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1.
Support Care Cancer ; 31(8): 450, 2023 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-37421495

RESUMO

PURPOSE: To assess oncologists' responsibility, comfort, and knowledge managing hyperglycemia in patients undergoing chemotherapy. METHODS: In this cross-sectional study, a questionnaire collected oncologists' perceptions about professionals responsible for managing hyperglycemia during chemotherapy; comfort (score range 12-120); and knowledge (score range 0-16). Descriptive statistics were calculated including Student t-tests and one-way ANOVA for mean score differences. Multivariable linear regression identified predictors of comfort and knowledge scores. RESULTS: Respondents (N = 229) were 67.7% men, 91.3% White and mean age 52.1 years. Oncologists perceived endocrinologists/diabetologists and primary care physicians as those responsible for managing hyperglycemia during chemotherapy, and most frequently referred to these clinicians. Reasons for referral included lack of time to manage hyperglycemia (62.4%), belief that patients would benefit from referral to an alternative provider clinician (54.1%), and not perceiving hyperglycemia management in their scope of practice (52.4%). The top-3 barriers to patient referral were long wait times for primary care (69.9%) and endocrinology (68.1%) visits, and patient's provider outside of the oncologist's institution (52.8%). The top-3 barriers to treating hyperglycemia were lack of knowledge about when to start insulin, how to adjust insulin, and what insulin type works best. Women (ß = 1.67, 95% CI: 0.16, 3.18) and oncologists in suburban areas (ß = 6.98, 95% CI: 2.53, 11.44) had higher comfort scores than their respective counterparts; oncologists working in practices with > 10 oncologists had lower comfort scores (ß = -2.75, 95% CI: -4.96, -0.53) than those in practices with ≤ 10. No significant predictors were identified for knowledge. CONCLUSION: Oncologists expected endocrinology or primary care clinicians to manage hyperglycemia during chemotherapy, but long wait times were among the top barriers cited when referring patients. New models that provide prompt and coordinated care are needed.


Assuntos
Hiperglicemia , Insulinas , Neoplasias , Oncologistas , Masculino , Humanos , Feminino , Pessoa de Meia-Idade , Estudos Transversais , Oncologia , Neoplasias/tratamento farmacológico , Inquéritos e Questionários , Hiperglicemia/induzido quimicamente , Hiperglicemia/prevenção & controle , Atitude do Pessoal de Saúde , Padrões de Prática Médica
2.
J Clin Transl Endocrinol ; 26: 100279, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34926167

RESUMO

Cystic fibrosis-related diabetes (CFRD) affects nearly 20% of adolescents and 40-50% of adults. However, the impact on patients and their families is poorly understood. Here, we examine how patients perceive CFRD and identify gaps in our understanding of the patient experience. Despite its relatively high prevalence, data suggest that many individuals are not aware of the possibility of developing CFRD or compare it to other types of diabetes. Annual oral glucose tolerance testing (OGTT) may serve as an opportunity to provide education and prepare individuals for the possibility of developing abnormalities in glucose tolerance. Many cite lack of awareness of CFRD as the most difficult part of the diagnosis. While factors such as older age and a strong support system promote acceptance, most individuals view the diagnosis negatively and struggle to balance the demands of diabetes with other obligations, including airway clearance, nebulizer therapies, supplementation nutrition, and administration of vitamins and medications. Relatively few people with CFRD monitor their blood glucoses consistently, which is attributed to time constraints or an attempt to avoid pain. In addition, many feel that they are not prone to hypoglycemia and are not concerned with long-term complications, anticipating that they will succumb to their pulmonary disease before these become problematic. The adolescent period presents unique challenges for adherence as children work to develop autonomy. Factors that promote CFRD adherence include incorporating management into daily CF routines and the support of knowledgeable providers to help develop an individualized approach to management. Diabetes technology has the potential to reduce treatment burden and improve glycemic control, but data in CFRD are limited, and additional study is needed. Given that CFRD is associated with a decline in health-related quality of life, it is critical that providers understand patients' perspectives and address gaps in understanding and barriers to management.

