Prevalence of HIV infection in seronegative high-risk individuals examined by virus isolation and PCR

Article Abstract:

Infection with the human immunodeficiency virus (HIV) causes the immune system of the individual to produce antibodies against the virus. When antibodies can be detected in the blood of infected individuals, the individuals are considered seropositive. Otherwise, they are seronegative. Sometimes individuals are seronegative but still show clinical symptoms of HIV infection. Individuals who were seronegative but were at high risk for developing HIV infection because of their behavior, such as having high numbers of sexual partners, having sexually transmitted disease, or having sexual contact with a HIV-infected individual, were tested using more sensitive methods for detecting the presence of HIV. One test requires isolating lymphocytes and macrophages, cells of the immune system which are normally infected by HIV, from the individual and growing them outside of the body, in culture. The cells are stimulated to divide by means of chemicals or other cells, and tested to see if virus is produced. A second test detects very small levels of the virus in cells, using the polymerase chain reaction, which amplifies the genetic sequence of the virus to levels that can be detected. None of the 31 individuals tested were shown to be infected with HIV by either of the tests. This study showed that even more sensitive techniques could not detect virus in individuals who were seronegative. This finding is important because it confirms the reliability of using the presence of antibodies as the criteria for infection. (Consumer Summary produced by Reliance Medical Information, Inc.)

Usage, Polymerase chain reaction

---

Lack of evidence of HIV-2 infection among at-risk individuals in Brazil

Article Abstract:

The human immunodeficiency virus type-2 (HIV-2) is found primarily in West Africa. However, isolated cases of HIV-2 infections have been found throughout the world. It has been reported that HIV-2 has been brought into Brazil. The presence of antibodies to both the human immunodeficiency virus type-1 (HIV-1) and HIV-2 was examined using 1,821 blood samples collected in 1987 and 1988 from individuals living in Brazil who were at high risk for infection. The samples were examined using various tests to confirm the results. Twenty percent (367 out of 1,821) of the blood samples contained antibodies to HIV-1, indicating infection. Two percent (33 samples) contained antibodies to HIV-2, by one type of testing. However, when the other tests were performed, the samples were shown in fact to contain antibodies against HIV-1 and not HIV-2. The two types of viruses are very similar and antibodies made against one virus can cross-react with the other virus. This study shows the necessity of confirmation of tests for infectivity with HIV-2. It was concluded that there remains no evidence that HIV-2 infections are occurring in Brazil. (Consumer Summary produced by Reliance Medical Information, Inc.)

Interpretation and construction, Measurement, Brazil, Examinations, Educational tests, HIV seropositivity, HIV positive, HIV antibodies

---

Detection of HIV-1 DNA in crude cell lysates of peripheral blood mononuclear cells by the polymerase chain reaction and nonradioactive oligonucleotide probes

Article Abstract:

The polymerase chain reaction, which amplifies (increases) the quantity of DNA (the genetic material of the cell), is a very sensitive method for detecting the human immunodeficiency virus (HIV). The DNA is usually analyzed with probes that are radioactive. However, this study describes a method of detection which uses a nonradioactive probe based on the chemical alkaline phosphatase. Mononuclear white blood cells were examined for the presence of HIV using this method. Using blood cells from 59 individuals who were known to have antibodies against HIV in their blood, this method detected HIV in 57 (97 percent) of the individuals. The technique also detected HIV in 11 out of 12 samples that were negative by other diagnostic tests that are normally used to detect HIV. The method described using the DNA polymerase chain reaction is a sensitive method for detecting small quantities of HIV in the tissues of individuals. Various types of cells or tissues can be examined in this way, and large numbers of samples can be tested because the technique is rapid. (Consumer Summary produced by Reliance Medical Information, Inc.)

Diagnosis, DNA probes

Similar abstracts:

• Abstracts: Parenteral influence on food selection in young children and its relationships to childhood obesity. Safety of glutamine-enriched parenteral nutrient solutions in humans
• Abstracts: Psychosocial aspects of chronic, clinically unconfirmed vulvovaginitis. Acute vulvovaginitis
• Abstracts: Views of a chiropractic critic: your real enemy is yourself. part 2 Philosophy and the future of chiropractic
• Abstracts: Cervical spondylolisthesis: a case report. Chiropractic and cognitive counseling in chronic pain: a case report
• Abstracts: DIfferent genomic and metabolic patterns between mass-screening-positive and mass-screening-negative later-presenting neuroblastomas

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.