scholarly journals The Aromatase–Estrogen System in the Testes of Non-Mammalian Vertebrates

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1763
Author(s):  
Luigi Rosati ◽  
Sara Falvo ◽  
Gabriella Chieffi Chieffi Baccari ◽  
Alessandra Santillo ◽  
Maria Maddalena Di Di Fiore
Keyword(s):  
Aromatase Inhibitors ◽  
Reproductive Performance ◽  
Sex Differentiation ◽  
Aromatase Activity ◽  
Seasonal Breeding ◽  
P450 Aromatase ◽  
17Β Estradiol ◽  
Positive Results ◽  
Reptilian Species

Estrogens are important physiological regulators of testicular activity in vertebrates. Estrogen levels depend on the activity of P450 aromatase, the enzyme responsible for the irreversible conversion of testosterone into 17β-estradiol. Therefore, P450 aromatase is the key player in the aromatase–estrogen system. The present review offers a comparative overview of P450 aromatase activity in male gonads of amphibians, reptiles, and birds, with a particular emphasis on the functions of the aromatase–estrogen system in these organisms during their developmental and adult stages. The aromatase–estrogen system appears to be crucial for the sex differentiation of gonads in vertebrates. Administration of aromatase inhibitors prior to sexual differentiation of gonads results in the development of males rather than females. In adults, both aromatase and estrogen receptors are expressed in somatic cells, Leydig and Sertoli cells, as well as germ cells, with certain differences among different species. In seasonal breeding species, the aromatase–estrogen system serves as an “on/off” switch for spermatogenesis. In some amphibian and reptilian species, increased estrogen levels in post-reproductive testes are responsible for blocking spermatogenesis, whereas, in some species of birds, estrogens function synergistically with testosterone to promote spermatogenesis. Recent evidence indicates that the production of the aromatase enzyme in excessive amounts reduces the reproductive performance in avian species of commercial interest. The use of aromatase inhibitors to improve fertility has yielded suitable positive results. Therefore, it appears that the role of the aromatase–estrogen system in regulating the testicular activity differs not only among the different classes of vertebrates but also among different species within the same class.

Different modulation of aromatase activity in frog testis in vitro by ACE and ANG II

1999 ◽  
Vol 277 (5) ◽  
pp. R1261-R1267
Author(s):  
Antonino Miano ◽  
Anna Gobbetti ◽  
Massimo Zerani ◽  
Luana Quassinti ◽  
Ennio Maccari ◽  
...  
Keyword(s):  
Physiological Role ◽  
Rana Esculenta ◽  
Aromatase Activity ◽  
Ang Ii ◽  
Prostaglandin Production ◽  
Testicular Steroidogenesis ◽  
17Β Estradiol ◽  
Prereproductive Period

The aim of the present research was to study the role of angiotensin-converting enzyme (ACE) and ANG II in amphibian ( Rana esculenta) testicular steroidogenesis and prostaglandin production. Hormonal effects of ACE, ACE inhibitors, synthetic bullfrog ANG I, and [Val5]ANG II were determined in frog testis of prereproductive period. Production of 17β-estradiol, progesterone, androgens, and PGE2 and PGF2α was determined by incubating frog testes with ACE (2.5 mU/ml), captopril (0.1 mM), lisinopril (0.1 mM), [Val5]ANG II (1 μM), and synthetic bullfrog ANG I (1 μM). The analysis of the data showed an independent modulation of 17β-estradiol and androgen production by ACE and ANG II. The ACE pathway caused a decrease of 17β-estradiol production and an increase of androgen production in frog testes; on the other hand, the ANG II pathway increased 17β-estradiol production and decreased androgen production. The determination of testicular aromatase activity showed a positive regulation by ANG II and a negative regulation by ACE. As for prostaglandin production, only ANG II influenced PGF2α. These results suggest a new physiological role of ACE and ANG II in modulating steroidogenesis and prostaglandin production.

