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1.
Support Care Cancer ; 31(8): 450, 2023 Jul 08.
Article in English | MEDLINE | ID: mdl-37421495

ABSTRACT

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.


Subject(s)
Hyperglycemia , Insulins , Neoplasms , Oncologists , Male , Humans , Female , Middle Aged , Cross-Sectional Studies , Medical Oncology , Neoplasms/drug therapy , Surveys and Questionnaires , Hyperglycemia/chemically induced , Hyperglycemia/prevention & control , Attitude of Health Personnel , Practice Patterns, Physicians'
2.
J Clin Transl Endocrinol ; 26: 100279, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34926167

ABSTRACT

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.
Article in English | MEDLINE | ID: mdl-31679733

ABSTRACT

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.


Subject(s)
Cystic Fibrosis/complications , Growth Disorders/etiology , Growth Disorders/therapy , Cystic Fibrosis/physiopathology , Humans
4.
Am J Med Genet A ; 179(5): 782-791, 2019 05.
Article in English | MEDLINE | ID: mdl-30848064

ABSTRACT

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.


Subject(s)
Genetic Association Studies , Genetic Predisposition to Disease , Genotype , Histone Deacetylases/genetics , Penetrance , Phenotype , Repressor Proteins/genetics , Chromosome Deletion , Chromosomes, Human, Pair 2/genetics , Developmental Disabilities/genetics , Female , Gene Expression , Humans , Infant , Intellectual Disability/genetics , Male , Mutation
6.
Curr Opin Endocrinol Diabetes Obes ; 25(6): 361-365, 2018 12.
Article in English | MEDLINE | ID: mdl-30239380

ABSTRACT

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.


Subject(s)
Cystic Fibrosis/drug therapy , Vitamin D Deficiency/drug therapy , Vitamin D/therapeutic use , Bone and Bones/drug effects , Bone and Bones/physiology , Cystic Fibrosis/complications , Cystic Fibrosis/metabolism , Humans , Inflammation/drug therapy , Inflammation/etiology , Metabolome/drug effects , Microbiota/drug effects , Vitamin D/blood , Vitamin D Deficiency/etiology , Vitamin D Deficiency/metabolism
7.
Minerva Pediatr ; 69(5): 434-443, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28497664

ABSTRACT

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.


Subject(s)
Hypoglycemic Agents/therapeutic use , Insulin Resistance , Polycystic Ovary Syndrome/drug therapy , Adolescent , Adult , Age Factors , Contraceptives, Oral, Hormonal/administration & dosage , Female , Humans , Hypoglycemic Agents/adverse effects , Inositol/adverse effects , Inositol/therapeutic use , Metformin/adverse effects , Metformin/therapeutic use , Polycystic Ovary Syndrome/diagnosis , Polycystic Ovary Syndrome/physiopathology , Thiazolidinediones/adverse effects , Thiazolidinediones/therapeutic use , Weight Loss
8.
Thyroid ; 26(10): 1441-1449, 2016 10.
Article in English | MEDLINE | ID: mdl-27599541

ABSTRACT

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.


Subject(s)
Cardiovascular Diseases/epidemiology , Dyslipidemias/epidemiology , Glucose Metabolism Disorders/epidemiology , Insulin Resistance , Thyroid Gland/metabolism , Thyrotropin/blood , Adolescent , Biomarkers/blood , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/metabolism , Cardiovascular Diseases/physiopathology , Child , Cohort Studies , Cross-Sectional Studies , Dyslipidemias/diagnosis , Dyslipidemias/metabolism , Dyslipidemias/physiopathology , Early Diagnosis , Female , Glucose Metabolism Disorders/diagnosis , Glucose Metabolism Disorders/metabolism , Glucose Metabolism Disorders/physiopathology , Humans , Male , Metabolic Syndrome/diagnosis , Metabolic Syndrome/epidemiology , Metabolic Syndrome/metabolism , Metabolic Syndrome/physiopathology , Nutrition Surveys , Predictive Value of Tests , Risk Factors , Thyroid Gland/growth & development , Thyroid Gland/physiology , Thyroid Gland/physiopathology , Thyrotropin/metabolism , Thyroxine/blood , Thyroxine/metabolism , Triiodothyronine/blood , Triiodothyronine/metabolism , United States/epidemiology
9.
Trends Endocrinol Metab ; 26(5): 238-47, 2015 May.
Article in English | MEDLINE | ID: mdl-25869212

ABSTRACT

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.


Subject(s)
Thermogenesis/physiology , Adaptation, Physiological , Adipose Tissue, Brown/metabolism , Adipose Tissue, Brown/physiology , Adult , Animals , Capsaicin , Carbohydrate Metabolism , Cold Temperature , Energy Metabolism , Humans , Models, Animal , Obesity , Weight Loss
10.
Genet Test Mol Biomarkers ; 17(7): 567-71, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23651351

ABSTRACT

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.


