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Hegazi A, Morton S, Pakianathan M, Cosgrove C, Aroney R, Dore E, Hempling M. A novel sexual health referral pathway for patients presenting to the emergency department with gamma-hydroxybutyrate or gamma-butyrolactone overdose. Int J STD AIDS 2017; 28:1466-1467. [PMID: 29113574 DOI: 10.1177/0956462417736637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- A Hegazi
- 1 The Courtyard Clinic, Wandsworth Integrated Sexual Health, St. George's University Hospital Foundation Trust, London, UK
| | - S Morton
- 2 Emergency Medicine Department, St. George's University Hospital Foundation Trust, London, UK
| | - M Pakianathan
- 1 The Courtyard Clinic, Wandsworth Integrated Sexual Health, St. George's University Hospital Foundation Trust, London, UK
| | - C Cosgrove
- 3 Clinical Infection Unit, St. George's University Hospital Foundation Trust, London, UK
| | - R Aroney
- 1 The Courtyard Clinic, Wandsworth Integrated Sexual Health, St. George's University Hospital Foundation Trust, London, UK
| | - E Dore
- 1 The Courtyard Clinic, Wandsworth Integrated Sexual Health, St. George's University Hospital Foundation Trust, London, UK
| | - M Hempling
- 2 Emergency Medicine Department, St. George's University Hospital Foundation Trust, London, UK
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2
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Sozeau C, Domaison S, Dore E, Kanold J, Deméocq F. P343 - Amélioration de la prise en charge globale de l’adolescent traité pour un cancer. Arch Pediatr 2010. [DOI: 10.1016/s0929-693x(10)70739-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Paillard C, Salmon A, Curtillet C, David A, Halle P, Cachin F, Bordigoni P, Michel G, Rousseau R, Dore E, Isfan F, Merlin E, Rochette E, Demeocq F, Kanold J. Evidence of a clinical response at one yr after reduced-intensity allogeneic hematopoietic stem cell transplantation in heavily pretreated adolescents with aggressive refractory Hodgkin's lymphoma. Pediatr Transplant 2010; 14:109-14. [PMID: 19490483 DOI: 10.1111/j.1399-3046.2009.01140.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report results of RIC AHSCT in four adolescents with aggressive refractory HL. They all received three or four lines of therapy prior to RIC-AHSCT including autografts. At the time of RIC, they were in partial response except for one patient who had progressive chemoresistant disease. The conditioning regimen consisted of fludarabin, busulfan and ATG. They all had a matched related donor. The median follow-up was 12-16-month post-allograft. All patient transplants engrafted rapidly. The median time of hospitalization was 35 days. The median time to neutrophil recovery (>or=500/muL) was 19 days. All the patients were in complete donor chimerism at day 60. Four patients developed skin (grade <or= II) acute GvHD. All responded and all are alive. Two patients are in CR, one in PR and one relapsed six months after grafting after a PR. Each of the patients in PR received two DLI. These observations, together with the responses after DLI, suggest the presence of a graft vs. lymphoma effect in patients with advanced active HL. Prospective studies are needed to identify the patients likely to benefit most from this treatment approach.
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Affiliation(s)
- C Paillard
- Centre Hospitalier et Universitaire de Clermont-Ferrand, Service de Pédiatrie B et Unité Bioclinique de Thérapie Cellulaire, Clermont-Ferrand, France.
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Curtillet C, Cuadras P, Dore E, Chambost H, Thuret I, Michel G. [Thyroid dysfunction after haematopoietic stem cell transplantation during childhood]. Arch Pediatr 2005; 11:1326-32. [PMID: 15519830 DOI: 10.1016/j.arcped.2004.07.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Accepted: 07/07/2004] [Indexed: 10/01/2022]
Abstract
UNLABELLED To evaluate the percentage and risk factors of thyroid dysfunction in 79 children who underwent bone marrow transplantation in a single centre. PATIENTS AND METHODS The mean age of the cohort was 6.8 and mean follow-up 5.5 years. The 79 patients were divided in two groups according to the pretransplant conditioning regimen: fractionated total body irradiation (TBI)(N=54), chemotherapy with Busulphan (N=25). Thyroid function was evaluated by thyroid-stimulating hormone (TSH) and free thyroxine (fT4) tests. Overt hypothyroidism was defined by low fT4 blood levels and TSH > 4 mU/l, and compensated hypothyroidism by normal fT4 index and TSH >4 mU/L. RESULTS The six-year probability of hypothyroidism was 36 +/-6% for the whole group of 79 patients, 49 +/-8% after TBI and 9 +/-6% in the Busulphan group (P <0.001). Neither gender, nor primary disease, nor presence of graft versus host disease were found to be statistically significant for occurrence of hypothyroidism in the TBI group. However, a younger age seemed to influence statistically the 6-year probability of hypothyroidism in the TBI group: 59 +/-9% if age <7.7 years versus 34 +/-13% if age >7.7 years (P =0.02). CONCLUSION A careful follow-up of thyroid function is recommended even without TBI conditioning regimen. Young age as a potential risk factor of hypothyroidism has never been described and needs to be studied in a larger cohort.
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Affiliation(s)
- C Curtillet
- Service hématologie pédiatrique du professeur Michel, hôpital Timone-Enfants, 264, rue Saint-Pierre, 13385 Marseille cedex 05, France.
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Ratel S, Lazaar N, Dore E, Baquet G, Williams CA, Berthoin S, Van Praagh E, Bedu M, Duche P. High-intensity intermittent activities at school: controversies and facts. J Sports Med Phys Fitness 2004; 44:272-80. [PMID: 15756166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In comparison to continuous aerobic type activity, little is known about high-intensity intermittent physical activity in children. Repeated short-term high-intensity activities (> maximal aerobic speed and <10 s) are more characteristic of the spontaneous physical activity of children. Recent studies have shown during repetitive bouts of sprints separated by short recovery intervals, that prepubescent children compared with adults are more able to maintain their performance without substantial fatigue. Moreover, repetitive runs at high velocities (near and higher than the maximal aerobic speed) separated by short recovery periods may elicit a high oxygen consumption in children. Several studies using interval training programmes for 7 weeks, twice a week for 30 min in physical education lessons showed that children's aerobic performance (maximal O2 uptake, maximal aerobic speed) could be enhanced. Training based on these repeated short-term high-intensity exercises could also improve children's anaerobic performance (short-term muscle power, strength and speed). Current evidence suggests that recovery from high-intensity exercises is faster in children than in adults and that repeated runs at high velocities separated by short recovery intervals can improve both aerobic and anaerobic performance. Although continuous aerobic type activity is more scientifically established as a training mode, repeated short-term high-intensity exercises in physical education programmes should be considered to enhance aerobic, as well as, anaerobic fitness in children.
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Affiliation(s)
- S Ratel
- Inter university Laboratory of Biology of Physical and Sport Activities, Blaise-Pascal University, Clermond-Ferrand, France.
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Tait BD, Colman PG, Morahan G, Marchinovska L, Dore E, Gellert S, Honeyman MC, Stephen K, Loth A. HLA genes associated with autoimmunity and progression to disease in type 1 diabetes. Tissue Antigens 2003; 61:146-53. [PMID: 12694582 DOI: 10.1034/j.1399-0039.2003.00013.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Insulin dependent diabetes mellitus (type I DM) is caused by an autoimmune process which culminates in destruction of pancreatic beta cells with resultant loss of insulin production. Preceding the clinical diagnosis of type I DM is a preclinical stage characterized by autoantibodies to insulin, glutamic acid decarboxylase (GAD) and a tyrosine phosphatase-like molecule (IA-2). We have studied both HLA class I and class 2 allele distributions in diabetic probands and autoantibody positive individuals in members of 452 families recruited for the Australian type I diabetes DNA repository. The results demonstrate that progression to autoimmunity as measured by the appearance of autoantibodies is strongly associated with the class 2 alleles DRB1*03 and DRB*04 and with DRB1*03/04 heterozygosity. In contrast, the progression to clinical disease appears associated with class I alleles A24, A30 and B18 while A1, A28, B14 and B56 appear negatively associated. The class 2 alleles appear to have a minimal role in the progression from autoantibody positivity to clinical disease. These results are consistent with the view that CD4+ T cells responding to peptides in the context of class 2 molecules are responsible for initiating autoantibody production, while the destruction of islet cells leading to clinical expression of the disease is the function of CD8+ T cells recognizing relevant peptides in the context of class I molecules.
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Affiliation(s)
- B D Tait
- Victorian Transplantation and Immunogenetics Service, Australian Red Cross Blood Service, Melbourne, Victoria, Australia
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Diallo O, Dore E, Duche P, Van Praagh E. Effects of plyometric training followed by a reduced training programme on physical performance in prepubescent soccer players. J Sports Med Phys Fitness 2001; 41:342-8. [PMID: 11533565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
BACKGROUND In adult population, stretch-shortening cycle exercise (plyometric exercise) is often used to improve leg muscle power and vertical jump performance. In children, limited information regarding this type of exercise is available. The purpose of this study was to examine the effectiveness of plyometric training and maintenance training on physical performances in prepubescent soccer players. METHODS Twenty boys aged 12-13 years was divided in two groups (10 in each): jump group (JG) and control group (CG). JG trained 3 days/week during 10 weeks, and performed various plyometric exercises including jumping, hurdling and skipping. The subsequent reduced training period lasted 8 weeks. However, all subjects continued their soccer training. Maximal cycling power (Pmax) was calculated using a force-velocity cycling test. Jumping power was assessed by using the following tests: countermovement jump (CMJ), squat jump (SJ), drop jump (DJ), multiple 5 bounds (MB5) and repeated rebound jump for 15 seconds (RRJ15). Running velocities included: 20, 30 and 40 m (V20, V30, V40 m). Body fat percentage (BF percent) and lean leg volume were estimated by anthropometry. RESULTS Before training, except for BF percent, all baseline anthropometric characteristics were similar between JG and CG. After the training programme, Pmax (p<0.01), CMJ (p<0.01), SJ (p<0.05), MB5 (p<0.01), RRJ15 (p<0.01) and V20 m (p<0.05), performances increased in the JG. During this period no significant performance increase was obtained in the CG. After the 8-week of reduced training, except Pmax (p<0.05) for CG, any increase was observed in both groups. CONCLUSIONS These results demonstrate that short-term plyometric training programmes increase athletic performances in prepubescent boys. These improvements were maintained after a period of reduced training.
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Affiliation(s)
- O Diallo
- UFR STAPS, Laboratoire de Biologie des Activités Physiques et Sportives, Université Blaise Pascal, Aubière Cedex, France
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Abstract
Non-uniform composition in telomeric repeats at the extremities of Plasmodium chromosomes was exploited in order to obtain data on intraclonal diversification of telomeric sequences, relevant for the study of telomere regeneration dynamics. Families of sibling telomeric clones were obtained from several chromosomal ends of Plasmodium berghei, and analysed so as to determine the exact points from which individual clones start to diverge. As much as 90% of the telomeric tract appears to be subject to events causing abrupt changes in the sequence of telomeric repeats. The results are compatible with the hypothesis that breakpoint probability is a continuously increasing function over the entire telomeric tract.
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Affiliation(s)
- E Dore
- Laboratorio di Biologia Cellulare, Istituto Superiore di Sanità, Rome, Italy
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Dore E, Frontali C, Pace T. Mobile repeat units in Plasmodium berghei. Parassitologia 1993; 35 Suppl:39-42. [PMID: 8233609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- E Dore
- Istituto Superiore di Sanità, Roma, Italy
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Ponzi M, Pace T, Dore E, Picci L, Pizzi E, Frontali C. Extensive turnover of telomeric DNA at a Plasmodium berghei chromosomal extremity marked by a rare recombinational event. Nucleic Acids Res 1992; 20:4491-7. [PMID: 1408751 PMCID: PMC334176 DOI: 10.1093/nar/20.17.4491] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The dynamics of telomere turnover were studied in Plasmodium, whose telomeric structures consist of linear, recognisable sequences of two distinct repeats (TTTAGGG and TTCAGGG). Independent recombinant clones containing a well-defined chromosomal extremity of Plasmodium berghei, both before and after a rare insertion event took place, were obtained from clonal parasite populations and analysed. The insertion, which splits the original telomere and causes a significant reduction in the size of the telomeric structure, is shown to consist of an integer number of subtelomeric repeats typical of P.berghei, flanked on both sides by telomere-derived motifs. Analysis of the telomeric repeat sequence heterogeneity in the otherwise homogeneous populations examined, is compatible with a model in which diversification of a given telomere is driven by the occurrence of breakpoints whose frequency rapidly increases along the telomeric tract when moving in the outward direction. The breakpoints might be due either to terminal deletions followed by random serial addition of the two repeat versions, or to recombination events. The shortening/elongation mechanism is favoured against the recombination hypothesis because of the absence of higher-order patterns in the sequence of telomeric repeats.
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Affiliation(s)
- M Ponzi
- Laboratorio di Biologia Cellulare, Istituto Superiore di Sanità, Rome, Italy
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Pace T, Ponzi M, Dore E, Janse C, Mons B, Frontali C. Long insertions within telomeres contribute to chromosome size polymorphism in Plasmodium berghei. Mol Cell Biol 1990; 10:6759-64. [PMID: 2174115 PMCID: PMC362954 DOI: 10.1128/mcb.10.12.6759-6764.1990] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
During prolonged in vivo mitotic multiplication of a Plasmodium berghei ANKA clone (8417HP), parasites that contained an enlarged version of chromosome 4 were observed. Restriction mapping and hybridization results demonstrated that the extra DNA present in the enlarged chromosome consists of 2.3-kb tandem repeats, known to be normally located in subtelomeric position at several chromosomal ends but absent in the original chromosome. The inserted 2.3-kb units appeared to interrupt one of the original telomeres and to create an internal (approximately 1-kb-long) telomeric sequence.
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Affiliation(s)
- T Pace
- Laboratory of Cellular Biology, Istituto Superiore di Sanità, Rome, Italy
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12
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Ponzi M, Janse CJ, Dore E, Scotti R, Pace T, Reterink TJ, van der Berg FM, Mons B. Generation of chromosome size polymorphism during in vivo mitotic multiplication of Plasmodium berghei involves both loss and addition of subtelomeric repeat sequences. Mol Biochem Parasitol 1990; 41:73-82. [PMID: 1974695 DOI: 10.1016/0166-6851(90)90098-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Extensive chromosome size polymorphism arises in Plasmodium berghei during in vivo mitotic multiplication. Size differences between homologous chromosomes involve rearrangements occurring in the subtelomeric portions while internal chromosomal regions do not contribute significantly to chromosome size polymorphism. Differences in the copy number of a 2.3-kb subtelomeric repeated unit are shown to correlate with size variations, and in at least one case to account completely for the size difference between two variants of the same chromosome.
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Affiliation(s)
- M Ponzi
- Laboratorio di Biologia Cellulare, Istituto Superiore di Sanità, Rome, Italy
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Abstract
Several (but not all) Plasmodium berghei chromosomes bear in the subtelomeric position a cluster of 2.3-kilobase (kb) tandem repeats. The 2.3-kb unit contains 160 base pairs of telomeric sequence. The resulting subtelomeric structure is one in which stretches of telomeric sequences are periodically spaced by a 2.1-kb reiterated sequence. This periodic organization of internal telomeric sequences might be related to chromosome-size polymorphisms involving the loss or addition of subtelomeric 2.3-kb units.
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Affiliation(s)
- E Dore
- Laboratory of Cell Biology, Istituto Superiore di Sanità, Rome, Italy
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Pace T, Ponzi M, Dore E, Scotti R, Mons B. Presence of contaminating mitochondrial DNA from host reticulocytes in experimental infections of Plasmodium berghei. Mol Biochem Parasitol 1989; 37:109-13. [PMID: 2693960 DOI: 10.1016/0166-6851(89)90107-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Superposition of two unrelated processes, namely terminal reticulocyte differentiation and synchronous plasmodial development, takes place in experimental infections of Plasmodium berghei. The first process is shown to be responsible for the appearance of some discrete restriction bands of host origin when DNA is extracted from leucocyte-free blood containing synchronous parasites at early stages of infection. These discrete DNA fragments cross-hybridize with host cell mitochondrial DNA. Purification steps are suggested to reduce this effect, which might be relevant also in the case of other plasmodial species exhibiting preference for reticulocytes as host cell.
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Affiliation(s)
- T Pace
- Laboratorio di Biologia Cellulare, Istituto Superiore di Sanità, Rome, Italy
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Abstract
The basic element of the 2.3 kb repetitive family, present in approximately 300 copies in the Plasmodium berghei genome, contains a bent DNA region. Indications of this given by anomalies in electrophoretic behaviour were confirmed by computational analysis of sequence data.
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Affiliation(s)
- E Dore
- Laboratory of Cellular Biology, Istituto Superiore di Sanità, Rome, Italy
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Pace T, Ponzi M, Dore E, Frontali C. Telomeric motifs are present in a highly repetitive element in the Plasmodium berghei genome. Mol Biochem Parasitol 1987; 24:193-202. [PMID: 3041211 DOI: 10.1016/0166-6851(87)90106-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Using as probes the subfragments of the telomeric sequence previously cloned by us from Plasmodium berghei DNA, we identified and cloned a 2.3 kb repeat, largely overlapping the original telomeric insert. Restriction mapping indicated that cloned inserts (2.3 kb in length) represented circularly permutated versions of a rather well conserved repeated element, at least in part organized in tandem. The 2.3 kb repeat family with a copy number of about 300 occupies about 4% of the whole genome. The copies are unevenly distributed among the chromosome-sized molecules revealed by pulsed field gradient electrophoresis. Complete sequence determination of the 2.3 kb element revealed that telomere-related motifs are present with a characteristic pattern in a set of tandem repeats, 27 bp long. The perfect conservation of these motifs as well as the pattern of chromosomal distribution suggest that we are dealing with a specialised structure subject to selective mechanisms of amplification and maintenance.
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Dore E, Pace T, Ponzi M, Scotti R, Frontali C. Homologous telomeric sequences are present in different species of the genus Plasmodium. Mol Biochem Parasitol 1986; 21:121-7. [PMID: 3024000 DOI: 10.1016/0166-6851(86)90015-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The telomeric sequence cloned from Plasmodium berghei (see M. Ponzi et al. (1985) EMBO J. 4, 2991-2995) was tested for species specificity. A telomeric and a subtelomeric fragment of the cloned insert served as separate, labelled probes on pulsed field gradient electrophoretical patterns and on genomic digests from the rodent malarias Plasmodium yoelii, Plasmodium chabaudi and from the human malaria Plasmodium falciparum. Results indicate that the subtelomeric fragment, abundantly represented in two chromosomes of P. berghei, is not present in the other DNA tested, while the telomeric fragment is present in every chromosome-sized molecule in all the species tested. The telomeric location in the other genomes of the sequences homologous to the P. berghei telomeric probe is confirmed by experiments with Bal 31 exonuclease. In all cases, the TaqI site appears to delimit the common telomeric portion.
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Abstract
A fragment of Plasmodium berghei DNA was cloned using a technique designed to select for telomeric sequences. The cloned fragment recognizes Bal31-sensitive bands in P. berghei genomic digests. It contains at its distal end at least 70 tandem repeats of the heptanucleotide sequence CCCTGAAA. The presence of natural single strand discontinuities in the telomeric regions of P. berghei DNA is demonstrated by the selective incorporation of deoxyribonucleoside triphosphates in the absence of DNase. The number of copies of the cloned sequence present in each genome agrees with an estimate of 6-12 chromosomes per nucleus.
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Casaglia O, Dore E, Frontali C, Zenobi P, Walliker D. Re-examination of earlier work on repetitive DNA and mosquito infectivity in rodent malaria. Mol Biochem Parasitol 1985; 16:35-42. [PMID: 2863751 DOI: 10.1016/0166-6851(85)90047-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Previous results, relating mosquito infectivity to percentage of repetitive DNA in the genome of Plasmodia, are re-examined in the light of the finding that a parasite line used in the previous studies and classified as Plasmodium berghei NK65, was a mixed infection, where the major component appeared to be Plasmodium yoelii. This conclusion was reached through cloning and isoenzyme typing of different clones. Isoenzyme typing alone is not sufficiently sensitive to reveal contamination amounting to less than 20% in a mixture. Attention is drawn to the risk inherent in work with uncloned lines, where the proportions of species or sub-species present may vary according to line history and gametocyte viability.
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Abstract
The average length and the interspersion pattern of repetitive DNA sequences in the Plasmodium berghei genome have been studied by electron microscopy. Within the limitations posed by the relatively high genome complexity, analysis of partially renatured total DNA indicates that repetitive sequences do not occupy preferential positions along the genome, but are widely dispersed (one in approx. 8000 base pairs of unique DNA). Structures appearing as loops flanked by inverted repeats are present. Analysis of the repetitive fraction purified by hydroxyapatite chromatography shows that the average length of rapidly reassociating repetitive structures is around 800 base pairs with 90% of the length distribution between 400 and 1400 base pairs. Suitable extraction methods, preserving circularity of extrachromosomal DNA components, allow the detection of molecules which can be identified as mitochondrial DNA, 10.5 +/- 0.4 microns long.
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21
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Birago C, Bucci A, Dore E, Frontali C, Zenobi P. Mosquito infectivity is directly related to the proportion of repetitive DNA in Plasmodium berghei. Mol Biochem Parasitol 1982; 6:1-12. [PMID: 7050700 DOI: 10.1016/0166-6851(82)90048-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A strain of Plasmodium berghei (NK 65) was followed during syringe transmission in mice for over 120 passages after the last complete cycle, while the following parameters were monitored: (a) capacity to infect mosquitoes, inducing oocyst formation; (b) presence in the peripheral blood of morphologically identifiable gametocytes; (c) presence of a repetitive component in the DNA extracted from intraerythrocytic population. The suggestion of a possible role of this component in gametogenesis came from an earlier work (Dore, E., Birago, C., Frontali, C. and Battaglia, P.A. (1980) Mol. Biochem. Parasitol. 1, 199-208). Present results confirm the correlation between proportion of repetitive DNA and infectivity towards mosquitoes with a correlation coefficient r = 0.92-0.07+0.04. A parallel decrease of the two quantities is observed in the course of syringe transmission. A limited number of cloned lines, derived from strain NK 65 at different times during syringe transmission, shared the infectivity properties of the parent strain at the moment of cloning, thus confirming that in the infective stage single asexual parasites from the schizogonic cycle are able to originate the whole cycle. The above arguments and results suggest that differentiation into active gametocytes involves amplification of a portion of the genome.
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Frontali C, Dore E, Ferrauto A, Gratton E, Bettini A, Pozzan MR, Valdevit E. An absolute method for the determination of the persistence length of native DNA from electron micrographs. Biopolymers 1979; 18:1353-73. [PMID: 465647 DOI: 10.1002/bip.1979.360180604] [Citation(s) in RCA: 141] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Donelli G, Dore E, Frontali C, Grandolfo ME. Structure and physico-chemical properties of bacteriophage G. III. A homogeneous DNA of molecular weight 5 times 10(8). J Mol Biol 1975; 94:555-65. [PMID: 810596 DOI: 10.1016/0022-2836(75)90321-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
A kinetic study of the alkaline transition of DNA, in clearly defined physico-chemical conditions, is presented, which allows us to identify, within the alkaline transition region, different pH ranges, corresponding to different ratelimiting factors. This analysis brings into consideration three distinct intervals of time which characterize the whole process, namely the time necessary for full hyperchromicity to be reached, the time required for strand separation in the case of a single DNA molecule, and the time for complete denaturation to be reached in the case of a DNA solution.THE RESULTS OBTAINED FROM ULTRACENTRIFUGAL, AND SPECTROPHOTOMETRIC MEASUREMENTS, INVOLVING RAPID MIXING EXPERIMENTS, SEEM TO INDICATE THE FOLLOWING CONCLUSIONS: whereas, in the lower pH ranges considered within the transition region, the denaturation process is limited by the first time constant, this same constant becomes extremely short at higher pH. On the other hand the fact that, in the higher pH range, the second and third time constants do not coincide (the time to unwind a single T2 DNA molecule being at least one order of magnitude shorter than the time required for bulk denaturation to be reached) suggests that in this pH range the overall denaturation rate is limited by a statistical process governing the initiation of unwinding.These observations are discussed in terms of a model in which the unwinding energy is given by the electrostatic repulsions which originate in the deprotonated DNA molecule. The model itself suggests some experiment which seem to confirm it.
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Toschi G, Dore E, Angeletti PU, Levi-Montalcini R, de Haën C. Characteristics of labelled RNA from spinal ganglia of chick embryo and the action of a specific growth factor (NGF). J Neurochem 1966; 13:539-44. [PMID: 5939728 DOI: 10.1111/j.1471-4159.1966.tb11949.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Ageno M, Dore E, Frontali C, Arca' M, Frontali L, Tecce G. Interaction between denatured DNA and RNA from Bacillus stearothermophilus involving only one-half of total DNA. J Mol Biol 1966; 15:555-72. [PMID: 5330748 DOI: 10.1016/s0022-2836(66)80127-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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