hormone stimulation
Recently Published Documents


TOTAL DOCUMENTS

532
(FIVE YEARS 39)

H-INDEX

48
(FIVE YEARS 3)

Author(s):  
George M Bright ◽  
Peter A Morris ◽  
Ron G Rosenfeld

Given the low prevalence rate of growth hormone deficiency (GHD) and the high false positive rates for growth hormone stimulation tests, the probability of GHD in a child with short stature and positive growth hormone stimulation tests is 0.028 (about 1 in 36). Without further information, most positive growth hormone stimulation tests will be false positives. Further study may yield the necessary improvements in the diagnostic accuracy for GHD in children.


2021 ◽  
Vol 206 (Supplement 3) ◽  
Author(s):  
Mohamed Al-Hussini ◽  
Essam A. Nada ◽  
Mohammed Abu El-Hamd ◽  
Wafaa M. Abd El-Maged ◽  
Awatuf El-Shirif ◽  
...  

2021 ◽  
Vol 16 (2) ◽  
pp. 99
Author(s):  
Wahyulia Cahyanti ◽  
Adang Saputra ◽  
Anang Hari Kristanto

Sejumlah penelitian terhadap ikan gabus (Channa striata Blkr) telah dilakukan mulai dari pembenihan dan pembesaran, namun masih belum banyak informasi ilmiah terkait performa reproduksi dan larva yang dihasilkan baik dari pemijahan alami maupun pemijahan semi-alami (induksi hormonal). Penelitian ini bertujuan untuk menentukan teknik pemijahan yang tepat untuk ikan gabus. Dalam penelitian ini digunakan induk jantan dan betina dengan tingkat kematangan gonad (TKG) yang seragam (yaitu pada TKG-IV). Penelitian memakai empat perlakuan stimulasi hormon, yaitu A (kontrol, tanpa stimulasi hormon), B (induk jantan dan betina distimulasi hormon), C (induk betina distimulasi hormon), D (induk jantan distimulasi hormon). Hormon yang digunakan untuk menginduksi induk betina dan jantan adalah LHRHa + anti dopamin. Masing-masing perlakuan menggunakan tiga pasang induk. Parameter performa reproduksi yang diamati meliputi fekunditas, diameter telur, lama waktu menetas, dan volume kuning telur. Untuk performa larva dilakukan pengamatan laju penyerapan kuning telur, pertumbuhan panjang dan bobot larva, laju pertumbuhan spesifik, dan sintasan. Dari penelitian diperoleh bahwa ikan perlakuan-A dan B mampu berovulasi hingga menetas, perlakuan-C berhasil ovulasi namun gagal menetas, sedangkan perlakuan-D tidak mampu ovulasi. Fekunditas dan derajat penetasan hasil pemijahan alami paling tinggi (1.832 ± 13 butir dan 97,20 ± 2,49%). Namun, waktu ovulasi dan waktu menetas pemijahan alami (159,50 ± 0,50 jam dan 3.210,00 ± 5,00 menit) lebih lama dibanding pemijahan buatan (26,00 ± 2,00 jam dan 2.370.00 ± 15,00 menit). Abnormalitas terjadi pada perlakuan-B (1,30 ± 0,42%), sedangkan larva hasil perlakuan-A tidak ada yang abnormal. Berdasarkan hasil penelitian ini selain pemijahan alami, ikan gabus dapat dipijahkan secara buatan melalui stimulasi hormon pada induk jantan dan betina.Various studies on snakehead fish (Channa striata Blkr) have been carried out from breeding, nursery, to grow-out. Nevertheless, information regarding reproductive performance and produced larvae either from natural spawning or semi-natural (hormonal induction) spawning are still limited in the literature. This study aimed to determine the appropriate spawning technique for snakehead fish. In this study, the fish males and females were used with a uniform gonad maturity level. The study used four hormone stimulation treatments, namely: A (control, without hormone stimulation), B (male and female parents were hormone-stimulated), C (hormone-stimulated female parent), D (hormone-stimulated male parent). The hormone used to induce female and male broodstock was LHRHa + anti-dopamine. Each treatment used three pairs of parents. Parameters of reproductive performance observed included fecundity, egg diameter, hatching time, and egg yolk volume. For larval performance, observations were made of the rate of egg yolk absorption, growth in length and weight of larvae, specific growth rate, and survival. The research found that fish in treatment-A and B were able to ovulate, and the produced eggs could hatch. Fish in treatment-C managed to ovulate but failed to hatch, while treatment-D could not ovulate. The fecundity and hatching rates of the natural spawning were the highest (1,832 ± 13 grains and 97.20 ± 2.49%). However, the time of ovulation and hatching time for natural spawning (159.50 ± 0.50 hours and 3,210.00 ± 5.00 minutes) were longer than those of artificial spawners (26.00 ± 2.00 hours and 2,370.00 ± 15.00 minutes). Abnormalities occurred in treatment-B (1.30 ± 0.42%), while the larvae from treatment-A were normal. Based on the results of this study, in addition to natural spawning, snakehead fish can be spawned artificially through hormonal stimulation of male and female broodstock.


BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Ellen Bronson ◽  
Emmet L. Guy ◽  
Kevin J. Murphy ◽  
Kevin Barrett ◽  
Andrew J. Kouba ◽  
...  

Abstract Background With Panamanian golden frogs (Atelopus zeteki; PGFs) likely extirpated from the wild, ensuring long-term sustainability of captive populations is crucial in order to conserve this critically endangered species. Unfortunately, PGFs display a unique reproductive behavior involving a prolonged period of amplexus leading to challenges in their successful captive propagation. The Maryland Zoo in Baltimore has observed high levels of mortality during the breeding season and suboptimal reproductive success leading to the use of hormone stimulation to aid in reproduction and health management. Methods This project aimed to develop induced ovulation and health management protocols by (1) evaluating different doses of gonadotropin releasing hormone analogue (GnRHa), (2) comparing the efficacy of GnRHa and GnRHa + metoclopramide, (3) determining latency periods and the effects of pulsed hormone sequences; and (4) establish if mortality is impacted by hormone therapy. Female PGFs (n = 174) were given GnRHa either in various concentrations (Experiment 1) or combined with metoclopramide (Experiment 2), and oviposition success, latency, and mortality were measured as binary response variables. Results Overall, the use of exogenous hormones significantly decreased mortality when compared to the control data of natural egg-laying females. GnRHa doses of 0.05 μg/g body weight produced similar ovulation rates compared to higher doses, and the addition of metoclopramide did not increase oviposition success compared to GnRHa alone. Lastly, results indicate the majority of female PGFs will release eggs within 48 h following the initial pulse of hormones with a small percentage ovipositing after a second pulse. Conclusion Findings from this study will benefit captive management of PGFs by documenting the increased survival of females when given hormone stimulation and defining appropriate GnRHa doses and expected latency to spawning.


Author(s):  
Leka-Emiri Sofia ◽  
Fani Athanasouli ◽  
Dimitra Tampouratzi ◽  
Maria Kafetzi ◽  
Eirini Dikaiakou ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document