Cytokine levels in children and adults with wheezing and asthma show specific patterns of variability over time.

Levels of cytokines are used for in-depth characterization of patients with asthma; however, the variability over time might be a critical confounder. To analyze the course of serum cytokines in children, adolescents and adults with asthma and in healthy controls and to propose statistical methods to control for seasonal effects. Of 532 screened subjects, 514 (91·5%) were included in the All Age Asthma Cohort (ALLIANCE). The cohort included 279 children with either recurrent wheezing bronchitis (more than two episodes) or doctor-diagnosed asthma, 75 healthy controls, 150 adult asthmatics and 31 adult healthy controls. Blood samples were collected and 25 µl serum was used for analysis with the Bio-Plex Pr human cytokine 27-Plex assay. Mean age, body mass index and gender in the three groups of wheezers, asthmatic children and adult asthmatics were comparable to healthy controls. Wheezers (34·5%), asthmatic children (78·7%) and adult asthmatics (62·8%) were significantly more often sensitized compared to controls (4·5, 22 and 22·6%, respectively). Considering the entire cohort, interleukin (IL)-1ra, IL-4, IL-9, IL-17, macrophage inflammatory protein (MIP)-1- α and tumor necrosis factor (TNF)- α showed seasonal variability, whereas IL-1ß, IL-7, IL-8, IL-13, eotaxin, granulocyte colony-stimulating factor (G-CSF), interferon gamma-induced protein (IP)-10, MIP-1 ß and platelet-derived growth factor (PDGF)-BB did not. Significant differences between wheezers/asthmatics and healthy controls were observed for IL-17 and PDGF-BB, which remained stable after adjustment for the seasonality of IL-17. Seasonality has a significant impact on serum cytokine levels in patients with asthma. Because endotyping has achieved clinical importance to guide individualized patient-tailored therapy, it is important to account for seasonal effects.

Prospective evaluation of CT-guided HDR brachytherapy as a local ablative treatment for renal masses: a single-arm pilot trial.

PURPOSE: In this pilot trial, we investigate the safety of CT-guided high-dose-rate brachytherapy (HDR-BT) as a local ablative treatment for renal masses not eligible for resection or nephrectomy. METHODS: We investigated renal function after irradiation by HDR-BT in 16 patients (11 male, 5 female, mean age 76 years) with 20 renal lesions (renal cell carcinoma n = 18; renal metastases n = 2). Two patients had previous contralateral nephrectomy and two had ipsilateral partial nephrectomy. Six lesions had a hilar localization with proximity to the renal pelvis and would have not been favorable for thermal ablation. Renal function loss was determined within 1 year after HDR-BT by renal scintigraphy and laboratory parameters. Further investigations included CT and MRI every 3 months to observe procedural safety and local tumor control. Renal function tests were analyzed by Wilcoxon's signed rank test with Bonferroni-Holm correction of p-values. Survival and local tumor control underwent a Kaplan-Meier estimation. RESULTS: Median follow-up was 22.5 months. One patient required permanent hemodialysis 32 months after repeated HDR-BT and contralateral radiofrequency ablation of multifocal renal cell carcinoma. No other patient developed a significant worsening in global renal function and no gastrointestinal or urogenital side effects were observed. Only one patient died of renal tumor progression. Local control rate was 95% including repeated HDR-BT of two recurrences. CONCLUSION: HDR-BT is a feasible and safe technique for the local ablation of renal masses. A phase II study is recruiting to evaluate the efficacy of this novel local ablative treatment in a larger study population.

[Recurrent pain and swelling of the left leg in a 49-year-old male patient]. / Rezidivierende Beinschwellungen und Schmerzen im linken Bein bei einem 49-jährigen Patienten.

A 49-year-old male patient presented due to recurrent pain and swelling in the left leg. The patient had had deep venous thrombosis with pulmonary embolism 5 years previously. Since then, he had been treated with Vit-k-antagonists. Pronounced paraumbilical collateral circulation of unknown origin was striking. Doppler sonographic evaluation pointed to May-Thurner syndrome. This was confirmed by phlebography. Venous stenting of the stenosis in the left iliac vein achieved long-term symptom improvement. This case report is intended to draw attention to the rare May-Thurner syndrome as an important differential diagnosis of deep vein thrombosis and, at the same time, identify diagnostic and therapeutic treatment strategies.

