Trypanosoma vivax in water buffalo (Bubalus bubalis)of the Amazon basin and the diagnosis of subpatent infection by anion exchange separation

London School of Hygiene and Tropical Medicine. Dept. of Medical Protozoology. Keppel Street, London.London School of Hygiene and Tropical Medicine. Dept. of Medical Protozoology. Keppel Street, London.Ministério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, Brasil

Further enzymic characeters of Trypanosoma cruzi and their evaluation for strain identification

Ministério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, Brasil / London School of Hygiene and Tropical Medicine. Departament of Medical Protozoology. Keppel Street, London.London School of Hygiene and Tropical Medicine. Departament of Medical Protozoology. Keppel Street, London.Ministério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, BrasilMinistério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, BrasilStarch-gel electrophoresis of 38 enzymes was attempted with extracts of Trypanosoma cruzi culture forms. 18 of the enzymes that gave discrete electrophoretic bands were selected for routine characterization of T. cruzi stocks; the enzymes were: aspartate aminotransferase (E.C.2.6.1.1, ASAT); alanine aminotransferase (E.C.2.6.1.2, ALAT); phosphoglucomutase (E.C.2.7.5.1, PGM); glucosephosphate isomerase (E.C.5.3.1.9, GPI); malate dehydrogenase (oxaloacetate decarboxylating) (NADP+) (E.C.l.l.l.40, ME); glucose 6- phosphate dehydrogenase (E.C.l.l.l.49, G6PD); malate dehydrogenase (E.C.l.l.l.37, MDH); aconitate hydratase (E.C.4.2.1.3, ACON); isocitrate dehydrogenase (NADP+) (E.C.l.l.l.42, ICD); alcohol dehydrogenase (NADP+) (E.C.l.l.l.2, ADH); lactate dehydrogenase (E.C.l.l.l.27,LDH); aminopeptidase (cytosol) (E.C.3.4.11.1, PEP); pyruvate kinase (E.C.2.7.1.40, PK); phosphoglycerate kinase (E.C.2.7.2.3, PGK); enolase (E.C.4.2.1.11, ENO); hexokinase (E.C.2.7.1.1, HK); mannosephosphate isomerase (E.C.5.3.1.8, MPI); and glutamate dehydrogenase (E.C.l.4.1.2, GD). ADH (NADP+) in the genus Trypanosoma, and PGK, MPI and ENO, in T. cruzi, were apparently demonstrated for the first time. Between six and 18 enzymes were used to characterize more than 250 T. cruzi stocks, newly isolated from a wide range of sources in northern and central Brazil. Ali stocks were identified as belonging to T. cruzi zymodemes 1, 2 or 3, as originally defined-that is, by combination of electrophoretic patterns of ASAT, ALAT, PGM, GPI, ME and G6PD. The composite range of results with ali enzymes confirmed the presence of three principal T. cruzi zymodemes, but some enzymic characters overlapped between zymodemes and others suggested subgroups within individual zymodemes. Seven (MDH, ACON, LDH, PK, PGK, ENO, HK) of the 18 enzymes did not distinguish the three zymodemes; tive (ASA T, PGM, GPI, ICD, PEP) distinguished ali three zymodemes; 10 (ASAT, ALAT, PGM, GPI, ME, G6PD, ICD, ADH, PEP, GD) distinguished zymodemes 1 and 2, of which seven plus MPI and eight plus MPI separated zymodemes 1 from 3 and 2 from 3 respectively. T. cruzi stocks were taken from a smali area of the natural species distribution; the fuli range of enzymic characters within the species T. cruzi is expected to be far more complex. The epidemiological distribution of the zymodemes continued to accord with local transmission cycles and supported the hypothesis that distinct T. cruzi strains might be responsible for the enigmatic distribution of chronic Chagas's disease. Some of the difficulties in the empirical selection of new electrophoretic methods and the interpretation of results were presented, and the present and prospective significance