Biomedical subjects
Publications and source records attributed to A Cosson.
This review summarizes the descriptive anatomy of cranial nerves III through XII, starting at their emergence from the neuraxis towards peripheral territories, as well as their functional anatomy. For each pair of cranial nerves, correlations are made between diseases, anatomo-clinical and anatomo-neurophysiological data.
The problem of the arterial vascularization of the human thalamus has been debated at length. Anatomical references concerning the thalamic arterial groups are contradictory and complex, preventing any solid application in practice. It is, therefore, difficult to produce reliable anatomical radio-clinical correlation. In this work, 12 adult human cerebellums (24 hemispheres) were dissected after intra-vascular injection. With care for clarification and standardization, the extra-parenchymal thalamic arteries were classified in six groups: pre-mamillary artery, perforating thalamic arteries, thalamo-geniculate arteries, perforating branches of the postero-medial, postero-lateral and anterior choroidal arteries. Variations in the pre-mamillary artery were rare. The origin of the perforating thalamic artery was unilateral in two of three cases. The origin of the thalamo-geniculate arteries arose between the posterior cerebral artery (53%) and the posterior choroidal arteries (43%). The postero-median choroidal artery was most often single and usually gave the perforating branches for the medial aspect of the thalamus. The postero-lateral choroidal artery was frequently multiple and essentially gave the perforating branches for the superior aspect of the thalamus. The pulvinarian branches most often rose from the postero-lateral choroidal arteries (two thirds of cases) and more rarely from the postero-median choroidal arteries (one third of cases). The anterior choroidal artery is a source of thalamic vascularization by its cisternal branches running towards the lateral thalamus. It can also participate in the vascularization of the pulvinar by the plexiform branches crossing the temporal horn of the lateral ventricle. This study has allowed definition of the intra-parenchymatous arterial map of the thalamus. This mapping is essential for producing anatomical radio-clinical correlations which are pertinent for therapeutic decisions.
INTRODUCTION: The aim of this work is to sum up how the use of EMG improves BT therapy. METHOD: A systematic review of the literature in the Pub Med computer database, along with a manual biography, allowed us to choose the most synthetic and the most pertinent publications according to our own practical experience. RESULTS: There is no consensus of opinion, but the great majority of authors emphasize the importance of EMG in the different stages of botulinum toxin treatment: before injections, at the time of the injection, and finally during the follow-up after the first injection or after the repeated injections that transient efficiency make necessary. DISCUSSION: A symptomatic therapeutic means recently recognized in focal dystonias and spasticity, BT is injected locally into the muscles to be treated. EMG can be used: at pre-injection for physiopathological evaluation but above all to establish a diagnosis and precise pre-intervention evaluation; at the moment of injection to provide guidance in precise muscle selection and for maximum efficiency with reduced, therefore less costly, doses. It also limits the risk of product diffusion susceptible of causing iatrogenic side effects and/or auto-immunisation resulting in resistance to the toxin; during follow-up, to understand why treatment failed and to look for changes in the dystonia pattern leading to objective re-evaluations and adapted reinjections. Although neglected by some, electrological logistics seem to us, as to many other practitioners who inject, to be a considerably helpful aid, particularly at the moment of injection when targeting the muscle to be treated.
