Valmore Bermudez

Prof. Valmore Bermudez

orcid

Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2014 in International Journal of Reproductive Medicine
Verified
Journal Article
Open access
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JRJoselyn Rojas
Joselyn Rojas
MCMervin Chávez
Mervin Chávez
LOLuis Olivar
Luis Olivar
MRMilagros Rojas
Milagros Rojas
JMJessenia Morillo
Jessenia Morillo
VBValmore Bermudez
Valmore Bermudez
Polycystic ovary syndrome (PCOS) is a highly prevalent endocrine-metabolic disorder that implies various severe consequences to female health, including alarming rates of infertility. Although its exact etiology remains elusive, it is known to feature several hormonal disturbances, including hyperandrogenemia, insulin resistance (IR), and hyperinsulinemia. Insulin appears to disrupt all components of the hypothalamus-hypophysis-ovary axis, and ovarian tissue insulin resistance results in impaired metabolic signaling but intact mitogenic and steroidogenic activity, favoring hyperandrogenemia, which appears to be the main culprit of the clinical picture in PCOS. In turn, androgens may lead back to IR by increasing levels of free fatty acids and modifying muscle tissue composition and functionality, perpetuating this IR-hyperinsulinemia-hyperandrogenemia cycle. Nonobese women with PCOS showcase several differential features, with unique biochemical and hormonal profiles. Nevertheless, lean and obese patients have chronic inflammation mediating the long term cardiometabolic complications and comorbidities observed in women with PCOS, including dyslipidemia, metabolic syndrome, type 2 diabetes mellitus, and cardiovascular disease. Given these severe implications, it is important to thoroughly understand the pathophysiologic interconnections underlying PCOS, in order to provide superior therapeutic strategies and warrant improved quality of life to women with this syndrome.

19 February 2018 in Journal of Diabetes Research
Verified
Journal Article
Open access
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JRJoselyn Rojas
Joselyn Rojas
VBValmore Bermudez
Valmore Bermudez
JPJim Palmar
Jim Palmar
MMMaría Sofía Martínez
María Sofía Martínez
LOLuis Olivar
Luis Olivar
MVManuel Velasco
Manuel Velasco
Purpose of Review. Describing the diverse molecular mechanisms (particularly immunological) involved in the death of the pancreatic beta cell in type 1 and type 2 diabetes mellitus. Recent Findings. Beta cell death is the final event in a series of mechanisms that, up to date, have not been entirely clarified; it represents the pathophysiological mechanism in the natural history of diabetes mellitus. These mechanisms are not limited to an apoptotic process only, which is characteristic of the immune-mediated insulitis in type 1 diabetes mellitus. They also include the action of proinflammatory cytokines, the production of reactive oxygen species, DNA fragmentation (typical of necroptosis in type 1 diabetic patients), excessive production of islet amyloid polypeptide with the consequent endoplasmic reticulum stress, disruption in autophagy mechanisms, and protein complex formation, such as the inflammasome, capable of increasing oxidative stress produced by mitochondrial damage. Summary. Necroptosis, autophagy, and pyroptosis are molecular mechanisms that modulate the survival of the pancreatic beta cell, demonstrating the importance of the immune system in glucolipotoxicity processes and the potential role for immunometabolism as another component of what once known as the “ominous octet.”

19 June 2022 in Pharmaceutics
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Journal Article
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Carla NavarroCarla Navarro
Carla Navarro
AOAngel Ortega
Angel Ortega
Raquel Gabriela SantelizRaquel Gabriela Santeliz
Raquel Gabriela Santeliz
Bermary GarridoBermary Garrido
Bermary Garrido
MCMaricarmen Chacin
Maricarmen Chacin
VBValmore Bermudez
Valmore Bermudez
The constant changes in cancer cell bioenergetics are widely known as metabolic reprogramming. Reprogramming is a process mediated by multiple factors, including oncogenes, growth factors, hypoxia-induced factors, and the loss of suppressor gene function, which support malignant transformation and tumor development in addition to cell heterogeneity. Consequently, this hallmark promotes resistance to conventional anti-tumor therapies by adapting to the drastic changes in the nutrient microenvironment that these therapies entail. Therefore, it represents a revolutionary landscape during cancer progression that could be useful for developing new and improved therapeutic strategies targeting alterations in cancer cell metabolism, such as the deregulated mTOR and PI3K pathways. Understanding the complex interactions of the underlying mechanisms of metabolic reprogramming during cancer initiation and progression is an active study field. Recently, novel approaches are being used to effectively battle and eliminate malignant cells. These include biguanides, mTOR inhibitors, glutaminase inhibition, and ion channels as drug targets. This review aims to provide a general overview of metabolic reprogramming, summarise recent progress in this field, and emphasize its use as an effective therapeutic target against cancer.

Verified
Journal Article
Open access
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GBGabriela Barros
Gabriela Barros
PDPablo Duran
Pablo Duran
IVIvana Paola Vera
Ivana Paola Vera
VBValmore Bermudez
Valmore Bermudez
Obesity is a major public health issue worldwide since it is associated with the development of chronic comorbidities such as type 2 diabetes, dyslipidemias, atherosclerosis, some cancer forms and skin diseases, including psoriasis. Scientific evidence has indicated that the possible link between obesity and psoriasis may be multifactorial, highlighting dietary habits, lifestyle, certain genetic factors and the microbiome as leading factors in the progress of both pathologies because they are associated with a chronic pro-inflammatory state. Thus, inflammation management in obesity is a plausible target for psoriasis, not only because of the sick adipose tissue secretome profile but also due to the relationship of obesity with the rest of the immune derangements associated with psoriasis initiation and maintenance. Hence, this review will provide a general and molecular overview of the relationship between both pathologies and present recent therapeutic advances in treating this problem.

