[Autologous stem cell transplantation for autoimmune diseases: recommendations from the SFGM-TC]. / Autogreffe des cellules souches hématopoïétiques dans les maladies auto-immunes : recommandations de la SFGM-TC.

Autologous hematopoietic stem cell transplantation is a valid alternative to immunosuppressive treatment in patients with auto-immune disease; however, the role of this approach remains subject to debate. In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) set up its fourth annual series of workshops which brought together practitioners from all of its member centers. These workshops took place in September 2013 in Lille. In this article we give an overview regarding the indications of autologous stem cell transplantation in auto-immune diseases as well as recommendations regarding post-transplant follow-up of patients.

Biotherapies in stroke.

Stroke is the second leading cause of death worldwide and the most common cause of severe disability. Neuroprotection and repair mechanisms supporting endogenous brain plasticity are often insufficient to allow complete recovery. While numerous neuroprotective drugs trials have failed to demonstrate benefits for patients, they have provided interesting translational research lessons related to neurorestorative therapy mechanisms in stroke. Stroke damage is not limited to neurons but involve all brain cell type including the extracellular matrix in a "glio-neurovascular niche". Targeting a range of host brain cells, biotherapies such as growth factors and therapeutic cells, currently hold great promise as a regenerative medical strategy for stroke. These techniques can promote both neuroprotection and delayed neural repair through neuro-synaptogenesis, angiogenesis, oligodendrogliogenesis, axonal sprouting and immunomodulatory effects. Their complex mechanisms of action are interdependent and vary according to the particular growth factor or grafted cell type. For example, while "peripheral" stem or stromal cells can provide paracrine trophic support, neural stem/progenitor cells (NSC) or mature neurons can act as more direct neural replacements. With a wide therapeutic time window after stroke, biotherapies could be used to treat many patients. However, guidelines for selecting the optimal time window, and the best delivery routes and doses are still debated and the answers may depend on the chosen product and its expected mechanism including early neuroprotection, delayed neural repair, trophic systemic transient effects or graft survival and integration. Currently, the great variety of growth factors, cell sources and cell therapy products form a therapeutic arsenal that is available for stroke treatment. Their effective clinical use will require prior careful considerations regarding safety (e.g. tumorgenicity, immunogenicity), potential efficacy, cell characterization, delivery route and in vivo biodistribution. Bone marrow-derived cell populations such as mesenchymal stromal/stem cells (MSC) or mononuclear cells (MNC), umbilical cord stem cells and NSC are most investigated notably in clinical trials. Finally, we discuss perspectives concerning potential novel biotherapies such as combinatorial approaches (growth factor combined with cell therapy, in vitro optimization of cell products, or co-transplantation) and the development of biomaterials, which could be used as injectable hydrogel scaffold matrices that could protect a cell graft or selectively deliver drugs and growth factors into the post-stroke cavity at chronic stages. Considering the remaining questions about the best procedure and the safety cautions, we can hope that future translational research about biotherapies will bring more efficient treatments that will decrease post-stroke disability for many patients.

Characteristics of respiratory viruses' circulation through a six-year period (2016-2022) in a pediatric population in Normandy, France, and the impact of COVID-19 pandemic.

IMPORTANCE: The report highlights an epidemiological change in the circulation of respiratory viruses in pediatric populations due to strategies adopted against COVID-19 pandemic. COVID-19 has resulted in a significant increase in requests for multiplex respiratory research to identify the virus responsible for the symptoms. The diagnostic needs have increased, and the number of samples analyzed in 2021-2022 is equal to the samples analyzed over the four epidemic periods preceding the pandemic. The report suggests the importance of active surveillance of respiratory viruses' circulation and new recommendations for respiratory virus detection in pediatric patients.

Effects of practolol on exercise tolerance and cardiac haemodynamics and metabolism in patients with coronary artery disease.