3.
J Cyst Fibros ; 18 Suppl 2: S82-S87, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31679733

RESUMO

Poor growth has long been a characteristic feature of cystic fibrosis (CF) and is significantly linked to lung function and overall health status. Improvements in pulmonary and nutrition care for patients with cystic fibrosis (CF) have resulted in better growth outcomes; however, height gains have not paralleled the improvements in weight in children with CF, and patients with more severe CF mutations remain significantly more affected. Many factors affect the growth hormone-IGF-1 axis and the growth plate of the long bones, including the chronic inflammatory state associated with CF. There are also increasing data on the direct effects of CFTR on bone and implications for CFTR modulators in attaining optimal growth. Treatments aimed at improving growth in CF are also reviewed here.


Assuntos
Fibrose Cística/complicações , Transtornos do Crescimento/etiologia , Transtornos do Crescimento/terapia , Fibrose Cística/fisiopatologia , Humanos
4.
Am J Med Genet A ; 179(5): 782-791, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30848064

RESUMO

The 2q37 deletion syndrome, also described in the literature as brachydactyly-mental retardation syndrome (MIM 600430), is caused by deletion or haploinsufficiency of the HDAC4 gene, which encodes the histone deacetylase 4 protein. Although the most commonly described hallmark features of the 2q37 deletion syndrome include brachydactyly type E, developmental delay, obesity, autistic features, and craniofacial or skeletal dysmorphism, a literature review of 101 published cases plus two newly reported individuals indicates that there is a high degree of variability in the presence of some of the features that are considered the most characteristic of the syndrome: overweight and obesity (34%), cognitive-behavioral issues (79%), dysmorphic craniofacial features (86%), and type E brachydactyly (48%). These features overlap with other neurodevelopmental conditions, including Smith-Magenis syndrome (SMS), and may be incompletely penetrant or demonstrate variable expressivity, depending on the specific chromosomal anomaly. With the advent of fluorescence in situ hybridization (FISH), array-based comparative genomic hybridization, and next-generation DNA sequencing, more detailed molecular diagnoses are possible than in years past, enabling refined characterization of the genotype-phenotype correlation for subjects with 2q37 deletions. In addition, investigations into molecular and gene expression networks are expanding in neurodevelopmental conditions, and we surveyed HDAC4 downstream gene expression by quantitative real-time polymerase chain reaction, further implicating HDAC4 in its role in the regulation of RAI1. Correlation of clinical data defining the impact on downstream gene expression and the potential clinical associations across neurodevelopment will improve our understanding of these complex conditions and potentially lead to common therapeutic approaches.


Assuntos
Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Histona Desacetilases/genética , Penetrância , Fenótipo , Proteínas Repressoras/genética , Deleção Cromossômica , Cromossomos Humanos Par 2/genética , Deficiências do Desenvolvimento/genética , Feminino , Expressão Gênica , Humanos , Lactente , Deficiência Intelectual/genética , Masculino , Mutação
6.
Curr Opin Endocrinol Diabetes Obes ; 25(6): 361-365, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30239380

RESUMO

PURPOSE OF REVIEW: To summarize recent developments the role of vitamin D and treatment of vitamin D deficiency in cystic fibrosis. RECENT FINDINGS: Although treatment of low vitamin D levels continues to be important for optimizing bone health in cystic fibrosis, increasing data on the extraskeletal effects of vitamin D are becoming available. Exploratory studies of vitamin D in modulation of respiratory and intestinal microbiomes, and the influence of vitamin D on the metabolomic signature of cystic fibrosis, suggest expanded roles for vitamin D in cystic fibrosis disease and treatment. SUMMARY: Emerging developments in cystic fibrosis regarding therapeutics and effects of vitamin D on bone health, inflammation, microbiome, and the metabolome are summarized.


