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Dive into the research topics where Gustavo F. Gonzales is active.

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Featured researches published by Gustavo F. Gonzales.


Andrologia | 2002

Effect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy men

Gustavo F. Gonzales; Amanda Cordova; K. Vega; Arturo Chung; Arturo Villena; Carmen Góñez; S. Castillo

Summary.  This study was a 12‐week double blind placebo‐controlled, randomized, parallel trial in which active treatment with different doses of Maca Gelatinizada was compared with placebo. The study aimed to demonstrate if effect of Maca on subjective report of sexual desire was because of effect on mood or serum testosterone levels. Men aged 21–56 years received Maca in one of two doses: 1500 mg or 3000 mg or placebo.


Aids Care-psychological and Socio-medical Aspects of Aids\/hiv | 2005

AIDS-related discrimination in Asia

S. Paxton; Gustavo F. Gonzales; K. Uppakaew; K. K. Abraham; S. Okta; C. Green; K. S. Nair; T. Parwati Merati; B. Thephthien; M. Marin; A. Quesada

The Asia Pacific Network of People Living with HIV/AIDS (APN+) conducted the first regional documentation of AIDS-related discrimination in Asia. This project was an action-based, peer-implemented study that aimed to develop an understanding of the nature, pattern and extent of AIDS-related discrimination in several Asian countries. Trained HIV-positive people interviewed 764 positive people in four countries (India 302; Indonesia 42; Thailand 338; the Philippines 82) using a structured questionnaire. Findings indicate that the major area of discrimination in each country is within the health sector, where over half of those surveyed experienced some form of discrimination. In all countries, the majority of people did not receive pre-test counselling before being tested for HIV. People who reported coerced testing were significantly more likely than other respondents to face subsequent AIDS-related discrimination. A considerable number of respondents were refused treatment after being diagnosed with HIV and many experienced delayed provision of treatment or health services. Breaches of confidentiality by health workers were common. Within the family and the community, women were significantly more likely to experience discrimination than men, including ridicule and harassment, physical assault and being forced to change their place of residence because of their HIV status. These findings have serious implications, particularly in light of the increasing trend in many countries to test all pregnant women in order to prevent transmission of HIV to their unborn children.


Toxicological Reviews | 2005

Toxicological Aspects of the South American Herbs Cat's Claw (Uncaria tomentosa) and Maca (Lepidium meyenii): A Critical Synopsis

Luis G. Valerio; Gustavo F. Gonzales

Recent exceptional growth in human exposure to natural products known to originate from traditional medicine has lead to a resurgence of scientific interest in their biological effects. As a strategy for improvement of the assessment of their pharmacological and toxicological profile, scientific evidence-based approaches are being employed to appropriately evaluate composition, quality, potential medicinal activity and safety of these natural products. Using this approach, we comprehensively reviewed existing scientific evidence for known composition, medicinal uses (past and present), and documented biological effects with emphasis on clinical pharmacology and toxicology of two commonly used medicinal plants from South America with substantial human exposure from historical and current global use: Uncaria tomentosa (common name: cat’s claw, and Spanish: uña de gato), and Lepidium meyenii (common name: maca). Despite the geographic sourcing from remote regions of the tropical Amazon and high altitude Andean mountains, cat’s claw and maca are widely available commercially in industrialised countries. Analytical characterisations of their active constituents have identified a variety of classes of compounds of toxicological, pharmacological and even nutritional interest including oxindole and indole alkaloids, flavonoids, glucosinolates, sterols, polyunsaturated fatty acids, carbolines and other compounds.The oxindole alkaloids from the root bark of cat’s claw are thought to invoke its most widely sought-after medicinal effects as a herbal remedy against inflammation. We find the scientific evidence supporting this claim is not conclusive and although there exists a base of information addressing this medicinal use, it is limited in scope with some evidence accumulated from in vitro studies towards understanding possible mechanisms of action by specific oxindole alkaloids through inhibition of nuclear factor (NF)-κB activation. Although controlled clinical studies have demonstrated reduction in pain associated with cat’s claw intake in patients with various chronic inflammatory disorders, there is insufficient clinical data overall to draw a firm conclusion for its anti-inflammatory effects. An important observation was that experimental results were often dependent upon the nature of the preparation used. It appears that the presence of unknown substances has an important role in the overall effects of cat’s claw extracts is an important factor for consideration. The available animal toxicological studies did not indicate severe toxicity from oral intake of cat’s claw preparations but rather were suggestive of a low potential for acute and subacute oral toxicity, and a lack of evidence to demonstrate genotoxic potential and mutagenic activity.Maca is a clear example of a herb with substantial medicinal use in traditional herbal medicine by indigenous cultures in South America since the first recorded knowledge of it in the seventeenth century. The hypocotyls of maca are the edible part of the plant used for nutritional and proposed fertility-enhancing properties. Maca has been described to possess many other medicinal properties in traditional herbal medicine but only a few of them have been well studied scientifically. Published clinical studies of maca seem to be related to its property as a nutrient, for male fertility and for energy. There are inadequate data regarding the precise mechanism of action of maca. Some studies suggest that secondary metabolites found in maca extracts are important constituents responsible for its physiological effects. Maca has been reported in the scientific literature to have a low degree of acute oral toxicity in animals and low cellular toxicity in vitro.An important finding unveiled by this review is the importance of standardisation in quality and additional basic and clinical research to scientifically validate and understand composition, biological activity, safety and risk. Development of a comprehensive pharmacological and toxicological profile through critical evaluation of existing and future experimental data, especially carefully conducted clinical studies would facilitate the scientific evidence-based approach to understanding potential biological effects of these major traditionally based herbals in current global use.