Sixteen male patients with typical angina pectoris secondary to coronary atherosclerosis performed two daily standardized exercise tests during two consecutive days. Three hours before each exercise they received placebo or 400 mg practolol administered orally in double-blind fashion in order to complete a cross-over design. Practolol significantly prolonged the exercise duration by 30.6% and delayed the appearance time of ischaemic electrocardiographic changes by 67.7%. Maximal heart rate, systolic pressure, and pressure-rate product were also reduced after medication. In order to investigate further the effects of this beta blocking agent, myocardial function and metabolism at rest and during supine exercise were assessed in 12 male patients with coronary artery disease before and after practolol 30 mg, iv. At rest, practolol produced a decrease in tension-time index (18%), cardiac index (17%), heart rate (10%), and stroke index (7%). A significant reduction was also observed in resting stroke work index (14%) and systolic and mean aortic pressure (6%). Left ventricular end-diastolic pressure remained unchanged. During supine exercise, only time-tension index (12%), heart rate (12%), and cardiac index (10%) were significantly reduced after the beta blocking agent. Practolol did not significantly change the arterial glucose, lactate, inorganic phosphate, potassium, calcium, magnesium, pH, PCO2, or PO2. The beta blocking agent did not modify the myocardial extraction of any of these substrates at rest or during exercise. In the dosage used in both studies, practolol significantly improved the exercise tolerance and reduced the ischaemic manifestations. The efficacy of practolol in angina pectoris may result mostly from its ability to decrease heart rate and systolic pressure during exercise.

In vivo parameters influencing 2-Cys Prx oligomerization: The role of enzyme sulfinylation.

2-Cys Prxs are H2O2-specific antioxidants that become inactivated by enzyme hyperoxidation at elevated H2O2 levels. Although hyperoxidation restricts the antioxidant physiological role of these enzymes, it also allows the enzyme to become an efficient chaperone holdase. The critical molecular event allowing the peroxidase to chaperone switch is thought to be the enzyme assembly into high molecular weight (HMW) structures brought about by enzyme hyperoxidation. How hyperoxidation promotes HMW assembly is not well understood and Prx mutants allowing disentangling its peroxidase and chaperone functions are lacking. To begin addressing the link between enzyme hyperoxidation and HMW structures formation, we have evaluated the in vivo 2-Cys Prxs quaternary structure changes induced by H2O2 by size exclusion chromatography (SEC) on crude lysates, using wild type (Wt) untagged and Myc-tagged S. cerevisiae 2-Cys Prx Tsa1 and derivative Tsa1 mutants or genetic conditions known to inactivate peroxidase or chaperone activity or altering the enzyme sensitivity to hyperoxidation. Our data confirm the strict causative link between H2O2-induced hyperoxidation and HMW formation/stabilization, also raising the question of whether CP hyperoxidation triggers the assembly of HMW structures by the stacking of decamers, which is the prevalent view of the literature, or rather, the stabilization of preassembled stacked decamers.

A novel A10E homozygous mutation in the HSD3B2 gene causing severe salt-wasting 3beta-hydroxysteroid dehydrogenase deficiency in 46,XX and 46,XY French-Canadians: evaluation of gonadal function after puberty.

Severe 3beta-hydroxysteroid dehydrogenase (3betaHSD) deficiency is a rare form of congenital adrenal hyperplasia resulting from mutations in the HSD3B2 gene that impair steroidogenesis in both the adrenals and gonads and cause salt-wasting in both sexes and incomplete masculinization of the external genitalia in genetic males. About two thirds of the reported patients are 46,XY. We describe two French-Canadian patients from two families without a known relationship who presented with severe salt-wasting 3betaHSD deficiency in infancy. Although the diagnosis was considered clinically, plasma steroid profiles were confusing. We have thus directly sequenced DNA fragments generated by PCR amplification of the four exons, exon-intron boundaries, and the 5'-flanking regions of the HSD3B2 gene. Sequencing of exon II revealed the presence of a C to A transversion in both alleles of these two cases, thus converting codon 10 (GCA), which codes for Ala, into GAA, encoding Glu. This Ala is highly conserved in the vertebrate 3betaHSD gene family and is located in the putative NAD-binding domain of the enzyme. The mutant type II 3betaHSD enzyme carrying an A10E substitution exhibited no detectable activity in intact transfected Ad293 cells. Both homozygous patients share the same haplotype, spanning approximately 3.3 centimorgans surrounding the HSD3B2 locus, which is consistent with a founder effect for this missense mutation. The 46,XY patient presented with ambiguous genitalia at birth and underwent normal masculinization at puberty, but was azoospermic at 18.5 yr of age. The 46,XX patient presented progressive breast development, menarche, and evidence of progesterone secretion. The only previously reported cases with pubertal follow-up revealed paternity in one male and hypogonadism in one female. These findings demonstrate the complex relationships between the genotype and the gonadal phenotype in severe 3betaHSD deficiency and the difficulty in predicting fertility.

