Publications by authors named "Louisa A Rispoli"

Despite serum ferritin's potential as an iron status indicator, its concentrations vary significantly throughout a black rhinoceros's (Diceros bicornis) life, sometimes irrespective of iron load. We explored acute phase response-related biomarkers, serum amyloid A (SAA) and ceruloplasmin (Cp), to better understand the mechanisms influencing serum ferritin changes in managed black rhinoceroses. The objective was to evaluate the relationships between circulating levels of ferritin, SAA, and Cp in black and white rhinoceroses (Ceratotherium simum).

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Poaching is again driving rhinos to the brink of extinction due to the demand for rhino horn products consumed for cultural, medicinal, and social purposes. Paradoxically, the same horn for which rhinos are killed may contain valuable clues about the species' health. Analyses of horn composition could reveal such useful bioindicators while elucidating what people actually ingest when they consume horn derivatives.

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Article Synopsis
  • Cows that experience heat stress after a surge in luteinizing hormone (LH) show changes in the proteins in their follicular fluid, which might affect both ovulation and the development of their eggs (oocytes).
  • Researchers studied gene expression in cumulus and granulosa cells from ovarian follicles in cows under different heat stress levels following the LH surge, noting how gene expression changed in response to rising temperatures.
  • A total of 112 genes were found to be differentially expressed due to hyperthermia, with most showing increased activity, suggesting significant impacts on cell function and egg quality even with moderate temperature increases.
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An acute heat stress event after the LH surge increased interleukin 6 (IL6) levels in the follicular fluid of the ovulatory follicle in hyperthermic cows. To examine direct consequences of a physiologically-relevant elevated temperature (41.0°C) on the cumulus-oocyte complex (COC), IL6 transcript abundance and related receptor components were evaluated throughout maturation.

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The development of replacement heifers is crucial for breeding success and herd efficiency. Nutritional management can affect not only reproductive development but also the inflammatory status of the uterine environment, which may impact reproductive functions such as pregnancy establishment and development. The study herein evaluated the concentration of cytokines and chemokines in the uterus of heifers supplemented with different levels of protein.

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  • The study explores how heat stress affects the cumulus cells and mural granulosa of ovarian follicles in lactating Holsteins, potentially altering the follicular fluid proteome.
  • Cows were subjected to controlled temperature conditions to evaluate the differences in protein abundance in follicular fluid after heat stress exposure, identifying 35 proteins with notable immune responses.
  • Results indicated an increase in specific inflammatory proteins and cytokines in the follicular fluid of heat-stressed cows, suggesting that heat may impact ovulation and the overall functioning of the cumulus-oocyte complex.
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Hyperthermia occurring 10-12 h after LH surge reduces quality of maturing oocyte, thereby reducing fertility. Objective was to examine consequences of an acute heat stress and the influence of certain hormones on the thermoregulatory responses of lactating cows during this critical period. Between the months of February through May, cows were transported to a facility and maintained at a temperature-humidity index (THI) of 65.

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The intimate association of cumulus cells with one another and with the oocyte is important for regulating oocyte meiotic arrest and resumption. The objective of this study was to determine the effects of heat stress on cumulus cell communication and functions that may be related to accelerated oocyte meiosis during early maturation. Bovine cumulus-oocyte complexes underwent in vitro maturation for up to 6 h at thermoneutral control (38.

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Hyperthermia during estrus has direct consequences on the maturing oocyte that carries over to the resultant embryo to compromise its ability to continue in development. Because early embryonic development is reliant upon maternal transcripts and other ooplasmic components, we examined impact of heat stress on bovine oocyte transcripts using microarray. Oocytes were matured at 38.

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Because latent form of matrix metallopeptidase-9 (proMMP9) levels are positively related to blastocyst development, it was hypothesized that addition during maturation may improve development of heat-stressed oocytes. To test hypothesis, 0, 30 or 300 ng/ml human proMMP9 (hMMP9) was added at 18 h of in vitro maturation (hIVM) to cumulus-oocyte complexes matured at 38.5 or 41.

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Two studies were conducted with the overarching goal of determining the extent to which lipolytic changes relate to germinal vesicle breakdown (GVBD) in bovine oocytes matured under thermoneutral or hyperthermic conditions. To this end, cumulus-oocyte complexes underwent in vitro maturation for 0, 2, 4, 6 or 24 h at 38.5 (first study) or 38.

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To determine if reductions in developmental competence related to heat stress exposure were correlated with perturbations in certain RNA populations, poly(A) RNA, total RNA, RNA size distribution, and the abundance of transcripts (cyclin B1, GDF9, BMP15, poly(A) polymerase, HSP70, 18S & 28S rRNA) were examined in oocytes matured at 38.5 or 41 C. Performing in vitro fertilization resulted in embryos for examining RNA.

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Results described herein provide insight regarding certain features of gamete RNA and how they compare to cumulus cell RNA. In particular, 28S/18S rRNA ratio and size distribution of RNA molecules differed in total RNA from oocytes versus surrounding cumulus cells. Specifically, oocyte total RNA had a lower rRNA ratio and an increased abundance of smaller RNA sizes compared to RNA from surrounding cumulus.

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  • * The blocking agent RU486 can prevent this inhibitory effect, indicating a specific mechanism involving type II glucocorticoid receptors (GR).
  • * Experiments showed that cortisol reduces the pituitary's LH response to GnRH within 30 minutes, but it doesn't change the levels of GnRH receptor mRNA or protein, confirming that cortisol impacts the pituitary directly without altering receptor expression.
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