Serum anti-GM2 and anti-GalNAc-GD1a IgG antibodies are biomarkers for acute canine polyradiculoneuritis

OBJECTIVES

A previous single-country pilot study indicated serum anti-GM2 and anti-GA1 anti-glycolipid antibodies as potential biomarkers for acute canine polyradiculoneuritis. This study aims to validate these findings in a large geographically heterogenous cohort.

MATERIALS AND METHODS

Sera from 175 dogs clinically diagnosed with acute canine polyradiculoneuritis, 112 dogs with other peripheral nerve, cranial nerve or neuromuscular disorders and 226 neurologically normal dogs were screened for anti-glycolipid antibodies against 11 common glycolipid targets to determine the immunoglobulin G anti-glycolipid antibodies with the highest combined sensitivity and specificity for acute canine polyradiculoneuritis.

RESULTS

Anti-GM2 anti-glycolipid antibodies reached the highest combined sensitivity and specificity (sensitivity: 65.1%, 95% confidence interval 57.6 to 72.2%; specificity: 90.2%, 95% confidence interval 83.1 to 95.0%), followed by anti-GalNAc-GD1a anti-glycolipid antibodies (sensitivity: 61.7%, 95% confidence interval 54.1 to 68.9%; specificity: 89.3%, 95% confidence interval 82.0 to 94.3%) and these anti-glycolipid antibodies were frequently present concomitantly. Anti-GA1 anti-glycolipid antibodies were detected in both acute canine polyradiculoneuritis and control animals. Both for anti-GM2 and anti-GalNAc-GD1a anti-glycolipid antibodies, sex was found a significantly associated factor with a female to male odds ratio of 2.55 (1.27 to 5.31) and 3.00 (1.22 to 7.89), respectively. Anti-GalNAc-GD1a anti-glycolipid antibodies were more commonly observed in dogs unable to walk (OR 4.56, 1.56 to 14.87).

CLINICAL SIGNIFICANCE

Anti-GM2 and anti-GalNAc-GD1a immunoglobulin G anti-glycolipid antibodies represent serum biomarkers for acute canine polyradiculoneuritis.

Prevention of Chronic Glomerular Uremia in Steroid Resistant Glomerulonephritis. A Clinical Trial with a New Antithrombotic Agent

To investigate the possibility of slowing down disease progression 27 patients with primary glomerular diseases unresponsive to steroids and cytotoxic drugs were treated with Defibrotide. This drug is a single stranded DNA fraction which has profibrinolytic and deaggregating properties and can promote the generation and release of prostacyclin from vascular tissue. Before treatment all patients showed proteinuria in excess of 1 g/day and 16 had a nephrotic syndrome (59%); 10 patients had serum creatinine above 1.6 mg/dl (37%) and 6 were hypertensive. After therapy a significant decrease in daily proteinuria was observed, although the reduction exceeded 50% of pre-treatment values in only 16 patients (59%). A progressive decrease in serum creatinine occurred in patients with abnormal renal function; serial measurement of renal plasma flow showed a progressive improvement with an average increase of 6 and 12%, after 1 and 3 months of treatment, respectively.

These observations confirm the view that drugs improving endothelial function and renal hemodynamics can be of value in the treatment of chronic glomerular diseases and can contribute to the maintenance of renal function.

(99m)Tc glucarate as a potential radiopharmaceutical agent for assessment of tumor viability: from bench to the bed side

Several radiotracers have been used for assessing cell death, whether by necrosis or apoptosis. ^99mTc glucarate, which has initially been reported to be concentrating/accumulating in myocardial infarction or zones of cerebral injury, has also shown some tumor-seeking properties in a few preliminary studies. Under International Atomic Energy Agency (IAEA)'s coordinated research program, we report here the standardization, quality control, and clinical evaluation (detection, evaluation of response, and comparison with ¹⁸F Fluorodeoxyglucose) of this tracer in well-characterized lung cancer and head neck malignancies in a single-arm prospective observational study. Forty-seven patients (29 inoperable lung carcinoma and 18 head and neck malignancies) were prospectively enrolled and underwent ^99mTc glucarate imaging [whole body planar and single-photon emission computed tomography of the region of interest] 4-5 hours after injection of 20 mCi of the radiopharmaceutical. Excellent ^99mTc glucarate concentration was noted in the target lesion in lung cancer and head and neck malignancies. The sensitivity was found to be better in lung cancer. Avid concentration of tracer was seen in the metastatic sites. During response evaluation, the glucarate concentration correlated well with the clinical and other radiological findings. ^99mTc glucarate showed avid concentration of tracer in the tumor, suggesting it to be a potential tumor imaging agent which can be used for detection and assessment of therapeutic response in malignancy.