Radioablation of adrenal gland malignomas with interstitial high-dose-rate brachytherapy : Efficacy and outcome.

PURPOSE: To assess the efficacy, safety, and outcome of image-guided high-dose-rate (HDR) brachytherapy in patients with adrenal gland metastases (AGM). MATERIALS AND METHODS: From January 2007 to April 2014, 37 patients (7 female, 30 male; mean age 66.8 years, range 41.5-82.5 years) with AGM from different primary tumors were treated with CT-guided HDR interstitial brachytherapy (iBT). Primary endpoint was local tumor control (LTC). Secondary endpoints were time to untreatable progression (TTUP), time to progression (TTP), overall survival (OS), and safety. In a secondary analysis, risk factors with an influence on survival were identified. RESULTS: The median biological equivalent dose (BED) was 37.4 Gy. Mean LTC after 12 months was 88%; after 24 months this was 74%. According to CTCAE criteria, one grade 3 adverse event occurred. Median OS after first diagnosis of AGM was 18.3 months. Median OS, TTUP, and TTP after iBT treatment were 11.4, 6.6, and 3.5 months, respectively. Uni- and multivariate Cox regression analyses revealed significant influences of synchronous disease, tumor diameter, and the total number of lesions on OS or TTUP or both. CONCLUSION: Image-guided HDR-iBT is safe and effective. Treatment- and primary tumor-independent features influenced survival of patients with AGM after HDR-iBR treatment.

[Prostate gland - what would urologists like to know from radiologists?] / Die Vorsteherdrüse ­ was möchte der Urologe vom Radiologen wissen?

A more than 100-year period, where the prostate was only seen and treated as a whole is coming to an end right now. Finally, high resolution imaging is providing deep insights and detailed information so that new therapeutic procedures can aim for the smallest targets within the gland. The long-standing wish of patients for individual noninvasive diagnostics and treatment of prostate diseases can now be fulfilled by providing new tailored concepts; however, in order to transfer the enormous amount of new information into the specific clinical patient situation, a closely knit interdisciplinary approach is required. In this setting, the traditional outpatient consultation service is overstretched in every aspect. It is now the time for new innovative constructs. The current one-sided service concept for urologists, radiologists and radiation therapists is therefore behind the times and the development of a "prostate management team" with equally cooperating partners from each specialty is the task for the future.

Assessment and monitoring of liver function by ¹³C-aminopyrine breath test after selective transarterial chemoembolisation of hepatocellular carcinoma.

BACKGROUND: Liver function and tumor staging are essential parameters for selection of treatment modalities in patients with hepatocellular carcinoma (HCC). Transarterial chemoembolization (TACE) is associated with a risk of deterioration of liver function. In clinical routine hepatic function in patients with liver cirrhosis is assessed by the Child-Pugh-classification. Dynamic breath tests allow the assessment of the hepatic functional mass and have the potential to give more accurate information on hepatic function periinterventionally. PATIENTS AND METHODS: A prospective clinical study was performed in 13 patients receiving a total of 18 TACE sessions. (13)C-aminopyrine breath test was performed the day before TACE, 2 days and 30 days after TACE and correlated with standard laboratory work-up of the patients. RESULTS: Fourteen TACE sessions were performed in Child A liver cirrhosis, 4 in Child B cirrhosis. All patients presented with impaired aminopyrine metabolism at baseline. No significant changes in the (13)C aminopyrine breath test following TACE were observed. Two patients treated in Child A cirrhosis decompensated to Child B, one of them recovered. No further decompensation was observed in patients treated in Child B cirrhosis. DISCUSSION AND CONCLUSION: Liver function assessment with (13)C-aminopyrine breath test and Child-Pugh-classification following TACE was discordant in a large proportion of patients. Whether a quantification of mitochondrial liver function in patients planned to undergo locoregional treatment of HCC in liver cirrhosis is helpful in the prediction of postprocedural liver decompensation needs to be addressed in larger prospective clinical trials.

[What does the visceral surgeon need to know about computed tomography in the diagnostic work-up of the acute abdomen?]. / Was muss der Viszeralchirurg über den Einsatz der Computertomografie in der Abklärung des akuten Abdomens wissen.

