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Gurgatz BM, Garcia MR, Cabral AC, de Souza AC, Nagai RH, Figueira RCL, de Mahiques MM, Martins CC. Polycyclic aromatic hydrocarbons in a Natural Heritage Estuary influenced by anthropogenic activities in the South Atlantic: Integrating multiple source apportionment approaches. Mar Pollut Bull 2023; 188:114678. [PMID: 36764149 DOI: 10.1016/j.marpolbul.2023.114678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 12/29/2022] [Accepted: 01/25/2023] [Indexed: 06/18/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) were analysed in the sediments of one of the most well-preserved estuaries in South Brazil, the Paranaguá Estuarine System (PES), using several source apportionment tools. The ∑PAH ranged from < DL to 125.6 ng g-1 dw (dry weight) (average 29.9 ± 26.1 ng g-1 dw), and the lowest levels detected were similar to those found in other protected areas of the world. In general, the PAH concentrations indicated excellent environmental quality for the entire estuary. Principal component analysis indicated that fine sediments and total organic carbon were the main factors controlling PAH concentrations in the PES. Multiple PAH sources were identified in the study area; biomass burning and fossil fuel combustion predominated but considerable amounts of petrogenic residues were also observed. We identified evidence of a contribution from an adjacent watershed resulting from the construction of interconnections between large rivers and from years of intense deforestation in the local Atlantic Forest.
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Affiliation(s)
- Bruno Martins Gurgatz
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil.
| | - Marina Reback Garcia
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil
| | - Ana Caroline Cabral
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil
| | - Amanda Câmara de Souza
- Programa de Pós-Graduação em Oceanografia, Instituto Oceanográfico, Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-900 São Paulo, SP, Brazil
| | - Renata Hanae Nagai
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil; Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 8325-976 Pontal do Paraná, PR, Brazil
| | - Rubens C L Figueira
- Programa de Pós-Graduação em Oceanografia, Instituto Oceanográfico, Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-900 São Paulo, SP, Brazil
| | - Michel Michaelovitch de Mahiques
- Programa de Pós-Graduação em Oceanografia, Instituto Oceanográfico, Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-900 São Paulo, SP, Brazil
| | - César C Martins
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil; Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 8325-976 Pontal do Paraná, PR, Brazil.
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Garcia MR, Martins CC. A systematic evaluation of polycyclic aromatic hydrocarbons in South Atlantic subtropical mangrove wetlands under a coastal zone development scenario. J Environ Manage 2021; 277:111421. [PMID: 33069149 DOI: 10.1016/j.jenvman.2020.111421] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/05/2020] [Accepted: 09/23/2020] [Indexed: 06/11/2023]
Abstract
Mangrove forests worldwide are threatened environments considered vulnerable to chronic contamination by hydrophobic contaminants such as polycyclic aromatic hydrocarbons (PAHs). These ecosystems have a key role in the dynamics of biogenic and anthropogenic carbon storage and provide proper conditions for accumulation. One of most important subtropical mangrove swamps in the South Atlantic is located in the Paranaguá Estuarine System (PES), the largest bay of South Brazil surrounded by well-preserved Atlantic rainforests; however, the PES is under imminent risks of damage, e.g., due to incidental oil spills during port operations. In this scenario, PAHs were assessed for the first time in the mangrove sediments of the PES. The concentrations of 16 priority PAHs (EPA) (<DL - 234.3 ng g-1, 36 samples) were higher than those observed in previous studies for bottom sediments and had a similar order of magnitude as those for other human-impacted mangroves but were lower than those of other heavily impacted mangroves. A moderate level of anthropic contamination was observed, and the main probable sources of PAHs were navigation and domestic effluents. Bulk parameters (TOC/TN ratio and δ13C) showed the estuarine land-sea gradient and helped define the preferential sites of PAH deposition due to its correlation with TOC and fine sediments. Marine hydrodynamics and/or dilution processes had a major influence on PAH distribution, resulting in higher concentrations in the inner/sheltered areas of the estuary and lower values in the outer zone of the estuary with higher hydrodynamic energy. The environmental features and anthropogenic forcing of the PES added to the relative absence of a detailed evaluation of the levels of and environmental risks posed by PAHs in other subtropical mangrove ecosystems located in the Southern Hemisphere, reinforcing the importance of the current study.