New insight into the molecular basis of 3beta-hydroxysteroid dehydrogenase deficiency: identification of eight mutations in the HSD3B2 gene eleven patients from seven new families and comparison of the functional properties of twenty-five mutant enzymes.

Classical 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase (3betaHSD) deficiency is a form of congenital adrenal hyperplasia that impairs steroidogenesis in both the adrenals and gonads resulting from mutations in the HSD3B2 gene and causing various degrees of salt-wasting in both sexes and incomplete masculinization of the external genitalia in genetic males. To identify the molecular lesion(s) in the HSD3B2 gene in the 11 patients from the seven new families suffering from classical 3betaHSD deficiency, the complete nucleotide sequence of the whole coding region and exon-intron splicing boundaries of this gene was determined by direct sequencing. Five of these families were referred to Morel's molecular diagnostics laboratory in France, whereas the two other families were investigated by Peter's group in Germany. Functional characterization studies were performed by Simard's group in Canada. Following transient expression in 293 cells of each of the mutant recombinant proteins generated by site-directed mutagenesis, the effect of the 25 mutations on enzyme activity was assessed by incubating intact cells in culture with 10 nM [14C]-DHEA as substrate. The stability of the mutant proteins has been investigated using a combination of Northern and Western blot analyses, as well as an in vitro transcription/translation assay using rabbit reticulocyte lysates. The present report describes the identification of 8 mutations, in seven new families with individuals suffering from classical 3betaHSD deficiency, thus increasing the number of known HSD3B2 mutations involved in this autosomal recessive disorder to 31 (1 splicing, 1 in-frame deletion, 3 nonsense, 4 frameshift and 22 missense mutations). In addition to the mutations reported here in these new families, we have also investigated for the first time the functional significance of previously reported missense mutations and or sequence variants namely, A82T, A167V, L173R, L205P, S213G and K216E, P222H, T259M, and T259R, which have not previously been functionally characterized. Furthermore, their effects have been compared with those of the 10 previously reported mutant enzymes to provide a more consistent and comprehensive study. The present results are in accordance with the prediction that no functional 3betaHSD type 2 isoenzyme is expressed in the adrenals and gonads of the patients suffering from a severe salt-wasting form of CAH due to classical 3betaHSD deficiency. Whereas the nonsalt-losing form also results from missense mutation(s) in the HSD3B2 gene, which cause an incomplete loss in enzyme activity, thus leaving sufficient enzymatic activity to prevent salt wasting. The functional data described in the present study concerning the sequence variants A167V, S213G, K216E and L236S, which were detected with premature pubarche or hyperandrogenic adolescent girls suspected to be affected from nonclassical 3betaHSD deficiency, coupled with the previous studies reporting that no mutations were found in both HSD3B1 and/or HSD3B2 genes in such patients strongly support the conclusion that this disorder does not result from a mutant 3betaHSD isoenzyme. The present study provides biochemical evidence supporting the involvement of a new molecular mechanism in classical 3betaHSD deficiency involving protein instability and further illustrates the complexity of the genotype-phenotype relationships of this disease, in addition to providing further valuable information concerning the structure-function relationships of the 3betaHSD superfamily.

cDNA cloning and expression of an Arabidopsis GTP-binding protein of the ARF family.