Maturitas | 1993

Blood serotonin levels in postmenopausal women: Effects of age and serum oestradiol levels

Gustavo F. Gonzales; Carlos Carrillo

This study investigated the effect of ageing and reduction in ovarian function on whole blood serotonin levels and the effect of the oestrogen replacement in postmenopausal women on blood serotonin levels. Amenorrheic, natural postmenopausal and ovariectomised women had lower blood serotonin levels than regularly menstruating women. Blood serotonin levels increased after oestrogen replacement in postmenopausal women to values similar to those observed in regularly menstruating women. In ovariectomised women, the blood serotonin levels were inversely correlated with age (P < 0.01). In women with different serum oestradiol levels ranging 30-1335 pg/ml, a direct relationship was observed between serum oestradiol levels and whole blood serotonin levels (P < 0.001). It was concluded that whole blood serotonin concentration is reduced during menopause by suppression of ovarian function but may also be an effect of ageing.


Andrologia | 2004

Update on the impact of Chlamydia trachomatis infection on male fertility.

Gustavo F. Gonzales; G. Muñoz; R. Sánchez; Ralf Henkel; G. Gallegos‐Avila; O. Díaz‐Gutierrez; P. Vigil; F. Vásquez; Graciela Kortebani; Alicia B. Mazzolli; E. Bustos‐Obregón

With approximately 90 million cases annually, infection with Chlamydia trachomatis is the most prevalent sexually transmitted bacterial disease in the world. Considering that these infections are often asymptomatic and cause major complications like acute pelvic inflammatory disease, ectopic pregnancy, infertility or infant pneumonia, the estimated costs for diagnosis and treatment in the USA amounts to 2.2 million US dollars for each 500 cases. Therefore, there is a high need for correct, quick and cost‐effective diagnosis and treatment of this urogenital tract infection. New innovative therapies provide good results with regard to efficacy and patients’ compliance. The success rates of treatments are at least 95%. However, the occurrence of antibiotic resistance should not be ignored and new treatment schemes must be developed. The state‐of‐the‐art of diagnosis and treatment of chlamydial infections as well as the pathophysiology is discussed in this review. In conclusion, infections with C. trachomatis is an important public health problem, especially in third world and developing countries, and more socio‐economic studies linking secondary prevention of chlamydial infections, infertility and adverse pregnancy outcome are needed to understand more of its aetiology. In addition, diagnosis and treatment should be improved. Data in men revealed that past infections but not present infections are more related to male infertility. There is still controversial results. In future studies, function of the seminal vesicles and evaluation of the antioxidant capacity should be taken into account when role of C. trachomatis infection on male fertility is assessed.