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Affiliation(s)
- Marina Reback Garcia
- Programa de Pós-Graduação Em Sistemas Costeiros e Oceânicos (PGSISCO), Universidade Federal Do Paraná, Caixa Postal 61, 83255-976, Pontal Do Paraná, PR, Brazil; Centro de Estudos Do Mar, Universidade Federal Do Paraná, Caixa Postal 61, 83255-976, Pontal Do Paraná, PR, Brazil
| | - César C Martins
- Centro de Estudos Do Mar, Universidade Federal Do Paraná, Caixa Postal 61, 83255-976, Pontal Do Paraná, PR, Brazil.
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Garcia MR, Cattani AP, da Cunha Lana P, Figueira RCL, Martins CC. Petroleum biomarkers as tracers of low-level chronic oil contamination of coastal environments: A systematic approach in a subtropical mangrove. Environ Pollut 2019; 249:1060-1070. [PMID: 31146312 DOI: 10.1016/j.envpol.2019.03.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/01/2019] [Accepted: 03/03/2019] [Indexed: 06/09/2023]
Abstract
Petroleum biomarkers (hopanes, terpanes and steranes) are frequently assessed in estuarine sediments as tracers of oil input. In order to compare distinct patterns of hydrocarbon accumulation in mudflats, salt marsh and mangrove, sediments from two transects (control and impacted areas) were sampled in Paranaguá Bay, SW Atlantic. Concentrations of n-alkanes, polycyclic aromatic hydrocarbons (PAHs) and petroleum biomarkers (hopanes, terpanes and steranes) were determined, as well as bulk parameters (TOC, grain size and δ13C). N-alkanes concentrations were similar between control and impacted sites (respectively, 3.03 ± 1.20 μg g-1 and 4.11 ± 3.02 μg g-1) and reflected a high biogenic input. Conversely, PAHs and petroleum biomarker concentrations were three to six times higher in impacted site than the control site (respectively, 60.4 ± 23.3 ng g-1 and 22.0 ± 25.0 ng g-1 for PAHs and 197.7 ± 51.8 ng g-1 and 40.2 ± 32. ng g-1 for hopanes). Despite these differences, concentrations were lower than those reported for highly impacted areas worldwide. Diagnostic ratios and hydrocarbon parameters (e.g. total PAHs and total petroleum biomarkers) helped to distinguish human impact in the ecological zones, suggesting different sources and/or levels of weathering, confirmed by ANOVA tests. TOC played a fundamental role to the concentration of hydrocarbons, showing similar distributions along the transects. Petroleum biomarkers could clearly indicate the preferential sites of deposition and assign different levels of anthropic contamination by hydrocarbons, thus providing clear information about the chronic petroleum pollution in coastal sediments.
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Affiliation(s)
- Marina Reback Garcia
- Programa de Pós-Graduação em Sistemas Costeiros e Oceânicos (PGSISCO), Universidade Federal do Paraná, Caixa Postal 61, 83255-976, Pontal do Paraná, PR, Brazil.
| | - André Pereira Cattani
- Centro de Estudos do Mar, Universidade Federal do Paraná, Caixa Postal 61, 83255-976, Pontal do Paraná, PR, Brazil
| | - Paulo da Cunha Lana
- Centro de Estudos do Mar, Universidade Federal do Paraná, Caixa Postal 61, 83255-976, Pontal do Paraná, PR, Brazil
| | - Rubens César Lopes Figueira
- Instituto Oceanográfico da Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-900, São Paulo, SP, Brazil
| | - César C Martins
- Centro de Estudos do Mar, Universidade Federal do Paraná, Caixa Postal 61, 83255-976, Pontal do Paraná, PR, Brazil.