A cDNA clone encoding a small GTP-binding protein, the ADP-ribosylation factor (ARF) was isolated from a cDNA library of Arabidopsis thaliana cultured cells. The predicted amino acid sequence was highly homologous to the known yeast, bovine and human ARF sequences. Southern analysis of Arabidopsis genomic DNA suggested the existence of at least two copies of ARF genes. The level of ARF mRNA was found to be nearly constant during all cell growth stages in suspension cultures.

Inapparent polycythemia vera: an unrecognized diagnosis.

PURPOSE: The Polycythemia Vera Study Group (PVSG) has established useful criteria for the diagnosis of polycythemia vera. In some circumstances, an increase of plasma volume (PV) masks that of red cell mass (RCM), with hemoglobin (Hb) and hematocrit (Ht) remaining normal. This defines the concept of inapparent polycythemia. PATIENTS AND METHODS: One hundred and three patients seen in the hematology unit with the diagnosis of polycythemia vera were studied. There were 55 males and 48 females with a median age of 59 years. Ninety-five patients fulfilled the PVSG criteria. Spontaneous erythroid colonies and low serum erythropoietin level confirmed the diagnosis in the 8 other cases. Patients were classified according to Hb and Ht level. RESULTS: Group A consisted of 85 patients with increased Hb and Ht defined, respectively, by Hb > 18 g/dl, Ht > 0.52 in males and Hb > 16 g/dL, Ht>0.47 in females. Group B included 18 patients (17%) with inapparent polycythemia vera (IPV) defined by a normal Hb and Ht value at diagnosis. In this group, the reasons to perform RCM were as follows: splenomegaly associated with increased platelets and/or leucocytes counts (n = 8), portal vein thrombosis (n = 5), increased platelets or leucocytes counts without splenomegaly (n = 3), and isolated splenomegaly (n = 2). The two groups were balanced in terms of age, sex, leucocyte, serum iron, and platelet level. Hemoglobin and Ht levels were significantly different between the two groups. The difference between the PV was indeed highly significant. The mean PV increase was + 9.5% (nL < +20%) in group A versus + 36.3% in group B (P < 0.00005). Red cell mass was not different between the two groups. CONCLUSIONS: Increased Hb or Ht should constitute the sole criteria for RCM determination. In the context of portal vein thrombosis, isolated hyperleucocytosis, thrombocytosis, or splenomegaly, a RCM should be performed. The frequency of IPV remains to be specified but the diagnosis of polycythemia vera is probably underestimated.

Splenectomy in idiopathic thrombocytopenic purpura: its correlation with the sequestration of autologous indium-111-labeled platelets.

We present a retrospective analysis of 111In-platelet sequestration studies in 111 patients with the clinical diagnosis of idiopathic thrombocytopenic purpura (ITP). Fifty-one of these patients underwent splenectomy, independent of the results of the 111In-platelet studies to determine if these isotopic results could accurately predict a beneficial response to splenectomy. Between January 1984 and June 1990, 111 patients who presented with ITP were subjected to a study of autologous 111In-labeled platelets through autotransfusion. The platelet sequestration site was splenic (81%), mixed (12%), or hepatic (7%). Fifty-one patients with persistent drug-resistant thrombocytopenia underwent splenectomy regardless of the isotopic results: 33 patients beyond 6 mo after diagnosis and 18 with high hemorrhagic risks before this delay. The follow-up median duration was 2.9 yr. Thirty-three of the 38 patients with splenic sequestration showed a normalized platelet count, as opposed to 2 of the 13 with mixed or hepatic sequestration (p < 0.001). In addition, platelet survival extended beyond 8 days in six patients, with no apparent sequestration site. The platelet isotopic study performed with this technique appears to be indicated in ITP: it guides clinicians in their decision to perform splenectomy and relates to a more central mechanism certain thrombocytopenias that are inappropriately categorized as ITP.

