Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Contraceptive research and development is currently addressing the preservation of female fertility through birth control, the promotion of birth control as an essential component of a healthy life-style, and prevention of the spread of sexually transmitted diseases. The combined oral contraceptive (OC) remains the most popular birth control method, and the introduction of new progestogens has lowered the incidence of cycle control problems and improved metabolic data. As protection against human immunodeficiency virus (HIV) transmission becomes a central concern among contraceptive users, the condom has increased in popularity. Recent innovations in the field of barrier methods include the female condom and cervical cap; plastic is being tested as a component of male condoms. Advances in IUD technology include Cu-safe 300 (a slim device with an anti-expulsion design), the flexigard (a frameless device associated with reduced pain and bleeding), and levonorgestrel-releasing devices. Among new contraceptive delivery systems are the vaginal ring, Norplant, and monthly combined injectables. Bioself 110, an electronic fertility indicator, refines the practice of natural family planning. For postpartum contraception, researchers are working on a delivery system for natural progesterone, and lactational amenorrhea has gained recognition as an effective method of pregnancy prevention.
 ...
PMID:New thinking in contraception. 184 13

A survey of medical and counseling staff at 13 family planning clinics in Texas suggested that contraceptive method selection, particularly with regard to Norplant, is closely linked to health care professionals; opinions about the various methods. Since all 13 clinics were operated by Planned Parenthood, the protocol for counseling was uniform. 65.2% of the 90 clinicians who completed questionnaires indicated they always or usually discussed Norplant with family planning patients. 7 facilities dispensed Norplant to less than 6% of their patients; the remaining 6 had distribution rates of at least 10.5%. Providers who had received in-service training on Norplant were significantly more likely than their informally educated counterparts to prescribe Norplant as were those who were aware the method had no permanent effect on future fertility. 29% of clinical staff at high distribution sites claimed they would recommend implants over sterilization compared to 8.3% of those at low distribution sites. An analysis of responses to opinion questions about Norplant indicated that there was a significant association (p 0.01) between the number of clients who received Norplant and staff members' agreement with the following items: a woman can use Norplant regardless of how many children she has, the high cost of the implants is worthwhile, the method is good for child spacing, the implants are a suitable method for women with human immunodeficiency virus (HIV) infection, and women under 18 years of age are appropriate candidates for its use. Overall, 35% of respondents believed Norplant posed a greater potential danger than the pill, 37% felt the implants were more dangerous than tubal ligation surgery, and 16% rated Norplant as more risky than the IUD; there was no association between perceptions of relative danger and patterns of distribution, however. Concerns about Norplant focused on the lack of screening criteria, its failure to protect against HIV, and a need for more research. The service provided to family planning clients would be improved with enhanced in-service training. The identification of women for whom Norplant is most suitable, and practitioner awareness of the extent to which personal opinions influence counseling approach.
 ...
PMID:The attitudes of clinic staff as factors in women's selection of Norplant implants for their contraception. 794 12

Although Thailand's National Family Planning Program introduced Norplant contraceptive implants in 1986, few women infected with human immunodeficiency virus (HIV) select this method, and its efficacy, clinical effects, and side effects in this population have not been investigated. To address these issues, a prospective cohort study was conducted during 1993-96 of 41 asymptomatic HIV-infected women who presented to the Family Planning Clinic at Ramathibodi Hospital in Bangkok, Thailand, and voluntarily accepted Norplant implants. All implants were inserted within 4 weeks after delivery or abortion. 63.4% of acceptors had not used any contraceptive method prior to pregnancy. At 6 and 12 months after insertion, 26% and 23%, respectively, reported irregular menstrual periods and 24.4% and 36.6%, respectively, reported amenorrhea. Side effects, reported by 3-10% of women, included headache, acne/chloasma, anorexia, and nausea. There were no significant changes in body weight, blood pressure, and hemoglobin between insertion and the 12-month follow-up. No pregnancies occurred during the study period. These findings suggest that Norplant implants are an effective, appropriate contraceptive method for HIV-infected women who want to avoid pregnancy but are not interested in sterilization.
 ...
PMID:Use of Norplant implants in asymptomatic HIV-1 infected women. 917 51