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Hanna JA, Garcia MR, Go JC, Finkelstein D, Kodali K, Pagala V, Wang X, Peng J, Hatley ME. PAX7 is a required target for microRNA-206-induced differentiation of fusion-negative rhabdomyosarcoma. Cell Death Dis 2016; 7:e2256. [PMID: 27277678 PMCID: PMC5143388 DOI: 10.1038/cddis.2016.159] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/05/2016] [Accepted: 05/09/2016] [Indexed: 01/12/2023]
Abstract
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood. RMS can be parsed based on clinical outcome into two subtypes, fusion-positive RMS (FP-RMS) or fusion-negative RMS (FN-RMS) based on the presence or absence of either PAX3-FOXO1 or PAX7-FOXO1 gene fusions. In both RMS subtypes, tumor cells show histology and a gene expression pattern resembling that of developmentally arrested skeletal muscle. Differentiation therapy is an attractive approach to embryonal tumors of childhood including RMS; however, agents to drive RMS differentiation have not entered the clinic and their mechanisms remain unclear. MicroRNA-206 (miR-206) expression increases through normal muscle development and has decreased levels in RMS compared with normal skeletal muscle. Increasing miR-206 expression drives differentiation of RMS, but the target genes responsible for the relief of the development arrest are largely unknown. Using a combinatorial approach with gene and proteomic profiling coupled with genetic rescue, we identified key miR-206 targets responsible for the FN-RMS differentiation blockade, PAX7, PAX3, NOTCH3, and CCND2. Specifically, we determined that PAX7 downregulation is necessary for miR-206-induced cell cycle exit and myogenic differentiation in FN-RMS but not in FP-RMS. Gene knockdown of targets necessary for miR-206-induced differentiation alone or in combination was not sufficient to phenocopy the differentiation phenotype from miR-206, thus illustrating that miR-206 replacement offers the ability to modulate a complex network of genes responsible for the developmental arrest in FN-RMS. Genetic deletion of miR-206 in a mouse model of FN-RMS accelerated and exacerbated tumor development, indicating that both in vitro and in vivo miR-206 acts as a tumor suppressor in FN-RMS at least partially through downregulation of PAX7. Collectively, our results illustrate that miR-206 relieves the differentiation arrest in FN-RMS and suggests that miR-206 replacement could be a potential therapeutic differentiation strategy.
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Affiliation(s)
- J A Hanna
- Department of Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - M R Garcia
- Department of Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - J C Go
- Department of Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - D Finkelstein
- Department of Computational Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - K Kodali
- St. Jude Proteomics Facility, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - V Pagala
- St. Jude Proteomics Facility, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - X Wang
- St. Jude Proteomics Facility, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - J Peng
- St. Jude Proteomics Facility, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.,Department of Structural Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.,Department of Developmental Neurobiology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
| | - M E Hatley
- Department of Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA
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Garcia MR, Amstalden M, Keisler DH, Raver N, Gertler A, Williams GL. Leptin attenuates the acute effects of centrally administered neuropeptide Y on somatotropin but not gonadotropin secretion in ovariectomized cows. Domest Anim Endocrinol 2004; 26:189-200. [PMID: 15036374 DOI: 10.1016/j.domaniend.2003.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2003] [Accepted: 10/01/2003] [Indexed: 11/27/2022]
Abstract
We tested the hypothesis that recombinant ovine leptin would attenuate the acute effects of neuropeptide Y (NPY) on secretion of GH and gonadotropins (LH and FSH) in cows. Ovariectomized cows (n=6) fitted with third ventricle guide cannulas were assigned randomly to each of three groups in a Latin square arrangement: (1) control; saline treatment only, (2) NPY; saline followed by NPY, and (3) L-NPY; leptin pretreatment followed by NPY. Treatments were: s.c. injection of saline or leptin (30 microg/kg BW) at time 0, i.v. injection of saline or leptin (30 microg/kg BW) at 70 min, and intracerebroventricular (i.c.v.) injection of saline or NPY (500 microg) at 90 min. Plasma leptin was elevated (P<0.01) at least four-fold throughout the experiment in the L-NPY group. Mean plasma concentrations of LH declined within 1 h and were lower (P<0.03) than controls in both the NPY and L-NPY groups beginning 2 h after NPY injection. An acute increase in plasma concentrations of GH was observed within 1 h after NPY in the NPY group and mean values were greater (P<0.01) than controls. However, in the L-NPY group, leptin pretreatment attenuated the NPY effect on GH. Treatments had no effect on FSH secretion. Results confirm suppressive and stimulatory effects of NPY on LH and GH secretion, respectively, and indicate that leptin can attenuate the acute effects of NPY on GH secretion in cattle.