Assuntos
Fibrose Cística/tratamento farmacológico , Deficiência de Vitamina D/tratamento farmacológico , Vitamina D/uso terapêutico , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/fisiologia , Fibrose Cística/complicações , Fibrose Cística/metabolismo , Humanos , Inflamação/tratamento farmacológico , Inflamação/etiologia , Metaboloma/efeitos dos fármacos , Microbiota/efeitos dos fármacos , Vitamina D/sangue , Deficiência de Vitamina D/etiologia , Deficiência de Vitamina D/metabolismo
7.
Minerva Pediatr ; 69(5): 434-443, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28497664

RESUMO

Polycystic ovary syndrome (PCOS) is the most common disorder of androgen excess in women of reproductive age. The diagnosis of PCOS can be more challenging in adolescents than in adult women given significant overlap between normal puberty and the signs of PCOS, including acne, menstrual irregularity, and polycystic ovarian morphology. Optimal treatments for adult women with PCOS vary depending on patient risk factors and reproductive goals, but mainly include hormonal contraception and insulin sensitizers. There is continued interest in targeting the intrinsic insulin resistance that contributes to metabolic and hormonal derangements associated with PCOS. The vast majority of published data on insulin sensitizing PCOS treatments are reported in adult women; these have included weight loss, metformin, thiazolidinediones, and the inositols. Furthermore, there is also a small but growing body of evidence in support of the use of insulin sensitizers in adolescents, with or without oral contraceptives. Discussion of the available treatments, including benefits, potential side effects, and incorporation of patient and family preferences is critical in developing a plan of care aimed at achieving patient-important improvements in PCOS signs and symptoms while addressing the longer-term cardiometabolic risks associated with the syndrome.


Assuntos
Hipoglicemiantes/uso terapêutico , Resistência à Insulina , Síndrome do Ovário Policístico/tratamento farmacológico , Adolescente , Adulto , Fatores Etários , Anticoncepcionais Orais Hormonais/administração & dosagem , Feminino , Humanos , Hipoglicemiantes/efeitos adversos , Inositol/efeitos adversos , Inositol/uso terapêutico , Metformina/efeitos adversos , Metformina/uso terapêutico , Síndrome do Ovário Policístico/diagnóstico , Síndrome do Ovário Policístico/fisiopatologia , Tiazolidinedionas/efeitos adversos , Tiazolidinedionas/uso terapêutico , Redução de Peso
8.
Thyroid ; 26(10): 1441-1449, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27599541

RESUMO

BACKGROUND: Increased thyrotropin (TSH) levels and free triiodothyronine to free thyroxine (fT3:fT4) ratios, even within the euthyroid range, have been associated with cardiometabolic risk factors in adults but are less characterized in youth. This study sought to determine relations between TSH, thyroid hormones, and cardiometabolic risk factors in euthyroid adolescents. METHODS: Data were extracted from the United States National Health and Nutrition Examination Survey, 2007-2010, for univariate and multivariate analyses of TSH, thyroid hormones, body mass index (BMI), blood pressure, lipids, and glucose metabolism. Subjects aged 12-18 years, with normal TSH and antithyroid peroxidase antibody levels, and without a history of thyroid disease, diabetes, or treatment of hypertension/dyslipidemia (n = 1167) were included. TSH and thyroid hormones were assessed for impact on BMI Z-score, systolic blood pressure (SBP) diastolic blood pressure, total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, triglycerides, and glucose metabolism. RESULTS: Univariate analyses revealed positive linear relations between TSH and SBP, TC, fasting and two-hour glucose, and homeostasis model assessment of insulin resistance (HOMA-IR). The fT3:fT4 ratio negatively correlated with high-density lipoprotein cholesterol but positively with BMI Z-score, SBP, triglycerides, fasting and two-hour glucose, fasting insulin, and HOMA-IR. In multivariate analyses controlling for age, sex, race/ethnicity, and BMI Z-score, relations between TSH and both TC and fasting glucose remained significant, and the fT3:fT4 ratio was positively associated with fasting glucose and HOMA-IR. CONCLUSIONS: In an unselected population of euthyroid U.S. adolescents, TSH and thyroid hormones correlate with multiple cardiometabolic risk factors, with age- and sex-independent effects on cholesterol and glucose metabolism.


