Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
Virol J ; 20(1): 50, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36949470

RESUMO

BACKGROUND: Plants are used in traditional healing practices of many cultures worldwide. Momordica balsamina is a plant commonly used by traditional African healers as a part of a treatment for HIV/AIDS. It is typically given as a tea to patients with HIV/AIDS. Water-soluble extracts of this plant were found to contain anti-HIV activity. METHODS: We employed cell-based infectivity assays, surface plasmon resonance, and a molecular-cell model of the gp120-CD4 interaction to study the mechanism of action of the MoMo30-plant protein. Using Edman degradation results of the 15 N-terminal amino acids, we determined the gene sequence of the MoMo30-plant protein from an RNAseq library from total RNA extracted from Momordica balsamina. RESULTS: Here, we identify the active ingredient of water extracts of the leaves of Momordica balsamina as a 30 kDa protein we call MoMo30-plant. We have identified the gene for MoMo30 and found it is homologous to a group of plant lectins known as Hevamine A-like proteins. MoMo30-plant is distinct from other proteins previously reported agents from the Momordica species, such as ribosome-inactivating proteins such as MAP30 and Balsamin. MoMo30-plant binds to gp120 through its glycan groups and functions as a lectin or carbohydrate-binding agent (CBA). It inhibits HIV-1 at nanomolar levels and has minimal cellular toxicity at inhibitory levels. CONCLUSIONS: CBAs like MoMo30 can bind to glycans on the surface of the enveloped glycoprotein of HIV (gp120) and block entry. Exposure to CBAs has two effects on the virus. First, it blocks infection of susceptible cells. Secondly, MoMo30 drives the selection of viruses with altered glycosylation patterns, potentially altering their immunogenicity. Such an agent could represent a change in the treatment strategy for HIV/AIDS that allows a rapid reduction in viral loads while selecting for an underglycosylated virus, potentially facilitating the host immune response.


Assuntos
Síndrome da Imunodeficiência Adquirida , HIV-1 , Momordica , Plantas Medicinais , Humanos , HIV-1/genética , Momordica/química , Momordica/metabolismo , Proteínas de Plantas/metabolismo , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp120 do Envelope de HIV/farmacologia
2.
J Health Care Poor Underserved ; 34(3S): xii-xiv, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38661908

RESUMO

Note from the editor: This column was originally published in 2013. Currently, Dr. Hildreth serves as president and CEO of Meharry Medical College, leading the technological, academic, and clinical transformation of the nation's largest private historically Black academic health sciences center. Because of his standing as a world-class infectious disease expert, Hildreth emerged as an important national figure in the response to the COVID-19 pandemic. In September 2020, he was appointed to the FDA Vaccines and Related Biological Products Advisory Committee that reviewed COVID-19 vaccine candidates for approval, and in February 2021, Dr. Hildreth was named to President Joseph Biden's Health Equity Task Force.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , História do Século XXI , Estados Unidos , Vacinas contra COVID-19/administração & dosagem , História do Século XX
3.
Breast Cancer (Auckl) ; 12: 1178223418759296, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29511356

RESUMO

OBJECTIVE: Increased mammographic breast density is a well-established risk factor for breast cancer development, regardless of age or ethnic background. The current gold standard for categorizing breast density consists of a radiologist estimation of percent density according to the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS) criteria. This study compares paired qualitative interpretations of breast density on digital mammograms with quantitative measurement of density using Hologic's Food and Drug Administration-approved R2 Quantra volumetric breast density assessment tool. Our goal was to find the best cutoff value of Quantra-calculated breast density for stratifying patients accurately into high-risk and low-risk breast density categories. METHODS: Screening digital mammograms from 385 subjects, aged 18 to 64 years, were evaluated. These mammograms were interpreted by a radiologist using the ACR's BI-RADS density method, and had quantitative density measured using the R2 Quantra breast density assessment tool. The appropriate cutoff for breast density-based risk stratification using Quantra software was calculated using manually determined BI-RADS scores as a gold standard, in which scores of D3/D4 denoted high-risk densities and D1/D2 denoted low-risk densities. RESULTS: The best cutoff value for risk stratification using Quantra-calculated breast density was found to be 14.0%, yielding a sensitivity of 65%, specificity of 77%, and positive and negative predictive values of 75% and 69%, respectively. Under bootstrap analysis, the best cutoff value had a mean ± SD of 13.70% ± 0.89%. CONCLUSIONS: Our study is the first to publish on a North American population that assesses the accuracy of the R2 Quantra system at breast density stratification. Quantitative breast density measures will improve accuracy and reliability of density determination, assisting future researchers to accurately calculate breast cancer risks associated with density increase.

