Performance of FDG PET/CT at initial diagnosis in a rare lymphoma: nodular lymphocyte-predominant Hodgkin lymphoma.

PURPOSE: Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare Hodgkin lymphoma distinguished from classical Hodgkin lymphoma (cHL) by the nature of the neoplastic cells which express B-cell markers. We wanted to determine the diagnostic performance of FDG PET/CT in initial assessment and its therapeutic impact on staging. METHODS: We retrospectively studied a population of 35 patients with NLPHL (8 previously treated for NLHPL, 27 untreated). All patients underwent an initial staging by pretherapeutic FDG PET/CT. The impact on initial stage or relapse stage was assessed by an independent physician. RESULTS: In a per-patient analysis, the sensitivity of the pretherapeutic FDG PET/CT was 100%. In a per-site analysis, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of pretherapeutic FDG PET/CT were 100%, 99%, 97%, 100% and 99%, respectively. Pretherapeutic FDG PET/CT led to a change in the initial stage/relapse stage in 12 of the 35 patients (34%). In contrast to previous results established without FDG PET/CT, 20% of patient had osteomedullary lesions. CONCLUSION: Pretherapeutic FDG PET/CT has excellent performance for initial staging or relapse staging of NLPHL.

Imaging diagnosis-multicentric lymphoma of granular lymphocytes imaged with FDG PET/CT in a dog.

A 5-year-old female spayed bulldog was referred for mild dyspnea, decreased activity and appetite, occasional nonproductive cough, polydipsia, and polyuria. A 2-deoxy-2-[(18) F]fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) scan revealed unexpected activity in the heart, lungs, and mild generalized lymphadenopathy that led to the diagnosis of lymphoma of granular lymphocytes after nonspecific findings on imaging with standard modalities of echocardiography, thoracic radiography, and abdominal ultrasound. PET/CT scanning is a useful whole body imaging modality with high sensitivity for changes associated with canine lymphoma.

Inflammation in the walls of asymptomatic abdominal aortic aneurysms is not associated with increased metabolic activity detectable by 18-fluorodeoxglucose positron-emission tomography.

OBJECTIVE: We hypothesized that the general inflammation observed in the wall of large, asymptomatic abdominal aortic aneurysms (AAAs) could be detected in vivo by 18-fluorodeoxglucose (FDG) positron-emission tomography (PET) and, if so, that this method could be used to study if active inflammation is an early pathogenetic finding in small AAAs detected by screening. METHODS: In this prospective clinical study, 12 men were examined with FDG-PET computed tomography. Seven had large asymptomatic AAAs (range, 52-66 mm) that required surgery, and five had small AAAs (range, 34-40 mm) under surveillance. In the surgery group, biopsy specimens were taken from the aneurysm wall for histologic examinations. RESULTS: Compared with normal segments of the aorta, liver, and blood and compared with healthy controls matched for age and sex, no increased FDG uptake, measured as standardized uptake value, was detected in any of the large or small AAAs. The SUV(mean) difference between infrarenal aorta and blood was -0.3 for cases and -0.1 for controls (P = .06). The corresponding differences between the infrarenal aorta and liver was -0.8 and -0.8 (P = .91) and between infrarenal aorta and suprarenal aorta was -0.2 and -0.1 for cases and controls, respectively (P = .20). The histologic examination of the aneurysm walls showed high inflammatory cell infiltration with T lymphocytes, B lymphocytes, and macrophages. CONCLUSIONS: The chronic inflammation observed in the wall of asymptomatic AAAs was not sufficiently metabolically active to result in an increased glucose metabolism detectable by FDG-PET by means of this standard protocol. To study the importance of inflammation in the pathogenesis of AAAs in vivo, PET tracers other than FDG need to be developed.

Pharmacokinetic modelling of N-(4-[(18)F]fluorobenzoyl)interleukin-2 binding to activated lymphocytes in an xenograft model of inflammation.