Verified
Journal Article
Open access
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RCRaquel Cano
Raquel Cano
JPJose Perez
Jose Perez
LALissé Angarita
Lissé Angarita
AOAngel Ortega
Angel Ortega
YGYosselin Gómez
Yosselin Gómez
VBValmore Bermudez
Valmore Bermudez
Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver disorder, affecting around 25% of the population worldwide. It is a complex disease spectrum, closely linked with other conditions such as obesity, insulin resistance, type 2 diabetes mellitus, and metabolic syndrome, which may increase liver-related mortality. In light of this, numerous efforts have been carried out in recent years in order to clarify its pathogenesis and create new prevention strategies. Currently, the essential role of environmental pollutants in NAFLD development is recognized. Particularly, endocrine-disrupting chemicals (EDCs) have a notable influence. EDCs can be classified as natural (phytoestrogens, genistein, and coumestrol) or synthetic, and the latter ones can be further subdivided into industrial (dioxins, polychlorinated biphenyls, and alkylphenols), agricultural (pesticides, insecticides, herbicides, and fungicides), residential (phthalates, polybrominated biphenyls, and bisphenol A), and pharmaceutical (parabens). Several experimental models have proposed a mechanism involving this group of substances with the disruption of hepatic metabolism, which promotes NAFLD. These include an imbalance between lipid influx/efflux in the liver, mitochondrial dysfunction, liver inflammation, and epigenetic reprogramming. It can be concluded that exposure to EDCs might play a crucial role in NAFLD initiation and evolution. However, further investigations supporting these effects in humans are required.

1 March 2007 in American Journal of Therapeutics
Verified
Journal Article
Closed access
NRNadia Reyna-Villasmil
Nadia Reyna-Villasmil
VBValmore Bermudez
Valmore Bermudez
EMEdgardo Mengual-Moreno
Edgardo Mengual-Moreno
NANelly Arias
Nelly Arias
CCClímaco Cano-Ponce
Clímaco Cano-Ponce
NANaikt Arraiz
Naikt Arraiz
To investigate the effect of bread formulated with 6 g of beta-glucan (oat soluble fiber) on serum lipids in overweight normotensive subjects with mild to moderate hypercholesterolemia. Thirty-eight male subjects [mean age 59.8 +/- 0.6 yr, mean body mass index (BMI) 28.3 +/- 0.6 kg/m(2)] who were eligible for the study ate an isocaloric diet for a 1-week period. They were then divided into 2 groups: group A (n = 19), who were maintained on American Heart Association (AHA) Step II diet, including whole wheat bread, and group B (n = 19), who were maintained on AHA Step II diet containing high levels of monounsaturated fatty acids plus bread containing 6 g of beta-glucan (Nutrim-OB) for 8 weeks. Plasma lipids and glucose were measured at baseline and after weeks 8 in all subjects. All subjects were advised to walk for 60 minutes every day. There was a significant increase (upward arrow 27.8%) in plasma high density lipoprotein (HDL) cholesterol in the beta-glucan group (group A) from 39.4 +/- 2.0 to 49.5 +/- 2.1 mg/dL (P < 0.001), but there was no change in group B. There was a significant reduction in total cholesterol in the 2 groups to approximately the same extent: group A, from 232.8 +/- 2.7 mg/dL to 202.7 +/- 6.7 mg/dL; P < 0.001; and group B, from 231.8 +/- 4.3 mg/dL to 194.2 +/- 4.3 mg dL; P < 0.001. Plasma low density lipoprotein (LDL) cholesterol also decreased significantly in the two groups: group A, from 160.3 +/- 2.8 mg/dL to 133.2 +/- 5.4 mg/dL; P < 0.001; group B, from 167.9 +/- 4.3 mg/dL to 120.9 +/- 4.3 mg/dL; P < 0.001; however, the beta-glucan fortified diet was significantly more effective (downward arrow 27.3% vs. downward arrow 16.8%; P < 0.04). There was a small and insignificant reduction in plasma very LDL (VLDL) cholesterol and triglycerides in the two groups. Similarly, non-HDL cholesterol levels were also decreased, with beta-glucan diet producing significantly higher effect (downward arrow 24.5% vs. downward arrow 16.1%; P < 0.04). The beta-glucan diet also produced higher reduction in total cholesterol/HDL cholesterol ratio (downward arrow 33.3% vs. downward arrow 8.4%; P < 0.003) and LDL cholesterol/HDL cholesterol ratio (downward arrow 42.1% vs. downward arrow 13.3%; P < 0.001) than the diet without beta-glucan. The beta-glucan diet also decreased fasting plasma glucose (P < 0.4), whereas the other diet had no effect. Interestingly, both diets reduced body weight and BMI significantly, with beta-glucan diet having a greater effect. Six grams of beta-glucan from oats added to the AHA Step II diet and moderate physical activity improved lipid profile and caused a decrease in weight and, thus, reduced the risk of cardiovascular events in overweight male individuals with mild to moderate hypercholesterolemia. The diet with added beta-glucan was well accepted and tolerated.