RESUMO
BACKGROUND: Cytotoxic chemotherapy remains the main systemic therapy for gastro-oesophageal adenocarcinoma, but resistance to chemotherapy is common, resulting in ineffective and often toxic treatment for patients. Predictive biomarkers for chemotherapy response would increase the probability of successful therapy, but none are currently recommended for clinical use. We used global gene expression profiling of tumour biopsies to identify novel predictive biomarkers for cytotoxic chemotherapy. METHODS: Tumour biopsies from patients (n=14) with TNM stage IB-IV gastro-oesophageal adenocarcinomas receiving platinum-based combination chemotherapy were used as a discovery cohort and profiled with Affymetrix ST1.0 Exon Genechips. An independent cohort of patients (n=154) treated with surgery with or without neoadjuvant platinum combination chemotherapy and gastric adenocarcinoma cell lines (n=22) were used for qualification of gene expression profiling results by immunohistochemistry. A cisplatin-resistant gastric cancer cell line, AGS Cis5, and the oesophageal adenocarcinoma cell line, OE33, were used for in vitro validation investigations. RESULTS: We identified 520 genes with differential expression (Mann-Whitney U, P<0.020) between radiological responding and nonresponding patients. Gene enrichment analysis (DAVID v6.7) was used on this list of 520 genes to identify pathways associated with response and identified the adipocytokine signalling pathway, with higher leptin mRNA associated with lack of radiological response (P=0.011). Similarly, in the independent cohort (n=154), higher leptin protein expression by immunohistochemistry in the tumour cells was associated with lack of histopathological response (P=0.007). Higher leptin protein expression by immunohistochemistry was also associated with improved survival in the absence of neoadjuvant chemotherapy, and patients with low leptin protein-expressing tumours had improved survival when treated by neoadjuvant chemotherapy (P for interaction=0.038). In the gastric adenocarcinoma cell lines, higher leptin protein expression was associated with resistance to cisplatin (P=0.008), but not to oxaliplatin (P=0.988) or 5fluorouracil (P=0.636). The leptin receptor antagonist SHLA increased the sensitivity of AGS Cis5 and OE33 cell lines to cisplatin. CONCLUSIONS: In gastro-oesophageal adenocarcinomas, tumour leptin expression is associated with chemoresistance but a better therapy-independent prognosis. Tumour leptin expression determined by immunohistochemistry has potential utility as a predictive marker of resistance to cytotoxic chemotherapy, and a prognostic marker independent of therapy in gastro-oesophageal adenocarcinoma. Leptin antagonists have been developed for clinical use and leptin and its associated pathways may also provide much needed novel therapeutic targets for gastro-oesophageal adenocarcinoma.
Assuntos
Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/metabolismo , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/metabolismo , Leptina/biossíntese , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/biossíntese , Biomarcadores Tumorais/genética , Processos de Crescimento Celular/fisiologia , Resistencia a Medicamentos Antineoplásicos , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Feminino , Perfilação da Expressão Gênica , Humanos , Leptina/genética , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologiaRESUMO
INTRODUCTION: The Oncotype DX Breast RS test has been adopted in Scotland and has been the subject of a large population-based study by a Scottish Consensus Group to assess the uptake of the recurrence score (RS), evaluate co-variates associated with the RS and to analyse the effect it may have had on clinical practice. MATERIALS & METHODS: Pan-Scotland study between August 2018-August 2021 evaluating 833 patients who had a RS test performed as part of their diagnostic pathway. Data was extracted retrospectively from electronic records and analysis conducted to describe change in chemotherapy administration (by direct comparison with conventional risk assessment tools), and univariate/multivariate analysis to assess relationship between covariates and the RS. RESULTS: Chemotherapy treatment was strongly influenced by the RS (p < 0.001). Only 30 % of patients received chemotherapy treatment in the intermediate and high risk PREDICT groups, where chemotherapy is considered. Additionally, 55.5 % of patients with a high risk PREDICT had a low RS and did not receive chemotherapy. There were 17 % of patients with a low risk PREDICT but high RS who received chemotherapy. Multivariate regression analysis showed the progesterone receptor Allred score (PR score) to be a strong independent predictor of the RS, with a negative PR score being associated with high RS (OR 4.49, p < 0.001). Increasing grade was also associated with high RS (OR 3.81, p < 0.001). Classic lobular pathology was associated with a low RS in comparison to other tumour pathology (p < 0.01). Nodal disease was associated with a lower RS (p = 0.012) on univariate analysis, with menopausal status (p = 0.43) not influencing the RS on univariate or multivariate analysis. CONCLUSIONS: Genomic assays offer the potential for risk-stratified decision making regarding the use of chemotherapy. They can help reduce unnecessary chemotherapy treatment and identify a subgroup of patients with more adverse genomic tumour biology. A recent publication by Health Improvement Scotland (HIS) has updated guidance on use of the RS test for NHS Scotland. It suggests to limit its use to the intermediate risk PREDICT group. Our study shows the impact of the RS test in the low and high risk PREDICT groups. The implementation across Scotland has resulted in a notable shift in practice, leading to a significant reduction in chemotherapy administration in the setting of high risk PREDICT scores returning low risk RS. There has also been utility for the test in the low risk PREDICT group to detect a small subgroup with a high RS. We have found the PR score to have a strong independent association with high risk RS. This finding was not evaluated by the key RS test papers, and the potential prognostic information provided by the PR score as a surrogate biomarker is an outstanding question that requires more research to validate.