PURPOSE: N-(4-[(18)F]Fluorobenzoyl)interleukin-2 ([(18)F]FB-IL2) specifically binds to interleukin-2 receptors (IL-2R) and thus may be used to detect inflammation processes using positron emission tomography (PET). We now validated whether [(18)F]FB-IL2 can be used to quantify activated human peripheral blood mononuclear cells (hPBMC) in rats by pharmacokinetic modelling. METHODS: Eleven Wistar rats were subcutaneously inoculated in the shoulder with different amounts of phytohaemagglutinin (PHA) activated hPBMC 15 min before i.v. injection of [(18)F]FB-IL2. A 60-min dynamic PET scan was acquired and arterial blood sampling and metabolite analysis were performed. At the end of the scan, animals were terminated and the inflammatory lesion dissected. PET data were analysed using Logan and Patlak analysis as well as one-tissue and two-tissue compartment models. Model preferences according to the Akaike information criterion (AIC) and correlation between PET measurements and the number of CD25-positive cells were evaluated. RESULTS: A high correlation between ex vivo tracer uptake (standardized uptake value) in the xenograft and the number of inoculated CD25-positive cells was observed (R (2) = 0.90). Plasma time-activity curves showed a rapid washout of the radiopharmaceutical from blood, while the time-activity curves of the inflammatory lesions showed slower washout. Time-activity curves could be fitted well by the Logan analysis method, indicating that the binding between [(18)F]FB-IL2 and CD25 is reversible. AIC indicated that data could be modelled best by a two-tissue reversible compartment model. A high correlation was observed between the binding potential and the number of CD25-positive cells (R (2) = 0.876, p < 0.0001). Based on binding potential measured by PET, the limit of detection was about 160,000 CD25-positive cells per 200 µl lesion (95 % confidence). CONCLUSION: [(18)F]FB-IL2 kinetics in this animal model of inflammation could be best described by a reversible two-tissue compartment model. The [(18)F]FB-IL2 binding potential is a suitable measure for accurate quantification of lymphocytic infiltration in pathological conditions with PET.

Leucocyte scintigraphy with 111In-oxine for assessment of cell trafficking after extracorporeal photopheresis.

Extracorporeal photopheresis (ECP) is an established therapy for transplant rejection, graft-versus-host disease (GvHD) after allogeneic stem cell transplantation, cutaneous T-cell lymphoma and systemic autoimmune disorders such as systemic sclerosis. Knowledge regarding the in vivo behaviour of the cells after reinfusion is very limited. The aim of this prospective study was to investigate the path of 8-MOP-/UVA-exposed radiolabelled cells after ECP treatment and reinfusion. In this prospective single-centre study, peripheral blood mononuclear cells (PBMC) and neutrophils of 10 patients undergoing ECP as part of their regular treatment were labelled separately with (111) In-oxine after exposure to 8-MOP/UVA and prior to reinfusion. The fate of the labelled leucocytes was monitored at 10 min, 3.5 and 24 h following reinfusion with whole-body scintigraphy. Comparison of distribution patterns showed that PBMC and neutrophils have different kinetic patterns after intravenous reinjection. The most prominent difference was immediate retention of PBMC but not of neutrophils in the lungs corresponding to a signal three times more intense. After 24 h, more than 80% of both cell populations could be detected in liver and spleen. By means of a novel tool allowing for tracking of 8-MOP-/UVA-exposed leucocytes in ECP, we could show that organ-specific homing of leucocytes after ECP can be visualized in vivo and that migration patterns differ between PBMC and neutrophils. Based on our results, further studies should (i) extend the morphometric studies described here to specific ECP-responsive conditions and (ii) functionally address the interaction of ECP-modified PBMC with pulmonary tissue in experimental models.

Evaluation of a B-cell leukemia-lymphoma 2-specific radiolabeled peptide nucleic acid-peptide conjugate for scintigraphic detection of neoplastic lymphocytes in dogs with B-cell lymphoma.

