus associated with otosclerosis, and who underwent stapedectomy by a single operator were questioned about their tinnitus one to 19 years after surgery. Of these, 73 per cent reported that their tinnitus had ceased following surgery, 17 per cent that it had improved and only 10 per cent that it was unchanged. No pre-operative audiometric or patient data were associated with a favourable outcome in terms of tinnitus improvement. Patients who had poor hearing outcomes reported abolition of their tinnitus, suggesting that this was due to the improvement in the fluid mechanics of the cochlea resulting from stapedectomy. The tinnitus status was unrelated to the length of follow-up time.
Otoacoustic emissions in patients with hypotension
Authors: Balatsouras Dimitrios G. , Korres Stavros , Simaskos Nikola , Kandiloros Dimitrios , Ferekidis Eleftherios , Economou Constantinos
Published: March 2003

The aim of this study was to investigate the relation between hypotension and slowly developing hearing impairment, using otoacoustic emissions. A group of 42 patients was examined, with diastolic blood pressure ≤60 mmHg and systolic blood pressure ≤105 mmHg. The subjects underwent biochemical, cardiological, ENT and audiological examinations. Distortion product otoacoustic emissions (DPOAE) were recorded in the format of DP-gram. The results were compared to the data of 30 normal persons of similar age and sex, examined at the same laboratory. Audiometric results showed that 18 patients had mild or moderate symmetrical hearing loss in one or more frequencies, mainly in the lower frequency range. DPOAE of the patients had reduced amplitude as compared to controls or were even absent, in one or more frequencies. It may be concluded that a hypotensive condition could be a possible factor in the origin of cochlear damage and DPOAE may be useful in monitoring hypotensive patients.
How frequent are accessory sinus ostia?
Authors: Jog M. , McGarry G. W.
Published: March 2003

The frequency of accessory sinus ostia (ASO) has been estimated at between four and 50 per cent in the findings of studies designed for other purposes or from uncontrolled observations. The literature revealed no study specifically designed to determine the prevalence of ASO. We have carried out a prospective cohort study to measure the prevalence of ASO.

The prevalence of ASO was determined in rhinology clinic patients and general ENT clinic controls. Overall ASO occurred in four per cent. Seven per cent of rhinology patients and two per cent of controls had ASO. Of the rhinology patients with rhinitis or sinusitis, eight per cent exhibited ASO. The overall prevalence in this study is lower than most quoted figures in the literature. There was increased prevalence of ASO in patients with rhinitis or sinusitis compared to controls. (p<0.05)

This study should be regarded as a pilot study and further investigations of the relationship between ASO and nasal disease is merited.
Ultrastructural ciliary changes of maxillary sinus mucosa following functional endoscopic sinus surgery: an image analysis quantitative study
Authors: Bassiouny Ahmed , Atef Ahmed M. , Raouf Mahmoud Abdel , Nasr Safaa Mohamed , Nasr Magdy , Ayad Essam Ezzat
Published: March 2003

This was a study of the effect of functional endoscopic sinus surgery (FESS) on the ciliary regeneration of maxillary sinus mucosa in patients with chronic maxillary sinusitis, using objective quantitative methods. Twenty specimens from the mucosa of both the superolateral wall and the ostium of the maxillary sinus were sampled during FESS and then six to 12 months later. They were light examined first by light microscopy and then by scanning electron microscopy in combination with image analysis software in order to study the cilia under higher magnification and to calculate proportion of the field that was ciliated. Samples were taken and studied at Cairo University hospital. This study showed that the maxillary sinus mucosa in chronic sinusitis is capable of regeneration and could return towards normal with the improvement of ventilation and drainage of the maxillary sinus following FESS. There were no significant changes in the degree of glandular hyperplasia, goblet cells or pathological glands after surgery.
Invasive sino-orbital aspergillosis: surgical decisions and dilemmas
Authors: Dhiwakar M. , Thakar A. , Bahadur S.
Published: March 2003