Assuntos
Neoplasias da Mama , Sistemas de Apoio a Decisões Clínicas , Humanos , Neoplasias da Mama/genética , Neoplasias da Mama/tratamento farmacológico , Feminino , Escócia , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco/métodos , Idoso , Adulto , Recidiva Local de Neoplasia/genética , Genômica , Receptores de Progesterona/metabolismoRESUMO
Endovascular repair of abdominal aortic aneurysm is a common procedure and not without complications. The aim of this study was to evaluate the early results of the Anaconda endograft (Vascutek Ltd., Inchinnan, Scotland, UK) in 106 patients in three hospitals in the west of Scotland. A prospective registry of 106 consecutive patients undergoing endoluminal repair of their abdominal aortic aneurysms using the Anaconda device was set up to record the clinical outcomes, with a mean follow-up of two years. There was no 30-day perioperative mortality in the 106 patients. Only type II endoleaks were detected on serial computed tomography scanning at follow-up. Technical success was achieved in 99% (105/106) in this study; one patient was converted to open surgical repair. Two cases of proximal device migration (>1 cm) were detected at one month and 19 months, respectively, with no associated endoleak or sac enlargement. Five cases of endograft limb thrombosis were noted in this study. Our early clinical experience with the Anaconda endograft compares favourably with other commercially available endografts in the treatment of abdominal aortic aneurysms. The main advantages of this device are that it is re-deployable and that it has a magnetic wire system which makes it easy to implant.
Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular/métodos , Prótese Vascular , Endoleak/cirurgia , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/epidemiologia , Endoleak/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Desenho de Prótese , Sistema de Registros , Escócia/epidemiologia , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disease (PTLD) arises in up to 10% of organ transplant recipients and is fatal in â¼50% of cases. PTLD can be modeled in SCID mice using EBV+ve human B lymphoblastoid cell lines (BLCLs), and the current study investigated intraperitoneal (ip) inoculation of such animals in experiments which assessed the effect of EBV-specific cytotoxic T lymphocytes (CTLs) and cytokines on PTLD growth. Ip transfer of one dose of autologous CTLs, or CD8-enriched T cells, into ip BLCL-inoculated animals significantly delayed tumor development (P = 0.001) and prevented tumor formation in a significant proportion (40%) of mice (P = 0.001). A combination of interleukin (IL)2, 7, and 15 conditioning of CTLs prior to ip injection significantly delayed ip BLCL-derived tumor formation in vivo when compared to CTLs expanded in vitro using only IL2 (P = 0.04) and prevented tumor outgrowth in a significant proportion (60%) of mice (P = 0.02). Daily ip IL2 dosing of ip CTL-inoculated mice significantly delayed tumor development in vivo (P = 0.004) and prevented tumor outgrowth in a significant proportion (78%) of mice (P = 0.02) when compared to animals dosed with vehicle only. In SCID mice, autologous CTLs, and CD8-enriched T cells, have significant capacity to hinder development of PTLD-like tumors. Whilst studies are needed to delineate the role of cytokine conditioning and CD4-enriched T cells, the results suggest that IL2 plays a key role in supporting CTL funtion in vivo.