5.
Contraception ; 74(2): 90-9, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16860045

RESUMO

INTRODUCTION: This 7-year, prospective, matched-cohort, clinical study evaluated the effects of intramuscular depot medroxyprogesterone acetate (DMPA) (150 mg/mL) on bone mineral density (BMD) in women aged 25-35 years. METHODS: Bone mineral density changes in new DMPA-IM users (n=248) were compared with those in women using nonhormonal contraception (n=360) for up to 240 weeks of treatment and 96 weeks of posttreatment follow-up (in subjects receiving >or=1 dose). RESULTS: At week 240 of treatment, mean percentage changes from baseline in DMPA-IM vs. nonhormonal subjects were: -5.16% (n=21) vs. +0.19% (n=65), total hip (p<.001); -5.38% (n=33) vs. +0.43% (n=105), lumbar spine (p<.001). At week 96 posttreatment, these values were: -0.20% (n=25) vs. +0.84% (n=43), total hip (p=.047); -1.19% (n=41) vs. +0.47% (n=66), lumbar spine (p=.017). CONCLUSIONS: These results show BMD declines during DMPA-IM use; following discontinuation, significant increases in BMD occur through 96 weeks posttreatment.


Assuntos
Densidade Óssea/efeitos dos fármacos , Anticoncepcionais Femininos/efeitos adversos , Acetato de Medroxiprogesterona/efeitos adversos , Adulto , Peso Corporal , Osso e Ossos/metabolismo , Estudos de Coortes , Anticoncepcionais Femininos/administração & dosagem , Feminino , Humanos , Lipídeos/sangue , Acetato de Medroxiprogesterona/administração & dosagem , Osteocalcina/sangue , Estudos Prospectivos
8.
Ann N Y Acad Sci ; 955: 343-52; discussion 389-93, 396-406, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11949960

RESUMO

Endometriosis is a common gynecologic disorder that affects approximately 14% of all women and 30% to 50% of infertile women. Since the most common symptoms of endometriosis--progressive dysmenorrhea, dyspareunia, chronic pelvic pain, and infertility--are also symptoms of multiple disorders, a diagnosis of endometriosis can be elusive and confirmed only by visualization, that is, laparoscopy. Endometriosis is often treated surgically upon diagnosis; however, the rate of recurrence is high, suggesting that a combination of therapeutic approaches might provide better outcomes than any one option alone. The most widely utilized hormonal treatments for endometriosis are GnRH agonists and oral contraceptives; agents indicated by the Food and Drug Administration include GnRH agonists and the androgen, danazol. The majority of evidence in support of medical therapy for endometriosis is largely observational, with the exception of studies of GnRH agonists, danazol, and a few progestins. Conventional treatment approaches for the medical management of endometriosis focus on suspected endometriosis, following a diagnosis of endometriosis, following surgical treatment of endometriosis, long-term management, and retreatment. Although major advances have been made in the treatment of endometriosis in recent decades, lack of randomized clinical trials evaluating the use of agents such as oral contraceptives alone or as add-back therapy for GnRH agonists, or those that examine combined medical and surgical treatments, has hampered the ability of physicians to provide the broadest range of medical therapies for this disorder. Future trials addressing these issues are warranted.


