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1.
Artigo em Inglês | MEDLINE | ID: mdl-36971771

RESUMO

BACKGROUND: Secukinumab has previously demonstrated sustained efficacy and favourable safety for up to 52 weeks in paediatric patients (children and adolescents aged 6 to <18 years) with severe chronic plaque psoriasis (NCT02471144). OBJECTIVE: To investigate the long-term (104 weeks) efficacy and safety of secukinumab. METHODS: After 52 weeks, patients continued to receive secukinumab low dose (LD [75/150 mg]) or high dose (HD [75/150/300 mg]). Patients on etanercept (0.8 mg/kg) until Week 52 entered follow-up. Data for patients receiving secukinumab LD from the beginning and those switching to secukinumab LD from placebo ('Any secukinumab' LD) and patients receiving secukinumab HD from the beginning and those switching to secukinumab HD from placebo ('Any secukinumab' HD) are presented. ASSESSMENTS: Psoriasis Area and Severity Index (PASI) score, PASI (75/90/100) responses, Investigator's Global Assessment modified 2011 (IGA mod 2011) 0/1 response, Children's Dermatology Life Quality Index (CDLQI) score and CDLQI 0/1 response up to Week 104, and, safety up to Week 104 for all patients and up to 4 years for some patients (~320 patient-years [PY] of treatment). RESULTS: Secukinumab-treated patients showed sustained PASI 75/90/100 and IGA mod 2011 0/1 responses up to Week 104. Throughout the second year of treatment, efficacy was similar for the 'Any secukinumab' LD and HD groups for PASI 75 and IGA mod 2011 0/1 responses. PASI 90/100 responses were mostly comparable between the dose groups up to Week 88, but higher in the 'Any secukinumab' HD than the 'Any secukinumab' LD group at Week 104. Patients achieved a sustained CDLQI 0/1 response that was similar between the 'Any secukinumab' LD (61.1%) and HD (65.0%) groups. Safety data were consistent with the established safety profile of secukinumab. CONCLUSION: Secukinumab demonstrated sustained long-term efficacy (up to 2 years) and a favourable safety profile (~320 PY of treatment) in paediatric patients with severe chronic plaque psoriasis.

2.
J Eur Acad Dermatol Venereol ; 35(4): 938-947, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33068444

RESUMO

BACKGROUND: Secukinumab has demonstrated sustained long-term efficacy with a favourable safety profile in various psoriatic disease manifestations in adults. OBJECTIVES: Here, the efficacy and safety of two secukinumab dosing regimens [low dose (LD) and high dose (HD)] in paediatric patients with severe chronic plaque psoriasis over one year are reported. METHODS: In this multicentre, double-blind study (NCT02471144), patients aged 6 to <18 years with severe chronic plaque psoriasis were stratified and randomized by weight (<25 kg, 25 to <50 kg, ≥50 kg) and age (6 to <12 years, 12 to <18 years) to receive low-dose (LD: 75/75/150 mg) or high-dose (HD: 75/150/300 mg) subcutaneous secukinumab or placebo or etanercept 0.8 mg/kg (up to a max of 50 mg). RESULTS: Overall, 162 patients were randomized to receive secukinumab LD (n = 40) or HD (n = 40), etanercept (n = 41) or placebo (n = 41). The co-primary objectives of the study were met with both secukinumab doses (LD and HD) showing superior efficacy compared to placebo (P < 0.0001) with respect to PASI 75 response (80.0%, 77.5% vs. 14.6%) and IGA mod 2011, 0 or 1 response (70%, 60% vs. 4.9%) at Week 12. Both secukinumab doses were superior to placebo (P < 0.0001) with respect to PASI 90 response at Week 12 (72.5%, 67.5% vs. 2.4%). The efficacy of both doses was sustained to Week 52 with secukinumab achieving higher responses vs. etanercept (PASI 75/90/100: LD, 87.5%/75.0%/40.0% and HD, 87.5%/80.0%/47.5.% vs. etanercept, 68.3%/51.2%/22.0% and IGA 0 or 1: LD, 72.5% and HD, 75.0% vs. etanercept, 56.1%). The safety profile of secukinumab was consistent with the adult Phase 3 studies, with no new safety signals identified. CONCLUSIONS: Both doses of secukinumab demonstrated high and sustained efficacy up to Week 52 with a favourable safety profile in paediatric patients with severe chronic plaque psoriasis.