Pulmonary uptake of Tc-99m-Labeled methylene diphosphonate in a patient with a parathyroid adenoma.

Intense diffuse uptake of Tc-99m-labeled methylene diphosphonate was seen in both lungs of a patient submitted to surgery for a primary parathyroid adenoma. Five scans performed over the 3 yr following the operation showed persistence of lung uptake despite restoration of normal blood calcium concentration. Mild chronic renal failure caused by the hypercalcemia also persisted postoperatively. The present case confirms that pulmonary uptake of bone tracer can occur asymptomatically when both hypercalcemia and renal failure are present. Lung uptake of a bone tracer probably reflects tissue deposition of hydroxyapatite rather than of amorphous structures. Correction of the hypercalcemia failed to resolve the abnormal scan pictures.

Scintigraphic assessment of indium-111-labeled granulocyte splenic pooling: a new approach to inflammatory bowel disease activity.

We have conducted a prospective study into the sensitivity and the specificity of the fall in splenic activity (FSA) as an index of activity in inflammatory bowel disease (IBD). FSA was measured on scintiscans obtained at 3 and 24 hr postinjection of indium-111-labeled granulocytes. One hundred and twenty-two scans were acquired in 96 patients who were divided into six groups: Gr. I = normal volunteers (n = 10); Gr. II = inflammatory rheumatism (n = 10); Gr. III = abscesses (n = 17); Gr. IV = ulcerative colitis (UC: n = 23); Gr. V = colonic Crohn's disease (CCD: n = 22); and Gr. VI = ileal Crohn's disease (ICD: n = 14). FSA for Groups I and II was constantly below 10%, but it was increased in the other four groups (abscesses: 39% +/- 12%; UC: 35% +/- 13.5%; CCD: 23.7% +/- 14.7%; ICD: 21.5% +/- 11.7%). There was a significant correlation between fecal excretion of 111In (FEI) and FSA in patients with IBD (UC: r = 0.71, p less than 0.001; CCD: r = 0.74, p less than 0.001; ICD: r = 0.43, p less than 0.001). FSA was followed in 16 patients with IBD after medical treatment and there was a significant correlation between variations in FSA and in FEI (r = 0.879, p less than 0.001). FSA is a very sensitive although nonspecific index of disease activity in IBD and may replace FEI in the assessment of IBD activity.

Vigorous physical training after aortic valve replacement: analysis of 10 patients.

Improved prosthetic aortic valves have reduced the incidence of complications to a point where it can be hypothesized that functional class I subjects after aortic valve replacement (AVR) should adapt to a vigorous training program without a significant increase of hemolytic activity or clinical signs of prosthesis malfunction. To test this hypothesis, 10 men (mean age 52 years) who had undergone AVR (7 Björk-Shiley and 3 Lillehei-Kaster) were submitted to an 8-week training program on ergometer, 3 times/week, from 60 to 80% of individual maximal heart rate. Ten other men who had undergone AVR but did not participate in the training program were control subjects. The exercise program produced significant improvements in posttraining maximum tolerated ergometer work load (210 kpm, p less than 0.001), in maximum total body oxygen consumption (5 ml/kg X min-1, p less than or equal to 0.01) and in double product at submaximal work load (-5,126, p less than or equal to 0.01). After training, hemoglobin decreased by about 1 g% (p less than or equal to 0.05) and hematocrit, reticulocyte counts and haptoglobin did not change significantly. Serum LDH and serum AST did not increase. Pre- and post-training echocardiograms did not show detectable alterations. Thus, patients with AVR who are in functional class I can adapt to a physical exercise program without significant adverse effects.

Labeled granulocyte scanning for the diagnosis of infected necrosis in acute pancreatitis: what kind of labeling should be used?

