Systematic single cell analysis of migration and morphological changes of human neutrophils over stimulus concentration gradients.

To compare the responses of individual neutrophils to chemoattractants, migration pathway data were obtained using TAXIScan, an optically accessible/horizontal apparatus in which a concentration gradient is established reproducibly for a given stimulus. The observed linear-mode trajectory pattern of neutrophils toward N-formyl-methionyl-leucyl-phenylalanine (fMLP) or Interleukin (IL)-8/CXCL8 was distinguished from random migration patterns toward leukotriene (LT) B4 or platelet activating factor (PAF). The median values of velocity and directionality calculated for individual cells toward fMLP and IL-8 were both relatively similar and high, whereas the values toward LTB4 and PAF were widely dispersed over a lower range of directionality and from low to high ranges of velocity.

Adipose tissue production of hepatocyte growth factor contributes to elevated serum HGF in obesity.

Serum HGF is elevated in obese individuals. This study examined the contribution of excess adipose tissue to increased circulating HGF levels in obesity. Serum HGF was measured by ELISA before and after weight loss due to bariatric surgery or a 24-h fast.

Regulation of adiponectin expression in human adipocytes: effects of adiposity, glucocorticoids, and tumor necrosis factor alpha.

Objective: Adiponectin mRNA expression in isolated subcutaneous and omental adipocytes was examined across a wide range of adiposity to determine whether adiponectin synthesis is impaired in these adipose tissue depots in obese humans. Tumor necrosis factor (TNF)alpha and dexamethasone were tested for inhibitory effects on adiponectin release from human adipocytes in vitro.

Research Methods And Procedures: Adipocytes were isolated by collagenase digestion of abdominal adipose tissue obtained from subjects undergoing surgical procedures or outpatient needle biopsy.

Changes in thrombolytic and inflammatory markers after initiation of indinavir- or amprenavir-based antiretroviral therapy.

HIV-infected subjects who have lipodystrophy and insulin resistance on prolonged antiretroviral therapy have elevated levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) antigens, markers of impaired thrombolysis that are associated with hyperinsulinemia and increased cardiovascular risk. We studied HIV-infected, protease inhibitor (PI)-naive adults treated with indinavir (n = 11) or amprenavir (n = 14) plus two nucleoside reverse transcriptase inhibitors enrolled in two independent prospective trials. Antiretroviral and immune responses were similar in both studies.

High serum resistin is associated with an increase in adiposity but not a worsening of insulin resistance in Pima Indians.

Resistin is an adipokine with putative prodiabetogenic properties. Like other hormones secreted by adipose tissue, resistin is being investigated as a possible etiologic link between excessive adiposity and insulin resistance. Although there is growing evidence that circulating levels of this adipokine are proportional to the degree of adiposity, an effect on insulin resistance in humans remains unproven.

Rapid inhibition of leptin signaling by glucocorticoids in vitro and in vivo.

Elevated secretion of glucocorticoids (GCs) or hypersensitivity to GCs has a permissive effect on the development of obesity and leads to abnormalities of body fat distribution. Recent studies demonstrated GCs act as antagonists of leptin in rodents. However, little is known about the interaction between GCs and leptin signaling.

Lower serum adiponectin levels in African-American boys.

Objective: To examine adiponectin, an adipocyte-secreted hormone with anti-inflammatory and insulin-sensitizing effects, in relation to race or gender in younger subjects.

Research Methods And Procedures: The relationship of adiponectin, quantitated by radioimmunoassay, to anthropometric and metabolic factors (fasting insulin, glucose, and leptin) and reproductive hormones was examined in 46 healthy African Americans (25 girls/21 boys) and 40 whites (20 girls/20 boys) ranging in age from 12 to 21 years.

Results: There was no statistical difference in BMI or in BMI percentile among the four groups.

Serum resistin (FIZZ3) protein is increased in obese humans.

The role of resistin in obesity and insulin resistance in humans is controversial. Therefore, resistin protein was quantitated by ELISA in serum of 27 lean [13 women/14 men, body mass index (BMI) 21.7 +/- 0.