OBJECTIVE: To evaluate use of a radiolabeled peptide nucleic acid-peptide conjugate (RaPP) targeting B-cell leukemia-lymphoma 2 (BCL2) mRNA for scintigraphic detection of neoplastic lymphocytes in dogs with B-cell lymphoma and to assess associations among RaPP uptake, time to tumor progression (TTP), and BCL2 mRNA expression. ANIMALS: 11 dogs with B-cell lymphoma and 1 clinically normal dog. PROCEDURES: Scintigraphic images were acquired 1 hour after IV injection of the RaPP. Regions of interest (ROIs) were drawn around lymph nodes, liver, and spleen; ROI intensity (relative to that of an equally sized region of muscle in the same image) was measured. Each ROI was also subjectively categorized as positive or negative for increased RaPP uptake. Expression of BCL2 mRNA was determined via quantitative reverse transcriptase PCR assay of a lymph node sample from dogs with lymphoma. Associations among imaging results, TTP, and BCL2 mRNA expression were evaluated. RESULTS: Increased RaPP uptake was detected in affected tissues of dogs with lymphoma. Dogs with superficial cervical lymph node ROIs categorized as negative (n = 8) for increased RaPP uptake had a significantly longer TTP than did dogs for which this ROI was considered positive (2). Measured intensity of mandibular and superficial cervical lymph node ROIs was negatively associated with TTP. Associations among BCL2 mRNA and ROI intensity or TTP were not significant. CONCLUSIONS AND CLINICAL RELEVANCE: Increased RaPP uptake at mandibular or superficial cervical lymph node ROIs may be a negative prognostic indicator in dogs with lymphoma. A larger investigation is needed to determine clinical value of the RaPP for disease detection and prognostication.

DNA double-strand breaks as potential indicators for the biological effects of ionising radiation exposure from cardiac CT and conventional coronary angiography: a randomised, controlled study.

OBJECTIVES: To prospectively compare induced DNA double-strand breaks by cardiac computed tomography (CT) and conventional coronary angiography (CCA). METHODS: 56 patients with suspected coronary artery disease were randomised to undergo either CCA or cardiac CT. DNA double-strand breaks were assessed in fluorescence microscopy of blood lymphocytes as indicators of the biological effects of radiation exposure. Radiation doses were estimated using dose-length product (DLP) and dose-area product (DAP) with conversion factors for CT and CCA, respectively. RESULTS: On average there were 0.12 ± 0.06 induced double-strand breaks per lymphocyte for CT and 0.29 ± 0.18 for diagnostic CCA (P < 0.001). This relative biological effect of ionising radiation from CCA was 1.9 times higher (P < 0.001) than the effective dose estimated by conversion factors would have suggested. The correlation between the biological effects and the estimated radiation doses was excellent for CT (r = 0.951, P < 0.001) and moderate to good for CCA (r = 0.862, P < 0.001). One day after radiation, a complete repair of double-strand breaks to background levels was found in both groups. CONCLUSIONS: Conversion factors may underestimate the relative biological effects of ionising radiation from CCA. DNA double-strand break assessment may provide a strategy for individualised assessments of radiation. KEY POINTS: • Radiation dose causes concern for both conventional coronary angiography and cardiac CT. • Estimations of the biological effects of ionising radiation may become feasible. • Fewer DNA double-strand breaks are induced by cardiac CT than CCA. • Conversion factors may underestimate the relative effects of ionising radiation from CCA.

An image processing application for the localization and segmentation of lymphoblast cell using peripheral blood images.

An important preliminary step in the diagnosis of leukemia is the visual examination of the patient's peripheral blood smear under the microscope. Morphological changes in the white blood cells can be an indicator of the nature and severity of the disease. Manual techniques are labor intensive, slow, error prone and costly. A computerized system can be used as a supportive tool for the specialist in order to enhance and accelerate the morphological analysis process. This research present a new method that integrates color features with the morphological reconstruction to localize and isolate lymphoblast cells from a microscope image that contains many cells. The localization and segmentation are conducted using a proposed method that consists of an integration of several digital image processing techniques. 180 microscopic blood images were tested, and the proposed framework managed to obtain 100% accuracy for the localization of the lymphoblast cells and separate it from the image scene. The results obtained indicate that the proposed method can be safely used for the purpose of lymphoblast cells localization and segmentation and subsequently, aiding the diagnosis of leukemia.

Perturbation in mitochondrial network dynamics and in complex I dependent cellular respiration in schizophrenia.