Technological behaviour and recycling potential of spent foundry sands in clay bricks

The feasibility of recycling spent foundry sand in clay bricks was assessed in laboratory, pilot line and industrial trials, using naturally occurring sand as a reference. Raw materials were analyzed by X-ray fluorescence, X-ray diffraction, particle size distribution, and leaching and combined to produce bodies containing up to 35% wt. sand. The extrusion, drying and firing behaviour (plasticity, drying sensitivity, mechanical strength, bulk density, water absorption, and shrinkage) were determined. The microstructure, phase composition, durability and leaching (EN 12457, granular materials, end-life step, European Waste Landfill Directive; NEN 7345, monolithic materials, use-life step, Dutch Building Material Decree) were evaluated for bricks manufactured at optimal firing temperature. These results demonstrate that spent foundry sand can be recycled in clay bricks. There are no relevant technological drawbacks, but the feasibility strongly depends on the properties of the raw materials. Spent foundry sand may be introduced into bricks up to 30% wt. Most of the hazardous elements from the spent foundry sand are inertized during firing and the concentrations of hazardous components in the leachates are below the standard threshold for inert waste category landfill excepting for chromium and lead; however, their environmental risk during their use-life step can be considered negligible.

Recycling PC and TV waste glass in clay bricks and roof tiles

Disposal of PC monitors and TV sets is a growing problem, with over 40% of the weight of these systems comprised of waste glasses with high Pb (funnel) or Ba-Sr concentrations (panel), making them unsuitable for recycling and manufacturing new glass. A possible way to re-use these glasses is in the manufacturing of clay bricks and roof tiles. This possibility was appraised by laboratory simulation of the brickmaking process and technological characterization of unfired and fired products. The recycling of both funnel and panel glasses into clay bodies is technologically feasible, resulting in a substantially reduced plasticity behaviour during shaping-drying (implying a reduction of mechanical strength), and a promotion of sintering during firing. No significant release of Pb, Ba, and Sr was observed during the firing and leaching test for the carbonate-poor body; in contrast, some Pb volatilization during firing and Sr leaching were observed for the carbonate-rich body. Additions of 2 wt.% appear to be practicable, while 5 wt.% glass induces unacceptable modifications of technological properties. The recommended amount is within 2 and 4 wt.%, depending on the characteristics of the clay bodies. The main constraint is that the glass must have a particle size below the limit of the pan mills used in brickmaking (<1mm).

The thermal transformation of Man Made Vitreous Fibers (MMVF) and safe recycling as secondary raw materials (SRM)

This work describes the high temperature reaction sequence of commercial Man Made Vitreous Fibers (MMVF) Cerafiber, Superwool, Rock wool and Glass wool which may be used as substitute for asbestos in some industrial applications. Knowledge of the reaction path and transformation sequence is very important to assess whether carcinogenic crystalline phases are formed during devitrification, which may occur when used as insulators. In addition, knowledge about the nature of the phases formed at high temperature is mandatory to assess if thermally transformed MMVF can be safely recycled as secondary raw material (SRM). In this scenario, this study provides useful information for the optimization of the industrial annealing process aimed to attain a safe, recyclable product. The results of this work show that one of the high-temperature products of Cerafiber and Superwool is cristobalite which is classified as a carcinogenic. It was possible to define the temperature interval at which Cerafiber and Superwool fibers can be safely used as thermal insulators (e.g. insulators in tunnel and/or roller kilns, etc.). As cristobalite is formed in both synthetic fiber products at temperatures higher than 1200 degrees C, their use should be limited to devices operating at lower temperatures. Rock and Glass wool melt upon thermal treatment. As far as the industrial process of inertization is concerned, a maximum firing temperature of 1100 and 600 degrees C is required to melt Rock wool and Glass wool, respectively, with the high-temperature products that can be safely recycled as SRM. Recycling of these products in stoneware tile mixtures were subsequently attempted. The addition of 1-2 wt.% of the melts of Rock and Glass wool gave promising results in terms of viscous sintering reactions and resistance to staining with the only weak characteristic being the color properties of the fired bodies which tend to worsen.