Reproductive Biology and Endocrinology | 2005

Red maca (Lepidium meyenii) reduced prostate size in rats

Gustavo F. Gonzales; Sara Miranda; Jessica Nieto; Gilma Fernández; Sandra Yucra; Julio Rubio; Pedro Yi; Manuel Gasco

BackgroundEpidemiological studies have found that consumption of cruciferous vegetables is associated with a reduced risk of prostate cancer. This effect seems to be due to aromatic glucosinolate content. Glucosinolates are known for have both antiproliferative and proapoptotic actions.Maca is a cruciferous cultivated in the highlands of Peru. The absolute content of glucosinolates in Maca hypocotyls is relatively higher than that reported in other cruciferous crops. Therefore, Maca may have proapoptotic and anti-proliferative effects in the prostate.MethodsMale rats treated with or without aqueous extracts of three ecotypes of Maca (Yellow, Black and Red) were analyzed to determine the effect on ventral prostate weight, epithelial height and duct luminal area. Effects on serum testosterone (T) and estradiol (E2) levels were also assessed. Besides, the effect of Red Maca on prostate was analyzed in rats treated with testosterone enanthate (TE).ResultsRed Maca but neither Yellow nor Black Maca reduced significantly ventral prostate size in rats. Serum T or E2 levels were not affected by any of the ecotypes of Maca assessed. Red Maca also prevented the prostate weight increase induced by TE treatment. Red Maca administered for 42 days reduced ventral prostatic epithelial height. TE increased ventral prostatic epithelial height and duct luminal area. These increases by TE were reduced after treatment with Red Maca for 42 days. Histology pictures in rats treated with Red Maca plus TE were similar to controls. Phytochemical screening showed that aqueous extract of Red Maca has alkaloids, steroids, tannins, saponins, and cardiotonic glycosides. The IR spectra of the three ecotypes of Maca in 3800-650 cm (-1) region had 7 peaks representing 7 functional chemical groups. Highest peak values were observed for Red Maca, intermediate values for Yellow Maca and low values for Black Maca. These functional groups correspond among others to benzyl glucosinolate.ConclusionsRed Maca, a cruciferous plant from the highland of Peru, reduced ventral prostate size in normal and TE treated rats.


Anti-cancer Agents in Medicinal Chemistry | 2006

Medicinal Plants from Peru: A Review of Plants as Potential Agents Against Cancer

Gustavo F. Gonzales; Luis G. Valerio

Natural products have played a significant role in drug discovery and development especially for agents against cancer and infectious disease. An analysis of new and approved drugs for cancer by the United States Food and Drug Administration over the period of 1981-2002 showed that 62% of these cancer drugs were of natural origin. Natural compounds possess highly diverse and complex molecular structures compared to small molecule synthetic drugs and often provide highly specific biological activities likely derived from the rigidity and high number of chiral centers. Ethnotraditional use of plant-derived natural products has been a major source for discovery of potential medicinal agents. A number of native Andean and Amazonian medicines of plant origin are used as traditional medicine in Peru to treat different diseases. Of particular interest in this mini-review are three plant materials endemic to Peru with the common names of Cats claw (Uncaria tomentosa), Maca (Lepidium meyenii), and Dragons blood (Croton lechleri) each having been scientifically investigated for a wide range of therapeutic uses including as specific anti-cancer agents as originally discovered from the long history of traditional usage and anecdotal information by local population groups in South America. Against this background, we present an evidence-based analysis of the chemistry, biological properties, and anti-tumor activities for these three plant materials. In addition, this review will discuss areas requiring future study and the inherent limitations in their experimental use as anti-cancer agents.


American Journal of Physiology-regulatory Integrative and Comparative Physiology | 2009