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Affiliation(s)
- M R Garcia
- Animal Reproduction Laboratory, Texas A&M University Agricultural Research Station, Hwy 59E, Beeville, TX 78102-9410, USA
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Amstalden M, Zieba DA, Garcia MR, Stanko RL, Welsh TH, Hansel WH, Williams GL. Evidence that lamprey GnRH-III does not release FSH selectively in cattle. Reproduction 2004; 127:35-43. [PMID: 15056768 DOI: 10.1530/rep.1.00022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Experiments were performed to test the hypothesis that lamprey GnRH-III (lGnRH-III) selectively releases FSH. Primary cultures of bovine adenohypophyseal cells were treated with mammalian GnRH (mGnRH) and lGnRH-III (10−9, 10−8, 10−7 and 10−6 M) or control media in Experiment 1. All doses of mGnRH and the two highest doses of lGnRH-III stimulated (P < 0.001) a non-selective release of LH and FSH. In Experiments 2–4, Latin Square designs were utilized in vivo to examine whether physiological and hormonal milieu regulate putative selective effects of lGnRH-III. In Experiments 2 and 3, ovariectomized cows with basal levels of estradiol only (Experiment 2) or in combination with luteal phase levels of progester-one (Experiment 3) were injected with mGnRH and lGnRH-III (0.055, 0.11, 0.165 and 1.1 μg/kg body weight (BW) and saline. All doses of mGnRH released (P < 0.001) LH and FSH, but only the highest dose of lGnRH-III stimulated (P < 0.001) a non-selective release of both LH and FSH (Experiment 3). For Experiments 4A and 4B, intact, mid-luteal phase cows were injected with mGnRH and lGnRH-III (1.1 μg/kg BW; Experiment 4A), lGnRH-III (1.1 and 4.4 μg/kg BW; Experiment 4B) and saline. As before, mGnRH released (P < 0.001) both LH and FSH at all doses. In contrast, lGnRH-III at the highest dose released (P < 0.001) LH but not FSH. These findings suggest that lGnRH-III may act as a weak competitor for the mGnRH receptor and do not support the hypothesis that it selectively releases FSH in cattle.
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Affiliation(s)
- M Amstalden
- Animal Reproduction Laboratory, Texas A&M University Agricultural Research Station, Beeville, Texas 78102, USA
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Garcia MR, Amstalden M, Morrison CD, Keisler DH, Williams GL. Age at puberty, total fat and conjugated linoleic acid content of carcass, and circulating metabolic hormones in beef heifers fed a diet high in linoleic acid beginning at four months of age. J Anim Sci 2003; 81:261-8. [PMID: 12597397 DOI: 10.2527/2003.811261x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In the current study, we hypothesized that diets high in linoleic acid would increase conjugated linoleic acid (CLA) tissue content, reduce adiposity and leptin production, and result in an increase in the age at puberty in heifers. Heifers were weaned and blocked by body weight (heavy, n = 10, and light, n = 10) and allocated randomly within block to receive isocaloric and isonitrogenous diets with either added fat (HF, n = 10) or no added fat (C, n = 10) from 4 mo of age until post-pubertal slaughter. Whole sunflower seed (55% oil; 70% linoleic acid) was used as the fat source in HF diets and provided 5% added fat from the start of the study until heifers weighed 250 +/- 8 kg, at which time added fat was increased to 7% of dry matter until slaughter. Body weights were recorded weekly, and blood samples were collected weekly for total cholesterol and hormone analyses. Puberty was confirmed based on serum concentrations of progesterone and ultrasonographic confirmation of corpora lutea. Heifers were slaughtered at 325 +/- 10 d of age, and longissimus muscle between the 9th and 11th rib was collected and analyzed to estimate carcass composition. Subcutaneous and kidney, pelvic, and heart fat were collected at slaughter for fatty acid analyses. The HF heavy group tended (P < 0.10) to reach puberty later than all other groups, and one HF light heifer did not reach puberty during the study. Linoleic acid and cis-9, trans-11 CLA tissue contents were higher (P < 0.03) in HF heifers than controls, but neither total carcass fat nor percentage of dry matter differed by dietary group, although the percentage of protein tended (P < 0.10) to be lower in HF heifers. Mean serum concentrations of leptin did not differ due to diet; however, leptin increased (P < 0.01) linearly as puberty approached. Circulating concentrations of growth hormone and insulin-like growth factor I increased or remained relatively constant between wk 2 to 10 of feeding, and then declined (P < 0.01) until the onset of puberty. Serum IGF-I was lower (P < 0.01) in heifers receiving the HF diet. Mean serum concentrations of insulin and total cholesterol increased (P < 0.01) with time in both groups, but only total cholesterol was increased by the HF diet (P < 0.05). Results indicate that diets high in linoleic acid fed to growing beef heifers beginning early in life have little or no effect on total carcass fat, circulating leptin, or age at puberty despite measurable increases in CLA accumulation.