Assuntos
Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/terapia , Transtornos Linfoproliferativos/imunologia , Transtornos Linfoproliferativos/terapia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/transplante , Animais , Linfócitos B/imunologia , Proliferação de Células , Modelos Animais de Doenças , Citometria de Fluxo , Herpesvirus Humano 4/imunologia , Imunoterapia , Hibridização In Situ , Interleucina-15/imunologia , Interleucina-15/farmacologia , Interleucina-2/imunologia , Interleucina-2/farmacologia , Interleucina-7/imunologia , Interleucina-7/farmacologia , Ativação Linfocitária , Transtornos Linfoproliferativos/prevenção & controle , Transtornos Linfoproliferativos/virologia , Camundongos , Camundongos SCID , Linfócitos T Citotóxicos/virologiaRESUMO
BACKGROUND: Regional variation in clinical practice may identify differences in care, reveal inequity in access, and explain inequality in outcomes. The study aim was to measure geographical variation in Scotland for adjuvant chemotherapy use and mortality in early-stage breast cancer. PATIENTS AND METHODS: In this retrospective cohort study using population cancer registry-based data linkage, patients with surgically treated early breast cancer between 2001 and 2018 were identified from the Scottish Cancer Registry. Geographical regions considered were based on NHS Scotland organisational structure including 14 territorial Health Boards as well as three regional Cancer Networks. Regional variation in the proportion receiving chemotherapy, breast cancer mortality and all-cause mortality was investigated. Inter-regional comparisons of chemotherapy use were adjusted for differences in case mix using logistic regression. Comparison of breast cancer-specific mortality and all-cause mortality used regression with a parametric survival model. Time trends were assessed using moving average plots. RESULTS: Chemotherapy use ranged from 35% to 46% of patients across Health Boards without adjustment. Variation reduced between 2001 and 2018. Following adjustment for clinical case mix, variation between cancer networks was within 3 percentage points, but up to 10 percentage points from the national average in some Health Boards. Differences in breast cancer mortality and all-cause mortality between cancer networks were modest, with hazard ratios of between 0.933 (95% confidence interval 0.893-0.975) and 1.041 (1.002-1.082) compared with the national average. Survival improved over the time period studied. CONCLUSION: With adequate case mix adjustment, variation in adjuvant chemotherapy use for early breast cancer in Scotland is small, with a trend towards greater convergence in practice and improved mortality outcomes in more recent cohorts. This suggests very limited regional inequity in access and convergence of clinical practice towards risk-stratified treatment recommendations. Outliers require assessment to understand the reasons for variance.
Assuntos
Neoplasias da Mama , Neoplasias da Mama/terapia , Quimioterapia Adjuvante , Feminino , Humanos , Armazenamento e Recuperação da Informação , Sistema de Registros , Estudos RetrospectivosRESUMO
Immunization registries are confidential, computerized information systems that collect and consolidate vaccination data from multiple health-care providers, generate reminder and recall notifications, and assess vaccination coverage within a defined geographic area. A registry with added capabilities, such as vaccine management, adverse event reporting, lifespan vaccination histories, and linkages with electronic data sources, is called an immunization information system (IIS). This report summarizes data from CDC's 2005 Immunization Information System Annual Report (IISAR), a survey of grantees in 50 states, five cities, and the District of Columbia (DC) that receive funding under section 317b of the Public Health Service Act. These data indicated that approximately 56% of U.S. children aged <6 years participated in an IIS, an increase from 48% in 2004. Moreover, 75% percent of public vaccination provider sites and 44% of private vaccination provider sites submitted vaccination data to an IIS during July-December 2005. These findings underscore the need to increase the number of participating children, from the current 13 million to approximately 21 million, to assure 95% participation of children aged <6 years and improve the effectiveness of U.S. immunization programs.
Assuntos
Programas de Imunização , Sistemas de Informação Administrativa , Sistemas Computadorizados de Registros Médicos , Vacinação/normas , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Estados UnidosRESUMO
INTRODUCTION: Currently self-expanding metallic stents are being used for palliation and acute decompression of colonic obstruction. The aim of this study is to review our experience of using these metallic stents over a 5-year period. MATERIALS AND METHODS: Case records of 102 patients who had colorectal stenting between 1998 and 2004 were reviewed retrospectively. The indications for colorectal stenting, efficacy of the procedure in relieving the obstruction, complications and clinical outcome were analysed. RESULTS: Ninety-nine patients had malignant disease and in three patients a benign cause of obstruction was demonstrated. All procedures were performed during normal working hours. Stenting was technically successful in 87 patients (85%). A single stent was placed in 80 patients. Seven patients required two stents. Of the successful cases, 67 had stents placed by fluoroscopy alone and 20 by a combined fluoroscopy/endoscopy procedure. Four percent had early complications (within 30 days) which included four perforations. There were late complications (over 30 days) in 9% which included five stent migrations, two blocked stents and one colovesical fistula. Ninety percent (n=76) of the successful patients needed no further radiological or surgical intervention later. Survival ranged from 14 days to 2 years. CONCLUSION: Colorectal stenting when technically successful is an effective procedure for both preoperative and palliative decompression of colonic obstruction.