Assuntos
Anticorpos Monoclonais , Psoríase , Adulto , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Criança , Método Duplo-Cego , Humanos , Psoríase/tratamento farmacológico , Índice de Gravidade de Doença , Resultado do Tratamento
3.
J Eur Acad Dermatol Venereol ; 31(5): 847-856, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28111801

RESUMO

BACKGROUND: User satisfaction is an important factor associated with treatment adherence in chronic diseases including moderate-to-severe psoriasis. OBJECTIVE: To evaluate the efficacy, safety and patient acceptability of 300 and 150 mg secukinumab - a fully human anti-interleukin-17A monoclonal antibody that has demonstrated efficacy in the treatment of patients with moderate-to-severe plaque psoriasis - self-administered by autoinjection. METHODS: Patients with moderate-to-severe plaque psoriasis were randomized to secukinumab 300 mg, secukinumab 150 mg or placebo self-administered by autoinjection at baseline, Weeks 1, 2 and 3 and then every 4 weeks from Week 4 to Week 48. Efficacy responses [≥75/90/100% improvement in Psoriasis Area and Severity Index (PASI 75/90/100) and clear/almost clear skin by Investigator's Global Assessment 2011 modified version (IGA mod 2011 0/1)] were measured at Week 52. Patient-reported usability of the autoinjector was evaluated by the self-injection assessment questionnaire to Week 48. RESULTS: At Week 52 with secukinumab 300 mg, PASI 75/90/100 and IGA mod 2011 0/1 responses were achieved by 81.4/64.1/38.8% and 69.6% of patients, respectively, by multiple imputation. At Week 52 with secukinumab 150 mg, PASI 75/90/100 and IGA mod 2011 0/1 responses were achieved by 75.2/57.4/33.1% and 60.2% of patients, respectively, by multiple imputation. Patient-assessed acceptability of the autoinjector remained high to Week 48. The proportion of patients experiencing adverse events was greater with secukinumab 300 mg (88.6%) than with secukinumab 150 mg (78.7%). CONCLUSION: Self-administration of secukinumab using an autoinjector was associated with robust and sustained efficacy, a good safety profile and high acceptability.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Psoríase/tratamento farmacológico , Anticorpos Monoclonais Humanizados , Método Duplo-Cego , Humanos , Placebos , Psoríase/patologia , Autoadministração , Índice de Gravidade de Doença , Resultado do Tratamento
4.
Osteoporos Int ; 23(3): 1083-90, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21975559

RESUMO

This study summarizes the treatment effect of zoledronic acid infusion on lumbar spine bone mineral density in different subgroups with glucocorticoid-induced osteoporosis. Zoledronic acid is significantly more effective than risedronate in increasing lumbar spine (LS) bone mineral density (BMD) in both prevention and treatment of glucocorticoid-induced osteoporosis. Introduction In patients on glucocorticoids, a single zoledronic acid infusion significantly increased BMD versus daily oral risedronate. We assessed treatment effect on LS BMD in different patient subgroups at month 12 that contributed to the risk of osteoporosis in addition to glucocorticoids. Methods Patients randomized to a single IV infusion of zoledronic acid 5 mg or risedronate (5 mg/day) and stratified based on glucocorticoids duration [treatment (>3 months) and prevention (≤ 3 months) subpopulations]were subgrouped by age; gender; menopausal status in women; dose and duration of prednisone during the trial; and baseline serum 25-OH vitamin D, LS BMD T-score, creatinine clearance, and concomitant medication use. Results At month 12, zoledronic acid significantly increased LS BMD versus risedronate in patients ≤ 74 years (P<0.05) in the treatment and 65-74 years (P = 0.0008) in the prevention subpopulation. At month 12, zoledronic acid significantly increased LS BMD versus risedronate in both subpopulations irrespective of gender (all P<0.05), cumulative prednisone dose (all P<0.01), and postmenopausal status (all P<0.05). In premenopausal women, in both subpopulations, zoledronic acid significantly increased total hip BMD (all P<0.05) versus risedronate at month 12 but not LS BMD. Osteoporotic patients in the prevention (P=0.0189) and osteopenic patients in the treatment subpopulation (P=0.0305) showed significant LS BMD increases with zoledronic acid versus risedronate at month 12. Conclusions This post hoc analysis suggests that zoledronic acid is significantly more effective than risedronate in increasing LS BMD in prevention and treatment of glucocorticoid-induced osteoporosis across a wide range of patients.