Assuntos
Endometriose/terapia , Danazol/farmacologia , Endometriose/tratamento farmacológico , Endometriose/cirurgia , Feminino , Hormônio Liberador de Gonadotropina/agonistas , Procedimentos Cirúrgicos em Ginecologia , Humanos , Acetato de Medroxiprogesterona/farmacologia , Recidiva
9.
Int J Fertil Womens Med ; 47(5): 205-10, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12469707

RESUMO

Over the last 5 years we have seen the evolution of several new products and several new regimens for estrogen replacement in menopause. Before this time, the decision surrounding hormone replacement therapy (HRT) mainly focused on whether to take estrogen or not, and if the addition of a progestogen was required. However, with new paradigms we now have several options for HRT, with various doses of estrogen ranging from very low doses of oral estrogen (0.3 mg conjugated equine estrogen [CEE], 0.25 mg 17beta-estradiol), transdermal patches which deliver a minimum of 20 microg of 17beta-estradiol per day, or intranasal methods which deliver 100-400 microg of 17beta-estradiol, to the more commonly prescribed doses of 0.625 mg of CEE or 0.5 mg 17beta-estradiol. The decision to add a progestogen to the regimen of replacement therapy is well accepted, particularly in a woman who has an intact uterus; however, now the controversy has focused on which progestogen least attenuates the lipid benefits received from the estrogen replacement therapy. Estrogen treatment in the postmenopausal woman has several proven benefits. For the woman who has vasomotor symptoms or complaints related to urogenital atrophy, there is little controversy regarding its use. However, a continuing controversial area is that of long-term prevention of osteoporosis and cardiovascular disease. It is in these areas that the decision on the dose and the addition of a progestin to hormone replacement therapy is under review.


Assuntos
Terapia de Reposição de Estrogênios/métodos , Idoso , Doenças Cardiovasculares/prevenção & controle , Combinação de Medicamentos , Endométrio/efeitos dos fármacos , Estradiol/administração & dosagem , Congêneres do Estradiol/administração & dosagem , Terapia de Reposição de Estrogênios/efeitos adversos , Estrogênios Conjugados (USP)/administração & dosagem , Etinilestradiol/administração & dosagem , Feminino , Humanos , Medroxiprogesterona/administração & dosagem , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/prevenção & controle , Congêneres da Progesterona/administração & dosagem , Hemorragia Uterina/etiologia
10.
J Cancer ; 5(8): 670-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25258648

RESUMO

OBJECTIVE: Overexpression of the epidermal growth factor receptor (EGFR) is associated with the malignant phenotype in many cancers including ovarian cancer, which leads to increased cell proliferation and survival. In spite of emerging EGFR inhibitors as a potentially useful agent, they are largely ineffective in patients with advanced or recurrent ovarian cancers. Since Akt as a key downstream factor of EGFR is highly activated in some high grade serous ovarian tumors, the augmented Akt activation may attribute to irregular EGFR-mediated signaling observed in ovarian cancer. Here we investigated the differential effect of Akt on the EGF-induced cell viability in a panel of ovarian cancer cell lines. METHODS: Cellular viability assay and western blot analysis were used to measure cell viability and expression levels of proteins, respectively. Knockdown of Akt was achieved with siRNA and stable transfection of expression vectors was performed. RESULTS: Cellular viability increased in OVCAR-3 ovarian cancer cells exposed to EGF, but little to no difference was observed in the 5 other ovarian cancer cells including SKOV-3 cells despite of the expression of EGFR. In OVCAR-3 cells, EGF activated Erk and Akt, but an Erk inhibitor had no impact on cellular viability. On the other hand, the EGFR and PI3K inhibitors decreased EGF-induced cellular viability, indicating the involvement of Akt signaling. Although EGF activated Erk in SKOV-3 cells, the Akt activation was very weak as compared to OVCAR-3 cells. Furthermore, we observed a different expression of Akt isoforms: Akt1 was constitutively expressed in all tested ovarian cancer cells, while Akt3 was little expressed. Interestingly, Akt2 was highly expressed in OVCAR-3 cells. Knockdown of Akt2 blocked EGF-induced OVCAR-3 cell viability whereas knockdown for Akt1 and Erk1/2 had no significant effect. Stable transfection of Akt2 into SKOV-3 cells phosphorylated more Akt and enhanced cell viability in response to EGF. CONCLUSIONS: Akt2-dependent signaling appears to play an important role in EGFR-mediated cellular viability in ovarian cancer and targeting specific Akt isoform may provide a potential therapeutic approach for EGFR-expressing ovarian cancers.