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Affiliation(s)
- M R Garcia
- Animal Reproduction Laboratory, Texas A&M University Agricultural Research Station, Beeville 78102, USA
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Garcia MR, Amstalden M, Williams SW, Stanko RL, Morrison CD, Keisler DH, Nizielski SE, Williams GL. Serum leptin and its adipose gene expression during pubertal development, the estrous cycle, and different seasons in cattle. J Anim Sci 2002; 80:2158-67. [PMID: 12211386 DOI: 10.2527/2002.8082158x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Circulating concentrations of leptin and IGF-I, leptin gene expression, and serum binding of [126I]ovine leptin in cattle during pubertal development, as well as leptin gene expression and circulating concentrations of leptin during the estrous cycle and different calendar seasons, were investigated. Multivariate regression analysis was utilized to evaluate temporal changes in BW, leptin mRNA, and serum concentrations of IGF-I and leptin normalized to the week of puberty (Exp. 1). Body weight accounted for most of the variation associated with the onset of puberty in the full regression model (R2 = 0.99; P < 0.01). However, serum leptin was closely related to changes in BW (r = 0.85; P < 0.02) and in the absence of BW was most predictive of pubertal onset (r2 = 0.73; P < 0.01). Mean concentrations of leptin increased (P < 0.0001) linearly from 16 wk before until the wk of pubertal ovulation in yearling heifers reaching sexual maturation from early spring to midsummer. Leptin mRNA transformed to a percent of the value at puberty increased (P < 0.02) as puberty approached, but serum leptin and leptin mRNA values were not well correlated. We found no evidence of leptin-binding proteins in serum of developing heifers. Combined mean serum concentrations of IGF-I (ng/mL) during periods III and IV (-9 wk to wk of puberty; 216.6 +/- 9) were 21% higher (P < 0.0001) than combined mean concentrations of IGF-I during periods I and II (-19 to wk of puberty; 193 +/- 10). In mature heifers and cows (Exp. 2), serum leptin tended to decrease (P = 0.10) during the late luteal/early follicular phase of the estrous cycle, which corresponded to a reduction (P < 0.03) in adipocyte leptin gene expression. In mature ovariectomized cows, serum concentrations of leptin increased (P < 0.001) by 34% from early winter to the summer solstice and remained unchanged throughout the remainder of the year (Exp. 3). Results from these studies indicate that marked increases in both circulating leptin and leptin gene expression occur in developing heifers during pubertal development and are associated with increases in serum IGF-I and BW. Seasonal effects on circulating leptin observed in mature cows from winter to summer could also plausibly account for a portion of the prepubertal rise in serum leptin observed in heifers.
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Williams GL, Amstalden M, Garcia MR, Stanko RL, Nizielski SE, Morrison CD, Keisler DH. Leptin and its role in the central regulation of reproduction in cattle. Domest Anim Endocrinol 2002; 23:339-49. [PMID: 12142250 DOI: 10.1016/s0739-7240(02)00169-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Leptin, a 16kDa product of the adipose obese (ob) gene, has been shown to contribute to the regulation of energy metabolism, feeding behavior, and reproduction in several monogastric species, including humans. Recent reports have provided evidence that the leptin gene is functionally relevant in cattle and sheep, and may contribute to an array of important reproductive events, including puberty. Leptin gene expression and circulating leptin increase markedly during sexual maturation in heifers reaching puberty during late spring or early summer. In addition, serum leptin concentrations increased by over 30% from early winter to the summer solstice in mature cows, and also increased with significant changes in adiposity. However, only limited changes in circulating leptin have been observed during the estrous cycle. Short-term fasting of growing peripubertal heifers causes marked reductions in leptin gene expression and circulating leptin, concomitant with declines in LH pulse frequency, and serum concentrations of insulin and IGF-1. Although short-term fasting of mature cows in excellent body condition is without effects on LH pulse frequency, it has remarkably similar metabolic effects to those observed in heifers. Moreover, ICV administration of recombinant oleptin resulted in a marked hypersecretion of LH in fasted cows, and in vitro studies using both hypothalamic and anterior pituitary explants have provided evidence that this effect is at the pituitary level. Paradoxically, ICV administration of oleptin normalized circulating insulin in fasted cows but hleptin was without effect on insulin in estradiol-implanted wethers. Collectively, work in cattle and sheep indicates that leptin can modulate both the hypothalamic-pituitary axis and endocrine pancreas under defined nutritional conditions. Additional work to more fully characterize these roles is clearly warranted and could lead to the development of novel strategies for modifying reproductive potential in food-producing species.
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Affiliation(s)
- G L Williams
- Animal Reproduction Laboratory, Texas A&M University Agricultural Research Station, Beeville 78102, USA.