Assuntos
Conservadores da Densidade Óssea/administração & dosagem , Difosfonatos/administração & dosagem , Ácido Etidrônico/análogos & derivados , Glucocorticoides/efeitos adversos , Imidazóis/administração & dosagem , Osteoporose/tratamento farmacológico , Administração Oral , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea/efeitos dos fármacos , Conservadores da Densidade Óssea/uso terapêutico , Difosfonatos/uso terapêutico , Método Duplo-Cego , Esquema de Medicação , Ácido Etidrônico/administração & dosagem , Ácido Etidrônico/uso terapêutico , Feminino , Glucocorticoides/administração & dosagem , Humanos , Imidazóis/uso terapêutico , Infusões Intravenosas , Vértebras Lombares/fisiopatologia , Masculino , Menopausa/fisiologia , Pessoa de Meia-Idade , Osteoporose/induzido quimicamente , Osteoporose/fisiopatologia , Osteoporose/prevenção & controle , Osteoporose Pós-Menopausa/induzido quimicamente , Osteoporose Pós-Menopausa/tratamento farmacológico , Osteoporose Pós-Menopausa/fisiopatologia , Osteoporose Pós-Menopausa/prevenção & controle , Prednisona/administração & dosagem , Prednisona/efeitos adversos , Ácido Risedrônico , Fatores Sexuais , Vitamina D/análogos & derivados , Vitamina D/sangue , Adulto Jovem , Ácido Zoledrônico
5.
BJU Int ; 93(6): 838-40, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15050001

RESUMO

OBJECTIVE: To investigate serum prostate specific antigen (PSA) levels with age and sex in childhood. SUBJECTS AND METHODS: This prospective study included 205 children (123 boys, 82 girls; mean age 59.27 months, sd 3.78, range 2 days to 204 months) with no urogenital or endocrine disorders. PSA levels were measured using a highly sensitive, "third-generation" PSA (time-resolved immunofluorometric) assay, able to detect PSA levels of > or = 1 ng/L (0.001 ng/mL). Children were divided into four groups by age, i.e. A (0-12 months; 34 boys/20 girls); B (13-48, 37/21); C (49-144, 41/32); and D (> 144, 11/9). The data were analysed statistically using analysis of variance. RESULTS: An accurate measurement of PSA was possible in both sexes using the assay. The median (sd, range) PSA level in boys was 38.41 (1.318, 1-2768) ng/L, and in girls 4.059 (1.392, 1-287) ng/L. There were no significant differences between girls at all age groups, or between the sexes for groups A-C, but levels were significantly higher in boys in group D (30 times that in girls), at 142.59 (1.53) and 4.85 (1.58) ng/L (P < 0.01). CONCLUSIONS: PSA levels do not differ significantly between boys and girls until 12 years old, after which there is a significant and steep increase in PSA in boys, reflecting the development of the prostate. Assessing PSA in children could be used as a potential marker in the diagnosis and follow-up of urogenital disorders.


Assuntos
Antígeno Prostático Específico/sangue , Análise de Variância , Criança , Pré-Escolar , Feminino , Fluorimunoensaio/normas , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos , Sensibilidade e Especificidade , Fatores Sexuais
6.
Prostate Cancer Prostatic Dis ; 6(3): 223-7, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12970725