BACKGROUND: Mitochondria have been suggested to be involved in the pathology of bipolar disorder (BD) and schizophrenia. However, the mechanism underlying mitochondrial dysfunction is unclear. Mitochondrial network dynamics, which reflects cellular metabolic state, is important for embryonic development, synapse formation, and neurodegeneration. This study aimed to investigate mitochondrial network dynamics and its plausible association with abnormal cellular oxygen consumption in schizophrenia. METHODS: Viable Epstein-Barr virus (EBV)-transformed lymphocytes (lymphoblastoids) from DSM-IV diagnosed patients with schizophrenia (n = 17), BD (n = 15), and healthy control subjects (n = 15) were assessed for mitochondrial respiration, mitochondrial dynamics, and relevant protein levels by oxygraph, confocal microscopy, and immunoblotting, respectively. RESULTS: Respiration of schizophrenia-derived lymphoblastoids was significantly lower compared with control subjects, and was twice as sensitive to dopamine (DA)-induced inhibition. Unlike DA, haloperidol inhibited complex I-driven respiration to a similar extent in both schizophrenia and the control cells. Both drugs interact with complex I but at different sites. At the site of DA interaction, we found alterations in protein levels of three subunits of complex I in schizophrenia. In addition, we observed structural and connectivity perturbations in the mitochondrial network, associated with alterations in the profusion protein OPA1, which was similarly reduced in schizophrenia prefrontal cortex specimens. None of these alterations were observed in the BD cells, which were similar to control cells. CONCLUSIONS: We show impaired mitochondrial network dynamics associated with reduced cellular respiration and complex I abnormalities in schizophrenia but not in BD. If these findings represent disease-specific alterations, they may become an endophenotype biomarker for schizophrenia.

Fine-needle aspiration of intrapancreatic accessory spleen, mimic of pancreatic neoplasms.

Intrapancreatic accessory spleen (IPAS) is a congenital abnormality, which mimics neoplasm. Distinguishing IPAS from pancreatic neoplasm/malignancy is extremely important from a treatment perspective. We report the case of a 67-year-old asymptomatic man who had a 1.3-cm, incidentally detected, pancreatic tail mass. The mass was round, well-circumscribed, and hypervascular with uniform enhancement. The image findings were highly suggestive of a pancreatic endocrine neoplasm. An endoscopic ultrasound-guided fine-needle aspiration was performed. Conventional smears revealed a polymorphous population of lymphocytes admixed with a subset of other inflammatory cells. Hematoxylin-eosin­stained cell block sections showed conspicuous thin-walled blood vessels in addition to inflammatory cells. Immunostaining for CD8 demonstrated strong positivity in endothelial cells of the thin-walled vessels. By correlating the cytologic findings with the result of immunostaining, we rendered the diagnosis of IPAS. Our experience supports the view that endoscopic ultrasound-guided fine-needle aspiration may enable a reliable, preoperative diagnosis of IPAS and thus prevent unnecessary surgery.

Diagnostic ultrasound patterns of parotid glands in human immunodeficiency virus-positive patients in Mulago, Uganda.

OBJECTIVES: The purpose of this study was to determine sonographically, in parotid glands of human immunodeficiency virus-positive patients, the condition of glands with or without enlargement, and propose a classification system for the patterns observed using diagnostic ultrasound imaging. METHODS: In this prospective clinical study, ultrasound scans were performed on 200 patients aged 4-62 years at Mulago Hospital, Uganda. RESULTS: There were four main distinct ultrasound pathological patterns in the parotids, i.e. lymphocytic aggregations (LAs), lymphoepithelial cysts (LECs), fatty infiltration (FI) and lymphadenopathy only. There were additional subdivisions depending on the presence of echogenic foci and intraparotid lymphadenopathy. Of those patients (n = 64) without parotid enlargement, only 8% showed normal ultrasound features, whereas 34% showed LECs and 31% showed LAs. Of those (n = 136) with parotid enlargement, 46% showed LECs, 23% showed FI and 15% showed LAs. The overall prevalence of LECs in the study sample was 42%. LECs were multiple, mainly between 7 mm and 12 mm in diameter and 26% showed internal echogenic foci either mobile or stationary. In contrast, LAs tended to be ill-defined, less than 5 mm and were not associated with posterior acoustic enhancement. Features differentiating LAs from LECs have not been previously described. Parotid FI (lipodystrophy) was noted in patients on highly active antiretroviral therapy, who showed lesser prevalence of LECs after 12 months of treatment. CONCLUSIONS: Our study of 200 patients is probably the largest such study in the English language literature. The wide spectrum of diagnostic ultrasound patterns was categorized into four main groups (ten subgroups).