N3 potentials in response to high intensity auditory stimuli in animals with suspected cochleo-saccular deafness

We describe a previously un-reported vertex-negative potential evoked by high intensity click auditory stimuli in some dogs and cats with suspected cochleo-saccular deafness. Brainstem auditory evoked potential tracings from 24 unilaterally or bilaterally deaf animals, 22 dogs and 2 cats, among which 21 belonged to breeds with high prevalence of suspected or histologically confirmed cochleo-saccular deafness, were studied retrospectively. Values for latency, amplitude and threshold of this potential in dogs were 2.15+/-0.23 ms, 0.49+/-0.25 microV, and 91.9+/-4.7 dB NHL, respectively (mean+/-SD). Latency and threshold values in cats were in the mean+/-2 SD range of the dog values. Sensitivity to click stimulus polarity and to click stimulus delivery rate pointed towards a neural potential instead of a receptor potential. The vertex-negative wave observed in these animals shares all characteristics with the N3 potential described in some deaf humans with cochlear deafness, where it is presumed to arise from saccular stimulation. The combined degeneration of cochlea and sacculus usually reported in deaf white dogs and cats suggest that N3 may have a different origin in these species.

EANM/ESC procedural guidelines for myocardial perfusion imaging in nuclear cardiology

The European procedural guidelines for radionuclide imaging of myocardial perfusion and viability are presented in 13 sections covering patient information, radiopharmaceuticals, injected activities and dosimetry, stress tests, imaging protocols and acquisition, quality control and reconstruction methods, gated studies and attenuation-scatter compensation, data analysis, reports and image display, and positron emission tomography. If the specific recommendations given could not be based on evidence from original, scientific studies, we tried to express this state-of-art. The guidelines are designed to assist in the practice of performing, interpreting and reporting myocardial perfusion SPET. The guidelines do not discuss clinical indications, benefits or drawbacks of radionuclide myocardial imaging compared to non-nuclear techniques, nor do they cover cost benefit or cost effectiveness.

Myocardial SPECT: what do we gain from attenuation correction (and when)?

AIM

This study aimed at assessing the impact of attenuation correction performed by means of a new hardware device (Beacon(tm)) in the assessment of coronary artery disease with myocardial SPECT and, afterwards, at identifying what specific risk class of patients would mostly benefit from the technique.

METHODS

The first 500 consecutive patients, referred to our facility for coronary artery disease (CAD) assessment, were included in this study. Myocardial SPECT was performed after i.v. of 740 MBq of (99m)Tc Tetrofosmin (Myoview, Amersham Health) both after stress and at rest. Studies were acquired by means of a 3 head system (IRIX, Philips Medical System) equipped with the Beacontm option to correct for non-uniform attenuation. Out of the whole population studied, 130 patients underwent coronary angiography (CAG), 108 of which were proven to be affected by significant CAD, defined as a >50% coronary vessel lumen reduction. Attenuation corrected (AC) as well as non-attenuation corrected studies (NAC) were reconstructed, blindly read and qualified as: normal; borderline normal; borderline abnormal and definitely abnormal.

RESULTS

In the group of 130 patients who underwent CAG, sensitivity for CAD detection did not vary significantly (96% and 93%, for NAC and AC studies, respectively, p=ns) whereas specificity increased from 73% (NAC studies) to 91% (AC studies), p<0.01. Normalcy rate, assessed in a small subgroup (n=21) with a <5% likelihood for CAD, was found to be 80% for NAC studies vs 93% for AC studies (p<0.05). As regards synthetic clinical judgements, when we grouped normal and probably normal readings into a single ''normal'' category and, conversely, probably abnormal and definitely abnormal into a single ''pathological'' category, we see that after attenuation correction studies reported as ''pathological'' are reclassified as ''normal'' in 17.8% of the cases (25.2% in males and 6.9% in females, p<0.05). The opposite is seen in only 1.6% of the cases (1.3% in males and 4.4% in females). According to established criteria, 155 patients were classified at low risk for CAD (<15%), 115 at intermediate risk (from >15% to <50%) and 230 at high risk (>50%). The intermediate risk class showed the greatest impact: ''normal'' findings increased from 52% to 72%, thus reducing the rate of ''pathological'' reports from 48% to 28%.

CONCLUSIONS

This study shows that, while sensitivity for CAD is not affected by attenuation correction, specificity increases significantly, as well as normalcy rate. Out of the whole population studied, the main finding was that attenuation correction increases the rate of normal reports, more frequently in males than in females, and that studies carried out in patients at intermediate risk for CAD are more likely to be affected.