Aromatase (CYP19) inhibition by biflavonoids obtained from the branches of Garcinia gardneriana (Clusiaceae)

2019 ◽  
Vol 74 (9-10) ◽  
pp. 279-282 ◽  
Author(s):  
Angelica Maria Recalde-Gil ◽  
Luiz Klein-Júnior ◽  
Juliana Salton ◽  
Sérgio Bordignon ◽  
Valdir Cechinel-Filho ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Aromatase Inhibitors ◽  
Anticancer Agents ◽  
Breast Cancer Cells ◽  
In Vitro Assay ◽  
Aromatase Activity ◽  
Vitro Assay

Abstract Overexpression of aromatase in breast cancer cells may substantially influence its progression and maintenance. In this sense, the inhibition of aromatase is a key target for the treatment of breast cancer in postmenopausal women. Although several flavonoids had already demonstrated the capacity of inhibiting aromatase activity, the role of biflavonoids as aromatase inhibitors is poorly studied. In this work, the biflavonoids isolated from Garcinia gardneriana, morelloflavone (1), Gb-2a (2) and Gb-2a-7-O-glucose (3) were submitted to in vitro assay to evaluate the aromatase modulatory effect. As results, it was demonstrated that all biflavonoids were able to inhibit the enzyme, with IC50 values ranging from 1.35 to 7.67 μM. This demonstrates that biflavonoids are an important source of scaffolds for the development of new aromatase inhibitors, focusing on the development of new anticancer agents.

Double-Balloon Enteroscopy in Detecting Small-Bowel Neuroendocrine Neoplasms: A Single-Center Prospective Study

Digestion ◽  
2020 ◽  
pp. 1-9
Author(s):  
Roberta Elisa Rossi ◽  
Luca Elli ◽  
Federica Branchi ◽  
Dario Conte ◽  
Sara Massironi
Keyword(s):  
Small Bowel ◽  
Neuroendocrine Neoplasm ◽  
Unknown Primary ◽  
Neuroendocrine Neoplasms ◽  
Double Balloon Enteroscopy ◽  
Balloon Enteroscopy ◽  
Double Balloon ◽  
Diagnostic Role ◽  
Positive Results

<b><i>Background and Aim:</i></b> Small-bowel neuroendocrine neoplasm (sbNEN) diagnosis has improved with double-balloon enteroscopy (DBE). DBE efficacy in the detection of sbNENs is unknown. We aimed to report the experience at a single referral center for NENs. <b><i>Methods:</i></b> All consecutive patients with a suspected sbNEN selected for diagnostic DBE were enrolled. <b><i>Results:</i></b> Between 2011 and 2016, 25 patients were referred for a suspected sbNEN. In 15/25 patients, a primary NEN was detected outside the small bowel; in 4, NEN was excluded. After extensive workup, 6 patients (4 males, median age 50 years) underwent DBE (3 anterograde, 2 retrograde, and 1 both; median time: 60 min; median insertion 200 cm). DBE was positive in 3 patients: one had an ileal 2-cm NEN G1, one had an ileal 1.3-cm NEN G1, and one had an ileal 1-cm NEN G2, all surgically removed. Of the 3 other patients, one had a metastatic NEN of unknown primary, the other two had small intestinal NENs, both surgically removed (1.6-cm G1 and G2 NEN). DBE showed a sensitivity of 60% and, in absence of false-positive results, a specificity of 100%. Accuracy resulted 67%. No complications were observed. <b><i>Conclusions:</i></b> In line with data from the literature, the present series showed that DBE is a safe and effective procedure in the diagnosis of sbNENs. Further studies are needed to better clarify the diagnostic role of DBE in the neuroendocrine tumor setting and its relationship with other techniques.

scholarly journals Role of Transperineal Ultrasound (TPUS) in Children with Ambiguous Genitalia