The acute abdomen is a very serious yet common condition of patients presenting in the emergency department. The clinical symptoms of patients with acute abdomen are often unspecific. The responsibility of the surgeon in charge is to differentiate acute life-threatening from less serious conditions with a high level of diagnostic accuracy in a minimal period of time. Imaging represents a cornerstone in the diagnostic work-up of patients with acute abdomen. Computed tomography (CT) is increasingly utilised to detect emergency conditions in patients with acute abdomen. In this review article we aim to elaborate the role of CT in the imaging strategy for acute abdomen in comparison to conventional radiography, ultrasonography and magnetic resonance imaging. In addition, relevant factors pertaining for the indication of CT such as exposure to ionising radiation and safety of iodinated contrast media are discussed.

[Differential Vascular Medical Management of Visceral Artery Aneurysms in a Single-Centre Consecutive Patient Cohort as Part of an Ongoing Disease-Specific Systematic Clinical Prospective Observational Study]. / Differenzielles gefäßmedizinisches Management des Viszeralarterienaneurysmas anhand einer unizentrischen konsekutiven Patientenkohorte im Rahmen einer laufenden krankheitsspezifischen, klinisch-systematischen, prospektiven Observationsstudie.

AIM, PATIENTS AND METHODS: By means of a systematic single-centre prospective observational study, spectrum (symptomatology, frequency) and diagnostics of the different visceral artery aneurysm sites as well as the postinterventional course of the various therapeutic options used according to local finding and patient's clinical status as well as risk factors were analysed to contrast the different procedures (conservative, image-guided radiological intervention, open vascular surgery) in consideration of their decision-making criteria and their early postinterventional outcome (on the basis of complication rate, peri-interventional morbidity and hospital lethality) including relevant references from the literature. RESULTS: During a time period of 14 years, 22 patients (sex ratio: 12 males/10 females; mean age: 54.3 [range: 22-76] years) were registered. Most frequently, visceral artery aneurysms occurred in the splenic artery (50 %). The gastroduodenal artery, the hepatic artery and the right renal artery were affected in each with 13.6 % (n = 3/22), the superior mesenteric artery in 9.1 % (n = 2/22). The majority of patients (54.5 %) were treated with image-guided radiological intervention, whereas in 31.8 %, the patient underwent open vascular surgery and 13.6 % of cases were managed with "watchful waiting". While morbidity was 21.1 % (n = 4/19), overall lethality was 9.1 % (n = 2/22). CONCLUSION: Decision-making for a specific therapeutic approach should be made (i) after adequate diagnostic measures (transabdominal ultrasound, MR angiography, duplex ultrasonography, CT-A/DSA if required), (ii) on an individual case-adapted base, (iii) in a vascular surgical centre, (iv) case-associated to the specific local finding (in particular, according to size/specific probability of rupture [cave: gravidity]) and (v) according to the individual risk profile using the whole spectrum of therapeutic options (conservative vs. interventional; image-guided radiological intervention [endovascular repair such as embolisation, stent or stent graft] vs. open vascular surgery [according to a step-up approach]; open vascular ligation vs. reconstruction after exclusion of the aneurysm) including sufficient quality assurance of the treatment results as well as control investigations (duplex ultrasonography; MR-A if required) in a specialised vascular surgical out-patient centre within appropriate time intervals.

[Radiation-induced cataract-an occult risk for urologists]. / Strahleninduzierter Katarakt ­ ein okkultes Berufsrisiko für Urologen.

BACKGROUND: Radiation-induced cataracts represent a relevant risk to people occupationally exposed to radiation. The annual limit dose for the eye lens was reduced to 20 mSv per year by German legislation (radiation protect law StrlSchG 2017; 2013/59/Euratom) based on recommendation of International Commission on Radiation Protection (2011 ICRP) to avoid radiation-induced cataracts. OBJECTIVES: Is there a risk of exceeding the annual limit dose for the eye lens in routine urological practice without special radiation protection for the head? METHODS: As part of a prospective, monocentric dosimetry study, of 542 different urological, fluoroscopically guided interventions, the eye lens dose was determined using a forehead dosimeter (thermo-luminescence dosemeter TLD, Chipstrate) over a period of 5 months. RESULTS: An average head dose of 0.05 mSv per intervention (max. 0.29 mSv) was found with an average dose area product of 485.33 Gy/cm2. Significant influencing factors for a higher dose were a higher patient body mass index (BMI), a longer operation time, and a higher dose area product. The level of experience of the surgeon showed no significant influence. DISCUSSION: With 400 procedures per year or an average of 2 procedures per working day, the critical annual limit value for the eye lenses or for the risk of radiation-induced cataract would be exceeded without special protective measures. CONCLUSION: Consistently effective radiation protection of the eye lens is essential for daily work in uroradiological interventions. This may require further technical developments.