Evaluation of thrombogenicity of fluoropassivated polyester patches following carotid endarterectomy

The use of a patch after carotid endarterectomy (CE) is recommended to reduce the incidence of restenosis. Most studies on this subject report the implantation of saphenous vein or PTFE patches, because polyester has always been considered to be a thrombogenic material. The purpose of this study was to evaluate the thrombogenicity of a knitted polyester patch passivated by fluoropolymer surface treatment (FPD patch), which experimental studies have demonstrated to be less thrombogenic than other materials. This prospective, randomized study was performed in 22 patients who underwent CE. In 11 patients the arteriotomy was sutured directly, while in the other 11 an FPD patch was applied. Patients' 111in-oxine labeled platelets were reinjected on the first postoperative day, and scintigraphies were performed after 4, 24, and 48 hr, respectively. The study confirmed that an FPD patch is no more thrombogenic than a simple carotid endarterectomy. The application of the patch, therefore, can be recommended to reduce restenosis without any adjunctive thromboembolic risk.

Retrospective analysis of the association of nodular goiter with primary and secondary hyperparathyroidism

BACKGROUND

The association of hyperparathyroidism (HPT) with thyroid disease has long been known, but the mechanisms underlying such an association have not yet been clarified.

OBJECTIVE

To elucidate the main factors determining this combination of endocrine diseases, in a retrospective multicenter study.

METHODS

We retrospectively reviewed all patients referred for parathyroid scintigraphy in the period 1990-1999. A total of 487 patients in the age range 17-65 years were selected for the analysis (339 women and 148 men); group A included 241 patients with primary and group B 246 patients with secondary HPT.

RESULTS

A total of 124/241 patients in group A (51.5%), but only 92/246 patients in group B (38.2%) had thyroid disorders (notably nodular goiter) associated with HPT (P=0.0035). Thyroid disorders were evenly distributed throughout the entire 17-65 years age range in group A, but 17-40-year-old patients in group B had significantly fewer thyroid disorders than the older patients of the same group (15.5% compared with 43.3%, P<0.002), as expected in a general population. In patients with primary HPT there was no difference in the prevalence of thyroid disease between women and men, whereas the ratio of women to men in secondary HPT patients with thyroid disease was about 3:1.

CONCLUSIONS

These results demonstrate an increased prevalence of nodular goiter in patients with primary rather than secondary HPT, and are consistent with a possible role of increased endogenous calcium concentrations (a hallmark of primary, but not of secondary, HPT) as a goitrogenic factor in patients with HPT.

Decomposition of nitrous oxide on pillared clays

Alumina-pillared smectites have been found to abate nitrous oxide in the presence of methane. The results indicate that the yield of the reaction (N20 --> N2 + (1/2)O2) increases when pillared clays are exchanged with transition metals, single-pass conversion rates of >70% being attainable. In particular, when double exchanged (calcium and subsequently copper) alumina pillared montmorillonite/beidellite is used as a catalyst, de-N2O activity reaches a maximum, which is maintained even after 4 h of work at a space velocity of 5.5 h(-1). A mechanism for the reaction is suggested, which implies that N2O is first adsorbed by the catalyst and then decomposes through two different paths: catalyst oxidation and catalyst reduction. Such a redox process explains the kinetic data.

High-performance liquid chromatography study of the enantiomer separation of chrysanthemic acid and its analogous compounds on a terguride-based stationary phase

The direct enantioseparation of chrysanthemic acid [2,2-dimethyl-3-(2-methylpropenyl)-cyclopropanecarboxylic acid] and its halogen-substituted analogues was systematically studied by HPLC using a terguride-based chiral stationary phase in combination with a UV diode array and chiroptical detectors. Isomers with (1R) configuration always eluted before those with (IS) configuration. The elution sequence of cis- and trans-isomers was strongly affected by mobile phase pH, whereas the enantioselectivity remained the same. Conditions for the separation of all the enantiomers were also examined. This method was used for monitor the hydrolytic degradation products of Cyfluthrin (Baythroid) in soil under laboratory conditions.

Can newborns discriminate between their own cry and the cry of another newborn infant?

Two experiments were conducted to test whether newborns could discriminate between their own cry and the cry of another newborn infant. Facial behavior and nonnutritive sucking rate were adopted as dependent measures. In Experiment 1, 20 newborns in an awake state were presented with either their own cry or the cry of another infant. In the latter condition, newborns showed the facial expression of distress more frequently and for a longer duration. In addition, the rate of sucking decreased significantly between the pretest phase and the 1st min of presentation of another infant's cry. Newborns' responses, although delayed and less intense, showed a similar trend in Experiment 2, during which 20 newborns in a sleep state were tested with the same procedure. These results indicate the newborns' capability to discriminate between the 2 cry stimuli and show the effectiveness of a newborn cry in inducing distress signals in another newborn infant.

