Biomedical subjects

D Reda

Publications and source records attributed to D Reda.

At least 19 recordsLinked to original sources

PubMed2001

Effect of endotoxin on ventilation and breath variability: role of cyclooxygenase pathway.

To evaluate the effects of endotoxemia on respiratory controller function, 12 subjects were randomized to receive endotoxin or saline; six also received ibuprofen, a cyclooxygenase inhibitor, and six received placebo. Administration of endotoxin produced fever, increased respiratory frequency, decreased inspiratory time, and widened alveolar-arterial oxygen tension gradient (all p < or = 0.001); these responses were blocked by ibuprofen. Independent of ibuprofen, endotoxin produced dyspnea, and it increased fractional inspiratory time, minute ventilation, and mean inspiratory flow (all p < or = 0.025). Endotoxin altered the autocorrelative behavior of respiratory frequency by increasing its autocorrelation coefficient at a lag of one breath, the number of breath lags with significant serial correlations, and its correlated fraction (all p < 0.05); these responses were blocked by ibuprofen. Changes in correlated behavior of respiratory frequency were related to changes in arterial carbon dioxide tension (r = 0.86; p < 0.03). Endotoxin decreased the oscillatory fraction of inspiratory time in both the placebo (p < 0.05) and ibuprofen groups (p = 0.06). In conclusion, endotoxin produced increases in respiratory motor output and dyspnea independent of fever and symptoms, and it curtailed the freedom to vary respiratory timing-a response that appears to be mediated by the cyclooxygenase pathway.

Adult↗

PubMed2001

Local inflammatory responses following bronchial endotoxin instillation in humans.

To study local lung inflammation, 34 subjects had endotoxin (1-4 ng/kg) instilled into a lung segment and saline instilled into a contralateral segment followed by bronchoalveolar lavage (BAL) at 2 h, 6 h, 24 h, or 48 h. Endotoxin instillation resulted in a focal inflammatory response with a distinct time course. An early phase (2 h to 6 h) revealed an increase in neutrophils (p = 0.0001) with elevated cytokines (tumor necrosis factor [TNF]-alpha, TNF receptors [TNFR], interleukin [IL]-1beta, IL-1 receptor antagonist, IL-6, granulocyte-colony-stimulating factor [G-CSF], all p < or = 0.002, but no change in IL-10) and chemokines (IL-8, epithelial neutrophil activating protein-78, monocyte chemotactic protein-1, macrophage inflammatory protein [MIP]-1alpha, MIP-1beta, all p < or = 0.001, but no change in growth-regulated peptide-alpha). A later phase (24 h to 48 h) showed increased neutrophils, macrophages, monocytes, and lymphocytes (all p < or = 0.02), and a return to basal levels of most mediators. Elevated levels of inflammatory markers (TNFR(1), TNFR(2), L-selectin, lactoferrin, and myeloperoxidase) persisted in the BAL at 48 h (p < or = 0.001). Increased permeability to albumin occurred throughout both phases (p = 0.001). Blood C-reactive protein, serum amyloid A, IL-6, IL-1ra, G-CSF, but not TNF-alpha increased by 8 h (all p < or = 0.008). The local pulmonary inflammatory response to endotoxin has a unique qualitative and temporal profile of inflammation compared with previous reports of intravenous endotoxin challenges. This model provides a means to investigate factors that initiate, amplify, and resolve local lung inflammation.

Adult↗

PubMed2000

The HAND1 basic helix-loop-helix transcription factor regulates trophoblast differentiation via multiple mechanisms.