OBJECTIVE: The first clinical studies indicate that Botox provides effective treatment for hyperhidrosis and sialorrhea. The aim of this work is to sum up current evaluation of this use. METHOD: A systematic literature search was conducted on the Pub Med database, along with on chapters in other publications. The most interesting articles in relation to our own personal experience were chosen. RESULTS: Despite recent use of BT to treat focal hyperhidrosis, there have been numerous publications since 1997. However, the injected areas have not been listed so frequently. Axillary hyperhidrosis has been studied most; it is also in this case and in the case of gustatory sweating that the best results have been obtained. Publications about palmar and especially plantar hyperhidrosis are much rarer, almost anecdotic. It has been demonstrated to a lesser extent that BT injections are effective in these cases. Literature about sialorrhea is just beginning. However, the reduction of the production of saliva following intra parenchymatic injection of toxin into the parotid and submandibular glands, thus rarifying drooling, has been demonstrated. For each of the pathological indications, both the injection techniques and the optimal doses remain to be determined. DISCUSSION: Because BT blocks all cholinergic transmission, including the autonomous nervous system, it was plausible to expect a reduction in sweating and salivation on local injection of the product. In fact, the first publications indicated such efficiency without serious side effects. For hyperhidrosis, there has developed a consensus for making intracutaneous injections only. Of the injections in axillary areas, the palms of the hands, the plantar regions, the face or other cutaneous areas, palmoplantar hyperhidrosis is the least accessible, in any case causes the most technical problems, because of difficulty in pain management. For sialorrhea and the drooling that accompanies certain chronical neurological diseases, BT seems to have very promising effects. However, it has not been precisely determined whether to inject the parotid gland, the submandibular gland, or both. Necessary and sufficient means of targeting are still imprecise. It also remains to be determined the number of sites per gland and the doses to be injected.
OBJECTIVE: Botulinum toxin (BT) injection into the external urethral sphincter is a promising therapy for neurogenic voiding disorders due to detrusor-sphincter dyssynergia (DSD). However the optimal treatment protocol remains unclear. METHOD: A PubMed reference search and manual bibliography review were performed, along with a search in the Annales de réadaptation et de médecine physique and in the reports of the International French-language Society of Urodynamics and the International Continence Society, which allowed us to select twelve pertinent articles with PubMed, two articles from the Annales and two conference reports. Our analysis gave special emphasis to assessment criteria, application, dosage and BT injection technique. RESULTS: Used for the first time in 1988 in spinal cord injury patients to reduce outflow obstruction due to DSD, BT injections have been shown to be a valuable alternative management of bladder dysfunction with DSD. They have been proposed in neurological patients unable to perform self-catheterisation, after drug failure and before surgery. Parameters for results assessment are mostly clinical (increased free interval between voiding, decreased post-void residual urine volumes), urodynamic (improvement in bladder emptying, increase in functional bladder capacity and decrease in urethral pressure) and electromyographic (denervation of striated urethral sphincter). The literature data regarding type of BT, dosage and protocol vary widely. Duration of action is from 2 to 12 months. Both transurethral and transperineal injections monitored by EMG are equally effective in improving detrusor-sphincter dyssynergia. CONCLUSION: With few side effects and satisfactory medium-term results, BT should be recommended as a component of DSD therapies. We propose a practical method for BT use.
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Trypanosoma cruzi proteinases are involved in host cell invasion in human patients and in mouse models. In mice, murine alpha(2)-macroglobulin (MAM) and murinoglobulin are circulating plasma proteinase inhibitors that also have important roles in inflammation and immune modulation. To define their role in experimental Chagas disease, we investigated the susceptibility to T. cruzi infection of mice that are deficient only in alpha2-macroglobulins (AM-KO) or in both MAM and monomeric murinoglobulin-1 (MM-KO), relative to the wild type (WT). Despite the high parasite load, parasitemia was lower in AM-KO and MM-KO mice than in WT mice. Nevertheless, we observed a significantly higher parasite load in the hearts of AM-KO and MM-KO mice, i.e., more amastigote nests and inflammatory infiltrates than in WT mice. This result demonstrates a protective role for MAM in the acute phase of murine T. cruzi infection. We further demonstrated in vitro that human alpha2-macroglobulins altered the trypomastigote morphology and motility in a dose-dependent way, and that also impaired T. cruzi invasion in cardiomyocytes. Finally, we demonstrated that the levels of transforming growth factor beta in AM-KO mice increased significantly in the third week postinfection, concomitant with high amastigote burden and important fibrosis. Combined, these in vivo and in vitro findings demonstrate that the MAM contribute to the resistance of mice to acute myocarditis induced by experimental T. cruzi infection.