Assuntos
Doenças Cardiovasculares/epidemiologia , Dislipidemias/epidemiologia , Transtornos do Metabolismo de Glucose/epidemiologia , Resistência à Insulina , Glândula Tireoide/metabolismo , Tireotropina/sangue , Adolescente , Biomarcadores/sangue , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/fisiopatologia , Criança , Estudos de Coortes , Estudos Transversais , Dislipidemias/diagnóstico , Dislipidemias/metabolismo , Dislipidemias/fisiopatologia , Diagnóstico Precoce , Feminino , Transtornos do Metabolismo de Glucose/diagnóstico , Transtornos do Metabolismo de Glucose/metabolismo , Transtornos do Metabolismo de Glucose/fisiopatologia , Humanos , Masculino , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/metabolismo , Síndrome Metabólica/fisiopatologia , Inquéritos Nutricionais , Valor Preditivo dos Testes , Fatores de Risco , Glândula Tireoide/crescimento & desenvolvimento , Glândula Tireoide/fisiologia , Glândula Tireoide/fisiopatologia , Tireotropina/metabolismo , Tiroxina/sangue , Tiroxina/metabolismo , Tri-Iodotironina/sangue , Tri-Iodotironina/metabolismo , Estados Unidos/epidemiologia
9.
Trends Endocrinol Metab ; 26(5): 238-47, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25869212

RESUMO

In homoeothermic organisms, the preservation of core temperature represents a primal function, and its costs in terms of energy expenditure can be considerable. In modern humans, the endogenous thermoregulation mechanisms have been replaced by clothing and environmental control, and the maintenance of thermoneutrality has been successfully achieved by manipulation of the micro- and macroenvironment. The rediscovery of the presence and activity of brown adipose tissue in adult humans has renewed the interest on adaptive thermogenesis (AT) as a means to facilitate weight loss and improve carbohydrate metabolism. The aim of this review is to describe the recent advancements in the study of this function, and to assess the potential and limitations of exploiting AT for environmental/behavioral, and pharmacological interventions.


Assuntos
Termogênese/fisiologia , Adaptação Fisiológica , Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/fisiologia , Adulto , Animais , Capsaicina , Metabolismo dos Carboidratos , Temperatura Baixa , Metabolismo Energético , Humanos , Modelos Animais , Obesidade , Redução de Peso
10.
Genet Test Mol Biomarkers ; 17(7): 567-71, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23651351

RESUMO

AIMS: Human placental lactogen (hPL) acts via the prolactin receptor (PRLR) on maternal ß-cells to mediate increases in ß-cell mass and function during normal pregnancy. This interaction between hPL and PRLR is essential to maintain normal glucose homeostasis and to address the increased metabolic demands of pregnancy. Given the importance of the PRLR-hPL axis in pancreatic islet cell adaptation to pregnancy, we hypothesized that genetic variation in the PRLR gene could influence risk of development of gestational diabetes mellitus (GDM). DNA samples from 96 mothers affected by GDM and 96 unaffected cases were genotyped for 8 selected single nucleotide polymorphisms (SNPs) in PRLR. RESULTS: Significant associations were identified in two SNPs analyzed. The minor alleles of PRLR SNPs rs10068521 and rs9292578 were more frequently observed in GDM cases than controls and were associated with a 2.36-fold increased risk for GDM in those carrying the minor allele. CONCLUSION: SNPs of the PRLR gene 5' UTR and promoter region are associated with increased risk for GDM in a population of Chilean subjects.


Assuntos
Diabetes Gestacional/genética , Polimorfismo Genético , Receptores da Prolactina/genética , Adulto , Estudos de Casos e Controles , Chile/etnologia , Feminino , Predisposição Genética para Doença , Humanos , Recém-Nascido , Masculino , Gravidez
11.
Trends Endocrinol Metab ; 23(1): 32-40, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22047952

RESUMO

Sex hormone-binding globulin (SHBG) has emerged as one of the multiple genetic and environmental factors that potentially contribute to the pathophysiology of type 2 diabetes mellitus (T2DM). In addition to epidemiologic studies demonstrating a consistent relationship between decreased levels of serum SHBG and incident T2DM, recent genetic studies also reveal that transmission of specific polymorphisms in the SHBG gene influence the risk of T2DM. At the molecular level, the multiple interactions between SHBG and its receptors in various target tissues suggest physiologic roles for SHBG that are more complex than the simple transport of sex hormones in serum. Taken together, these data provide support for an expanded role of SHBG in the pathophysiology of insulin resistance and T2DM.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Globulina de Ligação a Hormônio Sexual/fisiologia , Animais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/genética , Regulação da Expressão Gênica , Humanos , Resistência à Insulina , Polimorfismo Genético , Receptores de Superfície Celular/metabolismo , Globulina de Ligação a Hormônio Sexual/análise , Globulina de Ligação a Hormônio Sexual/química , Globulina de Ligação a Hormônio Sexual/genética
12.
Hybridoma ; 9(5): 481-91, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2258185

RESUMO

The immunization procedure and immunogen characteristics required to optimize the production of anti-steroid monoclonal antibodies have been studied. Five different estradiol-bovine serum albumin conjugates were tested for immunizing mice, as were two different immunization protocols (high and low dose) and the effect of varying the myeloma/spleen cell ratio for cell fusion. Antibody-producing hybridomas, obtained using the spleens of 9 high anti-steroid titre mice, were detected by RIA and EIA. The latter method was less specific than the former for higher affinity anti-estrogen antibodies. All the immunogens elicited anti-estrogen antibodies and the efficiency appeared related to the steroid density on the immunogen rather than the chemical nature of the derivative or the immunization and fusion protocols. Thirty-six anti-estrogen producing hybridomas were detected. Comparison showed that all the immunogens elicited antibodies in a wide range of affinities and specificities. None of the antibodies recognized corticosteroids or progesterone. Cross reactions with testosterone and other estrogens were not clearly related to the nature of the immunogen except that estradiol coupled to the BSA via its carbon 17 yielded antibodies specific for steroids with a non-derivatized phenolic A-ring.


Assuntos
Anticorpos Monoclonais , Estradiol/imunologia , Animais , Afinidade de Anticorpos , Especificidade de Anticorpos , Antígenos , Estrogênios/imunologia , Hibridomas/imunologia , Camundongos , Soroalbumina Bovina/imunologia
13.
J Steroid Biochem ; 28(5): 459-63, 1987 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3316848

RESUMO

Hybridomas secreting monoclonal antibodies to aldosterone were obtained by fusion of myeloma cells and spleen cells from Balb/c mice immunized with aldosterone-3-carboxylmethyloxime-bovine serum albumin. A monoclonal antibody was purified from ascites fluid and characterized. An affinity constant of 1.61 x 10(9) M-1 has been measured and no cross-reactivity with tetrahydroaldosterone (THA), cortisol, cortisone, corticosterone, deoxycorticosterone (DOC), dehydroepiandrosterone (DHA), progesterone and estrone, could be detected. A peroxidase conjugated-antibody (1.5 mole of enzyme per mole of antibody) was obtained and used for microwell enzyme immunoassay and Immun-Blot assay. The high affinity and specificity of this antibody should make the direct determination of aldosterone in biological fluids possible at concentrations as low as 5 x 10(-10) M.


Assuntos
Aldosterona/análise , Anticorpos Monoclonais , Aldosterona/imunologia , Animais , Anticorpos Monoclonais/isolamento & purificação , Feminino , Hibridomas/imunologia , Técnicas Imunoenzimáticas , Indicadores e Reagentes , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Radioimunoensaio/métodos
14.
Parasitol Today ; 3(8): 247-9, 1987 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15462967

RESUMO

Hookworms rank with Ascaris as the most prevalent soil-transmitted helminths of man. Up to 1000 million people may be infected. Not all suffer the life-threatening anaemia that reflects heavy burdens of hookworms, but even mild iron-deficiency anaemia due to hookworms can lead to intellectual and growth retardation - especially among infected children. Health education, mass chemotherapy and the sanitary disposal of faeces have been the traditional mainstays of hookworm control, but more recently chemotherapy targeted only to heavily infected individuals who appear predisposed to hookworm anaemia has emerged as a realistic alternative. Ultimately, however, knowledge of the molecular immunology of hookworm infection may provide the basis for rational vaccine development. Although the evidence for acquired immunity to hookworms in man is not strong, work is now underway to identify and to characterize antigens from third and fourth larval stages and adults of Necator americanus and species of Ancylostoma (Table 1). As this article shows, the work provides real promise for improved immunodiagnosis and possible vaccination.

15.
J Exp Med ; 161(5): 984-95, 1985 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-3872925

RESUMO

Previous studies have indicated that endotoxin and other bacterial and protozoal products can stimulate macrophages to produce a factor that can suppress the activity of the enzyme lipoprotein lipase (LPL), in vivo and in vitro. In the present report we describe the purification of this factor, cachectin, to apparent homogeneity from the conditioned medium of endotoxin-stimulated RAW 264.7 cells. The isolated protein has an isoelectric point of 4.7 and a subunit molecular weight of 17,000. Although cachectin's isoelectric point and molecular weight are similar to those described for interleukin 1, pure cachectin has no leukocyte-activating factor (LAF) activity. Cachectin at a concentration of 10(-11) M has the ability to suppress the LPL activity of the 3T3-L1 adipocyte cell line by 80%. Binding studies using radio-labeled cachectin and 3T3-L1 adipocytes and C2 myotubules revealed approximately 10(4) high-affinity receptors per cell on both cell types (Ka, 3 X 10(9]. Cachectin receptors were also present on liver membranes but were absent on erythrocytes and lymphocytes. The isolation of cachectin and characterization of its receptor should facilitate further investigations into the role of cachectin and other macrophage mediators in the metabolic derangements that occur during infection and cachexia.


Assuntos
Lipase Lipoproteica/antagonistas & inibidores , Ativação de Macrófagos , Macrófagos/metabolismo , Proteínas/isolamento & purificação , Tecido Adiposo/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Cromatografia de Afinidade , Eletroforese em Gel de Poliacrilamida , Endotoxinas/farmacologia , Interleucina-1/análise , Focalização Isoelétrica , Camundongos , Peso Molecular , Músculos/metabolismo , Proteínas/análise , Proteínas/metabolismo , Fator de Necrose Tumoral alfa
16.
J Immunol ; 134(3): 1673-5, 1985 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3968430

RESUMO

RAW 264.7 cells upon stimulation with lipopolysaccharide secrete a protein mediator(s) that suppresses lipoprotein lipase activity in differentiated 3T3-L1 cells. The mediator(s), which is absent from unstimulated culture supernatants, is nondialyzable and thermolabile. Preliminary characterization suggests that this mediator(s) may be the same as that previously found in medium from lipopolysaccharide-treated thioglycollate-elicited mouse peritoneal macrophage cultures.


Assuntos
Lipopolissacarídeos/farmacologia , Lipase Lipoproteica/antagonistas & inibidores , Macrófagos/metabolismo , Tecido Adiposo/citologia , Animais , Líquido Ascítico/metabolismo , Linhagem Celular , Meios de Cultura , Fibroblastos/enzimologia , Humanos , Masculino , Camundongos
17.
Immunol Lett ; 11(3-4): 173-7, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-3910566

RESUMO

Endotoxin-induced cells of the reticuloendothelial system were shown to produce mediator(s) that evoke a state of cachexia in recipient animals. The factor(s) responsible were assayed in endotoxin-resistant (C3H/HeJ) mice, which were injected with dialyzed conditioned medium obtained from lipopolysaccharide-induced peritoneal macrophages. The mice exhibited weight loss and anorexia, and they died if sufficient quantities of medium were administered. The syndrome was reversible if injections were discontinued. Endotoxin alone did not produce this effect, and no gross pathologic lesions were discernable in the treated animals. In this model system, cachexia appears to result from the action of soluble macromolecules produced by activated macrophages in vitro. Cachectin (murine tumor necrosis factor) is thought to play a central role in this phenomenon.


Assuntos
Caquexia/etiologia , Macrófagos/fisiologia , Proteínas/fisiologia , Animais , Líquido Ascítico/patologia , Endotoxinas/farmacologia , Hiperlipidemias/etiologia , Ativação de Macrófagos , Masculino , Camundongos , Camundongos Endogâmicos C3H , Fator de Necrose Tumoral alfa
18.
Parasite Immunol ; 6(3): 203-9, 1984 May.
Artigo em Inglês | MEDLINE | ID: mdl-6377200

RESUMO

Lysates of the haematoprotozoa Trypanosoma brucei or Plasmodium berghei stimulated murine peritoneal exudate cells to release a mediator, which suppressed lipoprotein lipase activity in differentiating 3T3-L1 preadipocytes. The parasite-induced mediator suppressed the activity of cell surface lipoprotein lipase up to 39% in a dose dependent manner. By impairing the activity of cell surface lipoprotein lipase, this mediator acts to inhibit the uptake of fatty acid, and ultimately the accumulation of lipid by the adipocyte. In vivo this defect in triglyceride removal may explain the hypertriglyceridemia commonly observed in haematoprotozoan infections. We suggest that the lipoprotein lipase suppression mediator is produced as a consequence of the immune response to these parasitic protozoa.


Assuntos
Líquido Ascítico/parasitologia , Lipase Lipoproteica/antagonistas & inibidores , Plasmodium berghei/fisiologia , Trypanosoma brucei brucei/fisiologia , Tecido Adiposo/citologia , Tecido Adiposo/enzimologia , Animais , Líquido Ascítico/enzimologia , Linhagem Celular , Meios de Cultura , Camundongos
19.
Mol Biochem Parasitol ; 9(1): 29-35, 1983 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6669159

RESUMO

Despite centuries of therapeutic use, the mechanism of action of arsenicals against various diseases remains unknown. Because of the known inhibition of sulfhydryl-containing enzymes by arsenicals, we investigated the possibility that the anti-filarial effects of arsenical drugs might be exerted specifically through impairment of parasite thiol metabolism. We find: (1) arsenicals readily inhibit glutathione reductase of Litomosoides carinii but have little effect upon mammalian enzyme. (2) Administration of Melarsen B to filaria-infected gerbils causes decreases in filarial - but not host - glutathione reductase and reduced glutathione. (3) Such in vivo treatment does not, however, acutely affect parasite energy (ATP) metabolism. These results support the proposition that arsenicals may act through preferential interference with parasite thiol metabolism. The much greater susceptibility of parasite glutathione reductase to inhibition by arsenicals suggests that this enzyme may be a useful point of attack for new drugs.


Assuntos
Arsenicais/farmacologia , Filarioidea/efeitos dos fármacos , Glutationa/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Eritrócitos/parasitologia , Filarioidea/metabolismo , Gerbillinae , Glutationa Redutase/metabolismo , Fatores de Tempo
20.
Anal Biochem ; 133(1): 94-9, 1983 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6638490

RESUMO

A new method for the isolation of glutathione reductase which successively utilizes chromatography on 2'-5'-ADP-Sepharose 4B and DEAE-Sepharose CL 6B, is described. With these two steps, it was possible to purify to homogeneity the glutathione reductase from gerbil liver. Some molecular properties of the purified enzyme are reported.


Assuntos
Glutationa Redutase/isolamento & purificação , Fígado/enzimologia , Animais , Cromatografia de Afinidade/métodos , Cromatografia por Troca Iônica/métodos , Etanolaminas , Gerbillinae , Focalização Isoelétrica , Sefarose/análogos & derivados
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