Investigation of 99mTc-labelling of recombinant human interleukin-2 via hydrazinonicotinamide.

INTRODUCTION: Interleukin-2 (IL-2) when radiolabelled with (99m)Tc has been proved useful in imaging the side of lymphocytic infiltration in patients with autoimmune disorders and plays a significant role as a T-cell imaging agent. However, the labelling procedures used so far appeared to be rather complex and laborious. The aim of present study was to develop an efficient procedure of (99m)Tc-labelling of recombinant human interleukin-2 (rhIL-2) via hydrazinonicotinamide (HYNIC) to develop a dry kit formulation. METHODS: Various molar ratios of rhIL-2/HYNIC (from 1:2 to 1:12) were used at the conjugation step. The conjugates were purified on a PD-10 column to remove the excess of unbound HYNIC, as well as of any aggregates. The final peptide concentration was quantified by the BCA method, and the number of HYNIC molecules incorporated into a rhIL-2 molecule was determined based on the reaction with 2-sulfobenzaldehyde. The (99m)Tc-labelling was optimized using various amounts of HYNIC-rhIL-2, (99m)Tc, SnCl(2), tricine and nicotinic acid (NA). Quality control included GF-HPLC, ITLC, SDS-PAGE and biological assay. Biodistribution studies were performed in Swiss mice and Wistar rats. RESULTS: Generally, the highest radiolabelling yields were achieved when the HYNIC-rhIL-2 conjugates of ca. 2-4 HYNIC molecule substitution ratios were used. The optimal pH of the reaction medium was found to be in the range of 6.5 to 7.0. GF-HPLC analysis indicated that monomer and aggregates of (99m)Tc-HYNIC-rhIL-2 are formed during radiolabelling. At optimized conditions of wet radiolabelling, the (99m)Tc-HYNIC-rhIL-2 monomer was obtained with radiochemical purity >99%, specific activity of ca. 4 GBq/mg rhIL-2 and overall yield of ca. 65%. The two-vial freeze-dried kit was prepared: the first vial contained 30 µg HYNIC-rhIL-2, co-ligands, buffer and antioxidant; the second vial contained tricine and SnCl(2). The monomer of (99m)Tc-HYNIC-rhIL-2 was obtained by gel chromatography on a PD-10 column. No differences between labelled and unlabelled IL2 in terms of biological activity were observed. CONCLUSIONS: Our study shows that rhIL-2 can be efficiently radiolabelled with (99m)Tc via HYNIC, with tricine and NA as co-ligands using a two-vial freeze-dried kit. This enables the preparation of sterile and ready-to-use (99m)Tc-HYNIC(tricine,NA)-rhIL-2 within 1 h.

Idiopathic lymphocytic pleuritis: radiographic and high-resolution CT appearances and changes in response to therapy in two adults.

Inflammatory conditions of the pleura characterized by a predominantly lymphocytic infiltrate are described in several disorders. The commonest underlying aetiologies include tuberculous infection, autoimmune disorders (particularly Sjogren's syndrome), and post coronary artery bypass graft surgery. Idiopathic lymphocytic pleuritis (ILP) is a rare form of diffuse pleural inflammation characterized by extensive lymphocytic infiltration for which no cause is found. Radiological descriptions of ILP are limited. We describe the radiographic and high-resolution computed tomography (HRCT) imaging features and response to corticosteroid therapy of ILP in two adults. Both patients presented with bilateral diffuse pleural thickening of >10 mm thickness extending >10 cm craniocaudally with small focal areas of atelectasis. Both cases demonstrated marked improvement in the degree and extent of pleural thickening and rounded atelectasis following corticosteroid therapy. HRCT provided a useful noninvasive method of assessing disease response to therapy.