11.
World J Transl Med ; 3(1): 1-8, 2014 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-25525571

RESUMO

Ovarian cancer is the second most common gynecological cancer and the leading cause of death in the United States. In this article we review the diagnosis and current management of epithelial ovarian cancer which accounts for over 95 percent of the ovarian malignancies. We will present various theories about the potential origin of ovarian malignancies. We will discuss the genetic anomalies and syndromes that may cause ovarian cancers with emphasis on Breast cancer type 1/2 mutations. The pathology and pathogenesis of ovarian carcinoma will also be presented. Lastly, we provide a comprehensive overview of treatment strategies and staging of ovarian cancer, conclusions and future directions.

12.
J Cancer ; 4(8): 671-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24155779

RESUMO

OBJECTIVE: Although aspirin has been associated with a reduction of the risk of cancer when used as a nonsteroidal anti-inflammatory drug, its use to reduce the risk of ovarian cancer is controversial. Ovarian cancer cells usually express high levels of cyclooxygenase-1 (COX)-1. Because aspirin is a rather selective inhibitor of COX-1, the ability of aspirin to reduce the risk of ovarian cancer may be dependent on the level of COX-1 expression in those cells. Furthermore, epidermal growth factor receptor (EGFR) is frequently overexpressed in the malignant phenotype of ovarian cancer leading to increased cell proliferation and survival. Here we investigated if aspirin attenuates EGFR-activated ovarian cancer cell growth in a COX-1 dependent manner. METHODS: Cell viability assays and Western blot analyses were used to determine the effect of aspirin on EGF-stimulated cell proliferation. Gene silencing and gene expression techniques were employed to knockdown or to express COX-1, respectively. RESULTS: Aspirin inhibited cell viability induced by EGF in a dose dependent manner in COX-1 positive ovarian cancer cells. On the other hand, aspirin had no effect on cell viability in COX-1 negative ovarian cancer cells. In particular, aspirin decreased phosphorylated Akt and Erk activated by EGF. COX-1 silencing in COX-1 positive cells attenuated the inhibitory effect of aspirin on EGF-stimulated cell viability. Furthermore, we developed a COX-1 expressing cell line (SKCOX-1) by stably transfecting COX-1 expression vector into COX-1 negative SKOV-3 cells. SKCOX-1 cells were more responsive to aspirin when compared to cells transfected with empty vector, and decreased EGF-activated Akt and Erk as well as cell viability. CONCLUSIONS: Taken together, aspirin inhibits viability of ovarian cancer cells by blocking phosphorylation of Akt and Erk activated by EGF. Thus it may potentiate the therapeutic efficacy of drugs used to treat COX-1 positive ovarian cancer subsets.

13.
HIV AIDS (Auckl) ; 4: 73-80, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22629115

RESUMO

PURPOSE: We sought to determine the relationship between acceptability of a hypothetical vaginal microbicide, cultural factors, and perceived HIV risk among African-American women in Nashville, TN, USA, and African women in Kafue and Mumbwa, Zambia. PATIENTS AND METHODS: Women in both sites completed a survey. Regression analyses were performed on valid samples (Nashville, 164; Zambia, 101) to determine cultural differences affecting microbicide acceptability. Regression analyses also tested whether individual risk perception affected acceptability. RESULTS: In Zambia, 89.6% of women were willing to use a microbicide versus 81.6% in Nashville (P < 0.0001). One cultural difference is that women in the Zambian cohort viewed risk of HIV infection as distinct from risk of acquiring STIs, with 48% believing they were certain to become infected with AIDS, compared to 4% of Nashville participants. CONCLUSION: These results suggest a high degree of acceptability toward use of a vaginal microbicide to prevent HIV infection.