The basic helix-loop-helix (bHLH) transcription factor genes Hand1 and Mash2 are essential for placental development in mice. Hand1 promotes differentiation of trophoblast giant cells, whereas Mash2 is required for the maintenance of giant cell precursors, and its overexpression prevents giant cell differentiation. We found that Hand1 expression and Mash2 expression overlap in the ectoplacental cone and spongiotrophoblast, layers of the placenta that contain the giant cell precursors, indicating that the antagonistic activities of Hand1 and Mash2 must be coordinated. MASH2 and HAND1 both heterodimerize with E factors, bHLH proteins that are the DNA-binding partners for most class B bHLH factors and which are also expressed in the ectoplacental cone and spongiotrophoblast. In vitro, HAND1 could antagonize MASH2 function by competing for E-factor binding. However, the Hand1 mutant phenotype cannot be solely explained by ectopic activity of MASH2, as the Hand1 mutant phenotype was not altered by further mutation of Mash2. Interestingly, expression of E-factor genes (ITF2 and ALF1) was down-regulated in the trophoblast lineage prior to giant cell differentiation. Therefore, suppression of MASH2 function, required to allow giant cell differentiation, may occur in vivo by loss of its E-factor partner due to loss of its expression and/or competition from HAND1. In giant cells, where E-factor expression was not detected, HAND1 presumably associates with a different bHLH partner. This may account for the distinct functions of HAND1 in giant cells and their precursors. We conclude that development of the trophoblast lineage is regulated by the interacting functions of HAND1, MASH2, and their cofactors.

Animals↗

PubMed2000

Redasoft Plasmid 1.1: software for easy, efficient cloning and map drawing.

A computer program is described which creates circular and linear genetic maps with or without sequences, performs restriction analysis, and simulates basic molecular cloning operations. Redasoft Plasmid 1.1 is a user-friendly program for Windows 95/98/NT/2000, designed to generate high quality genetic maps for presentation and publication and to aid the molecular biologist in selecting restriction endonucleases for common molecular cloning experiments. The program incorporates an integrated web browser and can automatically generate complete, labeled maps from sequences on the Internet.

Chromosome Mapping↗

PubMed1999

Detection of macrophage inflammatory protein (MIP)-1alpha and MIP-1beta during experimental endotoxemia and human sepsis.

Macrophage inflammatory protein (MIP)-1alpha and MIP-1beta regulate leukocyte activation and trafficking. To assess the role of MIP-1alpha and MIP-1beta in human inflammation, healthy subjects were studied during experimental endotoxemia with prior administration of ibuprofen, a cyclooxygenase inhibitor, or dimeric p75 tumor necrosis factor (TNF)-alpha receptor, a TNF antagonist; septic patients were also studied. Following endotoxin, blood levels of both MIP-1 molecules rose acutely and fell to baseline by 6 h (P=. 001). While MIP-1 mediates fever in animals independent of cyclooxygenase blockade, in subjects given endotoxin and ibuprofen, MIP-1 levels increased and fever was suppressed. MIP-1 levels were not diminished by inhibiting circulating TNF-alpha in humans. In septic patients, elevated levels of MIP-1alpha and MIP-1beta were detected within 24 h of sepsis and fell in parallel with TNF-alpha and interleukin-6 (P<.01). MIP-1alpha and MIP-1beta increase during acute inflammation but are not associated with fever in endotoxemic humans during cyclooxygenase blockade.

Adolescent↗

PubMed1999

Measuring costs in multisite randomized controlled trials: lessons from the VA Cooperative Studies Program.

OBJECTIVES: The interest in the economic impact of new health care interventions has increased dramatically over recent years; however, the results can be highly variable depending upon the economic assumptions made and the approaches taken in collecting the data and in conducting the analyses. This paper describes experiences from the VA Cooperative Studies Program in measuring health care utilization and costs for studies that evaluate clinical interventions. METHODS: Experiences from two multisite randomized clinical trials (RCTs) are highlighted to illustrate strategies used to measure costs by directly measuring health care utilization and economic data within the context of the trials. CONCLUSIONS: Despite the substantial resources required to gather evidence about the cost of care for health care innovations, future VA multisite studies should include accepted health economic approaches to make important contributions to health planning and health policy within and outside the VA health care system.

Costs and Cost Analysis↗

PubMed1999

Sulfasalazine treatment for rheumatoid arthritis: a metaanalysis of 15 randomized trials.