Subject(s)
Diabetes, Gestational/genetics , Polymorphism, Genetic , Receptors, Prolactin/genetics , Adult , Case-Control Studies , Chile/ethnology , Female , Genetic Predisposition to Disease , Humans , Infant, Newborn , Male , Pregnancy
11.
Trends Endocrinol Metab ; 23(1): 32-40, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22047952

ABSTRACT

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.


Subject(s)
Diabetes Mellitus, Type 2/metabolism , Sex Hormone-Binding Globulin/physiology , Animals , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/genetics , Gene Expression Regulation , Humans , Insulin Resistance , Polymorphism, Genetic , Receptors, Cell Surface/metabolism , Sex Hormone-Binding Globulin/analysis , Sex Hormone-Binding Globulin/chemistry , Sex Hormone-Binding Globulin/genetics
12.
Hybridoma ; 9(5): 481-91, 1990 Oct.
Article in English | MEDLINE | ID: mdl-2258185

ABSTRACT

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.


Subject(s)
Antibodies, Monoclonal , Estradiol/immunology , Animals , Antibody Affinity , Antibody Specificity , Antigens , Estrogens/immunology , Hybridomas/immunology , Mice , Serum Albumin, Bovine/immunology
13.
J Steroid Biochem ; 28(5): 459-63, 1987 Nov.
Article in English | MEDLINE | ID: mdl-3316848

ABSTRACT

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.


Subject(s)
Aldosterone/analysis , Antibodies, Monoclonal , Aldosterone/immunology , Animals , Antibodies, Monoclonal/isolation & purification , Female , Hybridomas/immunology , Immunoenzyme Techniques , Indicators and Reagents , Male , Mice , Mice, Inbred BALB C , Radioimmunoassay/methods
14.
Parasitol Today ; 3(8): 247-9, 1987 Aug.
Article in English | MEDLINE | ID: mdl-15462967

ABSTRACT

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.
Article in English | MEDLINE | ID: mdl-3872925

ABSTRACT

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.


Subject(s)
Lipoprotein Lipase/antagonists & inhibitors , Macrophage Activation , Macrophages/metabolism , Proteins/isolation & purification , Adipose Tissue/metabolism , Animals , Binding Sites , Cell Line , Chromatography, Affinity , Electrophoresis, Polyacrylamide Gel , Endotoxins/pharmacology , Interleukin-1/analysis , Isoelectric Focusing , Mice , Molecular Weight , Muscles/metabolism , Proteins/analysis , Proteins/metabolism , Tumor Necrosis Factor-alpha
16.
J Immunol ; 134(3): 1673-5, 1985 Mar.
Article in English | MEDLINE | ID: mdl-3968430

ABSTRACT

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.


Subject(s)
Lipopolysaccharides/pharmacology , Lipoprotein Lipase/antagonists & inhibitors , Macrophages/metabolism , Adipose Tissue/cytology , Animals , Ascitic Fluid/metabolism , Cell Line , Culture Media , Fibroblasts/enzymology , Humans , Male , Mice
17.
Immunol Lett ; 11(3-4): 173-7, 1985.
Article in English | MEDLINE | ID: mdl-3910566

ABSTRACT

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.


Subject(s)
Cachexia/etiology , Macrophages/physiology , Proteins/physiology , Animals , Ascitic Fluid/pathology , Endotoxins/pharmacology , Hyperlipidemias/etiology , Macrophage Activation , Male , Mice , Mice, Inbred C3H , Tumor Necrosis Factor-alpha
18.
Parasite Immunol ; 6(3): 203-9, 1984 May.
Article in English | MEDLINE | ID: mdl-6377200

ABSTRACT

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.


Subject(s)
Ascitic Fluid/parasitology , Lipoprotein Lipase/antagonists & inhibitors , Plasmodium berghei/physiology , Trypanosoma brucei brucei/physiology , Adipose Tissue/cytology , Adipose Tissue/enzymology , Animals , Ascitic Fluid/enzymology , Cell Line , Culture Media , Mice
19.
Mol Biochem Parasitol ; 9(1): 29-35, 1983 Sep.
Article in English | MEDLINE | ID: mdl-6669159

ABSTRACT

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.


Subject(s)
Arsenicals/pharmacology , Filarioidea/drug effects , Glutathione/metabolism , Adenosine Triphosphate/metabolism , Animals , Erythrocytes/parasitology , Filarioidea/metabolism , Gerbillinae , Glutathione Reductase/metabolism , Time Factors
20.
Anal Biochem ; 133(1): 94-9, 1983 Aug.
Article in English | MEDLINE | ID: mdl-6638490

ABSTRACT

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.


Subject(s)
Glutathione Reductase/isolation & purification , Liver/enzymology , Animals , Chromatography, Affinity/methods , Chromatography, Ion Exchange/methods , Ethanolamines , Gerbillinae , Isoelectric Focusing , Sepharose/analogs & derivatives
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