16.
Fertil Steril ; 94(7): 2503-6, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20189168

RESUMO

To expand the availability of stem cell lines suitable for basic research and clinical application, somatic cell nuclear transfer has been proposed and will require human oocyte donation. The recommendations made by the California Institute of Regenerative Medicine advisory committee on oocyte donation are based on peer-reviewed, best practices, and best clinical judgment and are intended to assist researchers in design and Institutional Review Board (IRB) evaluation of research protocols for oocytes donated exclusively for research purposes.


Assuntos
Guias como Assunto , Doação de Oócitos , Pesquisa com Células-Tronco , Feminino , Humanos , Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/transmissão , Pesquisas com Embriões/ética , Pesquisas com Embriões/legislação & jurisprudência , Programas de Rastreamento/legislação & jurisprudência , Programas de Rastreamento/métodos , Doação de Oócitos/ética , Doação de Oócitos/legislação & jurisprudência , Doação de Oócitos/métodos , Doação de Oócitos/estatística & dados numéricos , Síndrome de Hiperestimulação Ovariana/etiologia , Síndrome de Hiperestimulação Ovariana/prevenção & controle , Projetos de Pesquisa , Comportamento de Redução do Risco , Pesquisa com Células-Tronco/ética , Pesquisa com Células-Tronco/legislação & jurisprudência , Guias de Prática Clínica como Assunto
18.
Int J Environ Res Public Health ; 6(3): 1124-44, 2009 03.
Artigo em Inglês | MEDLINE | ID: mdl-19440437

RESUMO

Two experiments were conducted to determine: 1) whether the adult male transgenic sickle cell mouse (Tg58 x Tg98; TSCM), exhibits the patterns of reproductive endpoints (hypogonadism) characteristic of men with sickle cell disease (SCD) and 2) whether hydroxyurea (HU) exacerbates this condition. In Experiment 1, blood samples were collected from adult age-matched TSCM and ICR mice (ICRM) (N = 10/group) for plasma testosterone measurements. Subsequently, mice were sacrificed, testes excised and weighed and stored spermatozoa recovered for the determination of sperm density, progressive motility and percentage of spermatozoa with normal morphology. In experiment 2, adult male TSCM were orally treated with 25 mg HU/kg body weight/day for 28 or 56 days. Control mice received the vehicle for HU (saline) as described above. At the end of the treatment periods, blood samples were collected for quantification of circulating testosterone. Subsequently, mice were sacrificed, testes and epididymides were recovered and weighed and one testis per mouse was subjected to histopathology. Stored spermatozoa were recovered for the determination of indices of sperm quality mentioned in Experiment 1. Testis weight, stored sperm density, progressive motility, percentage of spermatozoa with normal morphology and plasma testosterone concentrations of TSCM were significantly lower by 40, 65, 40, 69 and 66%, respectively than those of ICRM. These data indicate that adult TSCM used in this study suffered from hypogonadism, characteristically observed among adult male SCD patients. In Experiment 2, HU treatment significantly decreased testis weight on day 28, (0.09 +/- 0.004 g) that was further decreased on day 56 (0.06 +/- 0.003 g; treatment x time interaction) compared with controls (day 28, 0.15 +/- 0.01 g; day 56, 2, 0.16 +/- 0.01 g). Concomitant with a 52% shrinkage (P<0.001) in area of testes in 56 days of HU treatment, testes from HU-treated TSCM exhibited significant atrophic degeneration in the seminiferous tubules compared with controls. Furthermore, treated TSCM had only Sertoli cells and cell debris remaining in most of the seminiferous tubules in comparison with controls. Leydig cell prominence and hyperplasia were more evident (P<0.05) in the steroidogenic compartments of testes of HU-treated TSCM compared with controls. However, plasma testosterone concentrations were reduced by HU treatment (P<0.05; treatment x time interaction) compared with controls on the two time periods studied. Epididymides from HU-treated TSCM sustained a 25% shrinkage (P<0.05), along with 69 (P<0.005) and 95% reduction (P<0.005), in stored sperm density and sperm progressive motility (treatment x time interaction P<0.05), respectively on day 56 of treatment compared with controls. These data demonstrate that TSCM used in this study exhibited SCD-induced hypogonadism, thus authenticating their use for studying the effect of HU on male reproductive endpoints observed in SCD patients. Secondarily, our data show that HU treatment exacerbated the already SCD-induced hypogonadism to gonadal failure.