OBJECTIVE: To assess the efficacy and safety of sulfasalazine (SSZ) compared to placebo and other disease modifying drugs. METHODS: A metaanalysis was performed on 15 randomized clinical trials of rheumatoid arthritis (RA) that included SSZ (2 g/day average dose, 36 weeks average followup) as a treatment. Eight trials included a placebo group (PL), 2 hydroxychloroquine (HCQ) (350 mg/day average dose), 3 D-penicillamine (D-Pen) (667 mg/day average dose), and 4 gold sodium thiomalate or aurothioglucose (GST) (25 mg, 1 g/wk). RESULTS: Compared to PL, SSZ was superior for improvement in erythrocyte sedimentation rate (ESR) (SSZ 37%, PL 14%; p < 0.0001), morning stiffness duration (SSZ 61%, PL 33%; p = 0.008), pain visual analog scale (SSZ 42%, PL 15%; p < 0.0001), articular index (SSZ 46%, PL 20%; p < 0.0001), number of swollen joints (SSZ 51%, PL 26%; p < 0.0001), number of painful joints (SSZ 59%, PL 33%; p = 0.004), and patient global assessment (SSZ 26%, PL 14%; p = 0.02). Withdrawals from study because of adverse drug reactions were increased (SSZ 24%, PL 7%; p < 0.0001), but lack of efficacy dropouts were decreased (SSZ 8%, PL 21%; p < 0.0001). Compared to HCQ, SSZ tended to have fewer lack of efficacy dropouts (SSZ 5%, HCQ 15%; p = 0.055) and improved ESR (SSZ 43%, HCQ 26%; p = 0.10) and morning stiffness duration (SSZ 59%, HCQ 40%; p = 0.09). Compared to GST, adverse drug reaction dropouts were significantly fewer (SSZ 12%, GST 29%; p < 0.0001), while withdrawals due to lack of efficacy were greater (SSZ 13%, GST 4%; p = 0.006). More patients tended to complete treatment taking SSZ (SSZ 69%, GST 61%; p = 0.09). CONCLUSION: Over all, the metaanalysis provides data that support the effectiveness of SSZ as a treatment for RA.

Antirheumatic Agents↗

PubMed1998

Recombinant tumor necrosis factor receptor p75 fusion protein (TNFR:Fc) alters endotoxin-induced activation of the kinin, fibrinolytic, and coagulation systems in normal humans.

The effects of inhibition of tumor necrosis factor (TNF) on cell and protease activation were evaluated in 18 normal volunteers given endotoxin (4 ng/kg, i.v.) after an infusion of low (10 mg/m2 i.v., n = 6) or high dose (60 mg/m2 i.v., n = 6) recombinant human dimeric TNF receptor protein (TNFR:Fc) or its vehicle (placebo n = 6). Activation of the coagulation system occurred by 2 h in the TNFR:Fc vehicle-placebo group manifested by decreased prekallikrein functional levels and increased levels of prothrombin F1+2 fragments (p < 0.0001). High or low dose TNFR:Fc delayed the fall in prekallikrein functional levels by 1 h and 4 h, respectively (p < 0.0002), but did not inhibit the increase in circulating levels of prothrombin F1+2 fragments. In contrast, endothelium activation, characterized by increased levels of tissue plasminogen activator, plasminogen activator inhibitor-1, and von Willebrand Factor antigen was blunted by both low and high dose TNFR:Fc (p < 0.001). While the endotoxin-associated decrease in platelet number was not altered, platelet-derived beta-thromboglobulin peak levels were blunted and delayed by TNFR:Fc (p < 0.02). Increased levels of neutrophil elastase were attenuated by low and high dose TNFR:Fc (p < 0.001). These results suggest that although TNF is functionally linked to the activation of endothelium, neutrophils, coagulation, and fibrinolysis, alternative pathways are present in vivo that result in activation of the kallikrein-kinin system after endotoxin-induced TNF release. These alternative pathways may limit some of the anti-inflammatory effects of TNFR:Fc.

Adult↗

PubMed1996

Comparison of plasma lipid and lipoprotein profiles in hypertensive black versus white men. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents.