Assuntos
Pseudo-Obstrução do Colo/mortalidade , Pseudo-Obstrução do Colo/cirurgia , Perfuração Intestinal/epidemiologia , Medição de Risco/métodos , Stents/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Pseudo-Obstrução do Colo/diagnóstico por imagem , Feminino , Humanos , Incidência , Perfuração Intestinal/diagnóstico por imagem , Pseudo-Obstrução Intestinal , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida , Resultado do Tratamento , Reino Unido/epidemiologiaRESUMO
The objective of this study was to quantify and assess for the first time the variability of total mercury in urban soils at a European level, using a systematic sampling strategy and a common methodology. We report results from a comparison between soil samples from Aveiro (Portugal), Glasgow (Scotland), Ljubljana (Slovenia), Sevilla (Spain), Torino (Italy) and Uppsala (Sweden). At least 25 sampling points (in about 4-5 ha) from a park in each city were sampled at two depths (0-10 and 10-20 cm). Total mercury was determined by pyrolysis atomic absorption spectrometry with gold amalgamation. The quality of results was monitored using certified reference materials (BCR 142R and BCR 141R). Measured total mercury contents varied from 0.015 to 6.3 mg kg(-1). The lowest median values were found in Aveiro, for both surface (0-10 cm) and sub-surface (10-20 cm) samples (0.055 and 0.054 mg kg(-1), respectively). The highest median mercury contents in soil samples were found in samples from Glasgow (1.2 and 1.3 mg kg(-1), for surface and sub-surface samples, respectively). High variability of mercury concentrations was observed, both within each park and between cities. This variability reflecting contributions from natural background, previous anthropogenic activities and differences in the ages of cities and land use, local environmental conditions as well as the influence of their location within the urban area. Short-range variability of mercury concentrations was found to be up to an order of magnitude over the distance of only a few 10 m.
Assuntos
Mercúrio/análise , Poluentes do Solo/análise , Cidades , Monitoramento Ambiental , Europa (Continente)RESUMO
Immunofluorescent serum IgM and/or a significant level of IgA antibody was detected in 87% of 39 cases of current or recent influenza A infection from two to 84 days after the onset of illness. Secondary IgM staining occurred in 5% of sera and a significant correlation was found between complement-fixing and class-specific antibodies. It was estimated that the immunofluorescent test could be diagnostic in 64% of single sera with levels of CF antibody between 32 and 256, and because anti-s antibody was detected in the IgM test this test did not differentiate primary and secondary influenza A infection.
Assuntos
Imunoglobulina A/análise , Imunoglobulina M/análise , Influenza Humana/imunologia , Idoso , Anticorpos Antivirais/análise , Formação de Anticorpos , Células Cultivadas , Testes de Fixação de Complemento , Imunofluorescência , Humanos , Técnicas In Vitro , Rim , Testes de Fixação do Látex , Pessoa de Meia-IdadeRESUMO
Virus isolation tests on 72 sudden unexplained infant deaths and 34 cases of explained death showed that 42 and 29% respectively had virus infections. A wide range of viruses was encountered, mainly enteroviruses and adenoviruses, mostly from bowel specimens. The findings did not suggest that overwhelming virus infection was a common feature of sudden death in infancy.