Invasive aspergillosis, one of the common paranasal sinus fungal infections, often secondarily involves the orbit. We report six such cases with orbital extension, all occurring in apparently immunocompetent hosts, to specifically address the difficult diagnostic and therapeutic issues involved. Limited biopsy procedures were often inconclusive, necessitating wide surgical excision to establish the histopathological diagnosis. Conservative orbital debridement proved adequate for cases with disease limited to the infero-medial compartment of the orbit, but resulted in residual progressive disease in the two of the four cases with retro-orbital and apical extension. Orbital exenteration in this latter group, however, proved successful in controlling disease. The present report emphasizes the importance of near-complete extirpation and adjuvant chemotherapy in ensuring a favourable outcome in invasive Aspergillus infections. Orbital exenteration appears justified for posterior orbital disease, regardless of the functional status of the eye, but is inappropriate for anterior orbital disease.
Distribution and prognostic significance of cell cycle proteins in squamous carcinoma of the larynx, hypopharynx and adjacent epithelial hyperplastic lesions
Authors: Volavšek Metka , Bračko Matej , Gale Nina
Published: March 2003

Alterations of cell cycle proteins contribute to the development and biological behaviour of malignant tumours. We evaluated the distribution and prognostic significance of immunohistochemically detected proteins p53, p21, Rb, and cyclin D1 in 101 laryngeal and hypopharyngeal squamous cell carcinomas (SCC) and adjacent epithelial hyperplastic lesions (EHL). Protein expression was correlated with tumour grade and stage.

Varying patterns of protein expression were found in SCC. A significant correlation (p <0.05) was found between Rb expression and tumour grade. Different grades of EHL exhibited randomly distributed p53 and cyclin D1 positive cell clusters with no association to the pattern of their expression in SCC.

Our study demonstrated derailment of cell cycle regulation in almost all cases of SCC of the larynx and hypopharynx. However, only cyclin D1 expression had an independent prognostic value for cancer-specific survival. The results also suggest that Rb gene inactivation, although rare, might be more important in the development of SCC than previously thought.
Use of polyethylene terephthalate and expanded-polytetrafluoroethylene in medialization laryngoplasty
Authors: Keskin Gürkan , Boyaci Zerrin , Ustundag Emre , Kaur Ahmet , Almaç Ahmet
Published: March 2003

Various materials have been used up to the present time in vocal fold augmentation. Although silicon has been the most frequently employed, the surgical difficulties encountered in shaping, positioning and placing this material have led to a search for a more easily applicable material. In our study, we investigated the local tissue reaction to implants in the laryngeal skeleton of 10 New Zealand rabbits in which we performed medialization laryngoplasty employing polyethylene terephthalate (PETP = Dacron®) and expanded polytetrafluoroethylene (e-PTFE = Gore-Tex®). When the local host tissue reaction to PETP and e-PTFE were compared, PETP was found to cause significant foreign body giant cell and histiocyte infiltration localized around fibres of the implant. The greater irregularity of the fibrous capsule formed in response to PETP and the density of foreign body giant cells around the PETP fibres suggested that resorption of the implant with time would decrease the degree of medialization.
Randomized controlled trial comparing argon plasma coagulation tonsillectomy with conventional techniques
Authors: Skinner Liam J. , Colreavy Michael P. , Lang Eimear , O’Hare Brendan , Charles David A. , Timon Conrad I.
Published: March 2003

Argon plasma coagulation (APC) is based on the principle of ionized argon creating a conductive plasma between an activating electrode and a tissue surface. To date, its use in tonsillectomy has not been extensively examined. The purpose of this randomized controlled trial was to assess the clinical efficacy of APC as a tool for this common surgical procedure. Forty patients were randomized into two groups - treatment A (conventional tonsillectomy, n = 20) and treatment B (APC tonsillectomy, n = 20). Trial end-points included a) operative time, b) intra-operative blood loss, and c) objective assessment of post-operative pain, by completion of a visual analogue pain score chart, over a two-week period. Thirty-one patients were available for analysis. There was a statistically significant reduction in the intra-operative blood loss with treatment B (p = 0.02). There was no statistical difference between both groups for the other outcome measures. First clinical experience with this treatment modality shows that it is an attractive alternative to conventional tonsillectomy and may offer possible benefits.
A new technique for the management of inaccessible anterior glottic lesions
Authors: Kanagalingam J. , Hurley R. , Grant H. R. , Patel A.
Published: March 2003