An abnormal plasma lipid and lipoprotein profile is an independent and strong predictor of mortality and morbidity from coronary artery disease (CAD). We report on plasma lipid and lipoprotein profiles with respect to race, age, obesity, blood pressure (BP), smoking, and drinking history in 1,292 male veterans with a diastolic BP of 95 to 109 mm Hg while off antihypertensive medications. Blacks had 24% (p <0.001) lower triglycerides than whites. In contrast, the following parameters were higher in blacks than in whites by the indicated percentages: high-density lipoprotein (HDL) cholesterol, 16% (p <0.001); HDL2 cholesterol, 36% (p <0.001); apolipoprotein (Apo) A1, 8% (p <0.001); HDL/low-density lipoprotein (LDL), 18% (p = 0.018); HDL2/LDL, 36% (p = 0.031); HDL2/HDL3, 21% (p <0.001); and Apo A1/Apo B, 15% (p <0.001). Triglycerides were unchanged up to age 60, but were lower by 24% (p <0.001) in those aged > or = 70. Apo A1 levels were higher (p <0.001), whereas LDL cholesterol was lower (p <0.008) in moderate alcohol consumers versus abstainers. Triglycerides were higher (p <0.001), whereas HDL, HDL2 cholesterol, and Apo A1 were lower (p <0.001) with increasing obesity. Moderate alcohol consumption had a strong favorable effect on HDL, HDL2, and HDL3 cholesterol among subjects of normal weight, but this effect was diminished in obese subjects. Total and LDL cholesterol were higher by 6.4% (p = 0.001) and 9.4% (p <0.003), respectively, whereas HDL cholesterol remained unchanged in those with diastolic BP of 105 to 109 mm Hg versus those with diastolic BP of 95 to 99 mm Hg. We conclude that hypertensive black men have lipid and lipoprotein profiles indicative of less CAD risk than white men. Chronic moderate alcohol consumption correlates with a favorable plasma lipid and lipoprotein profile in normal, but not obese, men. Obesity is associated with an adverse plasma lipid and lipoprotein profile. Thus, race, alcohol intake, and obesity may be important modifiers of CAD in untreated hypertensive men.

Apolipoprotein A-I↗

PubMed1996

Effects of recombinant soluble type I interleukin-1 receptor on human inflammatory responses to endotoxin.

Effects of soluble recombinant human type I interleukin-1 receptor (sIL-1RI) were evaluated in 18 volunteers given intravenous endotoxin and randomized to placebo (n = 6), low-dose (n = 6), or high-dose (n = 6) sIL-1RI. Soluble IL-1RI decreased IL-1 beta (P = .001), but decreased IL-1ra (P = .0001), and resulted in 10-fold and 43-fold dose-related increases in sIL-1RI-IL-1ra complexes compared with placebo (P < or = .001). High-dose sIL-1RI was associated with increased levels of immunoactive tumor necrosis factor-alpha (P = .02), IL-8 (P = .0001), and cell-associated IL-1 beta (P = .047). C-reactive protein levels were higher after sIL-1RI than placebo (P = .035). Soluble IL-1RI decreased the severity of chills (P = .03), but did not alter other symptoms, changes in temperature, systemic hemodynamic responses, or changes in leukocyte and platelet number. Thus, sIL-1RI had no discernable antiinflammatory effect following endotoxin administration due in part to low levels of circulating IL-1 beta and neutralization of IL-1ra inhibitory function. This latter interaction represents an indirect mechanism of agonist activity elicited by sIL-1RI and may contribute to increases in inflammatory mediators, limiting therapy with sIL-1RI during endotoxemia.

Acute-Phase Reaction↗

PubMed1995

Effects of regular exercise on blood pressure and left ventricular hypertrophy in African-American men with severe hypertension.

BACKGROUND: The prevalence of hypertension and its cardiovascular complications is higher in African Americans than in whites. Interventions to control blood pressure in this population are particularly important. Regular exercise lowers blood pressure in patients with mild-to-moderate hypertension, but its effects in patients with severe hypertension have not been studied. We examined the effects of moderately intense exercise on blood pressure and left ventricular hypertrophy in African-American men with severe hypertension. METHODS: We randomly assigned 46 men 35 to 76 years of age to exercise plus antihypertensive medication (23 men) or antihypertensive medication alone (23 men). A total of 18 men in the exercise group completed 16 weeks of exercise, and 14 completed 32 weeks of exercise, which was performed three times per week at 60 to 80 percent of the maximal heart rate. RESULTS: After 16 weeks, mean (+/- SD) diastolic blood pressure had decreased from 88 +/- 7 to 83 +/- 8 mm Hg in the patients who exercised, whereas it had increased slightly, from 88 +/- 6 to 90 +/- 7 mm Hg, in those who did not exercise (P = 0.002). Diastolic blood pressure remained significantly lower after 32 weeks of exercise, even with substantial reductions in the dose of antihypertensive medication. In addition, the thickness of the interventricular septum (P = 0.03), the left ventricular mass (P = 0.02), and the mass index (P = 0.04) had decreased significantly after 16 weeks in the patients who exercised, whereas there was no significant change in the nonexercisers. CONCLUSIONS: Regular exercise reduced blood pressure and left ventricular hypertrophy in African-American men with severe hypertension.

Adult↗

PubMed1995

Effects of recombinant dimeric TNF receptor on human inflammatory responses following intravenous endotoxin administration.

Effects of dimeric TNF receptor (p80) Fc (TNFR:Fc) on acute phase responses were evaluated in 18 volunteers given endotoxin (4 ng/kg i.v.). Subjects were randomized to receive either placebo (n = 6), low dose TNFR:Fc (10 mg/m2 i.v., n = 6), or high dose TNFR:Fc (60 mg/m2 i.v., n = 6). TNFR:Fc blocked plasma TNF bioactivity (p = 0.001) and increased, in a dose-ordered fashion, TNF immunoactivity (p < 0.001). TNFR:Fc decreased secondary cytokine levels including IL-1 beta (p = 0.007), IL-8 (p < 0.001), IL-1 receptor antagonist (p < 0.001), granulocyte-CSF (p = 0.03), and growth regulated peptide-alpha (p = 0.001) but not macrophage inflammatory protein-1 alpha or IL-10. Low dose, but not high dose, TNFR:Fc blunted or delayed the release of epinephrine and cortisol (p < or = 0.026). Despite the absence of plasma TNF bioactivity, high dose TNFR:Fc was less immunosuppressive than low dose TNFR:Fc as measured by cytokine and stress hormone responses. Endotoxin-related symptoms were not altered by TNFR:Fc and the febrile response was delayed but not diminished (p = 0.004). Increases in cardiac index (72 +/- 19%) and heart rate (60 +/- 10%) and decreases in systemic vascular resistance index (47 +/- 7%) were unaltered by TNFR:Fc. These data suggest that the inflammatory response to endotoxin can escape from high levels of circulating TNF-blocking activity and redundant pathways, independent of circulating TNF, can sustain inflammation and clinical responses caused by acute endotoxemia.

Animals↗

PubMed1995

Pneumocystis carinii pneumonia: a major complication of immunosuppressive therapy in patients with Wegener's granulomatosis.

The risk factors and clinical and laboratory parameters in Pneumocystis carinii pneumonia in patients with Wegener's granulomatosis have not been well characterized. We undertook a retrospective chart review of all patients with a diagnosis of Wegener's granulomatosis and P. carinii pneumonia who were followed at the National Institute of Allergy and Infectious Diseases of the National Institutes of Health. The chart review focused on clinical, laboratory, and roentgenologic evidence of P. carinii pneumonia. Eleven cases of P. carinii pneumonia were diagnosed in some 180 patients with Wegener's granulomatosis, for an overall incidence of approximately 6%. All patients developed P. carinii pneumonia either during the initial course of treatment or during therapy for recurrent Wegener's granulomatosis. All patients were receiving daily glucocorticoids and a second immunosuppressive therapy. Lymphocytopenia was noted in all patients, with a mean +/- SEM total lymphocyte count of 303 +/- 69 cells/microL. All patients tested (10 of 11) were seronegative for human immunodeficiency virus (HIV) infection. Eight presented with worsening chest roentgenograms compared with baseline, whereas three presented with normal chest roentgenograms. We conclude that P. carinii is a common opportunistic pathogen in patients with Wegener's granulomatosis receiving immunosuppressive therapy. Therapeutic immunosuppression (daily glucocorticoids and immunosuppressive agents) and the resultant lymphocytopenia, as well as the lymphocyte and monocyte functional abnormalities caused by glucocorticoids, may be the most likely factors predisposing to P. carinii pneumonia in patients with Wegener's granulomatosis. Based on our data, all patients with Wegener's granulomatosis should be given chemoprophylaxis against P. carinii while they are receiving daily glucocorticoids.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

PubMed1994

The effect of in vitro ethanol exposure on luteinizing hormone and follicle stimulating hormone mRNA levels, content, and secretion.

It has been previously shown that acute ethanol (EtOH) exposure in vivo resulted in suppression of serum LH and pituitary beta-LH subunit mRNA levels in castrated male rats. While serum FSH levels also were noted to fall after in vivo, the mRNA for beta-FSH was not altered. The aim of the present studies was to determine whether these effects could be accounted for by a direct EtOH effect at pituitary level. To this end we examined the direct effect of EtOH on LH and FSH synthesis and secretion utilizing dispersed anterior pituitary cells from gonadectomized adult male rats. After a 72 hour post dissociation healing period, the cells were exposed to media containing 0 or 200 mg% EtOH for one hour. The media was removed and the cells incubated with EtOH-free media for an additional 1, 3 or 6 hrs. In the EtOH exposed cells, secretion of both LH and FSH increased to > 300% (p < 0.001) of control. At 6 hrs after withdrawal of EtOH a significant reduction in both LH and FSH secretion was seen. Intracellular content of LH and FSH was unchanged before and after withdrawal of EtOH. Steady state levels of beta LH and beta FSH mRNA were unchanged at all time points. In a separate series of experiments, pituitary cells from gonadectomized adult male rats were continuously exposed to different concentrations of EtOH ranging from 0-400 mg% for 3 hrs. LH secretion was stimulated by 400 mgm% EtOH only, while the intracellular content of LH was significantly reduced with the 400 mg% dose. The secretion of FSH was stimulated by 200 mg% and 400 mg% high dose EtOH after 3 hours, with concomitant reduction in FSH pituitary content at both these EtOh dose levels. The mRNA for both beta-LH and beta FSH was not different with any dose of EtOH compared to levels of control, non-EtOH exposed cells. We conclude that though there were similarities between in vivo and in vitro LH and FSH responses to EtOH, the differences reported here indicate that the in vivo responses are not totally explained by a direct EtOH effect at pituitary level. Rather, they must, in addition, reflect action at suprapituitary site(s), pituitary effects of EtOH metabolites or condensation products, and/or alterations in LH and FSH clearance.

Animals↗

PubMed1993

High-dose ifosfamide is associated with severe, reversible cardiac dysfunction.

OBJECTIVE: To determine the incidence and characterize the occurrence of cardiac toxicity with high-dose ifosfamide. DESIGN: Retrospective chart review. SETTING: Biomedical research referral center. PATIENTS: Fifty-two consecutive patients with advanced lymphoma or carcinoma enrolled in phase I trials of high-dose ifosfamide as part of combination chemotherapy with autologous bone marrow transplantation. INTERVENTIONS: Patients were given escalating doses (10 to 18 g/m2) of ifosfamide in combination with carboplatin and etoposide or with lomustine and vinblastine. MEASUREMENTS: The chart review focused on clinical, radiographic, or electrocardiographic evidence of cardiovascular dysfunction. Data from invasive hemodynamic monitoring, radionuclide cineangiography, and echocardiography were also reviewed. RESULTS: Nine of the patients treated with ifosfamide developed congestive heart failure (17%; 95% Cl, 8% to 30%). Eight of these patients, experiencing dyspnea, tachycardia, weight gain, and signs of pulmonary edema, required admission to an intensive care unit. Left ventricular contractility was found to be depressed when evaluated by radionuclide cineangiography, echocardiography, or both. Most patients responded to diuretic, vasodilator, and inotropic therapies. Two patients developed malignant ventricular arrhythmias. One patient died of intractable cardiogenic shock. Five patients died of multiorgan failure, despite showing improvement in left ventricular ejection fraction. Three patients survived and regained baseline left ventricular ejection fraction. CONCLUSIONS: High-dose ifosfamide is associated with severe but usually reversible myocardial depression and malignant arrhythmias.

Adolescent↗

PubMed1993

Antidiabetic agent pioglitazone enhances adipocyte differentiation of 3T3-F442A cells.

Adipocytes play an important role in normal physiology as a major site for systemic energy homeostasis. In disorders such as diabetes, adipocyte function is markedly altered. In this study, we investigated the effect of pioglitazone, a novel antidiabetic agent known to lower plasma glucose in animal models of diabetes mellitus, on cellular differentiation and expression of adipose-specific genes. Treatment of confluent 3T3-F442A preadipocyte cultures for 7 days with pioglitazone (Pio; 1 microM) and insulin (Ins; 0.17 microM) resulted in > 95% cell differentiation into lipid-accumulating adipocytes in comparison with 60-80% cell differentiation by treatment with either agent alone. Analysis of triglyceride accumulation showed increases of triglyceride content over time above untreated preadipocytes by treatment of the cells with Ins, Pio, and especially with Ins + Pio. Basal glucose transport, as measured by cellular uptake of 2-deoxy-D-[14C]glucose, was likewise enhanced in a time-dependent manner by treatment of preadipocytes with Ins, Pio, or Ins + Pio, such that a synergistic effect resulted from the combined treatment with both agents. It was further determined that RNA transcript abundance for genes encoding glucose transporters GLUT-1 and GLUT-4, as well as the adipose-specific genes encoding adipsin and aP2, were increased by the Ins, Pio, or Ins + Pio treatment. Taken together, these findings indicate that pioglitazone is a potent adipogenic agent. By promoting differentiation, this agent may move cells into a state active for glucose uptake, storage, and metabolism.

3T3 Cells↗

PubMed1993

The antidiabetic agent pioglitazone increases expression of glucose transporters in 3T3-F442A cells by increasing messenger ribonucleic acid transcript stability.

Whereas adipocytes normally play an important role as a major site for systemic energy homeostasis, adipocyte function is markedly altered in disorders such as diabetes. In this study, we investigated the effect of pioglitazone, a novel antidiabetic agent known to lower plasma glucose in animal models of diabetes mellitus, on expression of glucose transporters GLUT1 and GLUT4 in 3T3-F442A cells. Treatment of confluent 3T3-F442A preadipocyte cultures for 7 days with pioglitazone (1 microM) and insulin (1 microgram/ml) resulted in nearly 100% differentiation of cells to lipid-accumulating adipocytes, and such adipocytes showed a markedly increased capacity for glucose uptake. Analysis of messenger RNA transcripts encoding GLUT1 and GLUT4 glucose transporters over the 7-day differentiation period indicated time-dependent increases in abundance of each type that were maximal at more than 5-fold with the combined presence of insulin and pioglitazone. In accord, GLUT1 and GLUT4 protein levels also increased to maximal levels of 10-fold and 7-fold, respectively, over those in undifferentiated preadipocytes. Increased messenger RNA half-lives from 2.2 to greater than 24 h for GLUT1 and from 1.2 to greater than 24 h for GLUT4 correlated with this induced adipocyte differentiation. Taken together, these findings indicated that pioglitazone markedly enhanced expression of cellular glucose transporters, and the mechanism for this action was mainly stabilization of transporter messenger RNA transcripts. Such increased expression of glucose transporters in adipocytes establishes the cells in a state active for glucose uptake, thus ultimately facilitating storage and metabolism as well.

3T3 Cells↗

PubMed1991

Reading performance of geriatric patients post exudative maculopathy.

This study was performed to evaluate any differences in reading speed and duration of comfortable reading speed in geriatric patients with post disciform stage exudative age-related macular degeneration (ARMD) or ocular histoplasmosis. Reading speed and duration with CCTV, illuminated stand magnifier, and spectacle lenses were compared for 37 patients in the Low Vision Program at the Central Blind Rehabilitation Center. Results indicate significantly faster reading speed with CCTV and spectacle lenses as compared to illuminated stand magnifiers. The difference between reading speeds measured with spectacle reading glasses and CCTVs was borderline significant. Patients read significantly longer with CCTVs than with spectacle lenses or illuminated stand magnifiers. No significant difference was found comparing spectacle lenses or illuminated stand magnifiers with regard to reading duration.

Aged↗