Can newborns discriminate between their own cry and the cry of another newborn infant?

Two experiments were conducted to test whether newborns could discriminate between their own cry and the cry of another newborn infant. Facial behavior and nonnutritive sucking rate were adopted as dependent measures. In Experiment 1, 20 newborns in an awake state were presented with either their own cry or the cry of another infant. In the latter condition, newborns showed the facial expression of distress more frequently and for a longer duration. In addition, the rate of sucking decreased significantly between the pretest phase and the 1st min of presentation of another infant's cry. Newborns' responses, although delayed and less intense, showed a similar trend in Experiment 2, during which 20 newborns in a sleep state were tested with the same procedure. These results indicate the newborns' capability to discriminate between the 2 cry stimuli and show the effectiveness of a newborn cry in inducing distress signals in another newborn infant.

Characterization of a small chondroitin sulfate proteoglycan isolated from the mucus surrounding the embryos of Viviparus ater (Mollusca Gastropoda)

A small chondroitin sulfate proteoglycan was isolated and partially characterized for core protein and glycosaminoglycan structures from the mucus surrounding embryos in the developmental pouch of Viviparus ater (Mollusca Gastropoda). The protein bearing polysaccharide nature was confirmed by gel-permeation chromatography separation of fractions positive to the uronic acid dosage, 7.5% SDS-PAGE under reducing conditions, sequential staining with alcian blue and ammoniacal silver. Its molecular mass was calculated at about 228,800. After degradation of the galactosaminoglycan components by chondroitinase ABC in the presence of proteinase inhibitors, the molecular mass of the core protein was determined at about 72,200. Treatment of the proteoglycan with keratanase did not modify its electrophoretic migration. Isoelectric focusing of the core protein demonstrated a micro-heterogeneity with the presence of two isoforms with different isoelectric point, pI=8.2 and 6.6, in a ratio of about 1:2.2. The glycosaminoglycan component of the proteoglycan was characterized as chondroitin sulfate with a molecular mass of about 30,750 composed of 5% non-sulfated unsaturated disaccharide, 94% monosulfated disaccharides (4-monosulfated to 6-monosulfated disaccharide ratio of 1.36) and 1. 5% disulfated disaccharides (in particular 1.3% 2,6-disulfated disaccharide) with a sulfate to carboxyl ratio of 0.96. Degradation of the chondroitin sulfate with chondroitinase ABC and ACII permitted to determine a percentage of glucuronic acid of about 78.4. The proteoglycan isolated from the mucus surrounding the embryos of Viviparus ater is formed by a small core protein bearing about five chondroitin sulfate chains (80% chondroitin sulfate/20% dermatan sulfate) with potential function in the developmental processes of molluscs embryos.

MAIA project: software for the management of toxicodependence treatment process

This chapter reviews the importance of information management in a therapeutic community, how to select the data collected by the interview and features of the software and its fitting in an operative context. New sections are projected to help staff who diagnose treatment candidates and treat patients. Use of statistical analysis as an instrument for management of therapeutic communities is based on the experience of "Centro Solidarietà di Modena". Some examples are included on the population of "Centro Solidarietà di Modena". Artificial neural networks have a viable role for treatment (primary, secondary and tertiary).

Bartter's syndrome: renal scintigraphic appearance after captopril administration

We report a case of Bartter's syndrome, a rare disease characterized by hypokalemia, increased plasma renin and angiotensin II levels with normal blood pressure. During the diagnostic work-up, the patient had renal scintigraphy in baseline and after captopril administration. Pharmacological blockade of the renin-angiotensin system with captopril resulted in bilateral and symmetrical renal abnormalities (increase of parenchymal transit time, time to maximum activity and retained cortical activity, with cortical trapping of the radiopharmaceutical). Baseline scintigraphy was normal. The findings are consistent with Bartter's syndrome pathogenesis. Captopril renography may be useful to differentiate Bartter's syndrome from other covert causes of hypokalemia.

Determination of individual renal function through noninvasive methodologies

Radioactive tracers provide a unique means of determining individual renal function and are therefore to be preferred for obtaining accurate information on the functional status of each kidney. New applications of computed tomography and magnetic resonance imaging appear promising, but results from large studies are not available to confirm their potential role.