[Irreversible electroporation - a new kid on the block?]. / Irreversible Elektroporation - "a new kid on the block?".

CLINICAL/METHODICAL ISSUE: Minimally invasive tumor therapies are well established options in multi-modal oncological therapy regimes. So far the methods applied have been of a thermal nature and thus there are inherent limitations, most of all the so-called heat-sink effect. STANDARD RADIOLOGICAL METHODS: Radiofrequency ablation (RFA) and laser-induced thermotherapy (LITT) are well-established techniques. METHODICAL INNOVATIONS: Irreversible electroporation (IRE) could potentially become a novel therapy option with an enlarged spectrum of treatable lesions, i.e. close to blood vessels and potentially a lower rate of complications. PERFORMANCE: The IRE technique is currently the subject of early prospective trials and clinical studies have not yet shown any serious side effects. However, complete tumor ablation was not achieved in all cases (46 out of 69). ACHIEVEMENTS: Preclinical as well as clinical studies seem to show a promising efficiency in tumor ablation as well as a favorable complication profile especially with tumors in thermally critical locations. PRACTICAL RECOMMENDATIONS: Clinical long-term studies are currently under way assessing safety as well as efficiency. The data published so far look promising and considerably enlarge the spectrum of ablation techniques.

Detection and characterisation of focal liver lesions in colorectal carcinoma patients: comparison of diffusion-weighted and Gd-EOB-DTPA enhanced MR imaging.

OBJECTIVE: To compare diffusion-weighted imaging (DWI) and Gd-EOB-DTPA-enhanced magnetic resonance (MR) imaging for the detection and characterisation of focal liver lesions (FLLs) in patients with colorectal carcinoma. METHODS: Seventy-three patients underwent MR imaging including echoplanar DWI (MR-DWI) and dynamic (MR-Dyn) and hepatobiliary phase (MR-Late) Gd-EOB-DTPA-enhanced images. Two blinded readers independently reviewed 5 different image sets using a 5-point confidence scale. Accuracy was assessed by the area (A(z)) under the receiver operating characteristic curve, and sensitivity and specificity were calculated. RESULTS: A total of 332 FLLs were evaluated. Detection rates were significantly higher for MR-Late images (94.4% for benign and 100% for malignant lesions) compared with MR-DWI (78.3% and 97.5%) and MR-Dyn images (81.5% and 89.9%). Accuracy was 0.82, 0.76 and 0.89 for MR-DWI, MR-Dyn and MR-Late images while sensitivity was 0.98, 0.87 and 0.95, respectively. For characterisation of subcentimetre lesions sensitivity was highest for MR-DWI (0.92). Combined reading of unenhanced and contrast-enhanced images had an identical high accuracy of 0.98. CONCLUSION: Late-phase Gd-EOB-DTPA-enhanced images were superior for the detection of FLLs, while DWIs were most valuable for the identification of particularly small metastases. Combined interpretation of unenhanced images resulted in precise characterisation of FLLs.

Older People Facing the Crisis of COVID-19: Between Fragility and Resilience.

The health crisis we are facing is challenging seniors' resources and capacities for adaptation and resilience. The PACOVID survey, set up a few days after containment, investigates their psychological and social experiences with regard to the COVID-19 crisis and to what extent these characteristics, representations and attitudes have an impact on health and mortality. A telephone survey is being carried out on 935 people already followed up in the framework of ongoing epidemiological studies. As we are writing this article, the interviews conducted during the containment have just ended. Even though we will have to wait for the analysis of the results to draw conclusions, words collected by the psychologists during the interviews already illustrate a great heterogeneity in the way older adults lived this experience: social isolation, anxiety, the importance of family and the difficulty of being deprived of it, but also remarkable coping skills and resilience capacities.

PDGF-BB modulates endothelial proliferation and angiogenesis in vitro via PDGF beta-receptors.

