human leptin quantikine quickit elisa  (R&D Systems)

Journal: American Journal of Human Biology

Article Title: Validation of an Enzyme‐Linked Immunosorbent Assay for Measuring Leptin, a Key Metabolic Hormone, in Dried Blood Spot Samples

doi: 10.1002/ajhb.70172

Figure Lengend Snippet: Passing–Bablok Regression for leptin measurement in matched DBS and serum samples ( n = 40). Results demonstrate strong agreement between leptin measurements in DBS and serum.

Article Snippet: The Human Leptin Quantikine QuicKit ELISA (R&D Systems, QK398) was validated using matched serum and DBS samples from 40 adults.

Techniques:

Journal: American Journal of Human Biology

Article Title: Validation of an Enzyme‐Linked Immunosorbent Assay for Measuring Leptin, a Key Metabolic Hormone, in Dried Blood Spot Samples

doi: 10.1002/ajhb.70172

Figure Lengend Snippet: Bland Altman plot of the difference in serum leptin and DBS leptin (serum‐equivalent) values vs. the average of these values. Results demonstrate general agreement between both measures, with no apparent bias.

Article Snippet: The Human Leptin Quantikine QuicKit ELISA (R&D Systems, QK398) was validated using matched serum and DBS samples from 40 adults.

Techniques:

Journal: Respiratory investigation

Article Title: Leptin-producing monocytes in the airway submucosa may contribute to asthma pathogenesis.

doi: 10.1016/j.resinv.2022.09.005

Figure Lengend Snippet: Fig. 1 e Immunohistochemical staining of the human airway tissues for the presence of leptin. Airway sections from three non-asthma and non-obese (upper panels), three asthma and non-obese individuals (middle panels), and three non-asthma and obese individuals (lower panels) were stained with an isotype-matched control antibody (A) or anti-leptin antibody (B). Magnified images of the yellow-framed area in leptin-stained sections are shown on the far right, and the cells staining positive for leptin are indicated with yellow arrows. The scale bars indicate 50 mm. (C) The percentages of leptin-positive cells among inflammatory cells counted in 2e10 high power fields (HPF) from two lung specimens ( £ 400) were quantified using ImageJ. The bars represent the standard error of the mean (SEM).

Article Snippet: Leptin protein levels were analyzed in CD14-positive cell lysates, adipocyte lysates, and human sera using Quantikine ELISA Human Leptin (R&D Systems), in accordancewith themanufacturer’s instructions.

Techniques: Immunohistochemical staining, Staining, Control

Journal: Respiratory investigation

Article Title: Leptin-producing monocytes in the airway submucosa may contribute to asthma pathogenesis.

doi: 10.1016/j.resinv.2022.09.005

Figure Lengend Snippet: Fig. 2 e Identification of leptin-positive cells. (A) Immunofluorescent staining for leptin (green) and CD163 (red), showing leptin expression in CD163-positive cells (yellow arrows). The nuclei were stained using DAPI (blue). The low magnification view (upper panel) and high magnification view of the area denoted by a square in the upper panel (lower panel) from the same specimen are shown. The scale bars indicate 50 mm. (B) Western blot analysis of leptin production by human monocytes. CD14-positive cells were isolated from the human peripheral blood from three healthy adults, and the cell lysates were analyzed by western blotting using anti-leptin and anti-GAPDH antibodies. Data for monocyte samples from three subjects (lanes 1e3) and 1 mg of recombinant human leptin (lane 4) are shown. DAPI, 4',6-diamidino-2-phenylindole; GAPDH, Glyceraldehyde-3-phosphate dehydrogenase.

Article Snippet: Leptin protein levels were analyzed in CD14-positive cell lysates, adipocyte lysates, and human sera using Quantikine ELISA Human Leptin (R&D Systems), in accordancewith themanufacturer’s instructions.

Techniques: Staining, Expressing, Western Blot, Isolation, Recombinant

Journal: Respiratory investigation

Article Title: Leptin-producing monocytes in the airway submucosa may contribute to asthma pathogenesis.

doi: 10.1016/j.resinv.2022.09.005

Figure Lengend Snippet: Fig. 3 e Expression of leptin receptor (Ob-R) and cytokine and chemokine production by asthmatic and healthy control (HC) fibroblasts. (A) Lung fibroblasts from asthmatic (dotted line) and HC (gray area) individuals were stained with fluorescein isothiocyanate (FITC)-conjugated anti-Ob-R antibody or FITC-conjugated isotype control antibody (white area) and analyzed by flow cytometry (left panel). Data are representative of nine independent experiments. The median fluorescence intensity (MFI) of Ob-R expression in asthmatic and HC fibroblasts was compared (right panel). (B) Asthmatic and HC lung fibroblasts were seeded in 24-well plates, cultured for 24 h, and then stimulated with 10 mM leptin for 48 h. CCL11/eotaxin, CCL2/MCP-1, and TGF-b1 levels in the supernatants were determined using Cytometric Bead Array (CBA) or Enzyme-Linked Immunosorbent Assay (ELISA). Error bars represent the standard error of the mean (SEM) (n ¼ 9). CCL11/eotaxin, CeC motif chemokine 11/eotaxin; CCL2/MCP-1, CeC motif chemokine 2/monocyte chemoattractant protein-1; TGF-b1, transforming growth factor-b1.