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Amstalden M, Garcia MR, Stanko RL, Nizielski SE, Morrison CD, Keisler DH, Williams GL. Central infusion of recombinant ovine leptin normalizes plasma insulin and stimulates a novel hypersecretion of luteinizing hormone after short-term fasting in mature beef cows. Biol Reprod 2002; 66:1555-61. [PMID: 11967223 DOI: 10.1095/biolreprod66.5.1555] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The present studies tested the hypotheses that short-term fasting would reduce leptin gene expression and circulating concentrations of leptin and insulin in mature, ovariectomized, estradiol-implanted cows and that intracerebroventricular infusions of recombinant ovine leptin (oleptin) would attenuate reductions in insulin concentration and stimulate LH secretion. Ovariectomized cows were assigned to either control (normal fed; n = 6) or fasted (60 h of fasting; n = 7) groups and infused with 200 microg recombinant oleptin three times at hourly intervals on Day 2 (n = 6 per group). Fasting decreased plasma concentrations of insulin (P < 0.01) and leptin (P < 0.04) but, as expected, did not reduce plasma concentrations of glucose or any LH secretion variable. Central infusion of leptin on Day 2 increased (P < 0.01) plasma concentrations of leptin in both control and fasted groups. Concomitantly, leptin treatment increased plasma insulin (P < 0.01) and LH (P < 0.03) concentrations in fasted but not in control cows. Increases in overall mean and baseline concentrations of LH after leptin treatment were the result of an augmentation of the size of LH pulses. The effects of fasting on leptin gene expression and the potential diurnal effects on circulating leptin were examined in a group of cows (n = 12) not treated with leptin. Fasting for 60 h reduced (P < 0.001) leptin gene expression by 30%, and no diurnal effects on circulating leptin were observed. These results indicate that although short-term fasting does not reduce the frequency or amplitude of LH pulses or the concentration of LH in mature cows, this nutritional perturbation clearly sensitizes both the hypothalamic-pituitary axis and endocrine pancreas to exogenous leptin, which in these experiments resulted in heightened secretion of both LH and insulin.
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Affiliation(s)
- M Amstalden
- Animal Reproduction Laboratory, Texas A&M University Agricultural Research Station, 3507 Highway 59 E, Beeville, TX 78102, USA
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Amstalden M, Garcia MR, Williams SW, Stanko RL, Nizielski SE, Morrison CD, Keisler DH, Williams GL. Leptin gene expression, circulating leptin, and luteinizing hormone pulsatility are acutely responsive to short-term fasting in prepubertal heifers: relationships to circulating insulin and insulin-like growth factor I(1). Biol Reprod 2000; 63:127-33. [PMID: 10859251 DOI: 10.1095/biolreprod63.1.127] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
In the present study, we tested the hypothesis that short-term fasting would reduce leptin gene expression, circulating leptin, and LH pulsatility in prepubertal heifers in association with a decrease in circulating concentrations of insulin and insulin-like growth factor I (IGF-I). Twelve prepubertal crossbred heifers (mean +/- SD = 315 +/- 5 kg body weight) were assigned randomly to one of two treatments in two replicates: 1) control; normal feed consumption (n = 6) and 2) fasted; 48 h of total feed restriction (n = 6). Blood samples were collected at 15-min intervals for 8 h on Days 0 and 2 of the experiment and twice on Day 1. Subcutaneous fat samples were collected before treatment onset (Day -1) and at the end of the intensive blood sampling on Day 2. Acute feed restriction markedly reduced leptin mRNA in adipose tissue (P < 0.01) and circulating concentrations of leptin (P < 0.05), IGF-I (P < 0.01), and insulin (P = 0.05) as compared with controls on Day 2. Moreover, the treatment x day interaction (P < 0.076) and within-day contrasts (expressed as a percentage of Day 0 values) revealed that the mean frequency of LH pulses in the fasted group was lower (P < 0.06) than in controls on Day 2. Neither mean concentrations of growth hormone (GH) nor GH secretory dynamics were affected by acute feed restriction. Fasting-mediated decreases in leptin gene expression and circulating leptin, in association with reductions in secretion of IGF-I, insulin, and LH, provide a basis for investigating leptin as a hormone signaling energy status to the central reproductive axis in cattle.
