Molecular basis of sequestration in severe and uncomplicated Plasmodium falciparum malaria: differential adhesion of infected erythrocytes to CD36 and ICAM-1

Article Abstract:

Malaria is a condition resulting from infection of red blood cells with the parasite sporozoan Plasmodium, which is transmitted through mosquito bites or blood transfusion. Infected red blood cells (IRBC) adhere to the endothelium, or tissue lining blood vessels. The mature, or more developed, IRBCs become sequestered, or isolated, in the vessel walls, whereas the immature, or less developed IRBCs remain in the circulation. Patients with low numbers of parasites in the blood can develop severe complications, probably due to the unknown numbers of sequestered parasites in the blood vessel walls, where they may interfere with blood flow and release toxic substances. IRBC can bind to three receptors, or specific protein sites, on the inner membrane of blood vessels. These include thrombospondin, CD36, and ICAM-1. Thrombospondin is a protein involved in the attachment of cells to each other or supporting tissue. CD36 is an antigen, or element capable of provoking an immune response, and is present on monocytes, a type of white blood cell; platelets, cells involved in blood clotting; and endothelial cells, which line blood vessels. CD36 is a receptor for thrombospondin and collagen, a structural protein found in connective tissue. ICAM-1, a surface protein found on many bone marrow cells and endothelial cells, can be regulated by growth factors and can bind to specific viral factors. The binding of IRBCs to CD36 and ICAM-1 was assessed. Although IRBC bind to CD36 and ICAM-1, binding was not related to disease severity. These findings suggest that Plasmodium may bind to these receptors to enhance the survival of the parasite and its prevent destruction by immune factors. (Consumer Summary produced by Reliance Medical Information, Inc.)

Infection, Physiological aspects, Erythrocytes, Red blood cells, Vascular endothelium, Cardiovascular receptors

---

Fatal Plasmodium falciparum malaria after an inadequate response to quinine treatment

Article Abstract:

Malaria is a disease caused by the protozoa Plasmodium falciparum. Since the organism is now highly resistant to the antiparasitic drug chloroquine, this treatment is no longer used. Although some treatment failures have been reported since the turn of the century, the alternative drug, quinine, still maintains a low resistance rate and is effective in eradicating the infection. A 24-year-old Burmese male was diagnosed with malaria in Thailand after he complained of a headache, fever, chills and nausea. He arrived at the hospital unconscious with a loss of urinary control. He began intravenous quinine but died after 77 hours of treatment. In order to assess the extent of drug resistance, the concentration of parasites circulating in the blood (parasitemia) must be determined over the course of therapy. Although in this patient the parasitemia had declined from its peak value, it remained higher than the concentration measured upon admission to the hospital. Therefore, this patient's condition met the criteria for quinine drug resistance classified by the World Health Organization. Fatal quinine resistance, classified as R3 drug resistance, has not been previously reported. The concentration of quinine in the blood was unusually low, indicating a problem in the action of the quinine. It is suggested that the dose of quinine be increased by 50 percent (or changed to another antiparasitic drug completely) if the concentration of circulating parasites does not drop by 75 percent within 48 hours of initiating treatment. (Consumer Summary produced by Reliance Medical Information, Inc.)

Case studies, Drug resistance in microorganisms, Microbial drug resistance

---

A controlled trial of artemether or quinine in Vietnamese adults with severe falciparum malaria

Article Abstract:

Artemether appears to be as effective in treating malaria as quinine and could be used in countries where the malaria parasite has become resistant to quinine. Of 560 Vietnamese people with severe malaria, 276 gave themselves intramuscular injections of quinine every 8 hours and 284 injected artemether. Treatments lasted at least 3 days. The mortality rate was 13% in those receiving artemether, compared to 17% in those receiving quinine. Artemether cleared the parasite from the blood more quickly, but those receiving artemether took longer to recover.

Antimalarials

Similar abstracts:

• Abstracts: Petrosal sinus sampling with and without corticotropin-releasing hormone for the differential diagnosis of Cushing's syndrome
• Abstracts: The risk of development of HTLV-I-associated myelopathy/tropical spastic paraparesis among persons infected with HTLV-I
• Abstracts: Partner notification and confidentiality of the index patient: its role in preventing HIV. Syphilis in San Diego County 1983-1992: crack cocaine, prostitution, and the limitations of partner notification
• Abstracts: Impact of nutrition status on morbidity and mortality in a select population of geriatric rehabilitation patients
• Abstracts: The role of definitive radiation therapy in squamous cell carcinoma of the oral tongue. A Phase I-II trial of multimodality management of bulky gynecologic malignancy: combined chemoradiosensitization and radiotherapy

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