The herpes virus family, particularly cytomegalovirus and Epstein-Barr virus, are often associated with acute polyradiculoneuritis (APRN). APRN following primary herpes simplex virus infection is much more uncommon, viral reactivation generally being involved. We report a patient who developed APRN following herpes simplex virus primary infection, probably HSV II.
The Xid mutation predominantly affects the development of B cells and consequently the levels and composition of natural antibodies in sera. In contrast to the congenic and susceptible BALB/c strain, immunodeficient BALB.Xid mice display a resistant phenotype both to acute Trypanosoma cruzi infection and to the development of severe cardiopathy. Because natural antibodies are known to be basically self-antigen driven, IgM and IgG natural antibody repertoires (NAR) were compared before and during infection in these two strains. The analysis revealed fundamental alterations of IgM and IgG NAR in pre- and post-infected Xid mice. In particular, relatively increased natural (pre-existing) autoreactive IgG, dominated by the unique recognition of a single band in autologous heart extracts, was typical for uninfected Xid mice. This natural autoreactive IgG directed to heart antigens disappeared early after infection not only in Xid, but also in individual BALB/c mice that survived the acute infection. Conversely, the subgroup of BALB/c mice that died early after infection presented the most pronounced instances of the rapid, relative increase of IgM reactivities to self and non-self proteins. These results suggest that self-reactive NAR may play a role in an immunoregulatory mechanism relevant for the determination of susceptibility/resistance to infections. This may act either by influencing specific responses, or by modulating the self-aggressive components responsible for pathology.
The AML1 gene, situated in 21q22, is often rearranged in acute leukemias through t(8;21) translocation, t(12;21) translocation, or less often t(3;21) translocation. Recently, point mutations in the Runt domain of the AML1 gene have also been reported in leukemia patients. Observations for mutations of the Runt domain of the AML1 gene in bone marrow cells were made in 300 patients, including 131 with acute myeloid leukemia (AML), 94 with myelodysplastic syndrome (MDS), 28 with blast crisis chronic myeloid leukemia (CML), 3 with atypical CML, 41 with acute lymphoblastic leukemia (ALL), and 3 with essential thrombocythemia (ET). Forty-one of the patients had chromosome 21 abnormalities, including t(8;21) in 6 of the patients with AML, t(12;21) in 8 patients with ALL, acquired trisomy 21 in 17 patients, tetrasomy 21 in 7 patients, and constitutional trisomy 21 (Down syndrome) in 3 patients. A point mutation was found in 14 cases (4.7%), including 9 (22%) of the 41 patients with AML of the Mo type (MoAML) (none of them had detectable chromosome 21 rearrangement) and 5 (38%) of the 13 myeloid malignancies with acquired trisomy 21 (1 M1AML, 2 M2AML, 1 ET, and 1 atypical CML). In at least 8 of 9 mutated cases of MoAML, both AML alleles were mutated: 3 patients had different stop codon mutations of the 2 AML1 alleles, and 5 patients had the same missense or stop codon mutation in both AML1 alleles, which resulted in at least 3 of the patients having duplication of the mutated allele and deletion of the normal residual allele, as shown by FISH analysis and by comparing microsatellite analyses of several chromosome 21 markers on diagnosis and remission samples. In the remaining mutated cases, with acquired trisomy 21, a missense mutation of AML1, which involved 2 of the 3 copies of the AML1 gene, was found. Four of the 7 mutated cases could be reanalyzed in complete remission, and no AML1 mutation was found, showing that mutations were acquired in the leukemic clone. In conclusion, these findings confirm the possibility of mutations of the Runt domain of the AML1 gene in leukemias, mainly in MoAML and in myeloid malignancies with acquired trisomy 21. AML1 mutations, in MoAML, involved both alleles and probably lead to nonfunctional AML1 protein. As AML1 protein regulates the expression of the myeloperoxidase gene, the relationship between AML1 mutations and Mo phenotype in AML will have to be further explored. (Blood. 2000;96:2862-2869)
In this article, Bernardo Reina-San-Martin, Alain Cosson and Paola Minoprio summarize the marked alterations in the immune system functions after infection that might account for the poor success of effective parasite vaccine development. Many of the studies on oligoclonal B- and T-cell responses to parasite antigens aiming at vaccination strategies would seem to ignore more general, and perhaps fundamental, aspects of parasite-immune system interactions. In essence, because of its consequences on immunopathology and parasite escape, the authors ascribe a central importance in the pathogenesis of parasitic diseases to the 'nonspecific' polyclonal lymphocyte activation that occurs during infection. Hence, novel targets and strategies for immune intervention should be considered.