Effects of acetylsalicylic acid on serotonin brain receptor subtypes

1. The lysine salt of acetyl salicylic acid (ASA) at a dose equivalent to 400 mg/kg of acetyl salicylic acid (ASA) was intraperitoneally administered in rats. 2. After 30 and 120 min ASA did not modify the number of receptors nor the affinity of [3H] 8-OH-DPAT binding sites in pons and cerebral cortex. On the other hand, the receptor number in the cortex membranes decreased significantly using [3H] ketanserin as ligand, while the receptor number in the pontine membranes did not change. 3. These data support the involvement of central 5-HT receptors in the mode of action of ASA.

Assessment of myocardial viability after thallium-201 reinjection or rest-redistribution imaging: a multicenter study. The Italian Group of Nuclear Cardiology

To establish the real nature of 201Tl defects in the assessment of myocardial viability (e.g., fixed versus reversible), 201Tl reinjection was evaluated in a multicenter trial involving 402 consecutive patients with ischemic heart disease and exercise 201Tl defects.

METHODS

Twelve hospitals, using the same type of gamma camera and computer software, adopted one of the two most widely used reinjection protocols. In 230 patients (Group A), reinjection was performed immediately after stress-redistribution planar imaging; in 172 patients (Group B), reinjection was performed on a separate day and followed by rest-redistribution imaging. The images were interpreted by three blinded observers in a core laboratory on a five-point qualitative scale; the reproducibility in visual scoring was excellent.

RESULTS

Groups A and B had a similar prevalence of myocardial segments with abnormal uptake at stress (39%, 40%), as well as with reversible (16%, 17%), partially reversible (21%, 19%) and irreversible (63%, 64%) defects at redistribution. After reinjection, 201Tl uptake improved in 27% and 36% of both partially reversible and irreversible defects in Groups A and B. No differences were found when comparing early and delayed reinjection imaging in Group B.

CONCLUSION

This study confirms the validity of 201Tl reinjection in a large, unselected population, but the discordance with stress/redistribution is less than has been previously reported for both 201Tl reinjection protocols, the prevalence of improved segments after reinjection was higher with the separate day approach.

Early pulmonary involvement in systemic sclerosis assessed by technetium-99m-DTPA clearance rate

Systemic sclerosis (SS) is frequently associated with interstitial lung disease, but clinical symptoms and radiologic abnormalities may occur late in the course of the disease. This study investigated early pulmonary involvement by assessing the clearance rate of inhaled 99mTc-diethylenetriaminepentaacetic acid (DTPA).

METHODS

Sixteen patients with proved SS, no clinical pulmonary symptoms and normal chest radiogram were prospectively studied. The 99mTc-DTPA clearance rate was calculated as the time to half clearance (T1/2) and compared with values obtained in healthy nonsmokers.

RESULTS

Six patients showed abnormally increased clearance (T1/2 < 53 min). Rapid clearance was not correlated to SS disease duration or to abnormal pulmonary function tests. Five of six patients with abnormally increased clearance underwent high-resolution CT, which in all five demonstrated pathologic findings that were suggestive of early interstitial disease.

CONCLUSION

These findings indicate that in SS asymptomatic patients may frequently present with abnormal 99mTc-DTPA clearance; 99mTc-DTPA lung scintigraphy may allow early detection of subclinical pulmonary involvement in SS.

A multicenter trial on interobserver and intraobserver reproducibility of segmental scoring of thallium-201 planar myocardial imaging before and after reinjection. Italian Group of Nuclear Cardiology

Inter- and intraobserver reproducibility (R) of segmental 201Tl scores after stress (ST), redistribution (RD) and reinjection (RI) planar imaging were evaluated.

METHODS

Images were examined from 396 patients with suspected coronary artery disease, demonstrated by means of post-ST imaging of at least one perfusion defect. To eliminate external sources of variability, the same gamma camera, acquisition protocol and computer software were used in this multicenter study. Thallium-201 images of the anterior, left anterior oblique and left lateral projections were obtained immediately, 4 hr after exercise and 30 min after the injection of additional 201Tl either on the same day or on a different day. The left ventricle was divided into 15 segments and evaluated by three independent observers, blinded to clinical data, according to a five-point scale.