Clinical and laboratory data or imaging results cannot provide a positive diagnosis of septic complications of pancreatic and peripancreatic necrosis in patients with acute pancreatitis. Confirmation can be obtained only after percutaneous computed tomography (CT)-guided aspiration of the necrotic tissues or fluid collection; although the important role of 99Tc(m)-HMPAO-labeled granulocyte scintigraphy has been recently emphasized. The aim of this study was to determine the sensitivity and specificity of 99m-technetium-hexamethylpropyleneamine oxime (99Tc(m)-HMPAO)- or 111In-oxine-labeled granulocyte scintigraphy for the diagnosis of infection in pancreatic or peripancreatic necrosis to define the ideal label for diagnosis. Thirty-six scintigraphic examinations were performed in 34 consecutive patients (mean age, 58 +/- 2 years) 20 +/- 2 days after the onset of acute pancreatitis (Balthazar classes A-C, n = 7; classes D and E, n = 29). The scintigraphic study included scintigraphic tomography and static acquisition 1 and 3 h, respectively, after reinjection of the autologous 99Tc(m)-labeled granulocytes and static images 3-4 and 24 h after the simultaneous reinjection of 111In-oxine-labeled autologous granulocytes. The diagnosis of infected pancreatic or peripancreatic necrosis was confirmed with percutaneous CT-guided aspiration (14 positive aspirates among 20 performed) and sterile necrosis after negative aspiration (6 negative aspirates) or after a 6 +/- 1-month follow-up free of clinical or biological signs of ongoing sepsis. The sensitivity and specificity were 86 and 73%, respectively, for scintigraphic tomography, 100 and 55% for 3-h 111In images, 93 and 68% for 3-4-h 111In images, and 100 and 64% for 24-h 111In images. The fall in splenic activity between the 3-4 and the 24-h 111In images was 26 +/- 3% in patients with septic pancreatic and peripancreatic necrosis (n = 14) and 16 +/- 3% in those with sterile necrosis (n = 22) (p < 0.01). Labeled granulocyte scintigraphy was thus shown to be an effective tool for the diagnosis of infection in pancreatic and/or peripancreatic necrosis due to acute pancreatitis, especially when the scintiscans are performed early after injection of 99Tc(m) or when the fall in splenic activity over the 24 h following reinjection of 111In is measured in particularly difficult cases. These promising preliminary results should be confirmed by a prospective study.

Diagnosis of osteomyelitis in the diabetic foot with a 99mTc-HMPAO leucocyte scintigraphy combined with a 99mTc-MDP bone scintigraphy.

BACKGROUND: The aim of this prospective study was to assess the role of 99mTc-HMPAO leucocyte scintigraphy combined with a 99mTc-MDP bone scintigraphy in the diagnosis of the diabetic foot infection (HMPAO-Leu/MDP). METHODS: 75 diabetic patients with suspected osteomyelitis were included. The HMPAO-Leu/MDP scan was considered to be consistent with osteomyelitis when the HMPAO-Leu uptake was concordant in all the incidences with an MDP bone uptake. A HMPAO-Leu uptake without concordant bone MDP activity was considered as a soft-tissue infection. The results of the HMPAO-Leu/MDP scan were compared to the following diagnostic criteria: bone infection was confirmed by radiological follow-up or bone biopsy; the absence of bone infection was confirmed by clinical (healing of the ulcer without antibiotherapy) and radiological follow up. RESULTS: According to these criteria, among the 83 ulcers, bone infection was observed in 41 (49.4%): the HMPAO-Leu/MDP scan was positive in 38 cases, including 14 ulcers with normal or doubtful radiographs at inclusion. In the group of 42 ulcers without proven bone infection, the HMPAO-Leu/MDP scan was negative in 41 cases, including 17 lesions with a soft-tissue infection. CONCLUSION: With a sensitivity of 92.6%, a specificity of 97.6%, the HMPAO-Leu/MDP scan is a reliable tool for the diagnosis of osteomyelitis in the diabetic foot. Neuroarthropathy did not affect the performances of the HMPAO-Leu/MDP scan. Owing to a high spatial resolution this test is very helpful to differentiate bone infection from soft-tissue infection especially in case of neuroarthropathy.