After a recent study showing that monkeys given progesterone are more likely to acquire simian immunodeficiency virus (SIV), women's reproductive health experts are advising clinicians to stress the importance of condom use and calm worried women by pointing out that other studies are needed to understand the relationship between hormones and HIV risk. Researchers have learned that progestin causes a thinning of the vaginal wall--possibly an explanation for the increase in SIV infection in the monkey study. Because Depo-Provera and Norplant are long-acting progestin-based contraceptives, women using them to prevent pregnancy may be especially alarmed by reports of the monkey study. Women should be advised that using these contraceptives do protect them from pregnancy; women should assess the risk of contracting HIV or other sexually transmitted diseases; and women should modify their behavior to lower their risk.
 ...
PMID:Advice for women seeking progesterone counseling. 1136 50

The recent finding that rhesus monkeys given progesterone were more likely to become infected after vaginal exposure to simian immunodeficiency virus than their nontreated counterparts has raised concerns about the effect of progestin-containing contraceptives on HIV risk. More research is needed to determine whether this finding extends to the progestins used in oral contraceptives, Norplant, injectables, and the levonorgestrel-containing IUD. Family Health International, in response to the animal study, reiterated its stance of support of dual contraceptive use: hormonal methods to prevent pregnancy and latex condoms to prevent sexually transmitted diseases.
 ...
PMID:Does progesterone increase HIV risk? Contraceptive update. 1229 87

Three women's groups registered their concerns and recommendations about the use of Norplant in Canada, where it was approved for use in November, 1993. The National Action Committee on the Status of Women had the following reservations: 1) Norplant requires trained personnel for its insertion and removal (both minor surgical procedures), which makes it controlled by the provider; 2) there is a potential for misuse without adequate informed consent, especially among welfare recipients, disabled women, or those whose first language is not English or French (women in the United States have been given financial incentives or had Norplant made a probation requirement); and 3) discontinuation rates have equalled 50% in clinical trials because of side effects that are often perceived differently because of culture. The Toronto Women's Health Network is concerned that Norplant use among teens, welfare recipients, and women of color will lead to higher rates of sexually transmitted disease (STD) and human immunodeficiency virus (HIV). The Women's Health Clinic has the following recommendations: 1) a clear policy with guidelines on informed consent, 2) an accredited certification program for health professionals that includes training and supervision of insertion, removal, and counseling techniques, and a process for client follow-up; 3) a policy limiting availability to centers with accredited staff and adequate infrastructure; 4) the development of a program that follows mobile patients, perhaps, via prescriptions; 5) the promotion of Norplant in professional literature only; 6) comprehensive and understandable patient education materials for women of diverse backgrounds; 7) ongoing qualitative and epidemiological studies designed with input from consumers and experts; and 8) reform of the drug approval process ensuring mechanisms for openness, consumer input and public discussion.
 ...
PMID:Norplant entered Canada through the back door. 1231 19

Human cells have developed innate immunity, exploiting several means to block virus infection, and viruses have evolved diverse strategies to resist these. We show here that the human immunodeficiency virus 1 (HIV-1) could neither progressively infect engrafted human leukemic T cells nor repress their growth in NOG mice. However, ED-40515(-) cells infected with HIV-1 before inoculation were found to significantly delay the onset of tumor growth and increased the survival period of NOG mice. ED-40515(-) tumor cells showed resistance to HIV-1 which was apparently correlated with the down-regulation of CD4 and CXCR4 molecules in NOG mice. Serum from three different mouse strains, including NOG, retained a suppressive effect on the CD4 molecule of ED-40515(-) cells in vitro. ED-40515(-) cells obtained from mice re-expressed CD4 and CXCR4 molecules upon in vitro culture and were again successfully infected with HIV-1. These findings indicate that HIV-1 may initially successfully delay or regress tumor growth in NOG mice, but eventually fails to do so because of the evolution of HIV-resistant cells due to a rapid down-modulation of CD4 and CXCR4. Our data also demonstrated that some unknown soluble factor(s) present in mouse serum was responsible for conferring resistance to HIV infection to human T cells.
 ...
PMID:Mouse serum factor(s) down-modulate the CD4 and CXCR4 molecules on human T cells conferring resistance to HIV infection in NOG mice. 1565 27

