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1.
J Immunol ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38647373

RESUMO

Using an Ig H chain conferring specificity for N-acetyl-d-glucosamine (GlcNAc), we developed transgenic (VHHGAC39 TG) mice to study the role of self-antigens in GlcNAc-reactive B-1 B cell development. In VHHGAC39 TG mice, GlcNAc-reactive B-1 B cell development during ontogeny and in adult bone marrow was normal. However, adult TG mice exhibited a block at transitional-2 immature B cell stages, resulting in impaired allelic exclusion and accumulation of a B cell subset coexpressing endogenous Ig gene rearrangements. Similarly, VHHGAC39 B cell fitness was impeded compared with non-self-reactive VHJ558 B TG cells in competitive mixed bone marrow chimeras. Nonetheless, adult VHHGAC39 mice immunized with Streptococcus pyogenes produce anti-GlcNAc Abs. Peritoneal cavity B cells transferred from VHHGAC39 TG mice into RAG-/- mice also exhibited robust expansion and anti-GlcNAc Ab production. However, chronic treatment of young VHHGAC39 mice with GlcNAc-specific mAbs leads to lower GlcNAc-binding B cell frequencies while increasing the proportion of GlcNAc-binding B1-a cells, suggesting that Ag masking or clearance of GlcNAc Ags impedes maturation of newly formed GlcNAc-reactive B cells. Finally, BCR H chain editing promotes expression of endogenous nontransgenic BCR alleles, allowing potentially self-reactive TG B cells to escape anergy or deletion at the transitional stage of precursor B cell development. Collectively, these observations indicate that GlcNAc-reactive B cell development is sensitive to the access of autologous Ags.

2.
J Immunol ; 211(9): 1320-1331, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37747293

RESUMO

Environmental factors and host microbiota strongly influence type 1 diabetes (T1D) progression. We report that neonatal immunization with group A Streptococcus suppresses T1D development in NOD mice by promoting clonal expansion of N-acetyl-d-glucosamine (GlcNAc)-specific B-1 B cells that recognize pancreatic ß cell-derived Ags bearing GlcNAc-containing posttranslational modifications. Early exposure to Lancefield group A cell-wall carbohydrate Ags increased production of GlcNAc-reactive serum Abs and enhanced localization of innate-like GlcNAc-specific B cells to pancreatic tissue during T1D pathogenesis. We show that B-1 B cell-derived GlcNAc-specific IgM engages apoptosis-associated ß cell Ags, thereby suppressing diabetogenic T cell activation. Likewise, adoptively transferring GlcNAc-reactive B-1 B cells significantly delayed T1D development in naive recipients. Collectively, these data underscore potentially protective involvement of innate-like B cells and natural Abs in T1D progression. These findings suggest that previously reported associations of reduced T1D risk after GAS infection are B cell dependent and demonstrate the potential for targeting the natural Ab repertoire in considering therapeutic strategies for T1D.


Assuntos
Diabetes Mellitus Tipo 1 , Camundongos , Animais , Camundongos Endogâmicos NOD , Glucosamina , Acetilglucosamina , Pâncreas/patologia
3.
Immunity ; 53(1): 172-186.e6, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32610078

RESUMO

B-1 B cells derive from a developmental program distinct from that of conventional B cells, through B cell receptor (BCR)-dependent positive selection of fetally derived precursors. Here, we used direct labeling of B cells reactive with the N-acetyl-D-glucosamine (GlcNAc)-containing Lancefield group A carbohydrate of Streptococcus pyogenes to study the effects of bacterial antigens on the emergent B-1 B cell clonal repertoire. The number, phenotype, and BCR clonotypes of GlcNAc-reactive B-1 B cells were modulated by neonatal exposure to heat-killed S. pyogenes bacteria. GlcNAc-reactive B-1 clonotypes and serum antibodies were reduced in germ-free mice compared with conventionally raised mice. Colonization of germ-free mice with a conventional microbiota promoted GlcNAc-reactive B-1 B cell development and concomitantly elicited clonally related IgA+ plasma cells in the small intestine. Thus, exposure to microbial antigens in early life determines the clonality of the mature B-1 B cell repertoire and ensuing antibody responses, with implications for vaccination approaches and schedules.