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Affiliation(s)
- M Amstalden
- Animal Reproduction Laboratory, Texas A&M University Agricultural Research Station, Beeville, Texas 78102, USA
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Garcia MR, Graham S, Harris RA, Beverley SM, Kaye PM. Epitope cleavage by Leishmania endopeptidase(s) limits the efficiency of the exogenous pathway of major histocompatibility complex class I-associated antigen presentation. Eur J Immunol 1997; 27:1005-13. [PMID: 9130657 DOI: 10.1002/eji.1830270430] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The activation of CD8+ T cell responses is commonplace during infection with a number of nonviral pathogens. Consequently, there has been much interest in the pathways of presentation of such exogenous antigens for major histocompatibility complex class I-restricted recognition. We had previously shown that Leishmania promastigotes transfected with the ovalbumin (OVA) gene could efficiently target OVA to the parasitophorous vacuole (PV), with subsequent recognition by class II-restricted T cells. We now report the results of studies aimed at evaluating the PV as a route of entry into the exogenous class I pathway. Bone marrow-derived macrophages can present soluble OVA (albeit at high concentrations) to the OVA(257-264)-specific T cell hybridoma 13.13. In contrast, infection with OVA-transfected Leishmania promastigotes failed to result in the stimulation of this hybridoma. This appeared unrelated to variables such as antigen concentration, parasite survival, and macrophage activation status. These results prompted an analysis of the effects of promastigotes on class I peptide binding using RMA-S cells and OVA(257-264). Our data indicate that the major surface protease of Leishmania, gp63, inhibits this interaction by virtue of its endopeptidase activity against the OVA(257-264) peptide. The data suggest that this activity, if maintained within the PV, would result in loss of the OVA(257-264) epitope. Although we can therefore draw no conclusions from these studies regarding the efficiency of the PV as a site of entry of antigen into the exogenous class I pathway, we have identified a further means by which parasites may manipulate the immune repertoire of their host.
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Affiliation(s)
- M R Garcia
- Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, GB
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13
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Yoshida K, Kasai T, Garcia MR, Sawada S, Shoji T, Shimizu S, Yamazaki K, Komeda Y, Shinmyo A. Heat-inducible expression system for a foreign gene in cultured tobacco cells using the HSP18.2 promoter of Arabidopsis thaliana. Appl Microbiol Biotechnol 1995; 44:466-72. [PMID: 8597550 DOI: 10.1007/bf00169945] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A system for the controlled expression of a foreign gene in cultured tobacco cells (Nicotiana tabacum, BY2) by temperature shift was constructed. A 925-base-pair (bp) DNA fragment containing the 5'-flanking region of a low-molecular-mass heat-shock protein gene (HSP18.2) of Arabidopsis thaliana was inserted upstream of the beta-glucuronidase reporter gene (GUS). The resulting HSP18.2-GUS construct was introduced into BY2 cells by electroporation or Agrobacterium-mediated transformation. Transient expression of the HSP18.2 promoter in protoplasts was very low regardless of the heat shock. Although expression of the HSP18.2-GUS chimeric gene in the stable transformants of BY2 was hardly detected in culture at 25 degrees C, the expression increased rapidly on the transcriptional level when the incubation temperature was shifted to 35-37 degrees C. The optimal temperature for heat-shock induction was 37 degrees C. After a 2-h incubation at 37 degrees C, GUS activity was about 1000-fold greater than that before heat shock. The amount of GUS mRNA was maximum 2 h after heat shock, and then decreased gradually.
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Affiliation(s)
- K Yoshida
- Department of Biotechnology, Faculty of Engineering, Osaka University, Japan
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Birmaher B, Rabin BS, Garcia MR, Jain U, Whiteside TL, Williamson DE, al-Shabbout M, Nelson BC, Dahl RE, Ryan ND. Cellular immunity in depressed, conduct disorder, and normal adolescents: role of adverse life events. J Am Acad Child Adolesc Psychiatry 1994; 33:671-8. [PMID: 8056730 DOI: 10.1097/00004583-199406000-00008] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To determine whether adolescents with major depressive disorder have disturbances in their cellular immunity and to study whether the immunological changes detected are specific to depression or are general responses to stress. METHOD Twenty subjects with major depressive disorder, 17 nondepressed subjects with conduct disorder, and 17 normal adolescents were recruited. Subjects were assessed with a clinical interview for DSM-III-R and a modified version of the Coddington Life Events Checklist. Blood samples were drawn for total white blood cells, lymphocytes subsets, natural killer cell activity, lymphocyte proliferation response to phytohemagglutinin, and cortisol plasma levels. RESULTS Overall, there were no significant between-group differences in any of the cellular immune measurements. Natural killer cell activity was significantly negatively correlated with past year and lifetime adverse life events across all effector-target cell ratios. Controlling for diagnoses and socioeconomic status yielded similar results. There were no significant effects of age, sex, race, sleep, nutrition, cigarette use, menstrual cycle, or cortisol on any of the immunological variables. CONCLUSIONS In this sample of adolescents, we found that independent of the diagnoses and socioeconomic status, increases in adverse life events were associated with low natural killer cell activity.