Assuntos
Anemia Falciforme/complicações , Antidrepanocíticos/efeitos adversos , Hidroxiureia/efeitos adversos , Hipogonadismo/etiologia , Infertilidade Masculina/etiologia , Anemia Falciforme/tratamento farmacológico , Animais , Modelos Animais de Doenças , Hipogonadismo/patologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos Transgênicos , Testículo/patologia
20.
Cancer Biol Ther ; 6(8): 1302-12, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17712227

RESUMO

Chronic inflammation is an important underlying condition for ovarian tumor development, growth and progression. Since chemokine networks are activated by inflammation, patterns of chemokine gene expression were investigated in ovarian cancer cells. Chemokine specific microarrays were performed after mouse (ID8) and human (SKOV-3) ovarian surface epithelial cancer cells were exposed to the inflammatory agent bacterial endotoxin lipopolysaccharide (LPS, 10 microg/ml) and pro-inflammatory cytokines interleukin-1beta (IL-1, 10 ng/ml) and tumor necrosis factor-alpha (TNF, 10 ng/ml). In the mouse ID8 cells, LPS, IL-1 and TNF led to robust upregulation of keratinocyte chemoattractant (KC) chemokines CXCL1/2, mouse homologues of human growth-regulated oncogenes (GRO). Other chemokines, interferong inducible protein (IP)-10 (CXCL10), CCL7 and CCL20 were moderately upregulated. ID8 cells constitutively expressed CXCL16 and CCL2, but only CCL2 expression was enhanced by LPS, IL-1 and TNF. In the human SKOV-3 cells, LPS had no effect on chemokines expression due to the absence of the LPS receptor, toll-like receptor 4 (TLR4). However, IL-1 and TNF induced GROalpha/beta (CXCL1/2) in human SKOV-3 cells in a similar manner as observed with mouse ID8 cells. In SKOV-3 cells, IL-8 (CXCL8) was highly expressed and other chemokines GROgamma (CXCL3) and CCL20 were moderately expressed in response to IL-1 and TNF. The nuclear factor-kappaB (NF-kappaB) is a known mediator of cytokine and chemokines signaling. The NFkappaB inhibitor BAY 11-7082 attenuated expression of inflammatory-induced chemokines in the mouse and human ovarian cancer cells. Taken together, the results indicate that KC/GRO chemokines are the principal chemokines induced by LPS and pro-inflammatory cytokines IL-1 and TNF via NFkappaB signaling in ovarian surface epithelial cancer cells.


Assuntos
Carcinoma/metabolismo , Quimiocina CXCL1/metabolismo , Quimiocinas/metabolismo , Fatores Quimiotáticos/metabolismo , Neoplasias Ovarianas/metabolismo , Animais , Carcinoma/genética , Quimiocina CXCL1/genética , Quimiocinas/genética , Fatores Quimiotáticos/genética , Feminino , Humanos , Interleucina-1/farmacologia , Lipopolissacarídeos/farmacologia , Camundongos , NF-kappa B/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Ovarianas/genética , Transdução de Sinais , Fator de Necrose Tumoral alfa/farmacologia
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa