Epidemiologie der Frühsommer-Meningoenzephalitis (FSME) in der Schweiz 1984 bis 2004

Von 1984 bis 2004 wurden in der Schweiz im Rahmen des obligatorischen Meldesystems insgesamt 1370 FSME-Erkrankungen gemeldet, mit einer deutlichen Zunahme in den 90er-Jahren. In den letzten sechs Jahren seit 1999 waren es durchschnittlich 101 Fälle pro Jahr. Dies entspricht einer gesamtschweizerischen Inzidenz von 1,4/105/Jahr oder von ca. 6/105/Jahr bezogen auf die Bevölkerung der betroffenen Regionen. Das männliche Geschlecht war doppelt so häufig betroffen im Vergleich zum weiblichen. Die Altersverteilung zeigte zwei Gipfel im Alter von 6 bis 14 und 60 bis 69 Jahren. Bei unter 6-Jährigen waren Erkrankungen sehr selten (zwei hospitalisierte Kinder pro Jahr). Der Schweregrad der Erkrankungen nahm mit dem Alter zu. Bei 86% der Patienten lag eine neurologische Symptomatik vor, 14% der Patienten wiesen nur grippale Symptome auf. Von den Patienten mit einer neurologischen Symptomatik mussten 90% hospitalisiert werden, 1,3% überlebten die Krankheit nicht (durchschnittlich ein Todesfall pro Jahr seit 1999). Erkrankungen bei vollständig geimpften Personen waren sehr selten. Die meisten Patienten dürften sich an ihrem Wohnort oder in dessen näheren Umgebung infiziert haben, wobei die Inzidenz in den Großstädten gering war (≤ 1/105/Jahr). In kleineren direkt in Endemiegebieten liegenden Städten stieg die Inzidenz bis auf 18/105/Jahr. Im Verlaufe der 21 Jahre haben sich die zu Beginn der 80er-Jahre bekannten Endemiegebiete in vier Kantonen deutlich ausgedehnt und neue Endemiegebiete sind in sieben weiteren Kantonen dazugekommen. Eine häufige Aktivität im Wald gaben 85% der Patienten an. Obwohl es sich dabei in 80% um Freizeitaktivitäten handelte (vor allem Spaziergänge), dürfte die Inzidenz bei den beruflich exponierten Personen immer noch deutlich höher sein. Dies weist darauf hin, dass die Durchimpfung nicht nur bei den Personen, die sich in der Freizeit exponieren, sondern auch bei den beruflich exponierten Personen immer noch zu gering ist, um die Häufigkeit dieser Krankheit und deren Folgen möglichst weitgehend einschränken zu können.

Cell motility and local viscoelasticity of fibroblasts

Viscoelastic changes of the lamellipodial actin cytoskeleton are a fundamental element of cell motility. Thus, the correlation between the local viscoelastic properties of the lamellipodium (including the transitional region to the cell body) and the speed of lamellipodial extension is studied for normal and malignantly transformed fibroblasts. Using our atomic force microscopy-based microrheology technique, we found different mechanical properties between the lamellipodia of malignantly transformed fibroblasts (H-ras transformed and SV-T2 fibroblasts) and normal fibroblasts (BALB 3T3 fibroblasts). The average elastic constants, K, in the leading edge of SV-T2 fibroblasts (0.48 +/- 0.51 kPa) and of H-ras transformed fibroblasts (0.42 +/- 0.35 kPa) are significantly lower than that of BALB 3T3 fibroblasts (1.01 +/- 0.40 kPa). The analysis of time-lapse phase contrast images shows that the decrease in the elastic constant, K, for malignantly transformed fibroblasts is correlated with the enhanced motility of the lamellipodium. The measured mean speeds are 6.1 +/- 4.5 microm/h for BALB 3T3 fibroblasts, 13.1 +/- 5.2 microm/h for SV-T2 fibroblasts, and 26.2 +/- 11.5 microm/h for H-ras fibroblasts. Furthermore, the elastic constant, K, increases toward the cell body in many instances which coincide with an increase in actin filament density toward the cell body. The correlation between the enhanced motility and the decrease in viscoelastic moduli supports the Elastic Brownian Ratchet model for driving lamellipodia extension.

Towards smaller and faster gas chromatography–mass spectrometry systems for field chemical detection

Gas chromatography-mass spectrometry (GC-MS) is already an important laboratory method, but new sampling techniques and column heating approaches will expand and improve its usefulness for detection and identification of unknown chemicals in field settings. In order to demonstrate commercially-available technical advances for both sampling and column heating, we used solid phase microextraction (SPME) sampling of both water and air systems, followed by immediate analysis with a resistively heated analytical column and mass spectrometric detection. High-concern compounds ranging from 140 to 466 amu were analyzed to show the applicability of these techniques to emergency situations impacting public health. A field portable (about 35 kg) GC-MS system was used for analysis of water samples with a resistively heated analytical column externally mounted as a retrofit using the air bath oven of the original instrument design to heat transfer lines. The system used to analyze air samples included a laboratory mass spectrometer with a dedicated resistive column heating arrangement (no legacy air bath column oven). The combined sampling and analysis time was less than 10 min for both air and water sample types. By combining dedicated resistive column heating with smaller mass spectrometry systems designed specificallyfor use in the field, substantially smaller high performance field-portable instrumentation will be possible.

Climatic conditions as a risk factor in canine gastric dilatation-volvulus

Canine acute gastric dilatation-volvulus (GDV) is a life-threatening condition of multifactorial origin. The risk of developing GDV is influenced by a variety of factors, including breed, age, gender, temperament, diet and management. A relationship between seasonal variations and the frequency of GDV has been previously documented although no association was found with any specific climatic event. Variables in weather conditions within a defined geographic region were investigated in a retrospective study of 287 client-owned dogs diagnosed with GDV between 1992 and 1999. Monthly incidences were evaluated and differences in atmospheric temperature, humidity and pressure between days in which GDV cases were observed and days in which no case was presented were examined. Although temperature was significantly associated with the occurrence of GDV, the difference in temperatures between days with and days without GDV cases was so small that it is unlikely to be of clinical relevance. Moreover, no significant association was found between GDV occurrence and atmospheric pressure or humidity, and a seasonal variation in GDV incidence was not observed.

Fixation of a proximal femoral physeal fracture in a dog using a ventral approach and two Kirschner wires

A Salter-Harris type I proximal femoral physeal fracture was diagnosed in a six-month-old Norfolk Terrier. The fracture was reduced using a ventromedial approach to the hip joint and fixation with two small Kirschner wires applied from the joint surface and countersunk below the cartilage. The ventromedial approach minimizes soft-tissue and vascular damage and affords direct visualization of the fracture, facilitating reduction and fixation. The two-year postoperative outcome was considered satisfactory in this case.

Coping Strategies and the Request for a Consultation on Complementary and Alternative Medicine – a Cross-Sectional Survey of Patients in a Psychosomatic and Three Medical Departments of a German University Hospital

OBJECTIVE

To identify factors, predicting which patients of a large German university hospital request for a consultation on complementary and alternative medicine (CAM).

PATIENTS AND METHODS

350 patients of 3 medical and a psychosomatic department of the University Hospital Freiburg were consecutively surveyed with respect to their coping strategies, health locus of control, anxiety, depression, and the request for a consultation on CAM. Predicting factors were identified via logistic regression models.

RESULTS

The request for a CAM consultation was primarily determined by an active coping strategy (odds ratio 1.66, 95% confidence interval 1.27-2.17, p = 0.0002) and a low Karnofsky index (odds ratio 0.79, 95% confidence interval 0.62-0.99, p = 0.0417). Anxiety, depression or internal health locus of control correlated with each other but could not be proved as independent factors for the request for a CAM consultation.

CONCLUSION

Patients of a university hospital with an active disease coping have a need for information about CAM.

Guiding neuronal growth with light

Control over neuronal growth is a fundamental objective in neuroscience, cell biology, developmental biology, biophysics, and biomedicine and is particularly important for the formation of neural circuits in vitro, as well as nerve regeneration in vivo [Zeck, G. & Fromherz, P. (2001) Proc. Natl. Acad. Sci. USA 98, 10457-10462]. We have shown experimentally that we can use weak optical forces to guide the direction taken by the leading edge, or growth cone, of a nerve cell. In actively extending growth cones, a laser spot is placed in front of a specific area of the nerve's leading edge, enhancing growth into the beam focus and resulting in guided neuronal turns as well as enhanced growth. The power of our laser is chosen so that the resulting gradient forces are sufficiently powerful to bias the actin polymerization-driven lamellipodia extension, but too weak to hold and move the growth cone. We are therefore using light to control a natural biological process, in sharp contrast to the established technique of optical tweezers [Ashkin, A. (1970) Phys. Rev. Lett. 24, 156-159; Ashkin, A. & Dziedzic, J. M. (1987) Science 235, 1517-1520], which uses large optical forces to manipulate entire structures. Our results therefore open an avenue to controlling neuronal growth in vitro and in vivo with a simple, noncontact technique.

Re-ventriculostomy for treatment of obstructive hydrocephalus in cases of stoma dysfunction

In this article, 12 re-ventriculostomies in the treatment for obstructive hydrocephalus are described. The etiology of the hydrocephalus was a benign aqueductal stenosis in 9 patients, a tumor around the aqueduct in 2 patients and intraventricular bleeding in one patient. In all cases the initial ventriculostomy was successful, but after a time interval of 2 weeks to 6 years the patients developed similar clinical symptoms as preoperatively. In all except one case the radiological findings spoke in favour of stoma closure. Intraoperatively the stoma was completely closed in 9 patients and in 3 patients a subtotal closure was observed. In all cases a re-ventriculostomy was performed bluntly with a Fogarty catheter in loco typico at the floor of the third ventricle. Of the 12 patients 6 had an excellent outcome postoperatively, one patient improved and one had a benefit from the re-ventriculostomy although he died of cardiac problems. In the remaining 4 patients the re-ventriculostomy was not successful and the patients needed a shunt operation. In conclusion, after initially successful endoscopic third ventriculostomy, re-ventriculostomy should be considered as a sufficient treatment option in case of suspected stoma dysfunction.

Recurrent cubital tunnel syndrome. Etiology and treatment

Controversy surrounds the treatment of recurrent cubital tunnel syndrome after previous surgery. Irrespective of the surgical technique, namely pure decompression in the ulnar groove and the cubital tunnel distal of the medial epicondyle, and the different methods of volar transposition (subcutaneous, intramuscular, and submuscular), the results of surgical therapy of cubital tunnel syndrome are often not favorable, especially in cases of long-standing symptoms and severe deficits. Twenty-two patients who had previously undergone surgical treatment for ulnar nerve entrapment at the elbow were evaluated because of persistent or recurrent pain, paresthesia, numbness, and motor weakness. Ten patients had undergone a nerve transposition, 5 patients underwent a simple decompression of the ulnar nerve, and 7 patients experienced two previous operations with different surgical techniques. Two patients underwent surgery at our hospital, whereas 20 patients underwent their primary surgery at other institutions. Various surgical techniques were used during the subsequent surgery, such as external neurolysis, subcutaneous anterior transposition, and subsequent transfer of the nerve back into the sulcus. The causes of continued or recurrent symptoms after initial surgery included dense perineural fibrosis of the nerve after subcutaneous transposition, adhesions of the nerve to the medial epicondyle and retention of the medial intermuscular septum. The average follow-up after the last procedure was 7 months (2 - 20 months). All 7 patients with subsequent transfer of the ulnar nerve back into the sulcus became pain-free, whereas only 11 of 15 patients who had external neurolysis or subcutaneous transposition became free of pain or experienced reduced pain. The recovery of motor function and return of sensibility were variable and unpredictable. In summary, reoperation after primary surgery of cubital tunnel syndrome gave satisfactory results in 18 of 22 cases. Subsequent transfer of the ulnar nerve back into the sulcus promises to be useful in cases in which subcutaneous transposition had not been successful.

Adult cochlear implant patient performance with evolving electrode technology

OBJECTIVE

In 1998, clinical trials were initiated to evaluate the CLARION Multi-Strategy Cochlear Implant (Advanced Bionics Corp., Sylmar, CA, U.S.A.), a precurved electrode with an electrode positioning system (EPS) in adults with severe to profound hearing impairments. In 1999, clinical trials were initiated to assess the CLARION HiFocus electrode with EPS in a similar group of adults. The purpose of this retrospective study was to evaluate and compare the preoperative and 1-, 3-, and 6-month postoperative speech perception scores obtained by the first 56 patients implanted with the precurved electrode with EPS and the first 56 patients implanted with the HiFocus electrode with EPS. Speech strategy preferences were additionally noted and compared at each test interval for each group.

STUDY DESIGN

All subjects participated in preoperative testing with hearing aids and postoperative (1, 3 and 6 months) testing with either the precurved electrode with EPS or the HiFocus electrode with EPS. Demographic characteristics and preoperative and postoperative speech perception results were compared within and between the 2 groups.

SETTING

Data presented here were collected at cochlear implant programs affiliated with tertiary medical centers located in the United States and Canada that participated in the clinical trials.

PATIENTS

Patients were postlinguistically deafened adults who received a CLARION cochlear implant.

RESULTS AND CONCLUSION

Within-group evaluations revealed that both groups demonstrated significant improvements on all speech perception measures when 1-month postoperative scores were compared with scores obtained preoperatively with hearing aids. Between-group comparison of demographic data showed that the HiFocus group had a significantly higher mean age at implant and a significantly longer mean duration of deafness than the precurved electrode with EPS group. Statistical comparison of mean speech perception scores showed no significant difference between subjects using the precurved electrode with EPS versus the HiFocus electrode with EPS at the preoperative, 1-, and 3-month test intervals. At the 6-month test interval, the mean CNC Monosyllabic Word Test score obtained by the HiFocus with EPS group was significantly better than the mean score obtained by the group with the precurved electrode with EPS (p < 0.05).

Reduced red cell 2,3-diphosphoglycerate concentrations in critical illness without decreased in vivo P50

We investigated whether red cell 2,3-diphosphoglycerate (2,3-DPG) concentrations are reduced in critical illness, whether acidaemia, hypophosphataemia or anaemia influence 2,3-DPG, and whether there is any net effect on in vivo P50. Twenty healthy, non-smoking, male volunteers were compared with 20 male intensive care patients with APACHE 2 scores >20 on the preceding day. Those transfused in this time were excluded. Venous red cell 2,3-DPG concentrations were measured in both groups. In the patient group, routine multichannel biochemical profile and arterial blood gas analysis were also performed and in vivo P50 calculated. The mean 2,3-DPG concentration was significantly lower in the patient group than in the controls (4.2+/-1.3 mmol/l vs 4.9+/-0.5 mmol/l, P=0.016). The patients were well oxygenated (lowest arterial PO2=75 mm Hg) and showed a tendency to acidaemia (median pH 7.37, range 7.06 to 7.48) and anaemia (median haemoglobin concentration 113 g/l, range 89 to 154 g/l). By linear regression of patient data, pH had a significant effect on 2,3-DPG concentrations (r=0.6, P=0.011). Haemoglobin and phosphate concentrations did not, but there were few abnormal phosphate values. There was no correlation between 2,3-DPG concentrations and in vivo P50 (r2 < or = 0.08). We conclude that 2,3-DPG concentrations were reduced in a broad group of critically ill patients. Although this would normally reduce the P50, the reduction was primarily linked with acidaemia, which increases the P50. Overall, there was no net effect on the P50 and thus no affinity-related decrease in tissue oxygenation.

Olefin metathesis in supercritical carbon dioxide

Liquid or supercritical carbon dioxide (scCO(2)) is a versatile reaction medium for ring-opening metathesis polymerization (ROMP) and ring-closing olefin metathesis (RCM) reactions using well-defined metal catalysts. The molybdenum alkylidene complex 1 and ruthenium carbenes 2 and 3 bearing PCy(3) or N-heterocyclic carbene ligands, respectively, can be used and are found to exhibit efficiency similar to that in chlorinated organic solvents. While compound 1 is readily soluble in scCO(2), complexes 2 and 3 behave like heterogeneous catalysts in this reaction medium. Importantly, however, the unique properties of scCO(2) provide significant advantages beyond simple solvent replacement. This pertains to highly convenient workup procedures both for polymeric and low molecular weight products, to catalyst immobilization, to reaction tuning by density control (RCM versus acyclic diene metathesis polymerization), and to applications of scCO(2) as a protective medium for basic amine functions. The latter phenomenon is explained by the reversible formation of the corresponding carbamic acid as evidenced by (1)H NMR data obtained in compressed CO(2). Together with its environmentally and toxicologically benign character, these unique physicochemical features sum up to a very attractive solvent profile of carbon dioxide for sustainable synthesis and production.