RESULTS

The R score for ST, RD and RI images, expressed as an intraclass correlation coefficient, was 0.76, 0.74 and 0.72, respectively. After averaging multiple observer scores, R increased to 0.91, 0.90 and 0.89, respectively. Individual observer measurement of the R score was 0.48, 0.51 and 0.32 for ST-RD, ST-RI and RD-RI image pairs, respectively, and multiple observer scores showed R increases to 0.74, 0.76 and 0.58.

CONCLUSION

This qualitative scale reliably assesses the severity of 201Tl perfusion defects, particularly when multiple-observer scores are averaged. Individual observer change scores should be taken with great caution, especially in studies involving the visual evaluation of RD-RI image changes.

Evaluation of hypertensive patients with a solitary kidney using captopril renal scintigraphy with 99Tcm-MAG3

The study aimed to evaluate the safety and reliability of captopril renal scintigraphy (CRS) for diagnosing functionally significant renal artery stenosis (RAS) in hypertensive patients with a solitary kidney. Radionuclide studies were carried out using 100 MBq 99Tcm-mercaptoacetyl triglycine (MAG3), 1 h after administration of 50 mg captopril, and repeated in baseline condition when abnormalities were observed in the provocative study. Scintigraphic diagnosis of RAS was based on analysis of captopril-induced changes of the radiorenographs. Overall, 12 patients with a solitary kidney were investigated, and scintigraphic results compared to angiographic findings. All five patients with positive CRS showed an RAS > 50%, whereas only one of the seven patients with negative CRS was affected by RAS. A significant fall in mean arterial pressure was recorded after captopril administration (123 +/- 12 mm Hg before versus 108 +/- 11 after), but no serious side effects were observed. Our results demonstrate that captopril-induced modifications of the renogram could effectively be used to diagnose the presence of RAS. Captopril renal scintigraphy may therefore be suggested as a reliable and safe noninvasive approach to evaluate hypertensive patients with a solitary kidney.

[Identification of viable myocardium by 201Tl scintigraphy: a comparison of methods]

The present study was undertaken to compare four different imaging approaches to evaluate uptake defect reversibility. 24 infarcted patients underwent standard stress/redistribution 201Tl imaging (R1). Then, after reinjection of 37 MBq of 201Tl, patients were re-imaged either after 15 min (R2) 24 h later (R3). A separate rest study (R4) following a new tracer injection was done within 2-3 days. Planar images were obtained in the standard three views and subdivided into 216 segments for qualitative analysis based on a visual score. A semiquantitative analysis based upon circumferential profiles was also applied. A stress defect was found in 127 segments (58.7%). By visual inspection reperfusion was considered to occur in 32.3%, 41.7%, 33.0% and 49.6% of the cases with R1, R2, R3, and R4, respectively. The semiquantitative method showed a high reperfusion only with R1 (62%), while the other procedures proved less effective. No improvement was found with R4. Six patients (25%) showed myocardial viability that was not detected with the early reinjection technique.

Diagnosis of renovascular hypertension with captopril renal scintigraphy in a patient with a solitary kidney

A patient with a solitary kidney due to renal agenesis and contralateral kidney perfusion impairment due to renal artery stenosis was successfully treated with percutaneous transluminal renal angioplasty. Preintervention diagnostic work-up included captopril renal scintigraphy, which was suggestive of high probability of renovascular hypertension. Scintigraphic assessment 2 mo after angioplasty failed to show any abnormality after captopril administration, a finding in line with blood pressure beneficial response to renal artery revascularization. A 12-mo follow-up confirmed cure of hypertension.

[Color-Doppler and angioplasty in renovascular hypertension]

Renovascular hypertension is defined as a kind of hypertension secondary to altered renal perfusion with the activation of the renin-angiotensin system. Since a large number of these patients benefits from treatment--be it medical, surgical or angioplastic--a non-invasive low-cost method allowing accurate screening was looked for. Color-Doppler was employed by many authors to evaluate renovascular hypertension, for both the early diagnosis of the condition and the evaluation of treatment results in renal artery stenoses. However, the authors agree that color-Doppler cannot play a major role in the screening of renovascular hypertension due to the various qualitative and quantitative variables not being adequately codified, to the lack of a single color-Doppler method and to the difficult comparison of the results from the different units. Nevertheless, improved results are promised by technological evolution, together with the possibility to codify color-Doppler variables more easily repeatable. B-mode units with 3.5 and 5 MHz probes were employed in the thinnest subjects. In 5-25% of cases accessory renal arteries were observed. After identifying the vessel to be studied with several spatial scans, the smallest possible sample volume (usually 3-5 mm) was positioned. The normal flowmetric range was 0.07-0.1 s: it must not exceed 0.16 s, with persistence of high diastolic flow. Some authors' criteria were followed to define either stenosis or renal artery obstruction; moreover, pulsatile flow index was considered, together with the resistive index, pulsatility index and stenosis index.