2021 ◽  
Author(s):  
Krithika Rangarajan ◽  
Manisha Jana ◽  
Nagesh Wadgera ◽  
Arun Kumar Gupta ◽  
Minu Bajpai ◽  
...  
Keyword(s):  
Gold Standard ◽  
Sex Differentiation ◽  
Ambiguous Genitalia ◽  
Transperineal Ultrasound ◽  
Transabdominal Ultrasound ◽  
Resonance Imaging ◽  
Normal Children ◽  
Genital Ambiguity ◽  
Magnetic Resonance Imaging Mri

Abstract Objectives Accurate delineation of anatomy in children with ambiguous genitalia early in life is important. This commonly involves conventional fluoroscopic genitogram (traumatic to the child) and magnetic resonance imaging (MRI) examination (involves sedation). In this study, our objectives were twofold: (1) to describe the findings on transperineal ultrasound (TPUS) in normal children and (2) to describe the findings on TPUS in children with ambiguous genitalia and correlate them with conventional genitogram. Materials and Methods TPUS was prospectively performed in 10 children without genital ambiguity (5 girls and 5 boys). Subsequently, 15 consecutive children having disorders of sex differentiation (DSDs) with genital ambiguity underwent TPUS. The presence or absence of müllerian structures was documented. Of these patients, 14 also underwent conventional genitogram as a part of routine evaluation. The gold standard was established either by comparison with surgical findings (in patients who underwent surgery) or by comparison with a combination of findings on genitogram and transabdominal ultrasound in patients who did not undergo surgery. Results In all normal children, lower urogenital tracts could be clearly delineated on TPUS. Out of the 15 children with ambiguous genitalia, TPUS could establish the presence/absence of müllerian structures in 14. This was concordant with findings on conventional genitogram/surgery. In one patient, müllerian structure was missed on TPUS but demonstrated on genitogram. In two children, TPUS showed the müllerian structure, which was not seen on genitogram. When both the controls and the cases were combined, TPUS had an accuracy of 95% and specificity of 100% in the detection of müllerian structures. Conclusion TPUS is feasible and accurate in demonstration of lower urogenital tract anatomy in children with DSDs having ambiguous genitalia. It can be performed without sedation, and is suitable for use as a screening modality in children with ambiguous genitalia.

A study of factors which influence the job satisfaction of stockpeople on commercial pig farms

1990 ◽  
Vol 1990 ◽  
pp. 95-95
Author(s):  
R C Segundo ◽  
P R English ◽  
G Burgess ◽  
S A Edwards ◽  
O MacPherson ◽  
...  
Keyword(s):  
Job Satisfaction ◽  
Reproductive Performance ◽  
Research Work ◽  
Farm Animals ◽  
Considerable Influence ◽  
Pig Farms ◽  
And Performance ◽  
The Uk ◽  
Farm Livestock

The role of stockmanship in relation to the wellbeing of farm animals has been emphasised in the UK Codes of Recommendations for the Welfare of Farm Livestock (MAFF, 1983). Moreover, previous research work has demonstrated important effects of good and bad stockmanship not only on welfare but also on growth, lactational and reproductive performance of pigs and other farm livestock (Hemsworth et al, 1987). There is a need, therefore, to establish the factors which motivate and demotivate stockpeople since the degree of job satisfaction is likely to have a considerable influence on the attitude and performance of stockpeople and on their empathy with the animals in their care. With this objective in mind, a questionnaire was designed to investigate the aspects which could have an influence on the job satisfaction of the stockpeople involved in pig production.

scholarly journals Sex Differentiation in Amphibians: Effect of Temperature and Its Influence on Sex Reversal

2021 ◽  
pp. 1-11
Author(s):  
Adrián Ruiz-García ◽  
Álvaro S. Roco ◽  
Mónica Bullejos
Keyword(s):  
Sexual Differentiation ◽  
Sex Differentiation ◽  
Environmental Contaminants ◽  
Natural Populations ◽  
Sex Reversal ◽  
The Other ◽  
Effect Of Temperature ◽  
Amphibian Species ◽  
Expected Increase