Lhermitte-Duclos disease: assessment with MR imaging, positron emission tomography, single-photon emission CT, and MR spectroscopy

SUMMARY

Lhermitte-Duclos disease (LDD) is a rare cerebellar lesion with features of both malformation and benign neoplasm. However, the fundamental nature of the entity, its pathogenesis, and the exact genetic alterations remain unknown. We describe MR findings (including perfusion- and diffusion-weighted images) in two patients with LDD, as well as findings from single-photon emission CT (SPECT), MR spectroscopy (MRS), and fluorodeoxyglucose (FDG) positron emission tomography (PET) that give additional information about tumor pathophysiology. MR imaging usually distinguishes the LDD by its characteristic "tiger-striped" appearance. The regions of increased regional cerebral blood volume (rCBV) within the lesion correlated closely to the regions of FDG-hypermetabolism and high thallium (201-Tl) uptake. Proton MRS revealed an increased level of lactate and decreased level of myo-inositiol and N-acetyl-aspartate, as observed in low-grade gliomas, but decreased levels of choline. Our cases indicate that the functional investigations give additional information about tumor pathophysiology and reflect the histopathologic controversial entity with both characteristics found in low-grade gliomas and characteristics not typical for tumors.

T-cell activation by recombinant receptors: CD28 costimulation is required for interleukin 2 secretion and receptor-mediated T-cell proliferation but does not affect receptor-mediated target cell lysis

Recombinant T-cell receptors with antibody-like specificity are successfully used to direct CTLs toward a MHC-independent immune response against target cells. Here we monitored the specific activation of receptor grafted CTLs in the context of CD28 costimulation. Peripheral blood T cells were retrovirally engrafted with recombinant anti-CD30 and anti-carcinoembryonic antigen receptors, respectively, that harbor either the Fc epsilonRI-gamma or the CD3-zeta intracellular signaling domain. Cross-linking of recombinant receptors by solid-phase bound ligand, i.e., CD30 and a carcinoembryonic antigen receptor-specific anti-idiotypic antibody, respectively, induces IFN-gamma secretion that is further enhanced by CD28 costimulation of grafted T cells. Induction of interleukin (IL)-2 secretion, in contrast, requires CD28 costimulation in addition to receptor cross-linking, irrespective of T-cell preactivation by anti-CD3 monoclonal antibody plus IL-2 or by anti-CD3 monoclonal antibody plus anti-CD28 monoclonal antibody. Accordingly, induction of IL-2 secretion upon receptor cross-linking by membrane-bound antigen requires CD28/B7 costimulation whereas IFN-gamma secretion and cell proliferation does not. The efficiency of cytolysis by receptor-grafted CTLs does not depend on and is not affected by CD28 costimulation. The data demonstrate that CTL proliferation, cytokine secretion, and cytolysis upon receptor cross-linking are differentially modulated by CD28 costimulation and that cytolysis does not require B7 expression on target cells.

Atypical teratoid/rhabdoid tumors in adult patients: case report and review of the literature

Atypical teratoid/rhabdoid tumors (AT/RT) of the central nervous system are rare and extremely aggressive malignancies of early childhood. We report a case of AT/RT in an adult patient. A 30-year-old woman presented with headache, vomiting and ataxia during the second trimester of pregnancy. Magnetic resonance imaging revealed a posterior fossa mass. A gross total resection was performed. Pathological examination revealed an AT/RT. Despite the dismal prognosis the patient decided not to undergo an abortion. For this reason postoperative accelerated hyperfractionated radiotherapy was limited to the tumor region. Six months later the woman delivered a healthy baby. One week postpartum, a central nervous system recurrence localized apart from the primary lesion was treated with radiosurgery. Two months later a diffuse progression was noted. Despite a 6 week course of oral temozolomide, the tumor progressed and the patient died 11 months after diagnosis. Although survival was short, surgery and involved field radiotherapy yielded a progression-free interval of 9 months. This allowed the patient to carry pregnancy to term. Radiosurgery resulted in a complete remission of the first recurrence. Oral chemotherapy was not effective in controlling diffuse tumor spread.

An entirely humanized CD3 zeta-chain signaling receptor that directs peripheral blood t cells to specific lysis of carcinoembryonic antigen-positive tumor cells

Recombinant T-cell receptors with antibody-like specificity for tumor-associated antigens are successfully used to direct the cytolytic activity of T cells toward tumor cells. Clinical application, however, needs to comply with the low immunogenicity of the recombinant receptor, efficient gene transfer into peripheral blood T cells, and enrichment of receptor-grafted cells. Here, we address these issues and describe an entirely humanized immune receptor for use in adoptive immunotherapy of colorectal carcinoma. The receptor consists of a single-chain antibody (scFv) binding domain specific for carcinoembryonic antigen (CEA), the IgG hinge and CH2/CH3 (Fc) joining region, and the transmembrane and intracellular CD3 zeta signaling chain. To express the receptor in peripheral blood T cells, both GALV envelope and MuLV 4070A pseudotyped retrovirus turned out to be equally efficient, with transduction efficiencies of about 5% to 40%, depending on the lymphocyte donor. Furthermore, receptor-grafted T cells could be 2- to 6-fold enriched by magnetic activated cell sorting, utilizing an antibody directed to the extracellular IgG domain of the receptor. Upon co-culture with CEA(+) tumor cells, receptor-grafted T cells are specifically and efficiently activated to cytolysis and IFN-gamma secretion, demonstrating their feasibility for the adoptive immunotherapy of CEA(+) carcinomas.