Assuntos
Morte Súbita , Mortalidade Infantil , Viroses/mortalidade , Adenoviridae/isolamento & purificação , Infecções por Adenoviridae/mortalidade , Tecido Adiposo/microbiologia , Sangue/microbiologia , Enterovirus/isolamento & purificação , Enterovirus Humano B/isolamento & purificação , Infecções por Enterovirus/mortalidade , Fezes/microbiologia , Gastroenteropatias/mortalidade , Humanos , Lactente , Intestinos/microbiologia , Rim , Pulmão/microbiologia , Poliovirus/isolamento & purificação , Sistema Respiratório/microbiologia , Infecções Respiratórias/mortalidade , Respirovirus/isolamento & purificação , Rhinovirus/isolamento & purificação , EscóciaRESUMO
A comparison of immunofluorescent tests for the diagnosis of respiratory syncytial (RS) virus infections was carried out on 42 hospitalized cases of respiratory infection in childhood. Respiratory syncytial virus was detected in 22 (52%) cases, the most sensitive method of detection being by indirect immunofluorescence of Bristol HeLa tissue cultures inoculated with nasopharyngeal aspirates. The highest detection rate was in bronchiolitis cases (92%). Detection of antibody rises in paired sera, eight days apart, confirmed RS virus infection in 13 of 16 cases, the most sensitive test being detection of a specific rise in IgG antibody by indirect immunofluorescence. A serodiagnosis was made in all 10 non-bronchiolitis cases. Recommendations are made for the application ofimmunofluorescence to routine diagnosis of RS virus infection.
Assuntos
Imunofluorescência , Infecções por Orthomyxoviridae/diagnóstico , Vírus Sinciciais Respiratórios/imunologia , Bronquiolite Viral/imunologia , Testes de Fixação de Complemento , Estudos de Avaliação como Assunto , Feminino , Células HeLa/imunologia , Humanos , Imunoglobulina A , Imunoglobulina G , Lactente , Masculino , Nasofaringe/imunologia , Nasofaringe/microbiologia , Testes de Neutralização , Infecções por Orthomyxoviridae/imunologia , Testes SorológicosRESUMO
Serum immunoglobulin concentrations, predominantly IgM, were raised in 72% of 39 sudden infant death cases, consistent with a state of prolonged or repeated antigenic stimulation.Anti-antibody was found in cases of sudden death significantly more frequently than in ill but living control infants. It is suggested that anti-antibody might participate in fatal anaphylaxis in such cases.
Assuntos
Anafilaxia , Morte Súbita , Mortalidade Infantil , Fatores Etários , Anticorpos Anti-Idiotípicos/análise , Feminino , Gastroenterite/imunologia , Humanos , Imunoglobulinas/análise , Lactente , Recém-Nascido , Masculino , Infecções Respiratórias/imunologia , Fatores SexuaisRESUMO
A modified haemagglutination inhibition test for rubella antibodies using prestandardized freeze-dried reagents was compared to a "standard" method. Tests of 707 serum samples showed that the modified test was sensitive and reliable by both macrotitration and microtitration techniques. The minor disadvantages of some reduction in antibody level when rubella sera were tested within one week of the rash and of spontaneous sheep erythrocyte agglutination in 0-7% of sera were out-weighed by the increased speed of the new test and the fact that it was carried out at room temperature.
Assuntos
Testes de Inibição da Hemaglutinação/métodos , Rubéola (Sarampo Alemão)/diagnóstico , Anticorpos Antivirais/análise , Humanos , Vírus da Rubéola/imunologiaRESUMO
Unresponsiveness to skin testing with PPD and tetanus toxoid was commonly seen in patients with haemophilia A but not infected with human immunodeficiency virus but was uncommon in controls. Vaccination history indicated that the unresponsive patients had not been immunised in childhood. Other tests of immune competence (skin tests with other antigens, lymphocyte stimulation with mitogens and antigens, and viral serology) showed that the haemophilia A patients had an adequate response to pathogens to which they had been exposed. Five of 12 such patients had a mild T4 lymphopenia, and this may have been related to parenteral administration of large quantities of protein.
Assuntos
Antígenos de Bactérias/imunologia , Hemofilia A/imunologia , Tolerância Imunológica , Adolescente , Adulto , Idoso , Anticorpos Antivirais/análise , Feminino , HIV/imunologia , Hemofilia B/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes Cutâneos , Toxoide Tetânico/imunologia , Tuberculina/imunologia , Vacinação , Doenças de von Willebrand/imunologiaRESUMO
When chronic Trypanosoma brucei infections of mice are treated with 20 mg/kg suramin, those trypanosomes which have escaped chemotherapy because they are residing in the brain, exhibit a higher degree of human serum resistance than the original infection. This resistance increases if the chronic infection is retreated for a second time, before the trypanosomes in the brain are tested by the blood incubation infectivity test. The transformation is not due to a selection of T. rhodesiense from a T. brucei/T. rhodesiense mixture in the original stabilates as cloned derivatives also exhibit these same characteristics. The implications of this finding are discussed.