Fate of mouse macrophages radiolabelled with PKH-95 and injected intravenously.

Mouse macrophages purified by elutriation from thioglycollate-induced peritoneal exudate cells were labelled with indium-111-oxine and injected intravenously into mice. A substantial amount of unbound radioactivity remained in the circulation, suggesting that the radionuclide was not stably bound to the cells. Culture experiments with radiolabelled cells showed that indium-111 was released in the medium. Another cell marker, PKH-95, an iodine-125-labelled aliphatic compound insertable into the cell membrane, bound more stably than indium-111. Five minutes after injection of 125I-PKH-95-labelled macrophages, about 98% of the cells were in a non-circulating pool. It was checked that PKH-95 labelling did not compromise the viability and functions of the macrophages and that autologous erythrocytes and blood mononuclear cells labelled with PKH-95 remained in the circulation after i.v. injection. One hour after injection, 125I-PKH-95-labelled macrophages were distributed mainly in lung (36%), liver (19%) and spleen (5%). Subsequently, radioactivity decreased in the lung while increasing in liver, spleen and in an artificially induced footpad inflammation. The radioactivity accumulation in the inflammation persisted at least for 7 days. It represented a small proportion of radioactivity injected (0.2%) but was trapped very specifically in the inflammation. This raised the hypothesis that macrophages of the non-circulating pool could be released in the circulation and recruited into the inflammation with slow kinetics.

Rhenium-188 and technetium-99m nitridobis(N-ethoxy-N-ethyldithiocarbamate) leucocyte labelling radiopharmaceuticals: [188ReN(NOET)2] and [99mTcN(NOET)2], NOET = Et(EtO)NCS2: their in vitro localization and chemical behaviour.

In this study, we have investigated the preparation of rhenium-188 nitridobis(N-ethoxy-N-ethyldithiocarbamate) [188ReN(NOET)2] (NOET = Et(EtO)NCS2), analogous to the known technetium-99m radiopharmaceutical. The new 188Re complex was synthesized in good yield with a satisfactory radiochemical purity, using a kit method. The subcellular localization of both radiopharmaceuticals in granulocytes was observed by microautoradiography. The uptake was independent of the radionuclide and predominantly nuclear. Furthermore, HPLC was used to characterize the 99mTc complex before and after blood cell labelling and revealed that the intact radiopharmaceutical was involved.

New bis(dithiocarboxylato) nitridotechnetium-99m radiopharmaceuticals for leucocyte labelling: in vitro and in vivo studies.

Dithiocarboxylate ligands were synthesized and characterised. New nitrido 99m-technetium complexes were obtained with these ligands and identified by thin layer chromatography. The nitrido complexes were tested in vitro in whole blood for leucocyte labelling and the design of the ligand was optimized. Best results were obtained with aliphatic linear ligands, containing 9 to 11 atoms of carbon. The in vivo experiment failed because an inflammated area could not be visualized by gamma imaging, the cell labelling mechanism being probably different.

Studies of technetium-99m nitridobisdithiocarboxylate leucocyte specific radiopharmaceutical: [99mTcN(DTCX)2], DTCX = CH3(CH2)8CS2. The cellular and subcellular distribution in human blood cells, and chemical behaviour. Synthesis of the analogous rhenium-188 radiopharmaceutical.

The distribution of the radiopharmaceutical ([99mTcN(DTCX)2], DTCX = CH3(CH2)8CS2) in the leucocyte population determined by a density separation with double gradient Polymorphprep was studied. Microautoradiographic analysis showed a subcellular distribution of the radiomarker in human blood cells. This technique confirmed the observed lymphocyte selectivity (69%) and revealed that the uptake was predominantly cytoplasmic around the nucleus. A labeling mechanism by passive endocytosis could be proposed involving a required lipophilicity of the radiopharmaceutical for lymphocyte targeting. Finally, we describe the new synthesis with an efficient yield and radiochemical purity of the analogous radiopharmaceutical [188ReN(DTCX)2].