Assuntos
Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Subpopulações de Linfócitos B/imunologia , Polissacarídeos Bacterianos/imunologia , Streptococcus pyogenes/imunologia , Acetilglucosamina/metabolismo , Animais , Animais Recém-Nascidos/imunologia , Vida Livre de Germes/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microbiota/imunologia
4.
Meteorit Planet Sci ; 55(3): 465-479, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32362737

RESUMO

The presence and accessibility of a sub-ice-surface saline ocean at Enceladus, together with geothermal activity and a rocky core, make it a compelling location to conduct further, in-depth, astrobiological investigations to probe for organic molecules indicative of extraterrestrial life. Cryovolcanic plumes in the south polar region of Enceladus enable the use of remote in situ sampling and analysis techniques. However, efficient plume sampling and the transportation of captured organic materials to an organic analyzer present unique challenges for an Enceladus mission. A systematic study, accelerating organic ice-particle simulants into soft inert metal targets at velocities ranging 0.5-3.0 km s-1, was carried out using a light gas gun to explore the efficacy of a plume capture instrument. Capture efficiency varied for different metal targets as a function of impact velocity and particle size. Importantly, organic chemical compounds remained chemically intact in particles captured at speeds up to ~2 km s-1. Calibration plots relating the velocity, crater, and particle diameter were established to facilitate future ice-particle impact experiments where the size of individual ice particles is unknown.

5.
Viral Immunol ; 33(4): 266-276, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31851873

RESUMO

Adaptive antibody responses provide a crucial means of host defense against viral infections by mediating the neutralization and killing infectious pathogens. At the forefront of humoral defense against viruses lie a subset of innate-like serum antibodies known as natural antibodies (NAbs). NAbs serve multifaceted functions in host defense and play an essential role in early immune responses against viruses. However, there remain many unanswered questions with regard to both the breadth of viral antigens recognized by NAbs, and how B cell ontology and individual antigenic histories intersect to control the development and function of antiviral human NAbs. In the following article we briefly review the current understanding of the functions and source of NAbs in the immune repertoire, their role during antiviral immune responses, the factors influencing the maturation of the NAb repertoire, and finally, the gaps and future research needed to advance our understanding of innate-like B cell biology for the purpose of harnessing NAbs for host defense against viral infections.


Assuntos
Anticorpos Antivirais/imunologia , Imunidade Inata , Polissacarídeos/imunologia , Viroses/imunologia , Animais , Anticorpos Antivirais/sangue , Linfócitos B/imunologia , Humanos , Imunidade Humoral , Camundongos , Viroses/sangue
6.
Oncogene ; 36(18): 2565-2576, 2017 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-27869162

RESUMO

Epithelial ovarian cancer (EOC) has poor prognosis and rapid recurrence because of widespread dissemination of peritoneal metastases at diagnosis. Multiple pathways contribute to the aggressiveness of ovarian cancer, including hypoxic signaling mechanisms. In this study, we have determined that the hypoxia-inducible histone demethylase KDM4B is expressed in ∼60% of EOC tumors assayed, including primary and matched metastatic tumors. Expression of KDM4B in tumors is positively correlated with expression of the tumor hypoxia marker CA-IX, and is robustly induced in EOC cell lines exposed to hypoxia. KDM4B regulates expression of metastatic genes and pathways, and loss of KDM4B increases H3K9 trimethylation at the promoters of target genes like LOXL2, LCN2 and PDGFB. Suppressing KDM4B inhibits ovarian cancer cell invasion, migration and spheroid formation in vitro. KDM4B also regulates seeding and growth of peritoneal tumors in vivo, where its expression corresponds to hypoxic regions. This is the first demonstration that a Jumonji-domain histone demethylase regulates cellular processes required for peritoneal dissemination of cancer cells, one of the predominant factors affecting prognosis of EOC. The pathways regulated by KDM4B may present novel opportunities to develop combinatorial therapies to improve existing therapies for EOC patients.