To delineate potential angiogenic roles of platelet-derived growth factor (PDGF), we have investigated PDGF and its receptors on bovine aortic endothelial cells that exhibit spontaneous angiogenesis in vitro (angiogenic endothelial cells). Initiation of cord/tube formation by angiogenic endothelial cells required bovine or human serum. Neutralization of PDGF-BB in human serum with a monoclonal anti-PDGF-BB antibody reduced cord/tube formation by 37 +/- 10%, whereas neutralizing anti-PDGF-AA and an IgG isotype-matched control antibody had no effect. DNA synthesis in response to PDGF-BB increased as the cords and tubes developed; furthermore, PDGF-BB induced the incorporation of BrdU in the nuclei of cells associated with these structures. PDGF beta-receptor (PDGF-beta) mRNA increased concomitantly with cord/tube formation, and PDGFR-beta were specifically localized by immunocytochemistry to developing and mature cords and tubes. However, PDGFR-beta transcripts and protein were undetectable in nonangiogenic endothelial cells, and PDGF alpha-receptor mRNA was not expressed in either endothelial cell strain. In contrast to nonangiogenic endothelial cells, angiogenic endothelial cells did not express the PDGF B-chain, the required ligand for the PDGFR-beta. We conclude that (a) PDGF-BB can contribute to angiogenesis in vitro, (b) PDGFR-beta are specific for cord/tube-forming endothelial cells and mediate endothelial proliferation and cord/tube formation, and (c) in angiogenic and nonangiogenic endothelial cells, the expression of PDGFR-beta and PDGF B-chain is inversely correlated. We therefore suggest that paracrine PDGF might amplify angiogenesis via direct action on endothelially expressed PDGFR-beta.

[Successful open vascular-surgical supracoeliac anastomosis of a bifurcational prosthesis with simultaneous prosthetomesenteric and renal revascularisation in Leriche's syndrome with high occlusion]. / Erfolgreiche offen-chirurgische, suprazöliakale Bifurkationsprothesen-implantation mit simultaner prothetomesenterialer und -renaler Revaskularisation bei hohem Leriche-Syndrom.

BACKGROUND: Based on an extraordinary case -report on a patient with almost symptomless supramesenteric occlusion of the aorta, the successful management and favourable outcome including almost normalised renal function (in addition to appropriate diagnostic and operative tactics) achieved by a technically challenging vascular-surgical intervention and subsequent intensive medical and nephrological care are described. RESULTS: In a 49-year-old male patient, a "high" aortic occlusion just below the branching of the coeliac trunk with arterial perfusion of the abdomen and the lower extremities via arterial collaterals from the 4 (th) to 6 (th) intercostal arteries was diagnosed. Both renal arteries were occluded leading to a consecutive renal insufficiency with need for dialysis and renovascularly induced hypertension. However, a residual perfusion of the parenchyma of the left kidney was detectable. Therapeutic measures comprised, after haemodialysis with accompanying antihypertensive medication, open supracoeliac aortobifemoral implantation of a prosthesis, revascularisation of the left renal artery (prosthetic bypass) and prostheticomesenteric bypass implantation. Postoperatively, a reestablished renal perfusion was observed in spite of the preoperatively prolonged lack of appropriate arterial perfusion (last dialysis, 11 (th) POD / discharge, 18 (th) POD). At 3 months postoperatively, the patient reported an increase of his body weight of 8 kg (at 6 months, 20 kg; improved but still elevated laboratory parameters indicating renal insufficiency; RR within normal range). Postinterventional MR angiography revealed a regular perfusion of the bifurcational prosthesis and of the bypasses to the superior mesenteric and left renal arteries. CONCLUSION: This exemplary case demonstrates impressively the individual therapeutic chances, options and the potential in the diagnostic and therapeutic interdisciplinary management and its combined expertise. The clinical course in this case indicates that the assessment of the arterial blood supply has to be included in the diagnostic of an acute renal insufficiency associated with anuria. If there is a minimal residual perfusion, which might just be sufficient for maintenance of structural integrity, there is a real chance for a restitution of renal function after successful revascularisation.

[Closure of a common iliac artery stump aneurysm after implantation of a bifurcational prosthesis. Combination of coil embolization and occlusion emulsion injection for iatrogenic bleeding]. / Aneurysmaausschaltung am Iliakalarterien-stumpf nach Bifurkationsprothesen-Implantation. Kombination vom Coil-Embolisation und Injektion von Okklusions-emulsion bei iatrogener Blutung.