The role of environmental factors in sexual differentiation in amphibians is not new. The effect of hormones or hormone-like compounds is widely demonstrated. However, the effect of temperature has traditionally been regarded as something anecdotal that occurs in extreme situations and not as a factor to be considered. The data currently available reveal a different situation. Sexual differentiation in some amphibian species can be altered even by small changes in temperature. On the other hand, although not proven, it is possible that temperature is related to the appearance of sex-reversed individuals in natural populations under conditions unrelated to environmental contaminants. According to this, temperature, through sex reversal (phenotypic sex opposed to genetic sex), could play an important role in the turnover of sex-determining genes and in the maintenance of homomorphic sex chromosomes in this group. Accordingly, and given the expected increase in global temperatures, growth and sexual differentiation in amphibians could easily be affected, altering the sex ratio in natural populations and posing major conservation challenges for a group in worldwide decline. It is therefore particularly urgent to understand the mechanism by which temperature affects sexual differentiation in amphibians.

Role of MR venography in the evaluation of deep venous thrombosis

1997 ◽  
Vol 38 (5) ◽  
pp. 907-912 ◽  
Author(s):  
C. Catalano ◽  
P. Pavone ◽  
A. Laghi ◽  
A. Scipioni ◽  
F. Fanelli ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Sensitivity And Specificity ◽  
Filling Defect ◽  
Clinical Suspicion ◽  
Mr Venography ◽  
Diagnostic Modalities ◽  
Positive Results ◽  
Intraluminal Filling Defect

Purpose: MR venography has been recommended for the evaluation of deep venous thrombosis. The purpose of our study was to determine the role of MR venography, in particular at the level of the pelvis where other diagnostic modalities show major limitations. Materials and Methods: Forty-three patients with clinical suspicion of deep venous thrombosis were examined by means of pelvic MR venography. In all cases, a 2D-TOF sequence was used with cranial arterial presaturation. In selected cases, i.e. when a small intraluminal filling defect was present, a cine-PC sequence was used in addition in order to exclude the presence of a pulsatility artifact as causing the filling defect. In all cases, contrast venography was also performed and considered to be the standard of reference. Results: MR venography showed 26 patients to be positive for deep venous thrombosis at the pelvic level. These positive results were correct in 25 cases. The analysis of the results provided values of sensitivity and specificity of respectively 100% and 94%, with an overall accuracy of 97.6%. Conclusion: Our results indicate that MR can provide highly accurate images, similar to those of contrast venography, in a noninvasive fashion. It is particularly useful in the pelvic region where the limitations of other imaging modalities are more evident.

scholarly journals A critical evaluation of the role of aromatase inhibitors as adjuvant therapy for postmenopausal women with breast cancer

2011 ◽  
Vol 18 (3) ◽  
pp. R79-R89 ◽  
Author(s):  
Thierry Petit ◽  
Patrick Dufour ◽  
Ian Tannock
Keyword(s):  
Postmenopausal Women ◽  
Aromatase Inhibitors ◽  
Critical Evaluation ◽  
Disease Free Survival ◽  
Current Evidence ◽  
Free Survival ◽  
Node Positive Disease ◽  
Expected Benefits ◽  
Disease Free

The introduction of aromatase inhibitors (AI) has provided more options for adjuvant treatment of postmenopausal women; they are associated with improved disease-free survival, but less commonly with improvements in overall survival. Current evidence suggests that women at high risk of recurrence, especially those with node-positive disease, should receive an AI for 2 years as part of their treatment, but routine prescription of AIs to postmenopausal patients with low-risk disease is not appropriate. Not only the expected benefits but also the specific toxicity of the prescribed hormone therapy, and its cost, should be considered when selecting treatment.

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