Assuntos
Biomarcadores Tumorais/genética , Histona Desmetilases com o Domínio Jumonji/genética , Neoplasias Ovarianas/genética , Neoplasias Peritoneais/genética , Peritônio/patologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Proteínas de Neoplasias/biossíntese , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Neoplasias Ovarianas/patologia , Neoplasias Peritoneais/patologia , Neoplasias Peritoneais/secundário , Prognóstico , Regiões Promotoras Genéticas , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Immunol Rev ; 270(1): 32-50, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26864103

RESUMO

Natural immunoglobulin derived from innate-like B lymphocytes plays important roles in the suppression of inflammatory responses and represents a promising therapeutic target in a growing number of allergic and autoimmune diseases. These antibodies are commonly autoreactive and incorporate evolutionarily conserved specificities, including certain glycan-specific antibodies. Despite this conservation, exposure to bacterial polysaccharides during innate-like B lymphocyte development, through either natural exposure or immunization, induces significant changes in clonal representation within the glycan-reactive B cell pool. Glycan-reactive natural antibodies (NAbs) have been reported to play protective and pathogenic roles in autoimmune and inflammatory diseases. An understanding of the composition and functions of a healthy glycan-reactive NAb repertoire is therefore paramount. A more thorough understanding of NAb repertoire development holds promise for the design of both biological diagnostics and therapies. In this article, we review the development and functions of NAbs and examine three glycan specificities, represented in the innate-like B cell pool, to illustrate the complex roles environmental antigens play in NAb repertoire development. We also discuss the implications of increased clonal plasticity of the innate-like B cell repertoire during neonatal and perinatal periods, and the prospect of targeting B cell development with interventional therapies and correct defects in this important arm of the adaptive immune system.


Assuntos
Anticorpos/imunologia , Anticorpos/uso terapêutico , Imunoterapia , Polissacarídeos/imunologia , Animais , Anticorpos/genética , Formação de Anticorpos , Especificidade de Anticorpos/imunologia , Antígenos/imunologia , Subpopulações de Linfócitos B/citologia , Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/metabolismo , Diferenciação Celular , Seleção Clonal Mediada por Antígeno/genética , Seleção Clonal Mediada por Antígeno/imunologia , Epitopos/imunologia , Rearranjo Gênico do Linfócito B , Humanos , Imunidade Inata , Imunoterapia/métodos , Microbiota/imunologia , Simbiose
8.
Br J Surg ; 102(7): 767-75, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25950998

RESUMO

BACKGROUND: Sepsis is associated with profound alterations in protein metabolism. The unpredictable time course of sepsis and the multiplicity of confounding factors prevent studies of temporal relations between the onset of endocrine and proinflammatory cytokine responses and the onset of protein catabolism. This study aimed to determine the time course of whole-body protein catabolism, and relate it to the endocrine, metabolic and cytokine responses in a human endotoxaemia model of early sepsis. METHODS: Six healthy male volunteers were studied twice in random order, before and for 600 min after administration of either an intravenous bolus of Escherichia coli lipopolysaccharide (LPS) or sterile saline. Whole-body protein synthesis, breakdown and net protein breakdown were measured by amino acid tracer infusion, and related to changes in plasma levels of growth hormone, glucagon, cortisol, insulin-like growth factor (IGF) 1, tumour necrosis factor (TNF) α and interleukin (IL) 6. RESULTS: Protein synthesis, breakdown and net protein breakdown increased and peaked 120 min after LPS administration (P < 0·001), the alterations persisting for up to 480 min. These peaks coincided with peaks in plasma growth hormone, TNF-α and IL-6 concentrations (P = 0·049, P < 0·001 and P < 0·001 for LPS versus saline), whereas plasma cortisol concentration peaked later. No alterations in plasma insulin or glucagon concentrations, or in the IGF axis were observed during the period of abnormalities of protein metabolism. CONCLUSION: LPS administration induced an early protein catabolic response in young men and this coincided with changes in plasma growth hormone, TNF-α and IL-6 concentrations, rather than changes in cortisol, glucagon, insulin or the IGF axis. Surgical relevance Sepsis in surgical patients is common and remains associated with substantial mortality. Although sepsis is a heterogeneous condition and its pathophysiology therefore difficult to study, a universal and profound clinical problem is protein catabolism not responsive to nutritional support. Human experimental endotoxaemia is a promising model of clinical sepsis that can be used to elucidate underlying pathophysiology and explore novel therapeutic approaches. This study demonstrates that human experimental endotoxaemia replicates the changes in whole-body protein turnover seen in clinical sepsis. Frequent measurements allowed identification of tumour necrosis factor (TNF) α, interleukin (IL) 6 and growth hormone as putative mediators. Human experimental endotoxaemia is a valid model for further study of mechanisms and putative therapies of catabolism associated with sepsis. In particular, effects of TNF-α and IL-6 blockade should be evaluated.


Assuntos
Citocinas/sangue , Endotoxemia/sangue , Inflamação/sangue , Proteínas/metabolismo , Adulto , Seguimentos , Voluntários Saudáveis , Humanos , Cinética , Masculino , Radioimunoensaio
9.
Diabet Med ; 32(5): 609-17, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25661981

RESUMO

AIMS: To investigate the best glucose monitoring strategy for maintaining euglycaemia by comparing self-monitoring of blood glucose with continuous glucose monitoring, with or without an alarm function. METHODS: A 100-day, randomized controlled study was conducted at four European centres, enrolling 160 patients with Type 1 or Type 2 diabetes, on multiple daily insulin injections or continuous subcutaneous insulin infusion. Participants were randomized to continuous glucose monitoring without alarms (n = 48), continuous glucose monitoring with alarms (n = 49) or self-monitoring of blood glucose (n = 48). RESULTS: Time spent outside the glucose target during days 80-100 was 9.9 h/day for the continuous glucose monitoring without alarms group, 9.7 h/day for the continuous glucose monitoring with alarms group and 10.6 h/day for the self-monitoring of blood glucose group (P = 0.18 and 0.08 compared with continuous glucose monitoring without and with alarms, respectively).The continuous glucose monitoring with alarms group spent less time in hypoglycaemia compared with the self-monitoring of blood glucose group (1.0 h/day and 1.6 h/day, respectively; 95% CI -1.2 to -0.1; P = 0.030). Among those treated with continuous subcutaneous insulin infusion, time spent outside the glucose target was significantly different when comparing continuous glucose monitoring without alarms and self-monitoring of blood glucose (-1.9 h/day; 95% CI -3.8 to 0.0; P = 0.0461) and when comparing continuous glucose monitoring with alarms and self-monitoring of blood glucose (-2.4 h/day; 95% CI -4.1 to -0.5; P = 0.0134). There was no difference in HbA1c reduction from baseline in the three groups; however, the proportion of participants with a reduction of ≥ 6 mmol/mol (≥ 0.5%) was higher in the continuous glucose monitoring without alarms (27%) and continuous glucose monitoring with alarms groups (25%) than in the self-monitoring of blood glucose group (10.6%). CONCLUSIONS: This study shows that the use of continuous glucose monitoring reduces time spent outside glucose targets compared with self-monitoring of blood glucose, especially among users of insulin pumps.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hemoglobinas Glicadas/metabolismo , Insulina/administração & dosagem , Insulina/uso terapêutico , Monitorização Fisiológica/métodos , Adolescente , Adulto , Idoso , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 2/sangue , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Infusões Subcutâneas , Injeções Subcutâneas , Sistemas de Infusão de Insulina , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Estudos Prospectivos , Qualidade de Vida , Autocuidado/métodos , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
10.
QJM ; 107(9): 721-6, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24652654

RESUMO

BACKGROUND: Gastric bypass surgery induces early remission or significant improvement in type 2 diabetes (T2D). AIM: To assess effectiveness of stopping glucose-lowering treatment at the time of surgery. DESIGN: Observational cohort analysis. METHODS: We identified 101 patients (62 women) with T2D who had undergone gastric bypass surgery at a mean (SD, standard deviation) age of 51.4 (9.0) years. We recorded weight, body mass index (BMI), glycosylated haemoglobin (HbA1c), blood pressure (BP), total and high-density lipoprotein (HDL) cholesterol preoperatively and at a median 4, 12 and 24 months postoperatively, and changes to glucose-lowering therapy. RESULTS: Mean (SD) baseline BMI was 50.3 (6.3) kg/m(2), HbA1c 65.3 (18.5) mmol/mol, systolic BP 146.0 (18.0) mmHg, diastolic BP 87.0 (10.8) mmHg and total cholesterol-to-HDL cholesterol ratio 4.0 (1.2). Mean (95% confidence interval) reduction in BMI was 16.4 (14.1-18.7) kg/m(2), HbA1c 23.6 (17.6-29.6) mmol/mol, systolic BP 12.9 (5.9-19.8) mmHg, diastolic BP 6.1 (1.8-10.5) mmHg and total cholesterol-to-HDL cholesterol ratio 1.1 (0.6-1.5) at 24 months (P < 0.001 for all measures). Although 91% of patients were receiving glucose-lowering therapies preoperatively, complete (HbA1c < 42 mmol/mol) and partial (HbA1c 42-48 mmol/mol) remissions of T2D were seen in 62.1% and 5.2% at 2 years postoperatively. CONCLUSIONS: Cessation of glucose-lowering therapies in people with T2D at the time of gastric bypass surgery was clinically effective. The majority of patients remained in complete or partial remission of diabetes up to 2 years postoperatively.


Assuntos
Glicemia/metabolismo , HDL-Colesterol/sangue , Diabetes Mellitus Tipo 2 , Derivação Gástrica , Obesidade , Redução de Peso , Adulto , Pressão Sanguínea , Índice de Massa Corporal , Estudos de Coortes , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade/complicações , Obesidade/cirurgia
11.
Clin Obes ; 4(2): 121-4, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25826735

RESUMO

Monogenic obesity is characterized by mutations in genes involved in the central regulation of food intake. Melanocortin-4 receptor (MC4R) mutations are the most frequent monogenic cause of severe early onset human obesity. Although bariatric surgery is the most effective therapy for idiopathic morbid obesity in adults, little is known about its effectiveness in patients with monogenic obesity syndromes. We report 5-year outcome of gastric bypass surgery in a young man with severe super-obesity associated with MC4R mutation. A 22-year-old man with a weight of 221.6 kg and body mass index of 76.7 kg m(-2) associated with a heterozygous MC4R mutation was referred to our centre for bariatric surgery. He underwent Roux-en-Y gastric bypass (RYGB) surgery and achieved weight loss of 76% of excess weight over a follow-up period of 58 months. Heterozygous MC4R mutations have been associated with dominantly inherited obesity in various ethnic groups, and non-surgical interventions are rarely effective in the long term. One previous report of bariatric surgery in a patient with complete MC4R deficiency reported poor weight loss after gastric banding. We speculate that patients with MC4R mutations achieve superior weight loss outcomes from procedures such as RYGB that produce neurohormonal changes rather than gastric restriction alone due to beneficial effects on appetite and satiety regulation.


Assuntos
Cirurgia Bariátrica , Obesidade/cirurgia , Receptor Tipo 4 de Melanocortina/genética , Redução de Peso , Humanos , Masculino , Resultado do Tratamento , Adulto Jovem
12.
QJM ; 106(8): 717-20, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23576775

RESUMO

BACKGROUND: Although bariatric surgery in women of childbearing age reduces the risks of pregnancy complications associated with maternal obesity, little is known of the effect of gestation on weight loss outcomes. AIM: To study weight loss and pregnancy outcomes after bariatric surgery in women of childbearing age. DESIGN AND METHODS: We performed a retrospective, observational cohort analysis of women aged 18-45 years in a university teaching hospital. The results shown represent mean ± standard deviation where appropriate. RESULTS: A total of 232 women aged 34.0 ± 5.9 years with pre-operative weight 137.7 ± 21.3 kg and body mass index (BMI) 50.6 ± 7.2 kg/m(2) underwent bariatric surgery that included 197 (84.9%) gastric bypass, 19 (8.2%) gastric banding, 8 (3.4%) sleeve gastrectomy and 8 other procedures. Twenty-one women had 28 pregnancies following bariatric surgery, of which 24 (85.7%) resulted in live births, 3 (10.7%) terminations of pregnancy and 1 (3.6%) spontaneous miscarriage. The pregnancy group was younger compared with the non-pregnancy group (28.0 ± 5.4 vs. 34.6 ± 5.6 years; P < 0.001) but well matched for pre-operative weight (136.5 ± 18.5 vs. 137.8 ± 21.6 kg), BMI (49.2 ± 7.4 vs. 50.7 ± 7.2 kg/m(2)) and bariatric procedure. The interval between bariatric surgery and first pregnancy was a median 11 months. The pregnancy group lost 70.4% of excess weight compared with 70.0% in the non-pregnancy group at median 30 months of follow-up. CONCLUSION: Pregnancy after bariatric surgery is safe and does not adversely affect weight loss outcomes.


Assuntos
Cirurgia Bariátrica/métodos , Obesidade Mórbida/cirurgia , Resultado da Gravidez/epidemiologia , Adolescente , Adulto , Estudos de Coortes , Feminino , Derivação Gástrica , Humanos , Obesidade Mórbida/complicações , Complicações Pós-Operatórias , Gravidez , Complicações na Gravidez , Estudos Retrospectivos , Resultado do Tratamento , Redução de Peso , Adulto Jovem
14.
J S Afr Vet Assoc ; 80(3): 151-6, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20169747

RESUMO

Feline immunodeficiency virus is a lentivirus of domestic cats that causes significant lifelong infection. Infection with this or similar lentiviruses has been detected in several nondomestic feline species, including African lions (Panthera leo). Although lion lentivirus (FIVple) infection is endemic in certain lion populations in eastern and southern Africa, little is known about its pathogenic effects or its epidemiological impact in free-ranging lions. This report describes the epidemiological investigation of lentivirus positivity of free-ranging lions in the Kruger National Park, South Africa. A nested polymerase chain reaction assay for virus detection was performed on all whole blood samples collected. In addition, serum samples were tested for cross-reactive antibodies to domestic feline lentivirus antigens and to puma lentivirus synthetic envelope peptide antigen. The results were analysed in conjunction with epidemiological data to provide a descriptive epidemiological study on lion lentivirus infection in a free-ranging population of lions. The overall prevalence of lentivirus infection was 69%, with a prevalence of 41% in the north of the park, and 80% in the south. Adult males had the highest prevalence when combining the factors of sex and age: 94%. The lowest prevalences were found among juveniles, with male juveniles at 29%. Adults were 5.58 times more likely to test positive for FIVple than juveniles, with adult males being 35 times more likely to be test positive for FIVple compared with juvenile males. This research represents the 1st epidemiological study of the lion lentivirus among free-ranging lions in the Kruger National Park.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Imunodeficiência Felina/imunologia , Infecções por Lentivirus/veterinária , Leões/virologia , Fatores Etários , Animais , Animais Selvagens , Antígenos Virais/imunologia , Feminino , Vírus da Imunodeficiência Felina/isolamento & purificação , Infecções por Lentivirus/epidemiologia , Masculino , Reação em Cadeia da Polimerase/veterinária , Estudos Soroepidemiológicos , Fatores Sexuais , África do Sul/epidemiologia
15.
Diabet Med ; 25(5): 564-9, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18445169

RESUMO

BACKGROUND: Anaemia occurs early in the course of diabetes-related chronic kidney disease (CKD). There is little evidence about the prevalence of anaemia in people with diabetes. The aim of this study was to assess the prevalence of anaemia, by stage of CKD, in the general diabetic population. METHODS: Haemoglobin (Hb) was measured on all glycated haemoglobin (HbA1c) samples and the most recent (< 4 months) estimated glomerular filtration rate (eGFR) was obtained. Anaemia (at treatment level) was defined as Hb < 110 g/l or the use of erythropoetic stimulating agents (ESA). RESULTS: Twelve per cent (10-14%) of people had Hb < 110 g/l. The prevalence of anaemia increased progressively with worsening CKD. People with CKD stage 3 accounted for the largest number of people with anaemia; 18% (95% CI 13-24%) had Hb < 110 g/l. Those with eGFR < 60 ml/min/1.73 m2 and not on ESA or dialysis were four (2-7) times more likely than patients with better renal function to have Hb < 110 g/l. The relation between Hb and eGFR became approximately linear below an eGFR of 83 ml/min/1.73 m2, where, for every 1 ml/min/1.73 m2 fall in eGFR, there was a 0.4 (0.3-0.5) g/l fall in haemoglobin. CONCLUSIONS: This study demonstrates that anaemia, at levels where treatment is indicated, occurs commonly in people with diabetes and CKD stage 3 or worse. The screening for anaemia in current diabetes management should be extended.


Assuntos
Anemia/etiologia , Nefropatias Diabéticas/complicações , Hemoglobinas Glicadas/metabolismo , Falência Renal Crônica/complicações , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia/epidemiologia , Nefropatias Diabéticas/epidemiologia , Nefropatias Diabéticas/fisiopatologia , Inglaterra/epidemiologia , Feminino , Taxa de Filtração Glomerular/fisiologia , Hemoglobinas Glicadas/análise , Humanos , Falência Renal Crônica/epidemiologia , Falência Renal Crônica/fisiopatologia , Masculino , Pessoa de Meia-Idade , Prevalência , Qualidade de Vida/psicologia
17.
Kidney Int ; 72(1): 92-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17440495

RESUMO

Early identification of patients with chronic kidney disease (CKD) may allow health-care systems to implement interventions aimed at decreasing disease progression and eventual morbidity and mortality. Primary care in the United Kingdom is computerized suggesting a separate screening program for CKD may not be necessary because identifying data already populates primary care databases. Our study utilized a data set of 163 demographic, laboratory, diagnosis, and prescription variables from 130 226 adults in the regions of Kent, Manchester, and Surrey. The patients were 18 years of age and older in a 5-year study period culminating in November 2003. Estimated glomerular filtration rate was calculated from the four-variable Modification of Diet in Renal Disease equation using calibrated creatinine levels. A valid creatinine value was recorded in almost 30% of this cohort. The age-standardized prevalence of stage 3-5 CKD was 10.6% for females and 5.8% for males. In these patients, the odds ratio for hypertension was 2.1, for diabetes 1.33, and for cardiovascular disease 1.69. Only 20% of the diabetic people with stage 3-5 CKD had a blood pressure less than or equal to 130/80 mm Hg. The proportion of patients with anemia significantly rose as renal function declined. We suggest that stage 3-5 CKD is easily detected in existing computerized records. The associated comorbidity and management is readily available enabling intervention and targeting of specialist resources.


Assuntos
Diagnóstico por Computador/métodos , Nefropatias/diagnóstico , Nefropatias/terapia , Programas de Rastreamento/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia/complicações , Anemia/diagnóstico , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/diagnóstico , Doença Crônica , Creatinina/sangue , Complicações do Diabetes/complicações , Complicações do Diabetes/diagnóstico , Progressão da Doença , Feminino , Taxa de Filtração Glomerular/fisiologia , Hemoglobinas/metabolismo , Humanos , Hipertensão/complicações , Hipertensão/diagnóstico , Rim/metabolismo , Rim/fisiopatologia , Nefropatias/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Reino Unido
18.
Diabet Med ; 24(4): 364-9, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17335468

RESUMO

AIMS: To compare rates of chronic kidney disease (CKD) in patients with diabetes and management of risk factors compared with people without diabetes using general practice computer records, and to assess the utility of serum creatinine and albuminuria as markers of impaired renal function. METHODS: The simplified Modification of Diet in Renal Disease (MDRD) equation was used to estimate glomerular filtration rate (eGFR) and stage of CKD. Further data were extracted to assess how effectively impaired renal function was being identified and how well potentially modifiable risk factors were being managed. The setting was 17 practices in Surrey, Kent and Greater Manchester (2003-2004). Participants were all patients with serum creatinine (SCr) recorded. RESULTS: Of the total population of 162 113, 5072 were recorded as having a diagnosis of diabetes, giving a prevalence of 3.1%. Of patients with diabetes, 31% had clinically significant CKD (defined as eGFR < 60 ml/min per 1.73 m(2); CKD stages 3-5) compared with 6.9% of those without diabetes. Only 33% of patients with diabetes at CKD stage 3 had serum creatinine > 120 micromol/l. Of patients with diabetes with eGFR < 60 ml/min per 1.73 m(2), 63% had normoalbuminuria. Considering those with eGFR 30-60 ml/min per 1.73 m(2), 42% of people with diabetes were on an ACE inhibitor compared with 25% of those without diabetes; 32% of patients with diabetes who had any record of micro- or macroalbuminuria at CKD stage 3 were taking an ACE inhibitor. Of people with diabetes and hypertension (BP > 140/80 mmHg), 26% were not prescribed any hypertensive medication, regardless of level of CKD. CONCLUSIONS: CKD is common in people with diabetes living in the community in the UK. The study found a similar rate of stage 3-5 CKD to that found previously in the USA. Currently used measures of renal function fail to identify CKD as effectively as eGFR. Risk factors for CKD and its progression are suboptimally managed.


Assuntos
Diabetes Mellitus/epidemiologia , Nefropatias Diabéticas/epidemiologia , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/epidemiologia , Albuminúria/etiologia , Doença Crônica , Creatinina/sangue , Diabetes Mellitus/diagnóstico , Nefropatias Diabéticas/diagnóstico , Nefropatias Diabéticas/terapia , Medicina de Família e Comunidade/estatística & dados numéricos , Estudos de Viabilidade , Taxa de Filtração Glomerular/fisiologia , Humanos , Testes de Função Renal , Sistemas Computadorizados de Registros Médicos , Prevalência , Prognóstico , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Reino Unido/epidemiologia
20.
Diabet Med ; 22(9): 1226-33, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16108853

RESUMO

BACKGROUND: Diabetes and its complications are more prevalent among South Asians than people of European origin and there is some evidence that patients of South Asian origin with diabetes receive poorer quality care. METHODS: Longitudinal study of patients with diabetes in Blackburn, UK. Processes of care indicators [measurement of blood pressure (BP), cholesterol and glycosolated haemoglobin (HbA1c)] and values of these intermediate outcomes were extracted for all patients registered on a diabetes information system for the period 1995-2001. Differences in processes of care indicators and intermediate outcomes between ethnic groups were estimated after adjusting for the potential confounding factors of sex, age and socioeconomic status (SES). Generalized estimating equations were used to model trends and to test for differences in trends over time. RESULTS: Process of care was similar in South Asian and European patients. Mean BP and cholesterol concentration fell during the study period. South Asians had a higher level of HbA1c throughout the study period. South Asians had lower levels of BP and cholesterol in 1995 but the differences diminished or were abolished over time. SES did not explain differences between ethnic groups. Analyses stratified by baseline levels of intermediate outcomes (above or within target) demonstrated improvements among above target patients were greater among European patients. CONCLUSIONS: Processes of care indicators are similar in diabetic patients of South Asian and European origin, irrespective of SES. However, there are worrying differences in improvements over time in the intermediate outcomes, and glycaemic control remained poorer among patients of South Asian origin patients throughout.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Adulto , Idoso , Ásia/etnologia , Pressão Sanguínea/fisiologia , Colesterol/sangue , Estudos Transversais , Diabetes Mellitus Tipo 2/etnologia , Diabetes Mellitus Tipo 2/terapia , Inglaterra/epidemiologia , Europa (Continente)/etnologia , Feminino , Hemoglobinas Glicadas/análise , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prognóstico , Qualidade da Assistência à Saúde , Fatores Socioeconômicos
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