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Affiliation(s)
- B Birmaher
- Dept. of Psychiatry, Univ. of Pittsburgh School of Medicine, Western Psychiatric Institute and Clinic, PA 15213
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Garcia MR, Ryan ND, Rabinovitch H, Ambrosini P, Twomey J, Iyengar S, Novacenko H, Nelson B, Puig-Antich J. Thyroid stimulating hormone response to thyrotropin in prepubertal depression. J Am Acad Child Adolesc Psychiatry 1991; 30:398-406. [PMID: 1905294 DOI: 10.1097/00004583-199105000-00008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In an effort to evaluate whether differences exist in the hypothalamic-pituitary-thyroid axis of depressed children, a thyrotropin releasing hormone (TRH) stimulation test was administered to 55 prepubertal subjects who were divided into three groups matched for age and sex: a depressed group (endogenous N = 15, nonendogenous N = 15), a psychiatric nondepressed control group (N = 16), and a normal control group (N = 9). Each subject was tested at two dosages of TRH, 2 micrograms/kg and 7 micrograms/kg. Increasing age and female sex were positively correlated with a greater thyroid stimulating hormone (TSH) response. TSH response to TRH was examined with subjects reclassified by severe suicidal ideation, severe aggression, and parental history of alcoholism. Results of this study are contrasted with the adult psychiatric literature.
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Faura CC, Garcia MR, Horga JF. Changes in gentamicin serum levels and pharmacokinetic parameters in the newborn in the course of treatment with aminoglycoside. Ther Drug Monit 1991; 13:277-80. [PMID: 1926285 DOI: 10.1097/00007691-199105000-00016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Gentamicin serum levels were determined in an unselected group of newborns treated with standard doses of the drug to study the changes in pharmacokinetic parameters (trough and peak serum levels/dose ratio, serum level increases/dose ratio, elimination half-life, and distribution volume) 48, 96, and 144 h after commencing treatment. However, no significant changes in the pharmacokinetic parameters were found in different groups of neonates, classified according to gestational age and days of life during the study period. It appears that the dose of gentamicin once it has been individually established does not have to be changed, at least during the first week of treatment.
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Affiliation(s)
- C C Faura
- Neurochemistry Department, University of Alicante, Spain
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Lombardi C, Junqueira TB, Garcia MR. [Temporal tendency in the detection of Hansen's disease in the municipality of Maringá-PR, 1977/1986]. Hansenol Int 1988; 13:1-12. [PMID: 3271235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This study was dedicated to the analysis the behaviour of the Hansen's, disease in Maringá, State of Paraná. Three hundred and forty eight clinical-epidemic cards were studied in patients who had Hansen's disease in the periods from 1977 to 1986. It was verified that the clinical forms Virchowian + Borderline had the highest percentual and prevailed in the age limit where people are economically active, concluding the same of a previous study which was performed by Belda & Lombardi and by Asseis et al. Tables and Figuras of the disease distribution are presented according to sex, origins, year of the detection, clinical form, age when it was diagnosed (the disease), time when symptoms appeared until the diagnosis with short comments, and its importance to the epidemic valuation of Hansen's disease in this city.
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Affiliation(s)
- C Lombardi
- Faculdade de Saúde Pública da Universidade de São Paulo
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Abstract
An improved knowledge of cryopreservation of primate embryos will have important research and clinical application. Fifty-six 4- to 8-cell in vitro fertilized embryos were frozen in HEPES-buffered Tyrode's solution containing 1.5 M dimethylsulfoxide (DMSO) and cooled at the rate of 0.3 degrees C/minute to -39 degrees C before being transferred into liquid nitrogen. Embryos were rapidly thawed at room temperature for 2 minutes. DMSO was diluted with medium in three steps at 5-minute intervals. Of the 56 embryos, 39 (70%) were classified as viable on the basis of surviving the freezing process with greater than 50% of their blastomeres intact. Twelve of the 39 embryos were cultured overnight, and 11 cleaved at least once. Twenty-five embryos were transferred to nine synchronized, unstimulated recipient monkeys 24 to 48 hours after ovulation. Three pregnancies (33.3%) resulted from the nine transfers.
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