Influence of GSTM1 null and low repair XPC PAT+ on anti-B[a]PDE-DNA adduct in mononuclear white blood cells of subjects low exposed to PAHs through smoking and diet.

The influence of low-activity NER genotypes (XPC PAT-/+, XPA-A23G, XPD Asp312Asn, XPD Lys751Gln) and GSTM1 (active or null) was evaluated on anti-benzo[a]pyrene diol epoxide-(B[a]PDE)-DNA adduct formed in the lymphocyte plus monocyte fraction (LMF). The sample population consisted of 291 healthy subjects with low exposure to polycyclic aromatic hydrocarbons (PAHs) (B[a]P) through their smoking (n=126 smokers) or dietary habits (n=165 non-smokers with high (>or=52 times/year) consumption of charcoaled meat or pizza). The bulky anti-B[a]PDE-DNA adduct levels were detected by HPLC/fluorescence analysis and genotypes by PCR. Anti-B[a]PDE-DNA was present (>or=0.5 adducts/10(8) nucleotides) in 163 (56%) subjects (median (range) 0.77 (0.125-32.0) adducts/10(8) nucleotides), with smokers showing a significantly higher adduct level than non-smokers with high consumption of PAH-rich meals (P<0.01). Our exposed-sample population with unfavourable XPC PAT+/- or +/+ and GSTM1 null genotypes has the significantly highest adduct level (P<0.01). Taking into account tobacco smoke and diet as sources of exposure to B[a]P, low-activity XPC PAT+ shows a major role in smokers (P<0.05) and GSTM1 null in non-smokers with frequent consumption of PAH-rich meals (P<0.01). The modulation of anti-B[a]PDE-DNA adduct in the LMF by GSTM1 null and low-activity XPC PAT+ polymorphisms may be considered as potential genetic susceptibility factors that can modify individual responses to low PAH (B[a]P) genotoxic exposure, with the consequent risk of cancer in the general population.

Value of CT-guided core-needle biopsy in diagnosis and classification of malignant lymphomas using automated biopsy gun.

AIM: To evaluate the value of CT-guided core-needle biopsy in diagnosis and classification of malignant lymphomas. METHODS: From January 1999 to October 2004, CT-guided core-needle biopsies were performed in 80 patients with suspected malignant lymphoma. Biopsies were performed with an 18-20 G biopsy-cut (CR Bard, Inc., Covington, GA, USA) needle driven by a spring-loaded Bard biopsy gun. RESULTS: A definite diagnosis and accurate histological subtype were obtained in 61 patients with a success rate of 76.25% (61/80). Surgical sampling was performed in 19 patients (23.75%) with non-diagnostic core-needle biopsies. The success rate of CT-guided core-needle biopsy varied with the histopathologic subtypes in our group. The relatively high success rates of core-needle biopsy were noted in diffuse large B-cell non-Hodgkin's lymphoma (NHL, 88.89%) and peripheral T-cell NHL (90%). However, the success rates were relatively low in anaplastic large cell (T/null cell) lymphoma (ALCL, 44.44%) and Hodgkin's disease (HD, 28.57%) in our group. CONCLUSION: CT-guided core-needle biopsy is a reliable means of diagnosing and classifying malignant lymphomas, and can be widely applied in the management of patients with suspected malignant lymphoma.

Assessing cell trafficking by noninvasive imaging techniques: applications in experimental tumor immunology.

Tracer methods are increasingly being exploited to examine the trafficking patterns of cells transferred into recipient models of diseases, to optimize immune cell therapies, and to assess cancer gene therapy and vaccines in various cancer models. In animal cancer models, noninvasive monitoring by imaging tumor response could significantly facilitate the development of immune cell therapies against cancer. Currently, ex vivo lymphocyte labeling is primarily done by direct labeling. Major advances in cell labeling procedures have led to the use of reporter constructs to assess gene expression in vivo. With this novel technique, the reporter gene marks the cell with a specific protein that distinguishes the cell and its cellular progeny from other cells after migration, homing and mitosis. Several in vivo imaging procedures, including positron emission tomography, single photon emission tomography and magnetic resonance imaging, have been rescaled for studies in small animals. Other methods initially used for in vitro bioluminescence and fluorescence studies have also been refined for in vivo studies. When combined, these methods allow to assess cell trafficking in a noninvasive fashion, beyond lymphocyte response to inflammation, including metastatic diffusion and stem cell transplantation.