Detection of Planetary Transits of the Star HD 209458 in the Hipparcos Data Set

A search of the Hipparcos satellite photometry data for the star HD 209458 reveals evidence for a planetary transit signature consistent with the planetary properties reported by Henry et al. and Charbonneau et al. and allows further refinement of the planet's orbital period. The long time baseline (about 2926 days or 830 periods) from the best Hipparcos transit-like event to the latest transit reported by Henry et al. for the night of 1999 November 15 (UT) allows for an orbital period determination of 3.524736 days with an uncertainty of 0.000045 days (3.9 s). The transit events observed by Charbonneau et al. fall at the interim times expected to within the errors of this newly derived period. A series of statistical tests was performed to assess the likelihood of these events occurring by chance. This was crucial given the ill-conditioned problem presented by the sparse sampling of the light curve and the non-Gaussian distribution of the points. Monte Carlo simulations using bootstrap methods with the actual Hipparcos HD 209458 data set indicate that the transit-like signals of the depth observed would only be produced by chance in 21 out of 1 million trials. The transit durations and depths obtained from the Hipparcos data are also consistent with those determined by Charbonneau et al. and Henry et al. within the limitations of the sampling intervals and photometric precision of the Hipparcos data.

A chimeric receptor that selectively targets membrane-bound carcinoembryonic antigen (mCEA) in the presence of soluble CEA

Chimeric T cell receptors with specificity for tumor-associated antigens are successfully used to target T cells to tumor cells. The efficacy of this approach, however, is reduced by soluble antigen that is frequently present in high serum concentrations. To overcome this situation, we constructed an anti-CEA chimeric receptor whose extracellular moiety is composed of a humanized single chain antibody fragment (scFv) derived from the anti-CEA mAb BW431/26 and the CH2/CH3 constant domains of human IgG. The intracellular moiety consists of the gamma-signaling chain of the human Fc epsilon RI receptor constituting a completely humanized chimeric receptor. After transfection, the humBW431/26 scFv-CH2CH3-gamma receptor is expressed as a homodimer on the surface of MD45 T cells. Co-incubation with CEA+ tumor cells specifically activates grafted MD45 T cells indicated by IL-2 secretion and cytolytic activity against CEA+ tumor cells. Notably, the efficacy of receptor-mediated activation is not affected by soluble CEA up to 25 micrograms/ml demonstrating the usefulness of this chimeric receptor for specific cellular activation by membrane-bound CEA even in the presence of high concentrations of CEA, as found in patients during progression of the disease.

Ongoing coding reviews: ways to ensure quality

As compliance becomes an increasingly hot topic, how can a facility ensure its coding quality? Here are some ways that HIM departments can improve the quality of coding on a daily basis.

Generation of the single chain antibody fragment conserves the idiotypic profile of the anti-CD30 monoclonal antibody HRS3

Recombinant single chain antibody fragments (scFv) derived by combining immunoglobulin VL and VH regions provide valuable antibody-like reagents. A number of them are shown to have retained the antigen specificity of the parental monoclonal antibody (MoAb). Little is known about the idiotypic profile of scFv fragments compared with that of the parental MoAb. To address this question we analysed the idiotypic profile of a scFv that was derived by phage-display techniques from the anti-CD30 MoAb HRS3. We assayed (i) binding of HRS3-scFv to recombinant CD30-Fc antigen and to four different anti-idiotypic MoAbs defining at least three different idiotopes on HRS3, and (ii) cross-competition with the parental MoAb HRS3 and the closely related anti-CD30 MoAb HRS4. The assays revealed that the HRS3-scFv fragment exhibits the same specificity for both CD30 antigen and the tested anti-idiotypic MoAbs compared with the parental MoAb demonstrating that the recombinant scFv fragment has retained the complete idiotope of the parental MoAb.