Lymphocyte polyclonal activation is a generalized mechanism of immune evasion among pathogens. In a mouse model of Trypanosoma cruzi infection (American trypanosomiasis), reduced levels of polyclonal lymphocyte responses correlate with resistance to infection and cardiopathy. We report here the characterization of a parasite protein with B-cell mitogenic properties in culture supernatants of infective forms, the cloning of the corresponding gene and the analysis of the biological properties of its product. We characterized the protein as a co-factor-independent proline racemase, and show that its expression as a cytoplasmic and/or membrane-associated protein is life-stage specific. Inhibition studies indicate that availability of the racemase active site is necessary for mitogenic activity. This is the first report to our knowledge of a eukaryotic amino acid racemase gene. Our findings have potential consequences for the development of new immune therapies and drug design against pathogens.
INTRODUCTION: Chromosomal translocations involving the chromosome 3q27 region are common in B-cell non-Hodgkin's lymphoma (NHL), mainly diffuse large cell lymphoma (DLCL) and less often in follicular lymphoma. Most of these rearrangements involve the same major translocation cluster (MTC) on the 3q27 region, disrupting the LAZ3/BCL6 gene. Some of those translocations are difficult to detect by cytogenetic analysis and/or Southern-blot analysis. In the present report we used a FISH assay to improve the detection of LAZ3/BCL6 rearrangements. METHODS: We isolated a YAC clone (803g3), containing the BCL6 gene, in order to analyze by FISH 19 cases of B-cell non-Hodgkin's lymphoma with cytogenetically detectable 3q27 rearrangement, including reciprocal translocation in 11 cases, deletion in two cases, and addition of undefined chromosomal material on 3q27 in six cases. RESULTS: In the 11 cases with reciprocal translocation, FISH results confirmed cytogenetic data and showed disruption of the LAZ3 region: four t(3;4)(q27;p13), two t(3;11)(q27;q23.1), four t(3;14)(q27;q32) and one t(2;3)(p12;q27). In two of the cases, reciprocal t(3;14) was associated with other cytogenetically detectable abnormalities of 3q27, but FISH showed that they did not affect the LAZ3 gene region. FISH demonstrated a reciprocal translocation with LAZ3 gene rearrangement in two of the six patients with add 3q27: one t(3;11) and one t(3;14). In the two patients with del(3q27), one had two 3q27 FISH signals and one had only one 3q27 FISH signal, but no LAZ3 gene rearrangement was observed. CONCLUSION: We have identified a YAC containing the LAZ3/BCL6 gene. This YAC probe could be useful in clinical practice to demonstrate LAZ3 rearrangements by FISH analysis on tumor samples in NHL.