Maternal hemoglobin level and fetal outcome at low and high altitudes

Gustavo F. Gonzales; Kyle Steenland; Vilma Tapia

Both, low (<7 g/dl) and high (>14.5 g/dl), maternal hemoglobin (Hb) levels have been related to poor fetal outcome. Most studies have been done at low altitude (LA). Here, we have sought to determine whether this relationship exists at both high and low altitude, and also whether there is an adverse effect of high altitude (HA) on fetal outcome independent of level of maternal hemoglobin. The study is based on a retrospective multicenter analysis of 35,449 pregnancies at LA and six other cities above 3000 meters. In analyses of all women at both LA and HA, those with Hb <9 g/dl had odds ratios (ORs) and 95% confidence intervals (CI) of 4.4 (CI: 2.8-6.7), 2.5 (CI: 1.9-3.2), and 1.4 (CI: 1.1-1.9) for stillbirths, preterm, and small for gestational age (SGA) births, respectively, compared with women with 11-12.9 g/dl of Hb, after adjustment for confounders. These risks by hemoglobin level differed little between women at LA and HA, suggesting that no correction of the definition of anemia is necessary for women at HA. Women living at high altitude with hemoglobin >15.5 g/dl had higher risks for stillbirths (OR: 1.3; CI: 1.05-1.3), preterm (OR: 1.5; CI 1.3-1.8), and SGA births (OR: 2.1, CI 1.8-2.3). There was also a significant adverse effect of living at HA, independent of hemoglobin level for all three outcomes (OR: 3.9, 1.7, and 2.3; CI: 2.8-5.2, 1.5-1.9, and 2.1-2.5) for stillbirths, preterms, and SGA respectively, after adjusting for hemoglobin level. Both, high and low maternal hemoglobin levels were related to poor pregnancy outcome, with similar effect of low hemoglobin in both LA and HA. Our data suggest, that maternal hemoglobin above 11 g/dl but below 13 g/dl is the area of minimal risk of poor adverse outcomes. Living at HA had an adverse effect independent of hemoglobin level.


International Journal of Occupational and Environmental Health | 2005

Lead Exposure and Semen Quality among Traffic Police in Arequipa, Peru

Lynn Eibensteiner; Ada Del Carpio Sanz; Howard Frumkin; Carla Gonzales; Gustavo F. Gonzales

Abstract This study examined lead exposure (n = 43) and semen quality (n = 18) among traffic police officers in Arequipa, Peru, where leaded gasoline is used. Blood lead (PbB), was measured using atomic absorption spectrophotometry, and semen was analyzed following World Health Organization (WHO) protocol. Mean PbB was 48.5 μg/dL. Although current PbBwas associated with declines in several semen parameters (sperm morphology, concentration and total number of sperm), only sperm motility and viability differed significantly between the ≤40 μg/dL and > 40 μg/dL categories, and decreased with increasing PbB in simple linear regression. Traffic police are an indicator group for excessive ambient lead exposure, and these results support earlier findings on the male reproductive toxicity of lead. The results should be interpreted cautiously since the numbers were small and the analysis was unable to controlfor all potential confounders due to incomplete data.


Fertility and Sterility | 1992

Leukocytospermia and function of the seminal vesicles on seminal quality

Gustavo F. Gonzales; Graciela Kortebani; Alicia B. Mazzolli

OBJECTIVE To determine possible relationships between number of leukocytes, function of seminal vesicles, and seminal quality. DESIGN The study was carried out on men who consecutively attended an infertility clinic between June 1989 to June 1991. SETTING This study was conducted in a private immunological center for infertility, a tertiary care center, The Centro Immunológico-Sección Esterilidad y Reproducción. PATIENTS Semen samples from 280 infertility patients attending an Immunological Center for Infertility were analyzed. MAIN OUTCOME MEASURE We evaluated the effect of leukocytospermia in the presence of normal or abnormal function of seminal vesicles on seminal quality. RESULTS Sperm count, percent of motile sperm, and percent of sperm vitality were significantly reduced when both leukocytospermia and hypofunction of seminal vesicles were present (P less than 0.01). Leukocytospermic subjects with normal function of seminal vesicles showed similar seminal parameters to those nonleukocytspermics. The incidence of subjects with antisperm antibodies measured by direct immunobeads was significantly higher in leukocytospermic men with hypofunction of seminal vesicles. No differences in the incidence of antisperm antibodies with nonleukocytospermic samples were observed in those with both leukocytospermia and normal function of seminal vesicles. CONCLUSIONS These data provide evidence that white blood cells were deleterious for seminal quality when seminal vesicles were also affected.

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Manuel Gasco

Cayetano Heredia University

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Vilma Tapia

Cayetano Heredia University

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Julio Rubio

Cayetano Heredia University

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Arturo Villena

Cayetano Heredia University

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Carla Gonzales

Cayetano Heredia University

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Sandra Yucra

Cayetano Heredia University

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Carlos Carrillo

Cayetano Heredia University

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Carmen Góñez

Cayetano Heredia University

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