Assuntos
Trypanosoma brucei brucei/imunologia , Tripanossomíase Africana/imunologia , Animais , Fenômenos Fisiológicos Sanguíneos , Encéfalo/parasitologia , Feminino , Humanos , Camundongos , Suramina/uso terapêutico , Tripanossomíase Africana/tratamento farmacológicoRESUMO
Mice infected with T. brucei GVR 23/1 or T. brucei GVR 35/1 for 21 days were treated with the Erlangen diamidine 98/202 (6-amidino-2-[4' amidino-phenyl] thionaphthene-dilacate) at either 5 mg/kg or 35 mg/kg. At both these dose levels the parasites were initially cleared from the circulation although the infections eventually relapsed due to reinvasion from the central nervous system. If the 98/202 therapy is followed by treatment with 5-nitroimidazole only a small number of mice are permanently cured. Adverse reactions, especially at the 35 mg/kg dose level, were noted in one experiment. The Erlangen diamidine given to infected mice three days after infection was able to permanently cure both Trypanosoma brucei stabilates.
Assuntos
Amidinas/uso terapêutico , Tripanossomicidas/uso terapêutico , Tripanossomíase Africana/tratamento farmacológico , Animais , Encéfalo/parasitologia , Bovinos , Camundongos , Camundongos Endogâmicos , Recidiva , Trypanosoma brucei brucei , Tripanossomíase Africana/parasitologiaRESUMO
Mice infected with either of two isolates of Trypanosoma brucei, GVR 23/1 or GVR 35/1, develop a chronic infection in which trypanosomes are localized in the central nervous system. These infected mice were used to evaluate the efficacy of a combination drug treatment comprising suramin and one of three 2-substituted 5-nitroimidazoles. None of the three 5-nitroimidazoles tested alone, cured mice when administered 21 days after infection. However, it was found that T. brucei GVR 23/1 infections could be cured by a single dose of 20 mg/kg suramin followed by a single dose of 80 mg/kg L611,744 [3a,4,5,6,7,8,9,9a-octahydro-3-(1-methyl-5-nitroimidazol-2yl)cycloocta(D) isoxazole]. The single dose of 20 mg/kg suramin had to be followed by four doses of 80 mg/kg L611,744 to cure mice infected with another stabilate, T. brucei GVR 35/1. A single dose of 20 mg/kg suramin followed either by four doses of 250 mg/kg MK 436 [3a,4,5,6,7,7a-hexahydro-3-(1-methyl-5nitro-1H-imidazol-2-yl)-1, 2-benzisoxazole] or four doses of 70 mg/kg of a dihydroxy analogue of MK 436 [cis-3a,4,5,6,7,7a-hexahydro-3-(1-methyl-5-nitro-1H-imidazol-2-yl)-1, 2-benzisoxazole-6,7-diol] also permanently cured all T. brucei GVR 35/1.
Assuntos
Antiprotozoários/uso terapêutico , Doenças do Sistema Nervoso Central/tratamento farmacológico , Nitroimidazóis/uso terapêutico , Suramina/uso terapêutico , Tripanossomíase Africana/tratamento farmacológico , Animais , Bovinos , Doenças do Sistema Nervoso Central/parasitologia , Quimioterapia Combinada , Feminino , Camundongos , Trypanosoma brucei bruceiRESUMO
The antigen recognition profiles of serum antibody from calves infected or vaccinated with irradiated Dictyocaulus viviparus larvae were analysed by immunoprecipitation of radio-iodinated in vitro-released excretory-secretory materials from live adult parasites. Immunoprecipitates were analysed by SDS-PAGE and considerable heterogeneity in antigen recognition between individual animals was observed, regardless of infection regimen. This heterogeneity was also found to occur amongst outbred guinea pigs infected with the parasite and permitted an examination of the genetics of the effect using inbred guinea pigs (Strains 2 and 13). The antibody repertoires of the two strains were distinct, with only slight variation occurring between individuals within a strain. Previous work on nematode infections in rodents has demonstrated a role for the major histocompatibility complex (MHC) in the control of the immune repertoire. If this, as is probable, holds for the guinea pig, then it can be ascribed to the MHC Class II region because Strain 2 and Strain 13 bear identical Class I alleles but disparate Class II alleles. Whilst there is no evidence to date that the efficiency of vaccination of cattle is influenced by genetic factors, the operation of vaccines based on a single or a few molecularly cloned parasite antigens might be seriously compromised by the kind of genetic restriction to the immune repertoire described here.