In the myelodysplastic syndromes (MDS), P-glycoprotein (P-gp) expression is clinically associated with drug resistance, whereas the clinical significance of multidrug resistance-associated protein (MRP1) is uncertain. Bone marrow from 56 patients with MDS, including six with refractory anaemia (RA)/RA with ringed sideroblasts (RARS), 23 cases of RA with excess blasts/in transformation (RAEB/T), four patients with chronic myelomonocytic leukaemia (CMML) and 23 cases of MDS having progressed to acute myeloid leukaemia (MDS-AML), were studied. MRP1 expression was investigated by immunocytochemistry (ICC) and by flow cytometry using MRPm6 monoclonal antibody. The efflux test using calcein-AM (CAM) +/- probenecid to evaluate MRP1 activity was performed in ten of the 56 patients. Twenty-eight of the 56 cases (50%) expressed MRP1. MRP1 expression was more frequent in MDS-AML than in MDS (70% vs. 36%). The efflux test using CAM was positive in three out of the ten patients tested. The results were in agreement with expression of MRP1 in six cases, and were discordant in four cases (1 MRP-/CAM+, 3 MRP+/CAM-). No correlation was observed between MRP1 expression and P-gp, lung resistance-associated protein (LRP) or CD34 expression, although there was a trend for more frequent MRP1 expression in P-gp-positive cases in MDS-AML (P = 0.08). Ten of the 26 patients treated with intensive chemotherapy achieved complete remission including six out of 16 MRP1+ and four out of ten MRP1- cases (P = NS). In conclusion, MRP1 expression was correlated with disease stage in MDS in our study. As for P-gp, discordant expression/function of MRP1 could be found in some cases, suggesting the existence of non-functional transport proteins in MDS. MRP1 expression did not seem to be a prognostic factor in MDS in our experience.
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Drug resistance often results in failure of anticancer chemotherapy in leukemias. A large number of studies have been published on the effect of P-glycoprotein (Pgp) expression on prognosis in AML. However, a consensus has been difficult to reach, due to the variable results obtained by different laboratories. Pgp expression was investigated here in bone marrow samples from 34 patients with AML including 19 newly diagnosed cases and 15 relapsing patients. Pgp expression was performed by immunocytochemistry (ICC) using the aviding-biotin-peroxydase technique with JSB1 and UIC2 MoAbs. Flow cytometry (FCM) analysis of Pgp expression was performed using UCI2 MoAbs in an indirect immunofluorescent assay without cell permeabilization. Rhodamine 123 (Rh 123) uptake was measured in the presence or absence of verapamil. Result was discordant in only 1/20 samples studied with both JSB1 and UIC2 by ICC. Results of Pgp expression were consistent on FCM and ICC in 23 of the 28 (82%) samples tested. Overall, Pgp expression was observed by ICC or FCM in 23 (67%) patients, including 11 (58%) newly diagnosed patients and 12 (80%) patients in relapse. Functional Rh123 efflux (Rh123+) was observed in 20 cases (59%): 10 de novo AML (53%) vs 10 AML in relapse (67%). The functional efflux was correlated with Pgp expression in 25 of the 34 cases analyzed (p = 0.013). 3 (9%) and 6 (18%) samples were Pgp-/Rh123+ and Pgp+/Rh123- respectively. Nine of the 14 pts (64%) treated with intensive anthracyclin-Ara C chemotherapy achieved complete remission, including 5/5 (100%) Pgp- cases vs 4/9 (44%) Pgp+ cases (p = 0.04) and 4/6 (67%) Rh 123- vs 4/7 (57%) Rh123+ cases (p = 0.5). In conclusion, assessment of Pgp expression by ICC and FMC using 2 different MoAbs coupled with functional efflux analysis confirms that Pgp expression is correlated with disease stage and response to treatment in AML. Discordant Pgp/Rh123 cases suggest a non functional Pgp or another alteration of drug transport.