A comparison of rest sestamibi and rest-redistribution thallium single photon emission tomography: possible implications for myocardial viability detection in infarcted patients

Thirty patients (26 men, 4 women, mean age 61 +/- 8 years) who had suffered myocardial infarction 15 +/- 6 months previously, were submitted to (1) standard stress-redistribution thallium-201 single photon emission tomography (SPET), (2) rest-redistribution 201T1 SPET and (3) stress-rest technetium-99m sestamibi SPET. Uptake modifications in relation to exercise-induced defects were evaluated in a total of 390 myocardial segments. Tracer uptake was scored as normal (=0), mildly reduced (=1), apparently reduced (=2), severely reduced (=3) or absent (=4). Comparison of stress studies failed to show any statistical difference (58% segmental abnormalities with sestamibi vs 61% with thallium). Uptake abnormalities (score 1-4) were detected in 55% of the segments with sestamibi, 55% with standard thallium redistribution, 55% with early imaging after thallium injection at rest and 54% with 3-h delayed rest imaging (P = NS). Absence of tracer uptake (score = 4) under resting conditions was recorded in 75 (19%) segments with standard 201T1 redistribution, 75 (19%) with rest sestamibi, 70 (18%) with rest 201T1 imaging and 62 (16%) with rst-redistribuion 201T1 (P < 0.05 vs other imaging modalities). Thus, 3-h delayed rest thallium imaging detected reversibility of uptake defects in a significantly higher number of myocardial segments. This finding might have important implications for both tracer and technique selection when myocardial viability is the main clinical issue.

Identifizierung des vitalen Myokards mit der 201T1-Szintigraphie: Ein Vergleich der Methoden

Es wurden die Ergebnisse der Standardtechnik Stress-Redistribution, (R1) mit jenen nach Reinjektion von 37 MBq sofort nach der ersten Spätaufnahme und Bilddokumentation nach 15 min (R2), mit jenen einer Spätaufnahme nach 24 h (R3) und mit jenen, die mit einer zeitlich versetzten Ruheinjektion (R4) gemacht wurden, bei 24 Patienten mit vorangegangenem Herzinfarkt verglichen. Die in drei Projektionsebenen angefertigten planaren Bilder wurden in 216 Segmente unterteilt. Die Anreicherung des 201TI wurde mittels eines subjektiven Scores bzw. semiquantitativer Analyse der Flächen, die aus dem Circumferenzprofil gewonnen wurden, bewertet. Ein Speicherungsdefekt wurde unter Belastung in 127 Segmenten bestätigt (58,7%); die visuelle Analyse konnte eine verbesserte Anreicherung in R1 (32,3%), in R2 (41,7%), in R3 (33%) und in R4 (49,6%) feststellen. Die semiquantitative Bewertung hat nur mit der R1- Methode (62% der Fälle) eine Verbesserung erbracht. Es wurde bei 6 Patienten (25% der Fälle) vitales Myokard nachgewiesen, welches nicht mit der konventionellen Analyse identifiziert werden konnte.

[Renal artery stenosis. Doppler color study before and after angioplasty]

Doppler flowmetry can be successfully employed to assess arterial patency after percutaneous transluminal angioplasty (PTA). The aim of this study was to assess color Doppler sensitivity in detecting renal artery stenosis prior to percutaneous angioplasty (PTRA) and vessel patency after it. Eleven patients (7 males and 4 females) affected with renal artery stenosis, unilateral in 9 cases and bilaterally in 2, underwent color-Doppler evaluation 1 day before and 7 days after PTRA. The operator was unaware of dilatation results. A total of 13 stenoses were treated. The qualitative and quantitative parameters we employed were: a) broadening of the spectrum, b) peak systolic frequency > 4000 Hz, c) stenosis index > 50%. Before PTRA, mean systolic peak at the stenosis was 7978 (range 4050-12500 Hz), while stenosis index was 71.9% (range 48-89%). After PTRA complete recovery was observed in 5 cases, no improvement in 1 and incomplete recovery in 7. Doppler results were in agreement with those of angiography in 6/13 while partial agreement only was seen in 7/13. Our results, although obtained in a small and highly selected group of patients, would seem to support the value of color-Doppler for the follow-up of patients after PTRA.