The transmission of human T-lymphotropic virus Type 1 (HTLV-1) occurs mainly via breast-feeding, sexual intercourse and blood transfusions. After transmission, the HTLV-1 infection is predominantly maintained by cell-to-cell infection and clonal expansion; however, the details have not yet been clarified. To investigate how HTLV-1 infected cells act in an environment without an effective immune reaction, peripheral blood mononuclear cells (PBMCs) from asymptomatic HTLV-1 carriers were inoculated into nonobese diabetic/severe combined immunodeficient (NOD/SCID)/gammac(null) (NOG) mice, which have immunological dysfunctions of T- and B-lymphocytes and NK cells. Human mononuclear cells including both CD4+ and CD8+ T cells were found to have infiltrated into various organs, including the liver, kidney, spleen and lung, when the mice were sacrificed 1 month after inoculation. The copy numbers of HTLV-1 provirus detected in the tissue-infiltrating human cells were much higher than those in the original PBMCs from the carriers. The expression of HTLV-1 mRNA was demonstrated in the tissue-infiltrating cells by reverse transcriptase-polymerase chain reaction. Inverse-long polymerase chain reaction showed that the pattern of HTLV-1 proviral integration was different from that of the original carrier and that it varied among NOG mice inoculated with PBMCs from the same carrier. These results suggest the selective proliferation of particular clones of HTLV-1 infected cells in NOG mice. Alternatively, transmission and new integration of HTLV-1 from infected cells to noninfected cells might have occurred in an environment without an effective immune reaction. The NOG mouse is considered a good animal model for the patho-physiological study of HTLV-1 infection with immunodeficiency.
 ...
PMID:Engraftment of peripheral blood mononuclear cells from human T-lymphotropic virus type 1 carriers in NOD/SCID/gammac(null) (NOG) mice. 1765 14

Inbred mice with specific genetic defects have greatly facilitated the analysis of complex biological events. Several humanized mouse models using the C.B.-17 scid/scid mouse (referred to as the SCID mouse) have been created from two transplantation protocols, and these mice have been utilized for the investigation of human immunodeficiency virus type 1 (HIV-1) and human T-lymphotropic virus type I (HTLV-I) pathogenesis and the evaluation of antiviral compounds. To generate a more prominent small animal model for human retrovirus infection, especially for examination of the pathological process and the immune reaction, a novel immunodeficient mouse strain derived from the NOD SCID mouse was created by backcrossing with a common gamma chain (gamma(c))-knockout mouse. The NOD-SCID gamma(c)null (NOG) mouse has neither functional T and B cells nor NK cells and has been used as a recipient in humanized mouse models for transplantation of human immune cells particularly including hematopoietic stem cells (HSC). From recent advances in development of humanized mice, we are now able to provide a new version of the animal model for human retrovirus infection and human immunity.
 ...
PMID:Humanized mice for human retrovirus infection. 1848 58

Genomic hypermutation of RNA viruses, including human immunodeficiency virus type 1 (HIV-1), can be provoked by intrinsic and extrinsic pressures, which lead to the inhibition of viral replication and/or the progression of viral diversity. Human APOBEC3G was identified as an HIV-1 restriction factor, which edits nascent HIV-1 DNA by inducing G-to-A hypermutations and debilitates the infectivity of vif-deficient HIV-1. On the other hand, HIV-1 Vif protein has the robust potential to degrade APOBEC3G protein. Although subsequent investigations have revealed that lines of APOBEC3 family proteins have the capacity to mutate HIV-1 DNA, it remains unclear whether these endogenous APOBEC3s, including APOBEC3G, contribute to mutations of vif-proficient HIV-1 provirus in vivo and, if so, what is the significance of these mutations. In this study, we use a human hematopoietic stem cell-transplanted humanized mouse (NOG-hCD34 mouse) model and demonstrate the predominant accumulation of G-to-A mutations in vif-proficient HIV-1 provirus displaying characteristics of APOBEC3-mediated mutagenesis. Notably, the APOBEC3-associated G-to-A mutation of HIV-1 DNA that leads to the termination of translation was significantly observed. We further provide a novel insight suggesting that HIV-1 G-to-A hypermutation is independently induced by individual APOBEC3 proteins. In contrast to the prominent mutation in intracellular proviral DNA, viral RNA in plasma possessed fewer G-to-A mutations. Taken together, these results provide the evidence indicating that endogenous APOBEC3s are associated with G-to-A mutation of HIV-1 provirus in vivo, which can result in the abrogation of HIV-1 infection.
 ...
PMID:Remarkable lethal G-to-A mutations in vif-proficient HIV-1 provirus by individual APOBEC3 proteins in humanized mice. 2061 Jul 8


1 2 Next >>