Methods of minimal residual disease (MRD) detection in chronic myelogenous leukemia (CML) include chromosome analysis, reverse transcriptase polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH) techniques. We report a novel method to detect intracellular BCR-ABL messenger on single cells using in situ RT-PCR, which can be performed on blood and marrow slides, without extraction of the nucleic acid. After cellular permeabilization and fixation, the mRNA BCR-ABL was reverse transcribed and amplified by PCR using digoxigenin-labelled dUTP. The reaction was revealed with the anti-digoxigenin FITC antibody. On the fluorescent microscope, a strong positive green fluorescence signal was observed in 98-99% cells in Ph1-positive cell lines. A faint signal was detected in 1.5% and 2% of negative cell lines. Likewise, a faint signal was found in 1.6-2.8% of the cells in five normal controls (mean 2.2 +/- 1.1%). The positive threshold for in situ RT-PCR was therefore determined as mean + 2 s.d. = 4.4% cells. We used in situ RT-PCR by comparison to cytogenetics (at least 30 mitoses examined), and two-step RT-PCR (10(-6) sensitivity in our hands) in bone marrow samples from 13 CML patients: two patients at diagnosis and 11 patients in hematological remission after alpha interferon (three patients), hydroxyurea (one patient) autologous bone marrow transplantation (BMT) (one patient) and allogeneic BMT (six patients). In the two diagnostic patients, 90 and 95% cells were respectively strongly positive by in situ RT-PCR. In the six patients treated by allogeneic BMT, the median percentage of positive cells was 2.4% (range 1.8-3.2). All six patients had normal karyotype and negative two-step RT-PCR results. In the five other patients, two were treated by hydroxyurea alone or autologous BMT, and 11 and 13% of the cells were strongly positive; three were treated with interferon and 14-62% of the cells were positive, generally weakly. All five patients had persistence of Ph1 (in 9-56% mitoses), and positive RT-PCR results after one round. In conclusion, in situ RT-PCR can specifically identify cells with BCR-ABL transcript and its results are concordant with those of karyotype and RT-PCR. Because of its limited sensitivity and specificity, however, it appears to have limited value in the analysis of MRD. On the other hand, it can evaluate the presence and intensity of BCR-ABL fusion transcript at the single cell level, and this could be useful in treatment monitoring.
Quantitative competitive RT-PCR techniques have been developed to detect BCR-ABL fusion transcripts in CML but they are hardly reproducible. In this work, we have developed BCR-ABL quantification by real time RT-PCR using the ABI PRISM 7700 (Perkin Elmer), a new technique which allows simple and rapid quantification of a target sequence during the extension phase of PCR amplifications. A fluorogenic probe labeled with both a reporter dye at the 5' end and a quencher-dye at the 3' end hybridizes to the target sequence on the third exon of the ABL gene. The exonuclease activity of the Taq DNA polymerase cleaves the probe and releases the reporter dye, resulting in an increase in the fluorescence signal. The absolute copy number of the target sequence (BCR-ABL) or a control gene (ABL) in an unknown sample can then be calculated using a calibration curve prepared from a set of BCR-ABL RNA standards, and results are expressed as a BCR-ABL/ABL ratio. In our hands, the sensitivity of a serial dilution of total RNA from a positive cell line (K562) in a negative cell line (HL60) was 10(-4). Fifteen CML patients in cytogenetic CR, including 11 allografted patients, two autografted patients and two patients treated by IFN were studied sequentially by this new real time quantitative RT-PCR technique in parallel with conventional qualitative two round nested RT-PCR. The two autografted patients showed high BCR-ABL/ABL ratio in all samples. The two patients treated by IFN showed a progressive decrease in the ratio. In the 11 allografted patients, four were sequentially studied 2 years or more after allo-BMT, and all ratios were below 10(-4). The four patients remained in clinical and cytogenetic CR. The seven other allografted patients were studied immediately after the procedure. Three of them showed a progressive decrease in the BCR-ABL/ABL ratio which reached 10(-4) 7 months after allo-BMT. The three patients remained in hematologic and cytogenetic CR. The remaining four allografted patients had progressive increase of BCR-ABL ratio; three developed cytogenetic relapse 9, 11, 28 months after allo-BMT, and the last patient remained in cytogenetic CR in the bone marrow but developed granulocytic sarcoma. Results of real-time quantitative RT-PCR were in agreement with those of qualitative two round nested PCR. However, evolution changes in the results of real-time quantitative RT-PCR often preceded those of the conventional technique: a decrease of the BCR-ABL/ABL ratio preceded progression from first round to second round positivity and then negativity with the classical technique; conversely, an increase in the ratio preceded evolution with the classical technique. Thus, real-time quantitative RT-PCR may show better correlation with clinical and cytogenetic evolution than conventional qualitative techniques and may help in making early therapeutic decisions in CML, especially after molecular relapse.