Article Snippet: Leptin protein levels were analyzed in CD14-positive cell lysates, adipocyte lysates, and human sera using Quantikine ELISA Human Leptin (R&D Systems), in accordancewith themanufacturer’s instructions.

Techniques: Expressing, Control, Staining, Cytometry, Cell Culture, Enzyme-linked Immunosorbent Assay

Journal: Respiratory investigation

Article Title: Leptin-producing monocytes in the airway submucosa may contribute to asthma pathogenesis.

doi: 10.1016/j.resinv.2022.09.005

Figure Lengend Snippet: Fig. 4 e Phosphorylation of signaling molecules in response to leptin by asthmatic and Healthy Control (HC) fibroblasts. (A) Normal lung fibroblasts (NHLFs) were seeded in 24-well plates and cultured for 1 h with the following inhibitors of intracellular signaling: AG490 (AG), 100 mM; SB203580 (SB), 10 mM; and U0126 (U), 30 mM. They were then stimulated with 10 mM leptin for 24 h. CCL11/eotaxin and CCL2/MCP-1 levels in the supernatant were determined using Cytometric Bead Array (CBA). Error bars represent the standard error of the mean (SEM) (n ¼ 5e6). *p < 0.05, **p < 0.01. (B) NHLFs were stimulated with 10 mM leptin for 0, 1, 3, 5, 10, or 60 min. The lysates were analyzed by western blotting with anti-p38 MAPK, anti-phospho-p38 MAPK, anti-ERK1/2, anti-phospho-ERK1/2, or anti-GAPDH antibodies (left panels). Data are representative of 3e4 independent replicates. Quantitative analysis was achieved by densitometry (right panels), and the data are presented as the ratios indicated in the figure. Error bars represent the SEM (n ¼ 3e4). *p < 0.05, ***p < 0.001 vs.

Article Snippet: Leptin protein levels were analyzed in CD14-positive cell lysates, adipocyte lysates, and human sera using Quantikine ELISA Human Leptin (R&D Systems), in accordancewith themanufacturer’s instructions.

Techniques: Phospho-proteomics, Control, Cell Culture, Western Blot

Journal: Nutrients

Article Title: Postnatal Leptin Levels Correlate with Breast Milk Leptin Content in Infants Born before 32 Weeks Gestation.

doi: 10.3390/nu14245224

Figure Lengend Snippet: Figure 1. Breast milk leptin levels during the initial week of maternal milk, intervening week of donor milk and final week of maternal milk are presented on a logarithmic scale. Compared to leptin levels in donor milk, leptin levels in maternal milk were over 100-times higher. Data are presented as mean (SD) with N = 8 and ** p < 0.01 for Donor versus Maternal 1 and Donor versus Maternal 2.

Article Snippet: Fasting plasma leptin and milk leptin were measured by the Quantikine human leptin ELISA (R&D Systems, Minneapolis, MN, USA).

Techniques:

Journal: Nutrients

Article Title: Postnatal Leptin Levels Correlate with Breast Milk Leptin Content in Infants Born before 32 Weeks Gestation.

doi: 10.3390/nu14245224

Figure Lengend Snippet: Figure 2. Plasma leptin levels among infants at the end of a week of maternal milk, an intervening week of donor milk and a final week of maternal milk. Leptin levels increased on conversion from donor milk back to maternal milk. Data are presented as mean (SD) with N = 8 and * p < 0.05 for Maternal 2 versus Donor.

Article Snippet: Fasting plasma leptin and milk leptin were measured by the Quantikine human leptin ELISA (R&D Systems, Minneapolis, MN, USA).

Techniques: Clinical Proteomics

Journal: Nutrients

Article Title: Postnatal Leptin Levels Correlate with Breast Milk Leptin Content in Infants Born before 32 Weeks Gestation.

doi: 10.3390/nu14245224

Figure Lengend Snippet: Figure 4. Plasma leptin levels were directly associated with breast milk leptin levels across the 3 weeks of the study protocol by simple linear regression (N = 24, R = 0.42, p < 0.05).

Article Snippet: Fasting plasma leptin and milk leptin were measured by the Quantikine human leptin ELISA (R&D Systems, Minneapolis, MN, USA).

Techniques: Clinical Proteomics

Journal: Nutrients

Article Title: Postnatal Leptin Levels Correlate with Breast Milk Leptin Content in Infants Born before 32 Weeks Gestation.

doi: 10.3390/nu14245224

Figure Lengend Snippet: Figure 5. Longitudinal plasma leptin levels (a) and body weight (b) for each of the 8 infants that completed the clinical study. Study day 7 followed at least 7 days of maternal milk, study day 14 followed 7 intervening days of donor milk, and study day 21 was 7 days following a return to maternal milk. Each infant is represented by a consistent color across both panels.

Article Snippet: Fasting plasma leptin and milk leptin were measured by the Quantikine human leptin ELISA (R&D Systems, Minneapolis, MN, USA).

Techniques: Clinical Proteomics