Multimodality imaging of lymphocytic migration using lentiviral-based transduction of a tri-fusion reporter gene.

PURPOSE: Previous work showed quantitative imaging of T-cell migration into a tumor site by positron emission tomography (PET), using retroviral transduction of mutated thymidine kinase (sr39TK) reporter genes into immunized T-lymphocytes. PROCEDURES AND RESULTS: In order to improve the sensitivity and flexibility of the imaging analysis, lentivirus, that expressed sr39TK, was used to transduce the lymphocytes that migrated to an immunogenic sarcoma site. In comparison to retrovirally transduced lymphocytes, the lentivirally transduced lymphocytes showed enhanced PET signal when equal numbers of transduced lymphocytes were transferred. Furthermore, in order to utilize multimodality in vivo imaging capability, a tri-fusion reporter gene containing sr39TK, synthetic Renilla luciferase (hRluc), and enhanced green fluorescent protein (eGFP) was inserted into a lentiviral transfer vector. Using the adoptive transfer model, tumor-specific lymphocytic migration was detected by both microPET scan and bioluminescence imaging. CONCLUSION: The multimodal imaging strategy coupled with lentiviral reporter construct delivery demonstrated here can facilitate future molecular imaging studies.

Folate deficiency induces aneuploidy in human lymphocytes in vitro-evidence using cytokinesis-blocked cells and probes specific for chromosomes 17 and 21.

Folate plays a critical role in the prevention of chromosome breakage and hypomethylation of DNA. Deficiency in this vitamin may lead to demethylation of heterochromatin causing structural centromere defects that could induce abnormal distribution of replicated chromosomes during nuclear division. Because aneuploidy of chromosomes 17 and 21 is often observed in breast cancer and leukaemia and increased risk for these cancers is associated with folate deficiency, we hypothesized that folate deficiency may lead to aneuploidy of chromosomes 17 and 21. To test these hypotheses we cultured lymphocytes from eight female volunteers (aged 40-48 years) in RPMI 1640 medium containing 12 or 120nM of folic acid (FA) or 5-methyltetrahydrofolate (MF) for 9 days. Chromosomes 17 and 21 aneuploidies induced by folate deficiency were measured in mononucleated (MONO) and cytokinesis-blocked binucleated (BN) lymphocytes after dual-color fluorescent in situ hybridization (FISH) with a digoxigenin-labeled probe for the alphoid satellite sequence of chromosome 17 and a biotin-labeled probe for the pericentric region of chromosome 21. The results showed that 12nm of MF or FA caused a significant 26-35% increment in frequency of aneuploidy of chromosome 17 (P = 0.0017) and aneupoidy of chromosome 21 (P = 0.0008) relative to 120nM MF or FA. The pattern of aneuploidy in binucleated cells was significantly correlated with that observed in mononucleated cells (R = 0.51-0.75, P < 0.0004) and was consistent with a model based on chromosome loss or partial aneusomy rescue as the cause rather than non-disjunction, although the latter mechanism could not be excluded. MF was not more efficient than FA in preventing aneuploidy in this in vitro system. We conclude that folate deficiency is a risk factor for chromosomes 17 and 21 aneuploidy.

Distribution of 99mTc-labeled lymphocytes in control and inflamed rats.

We studied the in vivo fate of CD8(+) lymphocytes, of naive (CD8(+)CD45RC(bright)) or memory (CD8(+)CD45RC(dim)) phenotype, injected in syngeneic rats, after their sorting and labeling with [(99m)Tc] HM-PAO. By using the scintigrafic method we showed that memory CD8(+) lymphocytes were able to recirculate into liver and lungs. The same method was also successfully used to in vivo study the homing of total blood lymphocytes obtained from inflamed rats.