Interventional radiology has an increasing spectrum of indications, in particular, for vascular medical problems. By Seldinger's puncture via the right femoral artery, an aneurysm of the right common iliac artery stump was sufficiently excluded with coil embolization. As a complication, an iatrogenic bleeding at the aneurysmatic neck was effectively stopped after the first interventional step with injection of an occlusion emulsion according to the bleeding site. Image-guided interventional measures in radiology allow a minimal invasive approach in a former classical field of vascular surgery. Furthermore, procedure-related complications can be increasingly controlled.

[Small renal cell carcinoma-active surveillance and ablation]. / Kleines Nierenzellkarzinom ­ Aktive Überwachung und Ablation.

The incidence of renal cell carcinoma has been rising for years. At the same time there is an increasing prevalence of chronic renal failure with subsequent higher morbidity and shorter life expectancy in those affected. In the last decades the gold standard has thus shifted from radical to partial nephrectomy or tumor enucleation. A treatment alternative can be advantageous for selected patients with high morbidity and an increased risk of complications in anesthesia or surgery. Active surveillance represents a controlled delay in the initiation of treatment with a curative intention. Percutaneous radiofrequency ablation and laparoscopic cryoablation are currently the most commonly used treatment alternatives. Newer ablation procedures, such as high-intensity focused ultrasound, irreversible electroporation, microwave ablation, stereotactic ablative radiotherapy and high-dose brachytherapy have a high potential in some cases but are still considered experimental for the treatment.

Upper-Urinary-Tract Effects After Irreversible Electroporation (IRE) of Human Localised Renal-Cell Carcinoma (RCC) in the IRENE Pilot Phase 2a Ablate-and-Resect Study.

PURPOSE: Irreversible electroporation (IRE) is a new potential ablation modality for small renal masses. Animal experiments have shown preservation of the urine-collecting system (UCS). The purpose of this clinical study was to perform the first evaluation and comparison of IRE's effects on the renal UCS by using urinary cytology, magnetic-resonance imaging, and resection histology in men after IRE of pT1a renal-cell carcinoma (RCC). METHODS: Seven patients with biopsy-proven RCC pT1a cN0cM0 underwent IRE in a phase 2a pilot ablate-and-resect study (IRENE trial). A contrast-enhanced, diffusion-weighted MRI and urinary cytology was performed 1 day before and 2, 7, and 27 days after IRE. Twenty-eight days after IRE the tumour region was completely resected surgically. RESULTS: Technical feasibility was demonstrated in all patients. In all cases, MRI revealed complete coverage of the tumour area by the ablation zone with degenerative change. The urographic late venous MRI phase (urogram scans) demonstrated normal morphological appearances. Urine cytology showed a temporary vacuolisation of the cyto- and caryoplasmas after IRE. Whereas the urothelium showed signs of regeneration 28 days after IRE-ablation, the tumour and parenchyma below it showed necrosis and permanent tissue destruction. CONCLUSIONS: Renal percutaneous IRE appears to be a safe treatment for pT1a RCC. The preservation of the UCS with unaltered normal morphology as well as urothelial regeneration and a phenomenon (new in urinary cytology) of temporary degeneration with vacuolisation of detached transitional epithelium cells were demonstrated in this clinical pilot study.

The 5' untranslated sequence of the c-sis/platelet-derived growth factor 2 transcript is a potent translational inhibitor.

c-sis/platelet-derived growth factor 2 (PDGF-2) is a prototype growth factor with transforming potential. The c-sis/PDGF-2 transcript contains a long 5' untranslated sequence (UTS) that is highly G.C rich. To examine the influence of this sequence on sis/PDGF-2 expression, we localized the c-sis/PDGF-2 promoter and used this promoter or the simian virus 40 early promoter to drive expression of the bacterial chloramphenicol acetyltransferase or sis/PDGF-2 gene. The 5' UTS of c-sis/PDGF-2 mRNA had no effect on RNA expression but was shown to exert a potent inhibitory effect on translation. By deletion analysis, we demonstrated that the 5' UTS inhibited protein expression by as much as 40-fold. The inhibitory effect was independent of reporter gene, cell type, or promoter used. A highly G.C-rich 140-base-pair sequence immediately preceding the c-sis/PDGF-2 initiation codon was shown to be nearly as effective as the entire 5' UTS in translational inhibition. Transfection analysis demonstrated that the 5' UTS significantly reduced the transforming efficiency of the sis/PDGF-2 gene as well. Thus, our findings raise the possibility that changes in regulation at the level of sis/PDGF-2 translation may play a role in development of the neoplastic phenotype.