RESUMO

Human kallikreins 6, 10 and 13 (hK6, hK10 and hK13) are expressed by many normal, mainly glandular tissues, including prostatic epithelium. Some kallikreins may function as tumor suppressors or are downregulated during cancer progression. The aim of this study was to evaluate the immunoexpression of these kallikreins in benign and malignant prostatic tissues and correlate their expression with prostate cancer (PC) prognosis. Included in the study were 25 cases of nonmalignant prostate and 179 cases of PC. Among them, 122 PC cases were immunostained for hK6, 94 for hK10 and 113 for hK13, respectively. The follow-up period for a subset of 68 patients who had undergone radical prostatectomy (RP) was 1-58 months (mean=13.4 +/- 1.7 and median=8.0 months). A cutoff value of 0.2 microg/l of serum PSA was established as a biochemical recurrence threshold. Follow-up information was available for 26/55 RP cases stained for hK6, 14/32 cases stained for hK10 and 25/59 cases stained for hK13. Gleason score (GS) 7 carcinomas were stratified as 7a and 7b, according to the primary grade. PC with GS 2-7a were histologically categorized as low malignant (LM) and PC with GS 7b-10 as high malignant (HM). The immunohistochemical method of streptavidin-biotin-peroxidase using monoclonal and polyclonal antibodies was performed. In the benign prostate and in prostatic intraepithelial neoplasia, a cytoplasmic immunostaining of varying intensity was evident. In PC, the immunoexpression of all kallikreins was decreased: 102/122 cases (84%) were positive for hK6, 73/94 (78%) for hK10 and 97/113 (86%) for hK13, respectively. A statistically significant difference in expression was found, in comparison to nonmalignant prostates (P=0.029, 0.009 and 0.045, respectively). Also, a positive correlation was observed between the immunoexpression of these three kallikreins. Concerning the histological grade, HM-PC expressed all three kallikreins with a slightly higher percentage than LM-PC: 79 vs 88% for hK6, 76 vs 79% for hK10 and 76 vs 92% for hK13. These differences were statistically significant only in the case of hK13 (P=0.024). Serum PSA did not correlate with kallikrein immunoexpression in PC. Furthermore, there was no significant correlation between kallikrein expression and pathological stage or recurrence, in the cases of RP. All three kallikreins are expressed in the nonmalignant and malignant prostate, with cancer tissues demonstrating slightly lower expression. Expression levels did not correlate with aggressiveness and they do not seem to have value for prostate cancer prognosis.


Assuntos
Próstata/citologia , Próstata/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Calicreínas Teciduais/metabolismo , Humanos , Hiperplasia/patologia , Imuno-Histoquímica , Masculino , Próstata/patologia
7.
Mol Biochem Parasitol ; 86(1): 13-27, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9178264

RESUMO

Trophozoites of Giardia duodenalis express at their cell surface variant-specific proteins (VSPs) that are believed to contribute to the protection of the parasite from immunological and other host defense mechanisms. In the present study, we have cloned and characterized the gene encoding a VSP (VSP4A1, originally designated CRISP-90) that is expressed by the sheep-derived Giardia variant clone O2-4A1. The gene was isolated by probing a genomic library with a near-full-length gene-specific polymerase chain reaction (PCR) product. The VSP4A1 gene specifies a 70729 Da protein with features common to all previously reported VSPs, including a high cysteine and threonine content, a highly conserved hydrophobic carboxy-terminal domain and little similarity in the remaining polypeptide sequence. Comparison of the predicted sequence with the amino-terminal sequence of purified VSP4A1 revealed the absence of an amino-terminal hydrophobic extension from the mature protein. VSP4A1 purified from the O2-4A1 variant clone was found to undergo conformational changes resulting in the formation of two additional electrophoretic species. Free thiol groups were not detected in purified VSP4A1, indicating that all cysteine residues may be involved in disulphide crosslinking. Possibly as a consequence of this VSP4A1 was found to be fairly resistant to proteolytic digestion. Although VSP4A1 is able to bind zinc following blotting to a nitrocellulose membrane, other analyses with both the purified and cell associated VSP have failed to confirm significant zinc ion binding to this protein. The latter result questions the assumption previously made by other authors that zinc binding to VSPs constitutes an important structural and functional aspect of these proteins.


Assuntos
Giardia/fisiologia , Hidrolases , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Sequência de Aminoácidos , Animais , Antígenos de Superfície/biossíntese , Antígenos de Superfície/química , Sequência de Bases , Sítios de Ligação , Clonagem Molecular , Primers do DNA , Giardia/química , Proteínas de Membrana/isolamento & purificação , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Conformação Proteica , Sinais Direcionadores de Proteínas/química , Proteínas de Protozoários/isolamento & purificação , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Ovinos , Zinco/metabolismo
8.
Biochem J ; 322 ( Pt 1): 49-56, 1997 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-9078242

RESUMO

The variant-specific surface proteins (VSPs) of the ancient protist Giardia duodenalis (syn.: Giardia intestinalis, Giardia lamblia) are cysteine- and threonine-rich polypeptides that can vary considerably in sequence and size. In the present study, we have purified a VSP (VSP4A1, formerly called CR1SP-90) from a cloned Giardia isolate, derived from a sheep, by Triton X-114 phase partitioning and anion-exchange chromatography. Analysis of the purified VSP4A1 showed that this protein is posttranslationally modified with both glycans and lipid. The glycans of VSP4A1 were detected and partially characterized by (1) compositional analysis, which indicated the presence of GlcNAc and Glc (0.5 and 1.0 mol/mol of protein respectively), and (2) the specific labelling of VSP4A1 with galactosyltransferase/UDP-[3H]Gal. The glycans were released by beta-elimination, suggesting that they are O-linked to the protein. Bio-Gel P4 chromatography of the released galactosylated glycans and further compositional analysis suggested that the major glycan on the VSP is a trisaccharide with Glc at the reducing terminus. These and other results indicate the absence of any N-linked glycans on the VSP and suggest instead that it is elaborated with a novel type of short O-linked glycan. Compositional analysis and radiolabelling experiments also indicated that VSP4A1 is modified with covalently linked palmitate (1 mol/mol of protein). Hydroxylamine treatment at neutral pH of[3H]palmitate-labelled VSP4A1 indicated that the acyl chain may be attached by a thioester linkage. A likely location for the lipid modification appears to be in the region of the C-terminal domain where it may facilitate association of the protein with the plasma membrane.


Assuntos
Giardia lamblia/metabolismo , Hidrolases , Proteínas de Membrana/metabolismo , Ácido Palmítico/metabolismo , Proteínas de Protozoários/metabolismo , Animais , Eletroforese em Gel de Poliacrilamida , Giardia lamblia/química , Glicosilação , Proteínas de Membrana/química , Proteínas de Membrana/isolamento & purificação , Polissacarídeos/química , Proteínas de Protozoários/química , Proteínas de Protozoários/isolamento & purificação
9.
Biochemistry ; 35(31): 10143-8, 1996 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-8756478

RESUMO

The trophozoites of Giardia duodenalis are covered by a coat composed of an apparently single species of a group of novel, cysteine-rich proteins. These variant-specific surface proteins (VSPs) can be changed by sequential expression of different VSP genes, a process for which a gradual exchange of VSP molecules appears to be required. In the present study, we have examined the in vitro release of one of these VSPs (VSP4A1, formerly named CRISP-90) expressed by a sheep-derived variant Giardia clone. During in vitro incubation of the cloned trophozoites, the membrane-associated form of VSP4A1 (mVSP4A1) was specifically converted to a water-soluble isoform that was continuously released into the culture medium. The time required for mVSP4A1 to decline to half of the initial amount was 7.8 h. Analysis of the two purified protein species by mass spectrometry revealed molecular mass values of 68,991 Da for mVSP4A1 and of 65,425 Da for its soluble counterpart. Amino-terminal sequencing and metabolic labeling experiments indicated that the release of mVSP4A1 was associated with the cleavage of a carboxy-terminal peptide carrying the palmitic acid recently demonstrated to be attached to mVSP4A1. Calculations using the molecular mass and predicted amino acid sequence data indicated that fragmentation of the protein possibly occurs at a site located between the lysine and serine residues of the highly conserved NKSGLS motif directly preceding the hydrophobic sequence previously postulated to serve as a membrane anchoring domain of other VSP molecules. The observed processing of the membrane-associated VSP to its soluble isoform is assumed to be an essential requirement for the ability of the parasite to undergo surface antigenic variation and thus for its establishment and survival within the vertebrate host.


Assuntos
Antígenos de Protozoários/biossíntese , Antígenos de Superfície/biossíntese , Giardia/metabolismo , Hidrolases , Proteínas de Membrana/biossíntese , Proteínas de Protozoários/biossíntese , Sequência de Aminoácidos , Animais , Antígenos de Protozoários/química , Antígenos de Superfície/química , Membrana Celular/metabolismo , Sequência Conservada , Cisteína/metabolismo , Cinética , Proteínas de Membrana/química , Proteínas de Membrana/isolamento & purificação , Dados de Sequência Molecular , Ácido Palmítico , Ácidos Palmíticos/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/isolamento & purificação , Homologia de Sequência de Aminoácidos , Ovinos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
10.
Kidney Int ; 46(1): 216-22, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7933840

RESUMO

We have developed an immunological procedure for measuring advanced glycosylation end-products (AGEs) in serum. Using this method, we measured AGEs in healthy volunteers, patients with diabetes, renal failure without treatment and in patients with renal failure, treated with hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD). We found that AGEs were moderately elevated in diabetics without renal failure and highly elevated in CAPD and HD patients irrespective of their glycemic status. AGE levels correlated significantly with creatinine levels but not with levels of glucose or patient age or sex. AGE levels were reduced significantly post-hemodialysis. Preliminary experiments have shown that circulating AGEs have a molecular weight of approximately 1.5 to 2.0 kDa. More studies are needed to establish if AGE measurements in serum are prognostic indicators of the complications of either diabetes or renal failure.


Assuntos
Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Produtos Finais de Glicação Avançada/sangue , Falência Renal Crônica/sangue , Diálise Peritoneal Ambulatorial Contínua , Diálise Renal , Adulto , Idoso , Animais , Glicemia/análise , Creatinina/sangue , Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 2/terapia , Feminino , Glicosilação , Humanos , Técnicas Imunoenzimáticas , Falência Renal Crônica/terapia , Pessoa de Meia-Idade , Peso Molecular , Coelhos
11.
Infect Immun ; 61(7): 2937-44, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8514398

RESUMO

Cloned Giardia isolates obtained from a sheep, a calf, and a human possessed a major membrane protein that showed marked intraspecific variations in size as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis following surface biotinylation and radioiodination. Metabolic labeling with [35S] cysteine and electrophoretic analysis also revealed for each cloned isolate a predominant protein that corresponded in size to the major surface protein demonstrated by surface labeling techniques. Immunoprecipitation studies with a polyclonal antiserum specifically directed against the 90-kDa major cysteine-rich protein purified from a subclone of the sheep isolate (O2-4A1) showed that the cysteine-rich protein and the major surface protein are identical. The surface location of the antigen was further corroborated by the reaction of fluorescence-labeled antibodies raised against the 90-kDa O2-4A1 cysteine-rich protein with the entire surface of live trophozoites of the homologous clone. The ability of the cloned Giardia isolates to undergo variations of their cysteine-rich surface protein (CRISP) was demonstrated by the spontaneous appearance of new CRISPs in clonally derived populations during prolonged in vitro culturing and in cultures of the O2-4A1 clone that had survived treatment with the cytotoxic anti-90-kDa CRISP antiserum specific for the surface antigen of this clone. The surviving progeny were devoid of the original CRISP, as judged by resistance to the immune serum. Subsequent cysteine metabolic labeling of the recloned surviving trophozoites demonstrated a large number of new variants, each expressing a single CRISP that varied significantly in molecular weight from those in the different cloned lines. These studies suggest that the presence of CRISPs and their variations are not restricted to Giardia isolates obtained from humans but are universal phenomena among the Giardia duodenalis types of organisms.


Assuntos
Cisteína/análise , Giardia/química , Proteínas de Membrana/análise , Proteínas de Protozoários/análise , Animais , Antígenos de Protozoários/análise , Antígenos de Protozoários/química , Antígenos de Superfície/análise , Bovinos , Eletroforese em Gel de Poliacrilamida , Humanos , Peso Molecular , Proteínas de Protozoários/química , Proteínas de Protozoários/imunologia , Ovinos
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