We describe a new technique for removing anterior vocal fold lesions, which cannot be visualized with conventional suspension laryngoscopy. These situations are rare and the only alternative surgeons have had previously is an open laryngeal procedure. The technique we describe involves the use of a laryngeal mask airway (LMA), a flexible bronchoscope with biopsy channel, a 400 μm laser fibre and KTP/532 nm laser. This method was used to treat two patients in whom conventional suspension laryngoscopy had previously been attempted and abandoned.
Hearing loss due to mannosidosis and otitis media with effusion. A case report and review of audiological assessments in children with otitis media with effusion
Authors: Ahmmed A. U. , O’Halloran S. M. , Roland N. J. , Starkey M. , Wraith J. E.
Published: March 2003

A case of a child with mannosidosis and bilateral otitis media with effusion (OME) is reported here along with some discussion of relevant literature to emphasize the need for age appropriate audiometricc assessment before and after insertion of grommets for glue ear (OME).

There is a need for multidisciplinary teamwork in the management of children with hearing loss. If OME is treated surgically, age-appropriate hearing assessment is required before and after insertion of grommets. The need for audiological assessments will be relevant even if children had passed the newborn hearing screening test.
Sudden unilateral deafness after bilateral knee replacement
Authors: Phillips J. S. , Prinsley P. R.
Published: March 2003

This case report presents profound unremitting hearing loss in a 76-year-old man after having a bilateral knee replacement. There have been no other cases of permanent post-operative deafness after joint replacement in the world literature. Sudden post-operative deafness is rare. We conclude that this man’s deafness is due to a fat embolism in his auditory circulation.
Bilateral benign paroxysmal positional vertigo following a tooth implantation
Authors: Kaplan Daniel M. , Attal Uriel , Kraus Mordechai
Published: March 2003

Benign paroxysmal positional vertigo (BPPV) is a common cause of vertigo and may occur following recent head trauma. Bilateral involvement in BPPV is considered rare and has received little attention in the medical literature. We describe an unusual case of bilateral BPPV in a middle-aged woman that presented during a dental implantation, performed with the use of osteotomes. We discuss the diagnostic and therapeutic challenge of this entity.
Unusual complication of tonsillectomy: taste disturbance and the lingual branch of the glossopharyngeal nerve
Authors: Uzun Cem , Adali Mustafa Kemal , Karasalihoglu Ahmet Rifat
Published: March 2003

Taste disturbance is an unusual complication of tonsillectomy of which there are very few reports in the literature. The possible causes of this rare complication are: (1) direct or indirect damage to the glossopharyngeal nerve or its lingual branch (LBGN), (2) lack of dietary zinc, and (3) habitual drug intake.

We report a 41-year-old man, who complained of taste disturbance following tonsillectomy that was performed for chronic tonsillitis and unilateral (left) tonsillar hypertrophy. During surgery, hypertrophic tonsils were found to be sited deeply into the tonsillar bed, especially at the lower pole of the left tonsil. Pathologic examination following tonsillectomy revealed a keratinous cyst and chronic infection at the left tonsil, and lymphoid hyperplasia and chronic infection at the right tonsil. Although his complaint had been getting better, qualitative examination of his taste function revealed bilateral impairment of the sense of sweet taste on the base of his tongue two months after the surgery, and a taste disturbance of sweet taste on the left side persisted the 10th month after the surgery. His serum zinc value was normal, and he did not take any drug that could affect his sense of taste. Depending on the literature data, possible indirect damage to the LBGN was suspected as the cause of the taste disturbance. This symptom may be reversible within two years after tonsillectomy, but it can also be irreversible. Therefore, tonsillectomy should be performed with minimal trauma to the tonsillar bed, especially when there is an additional pathology extending into the lower pole, and such a patient should be informed of the risk of post-operative taste disturbance after tonsillectomy as being one of the rare complications of this surgery.