of T. cruzi enzymic characters was discussed. Until the stability and genetic basis of T. cruzi enzymic characters are better understood it is recommended that isoenzymic profiles be confirmed routinely, botIl before and after stocks are used experimentally, as representative of a given zymodeme. A multiple biochemical approach to T. cruzi strain identification is recommended, using characters suitable for a numerical taxonomy.Electroforese em gel de amido de 38 enzimas foi tentada com extratos de formas de cultura de T. cruzi. Dezoito das enzimas, as quais deram discretas manchas electroforéticas, foram selecionadas para carcaterização de rotina dos stocks de T. cruzi; as enzimas foram asparato aminotransferase (E.C. 2.6.1.1, ASAT); alanina aminotransferase (E.C. 2.6.1.2, ALAT); fosfoglucomutase (E.C.2.7.5.1, PGM); glicosefosfato isomerase (E.C.5.3.1.9, GPI); malato dehidrogenase (oxaloacetato descarboxilando (NADP+) (E.C.l.l.l.40, ME); glicose 6-fosfato dehidrogenase (E.C.l.l.l.49, G6PD); malate dehidrogenase (E.C.l.l.l.37, MDH); aconitato hidratase (E.C.4.2.1.3, ACON); isocitrato dehidrogenase (NADP+) (E.C.l.l.l.42, ICD); alcool dehidrogenase (NADP+) (E.C.l.l.l.2, ADH); lactato dehidrogenase (E.C.l.l.l.27, LDH); aminopeptidase (citosol) (E.C.3.4.11.1, PEP); piruvato quinase (E.C.2.7.1.40, PK); fosfoglicerato quinase (E.C.2.7.2.3, PGK); enolase (E.C.4.2.1.11, ENO); hexoquinase (E.C.2.7.1.1, HK); manosefosfato isomerase (E.C.5.3.1.8, MPI); e glutamato dehidrogenase (E.C.I.4.1.2, GD). ADH (NADP+), no genero Trypanosoma e MPI, PGK e ENO, em T. cruzi, foram demonstradas pela primeira vez. Entre 6 e 18 enzimas foram usadas para caracterizar mais de 250 stocks de T. cruzi, recentemente isoladas de varias origens nas partes norte e central do Brasil. Todos os stocks foram identificados como pertencentes aos zymodemes de T. cruzi I, 2 ou 3, como originalmente definidosisto é, pela combinação de padrões electroforéticos de ASAT, ALAT, PGM, GPI, ME e G6PD. A variabilidade de resultados combinados com todas as enzimas confumaram a presença de 3 zymodemes principais de T. cruzi mas alguns caracteres enzimaticos sobrepostos entre os zymodemes, e outros sugeriram subgrupos dentro de zymodemes individuais. Sete (MDH, ACON, LDH, PK, PGK, ENO, HK) das 18 enzimas não distinguiram os 3 zymodemes; 5 (ASAT, PGM, GPI, ICD, PEP) distinguiram todos os 3 zymodemes; 10 (ASA T , ALAT, PGM, GPI, ME, G6PD, ICD, ADH, PEP, GD) distinguiram zymodemes 1 e 2; dos quais 7 mais MPI e 8 mais MPI separaram zymodemes 1 de 3 e 2 de 3 respectivamente. Stocks de T. cruzi foram trazidos de uma pequena área de distribuição natural da espécie; é considerado que a total variedade dos caracteres enzimáticos dentro das espécies de T. cruzi sera muito mais complexa. A distribuição epidemiol6gica dos zymodemes continuou em acordo com os ciclos de transmissão local e reforçou a hipotese que amostras distintas de T. cruzi poderiam ser responsaveis pela distribuição enigmática de Doença de Chagas crônica. Algumas dificuldades na seleção empirica de novos métodos eletroforéticos e a interpretação dos resultados foram descritos, e o valor, presente e prospectivo, de caracteres enzimáticos de T. cruzi foi discutido. A stabilidade e base genética de caracteres enzimáticos de T. cruzi não são completemente entendidos então é recomendade que perfis isoenzimaticos sejam confirmados rotineiramente, ambos antes e depois dos stocks serem usados experimentalmente, como representativo de um dado zymodeme. Uma multipla proximidade bioquimica para identificação de amostras de T. cruzi é recomendada, usando caracteres apropriados para uma taxonomia numérica

Anion-exchange separation for neotropical trypanosomes: a preliminary trial and a description of Trypanosoma devei from the tamarinSaguinus midas niger

Ministry of Overseas Development of H.M. Government, the Wellcome Trust and Fundação SESP and UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases.London School of Hygiene and Tropical Medicine. Department of Medical Protozoology. London, England.London School of Hygiene and Tropical Medicine. Department of Medical Protozoology. London, England / Ministério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, Brasil.Anion-exchange separation trials using DEAE-cellulose columns were performed with blood from two single species of marsupial and edentate, three species of rodent and single species of carnivore, primate, cayman and lizard.Trypanosoma cruzi was isolated fromDidelphis marsupialis, Dasypus novemcinctus andCoendou sp.T. (Megatrypanum) devei was isolated from the tamarinSaguinus midas niger and the mensural characters of the organism were redescribed. Anion-exchange separation was considered to be a valuable procedure for the taxonomist searching for new or little-known trypanosomes

A comparison of electrophoretic methods for isoenzyme characterization of trypanosomatids. In Standard stocks of Trypanosoma cruzi zymodemes from northeast Brazil

London School of Hygiene and Tropical Medicine. Departament of Medical Protozoology. London, UK.London School of Hygiene and Tropical Medicine. Departament of Medical Protozoology. London, UK.Ministério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, Brasil.Ministério da Saúde. Fundação Serviços de Saúde Pública. Instituto Evandro Chagas. Belém, PA, Brasil.An investigation of the relative merits of cellulose acetate electophoresis (CAE) and starch-gel electrophoresis (SGE) was made for 18 enzymes of T. cruzi using standard stocks of zymodemes ZI, Z2 and Z3. The 18 enzymes were those shown previously to be the most suited to routine screening of T. cruzi on starch-gel, namely, aspartate aminotransferase (E.C.2.6.1.1. ASAT); alanine aminotransferase (E.C.2.6.1.2. ALAT); phosphoglucomutase (E.C.- 2.7.5.1. PGM); glucosephosphate isomerase (E.C.- 5.3.1.9. GPI); malate dehydrogenase (oxaloacetate decarboxylating) (NADP+) (E.C.l.l.l.40. ME); glucose-6-phosphate dehydrogenase (E.C.l.l.l.49 G6PD); malate dehydrogenase (E.C.l.l.l.37. MDH); aconitate hydratase (E.C.4.2.1.3. ACON); isocitrate dehydrogenase (NADP+) (E.C.l.l.1.42. ICD); alcohol dehydrogenase (NADP+) (E.C.- 1.1.1.2. ADH); lactate dehydrogenase (E.C.l.l.l.27. LDH); aminopeptidase (cytosol) (E.C.3.4.11.1. PEP);pyruvate kinase (E.C.2. 7.1.40. PK);phosphoglycerate kinase (E.C.2.7.2.3. PGK); enolase (E.C.4.2.1.11. ENO); hexokinase (E.C.2.7.1.1. HK); mannose phosphate isomerase (E.C.5.3.1.8. MPI); and glutamate dehydrogenase (E.C.l.4.1.2. GD). Of these MDH and PEP failed to give satisfactory pattems on CAE. The cellulose acetate zymograms of the other 16 enzymes were as good as, and in some cases better than, those of starch. Increased CAE resolution for ME and G6PD enabled all three zymodemes to be distinguished. Single CAE bands replaced double SGE bands in some cases, and vice versa, without affecting the zymodeme classification. It was concluded that CAE and SGE were both suitable for isoenzyme characterization and were complementary to each other. CAE characterization of T. cruzi was recommended for use in field work and simple laboratories because of its simplicity, transportability, low maintenance requirements and low capital expenditure. Isoelectric focusing (IEF) of ASA T, ALA T , GPI and PGM on Ampholine P AG plates gave poor results, in our hands, and was considered impracticable for routine characterization of T. cruzi

Relationship between p53 codon 72 polymorphism and susceptibility to sunburn and skin cancer.

Upregulation of p53 protein induces either growth arrest or apoptosis in response to cellular injury This is signaled from a highly conserved p53 domain between codons 64 and 92, where a functional polymorphism results in either a proline (p53-72P) or an arginine (p53-72R) at codon 72. Preliminary studies suggest that p53-72R may be a risk factor for cervical cancer and, consistent with this, preferential mutation and retention of the p53-72R allele has also been demonstrated in other cancers of squamous cell origin. Here we examine the relationship between allelic forms of p53 and nonmelanoma skin cancer, by determining the correlation with susceptibility to sunburn, which is a known risk factor, and then by p53 sequence analysis of a large series of tumors. We found a significant positive association between p53-72R and susceptibility to sunburn, as assessed by skin phototype and minimal erythemal dose following solar-simulated radiation (p = 0.0001 for trend). We also found a significant association between p53-72R homozygosity and nonmelanoma skin cancer in renal transplant recipients (basal cell carcinoma, p < 0.01; squamous cell carcinoma, p < 0.05) but not in immunocompetent patients compared with skin type matched controls. p53 sequence data revealed mutations in 30 of 70 (42.9%) nonmelanoma skin cancers, 28 (93%) of which were in the p53-72R allele. Loss of heterozygosity occurred more frequently in p53-72RP than in p53-72RR tumors (p = 0.0001) with preferential loss of p53-72P in heterozygotes (p = 0.016), irrespective of the mutant status of the concomitant allele. Together these data infer functional differences between polymorphic forms of p53 that are likely to be relevant to skin carcinogenesis

Looking Backward, Looking Forward: MLA Members Speak

In 1997 I was asked to organize humanities outreach activities at the University of California, Irvine. The result was the formation of Humanities Out There (HOT). In our workshops, faculty members and graduate students supervise teams of undergraduates in order to take the methods and materials of the university into the larger community.I believe that programs like these will  become increasingly important in the next century, as economic, cultural, and educational divisions deepen in the wake of the demise of affirmative action and as the humanities fight to define their missions in a world driven by technology and its discontents. In this brave new world, what I call the new outreach may have a role to play in responding to social crises as they are visited on the life of the university. The new outreach will be driven by intellectual content, not public relations.It will take its orientation from the faculty rather than administrators. It will engage all the research disciplines rather than remain the purview of education departments. It will be integrated into the professional lives of its participants rather than rely on the spirit of volunteerism alone