Primate study suggests pentobarbital may help protect the brain during radiation therapy

Article Abstract:

Children's lives are often saved by radiation therapy for brain tumors, but longer-term consequences include incomplete sexual development, growth retardation, cognitive deficits, and lethargy. It now appears that pentobarbital (a barbiturate) and related drugs may eventually be useful as protective agents to shield the brain from these damaging effects. A study that involved eight young male rhesus monkeys was reported at a recent meeting of the Endocrine Society. The animals, four of whom had been given intravenous pentobarbital, received whole-brain X-irradiation in one dose. Hormone levels were measured in the animals before treatment and at intervals thereafter, and the control group (unprotected) experienced declines in luteinizing hormone (a sex hormone) and a reduced release of thyroid-stimulating hormone after thyrotropin-releasing hormone was administered (hormones important in the synthesis of thyroid hormone). Other endocrinologic differences between the two groups were noted, suggesting a protective effect. However, humans are typically not treated in one dose, and so another primate study, using multiple doses, will begin in August 1991. Trials on humans are not yet being considered. However, children often receive sedation, including barbiturates, before they undergo radiation treatment. Other barbiturate agents besides pentobarbital are under investigation. It seems that these compounds suppress neuronal (brain cell) metabolism without altering metabolism in other ways. Their influence may be most apparent in cells with the fastest metabolic activity, such as tumor cells, and the drugs must still allow radiation's damaging effects to reach these cells. Other animal studies indicate that pentobarbital given prior to irradiation leads to increased survival, as compared with animals that did not receive the barbiturate. Tumor cells, lacking the receptors for barbiturates, may remain unshielded. (Consumer Summary produced by Reliance Medical Information, Inc.)

Prevention, Complications and side effects, Children, Radiation, Cancer treatment, Radiotherapy, Radiation effects, Brain damage, Pentobarbital, Barbiturates

---

Molecular biology research offers new weapons against cancer

Article Abstract:

New cancer treatments that use the tools of molecular biology were described at the American Cancer Society's 32nd Science Writers' Seminar. Molecules that normally aid cell adhesion, motility (movement) and invasion (entering new tissues) during early development may also be important in the spread of cancer (metastasis), and if they can be prevented from functioning (blocked), metastasis will stop. Beta 1-6 branching on oligosaccharides (a molecular component of the cell surface) is a pattern associated with some cancers. When Beta 1-6 branching is blocked, tumor cells grow more slowly. One such blocker is called swainsonine. This compound can inhibit growth of tumors in mice by more than 50 percent. Human trials of swainsonine will soon begin in Canada. Another line of research is the development of drugs that stimulate macrophage production (cells that ingest and kill foreign molecules or particles). Muramyl tripeptide phosphatidylethanolamine (MTP-PE), a macrophage stimulator, can be packaged in fat membranes so it will be ingested by macrophages. Once the globule is inside the cell, MTP-PE is released, leading to eradication of metastases in mice with lung tumors. MTP-PE has been administered to people in trials with minimal side effects and is now being tried against lung metastases resulting from osteosarcoma (bone cancer). The drug is given in conjunction with other treatments, such as chemotherapy. A new protein, macrophage-colony stimulating factor (M-CSF), can increase the number of monocytes (a cell type of the immune system) and increase their tumor-killing activity. Another approach to 'turn on' the body's tumor killing response is a vaccine, now being developed, against a specific molecule known to be located on tumor cells of certain breast and pancreatic adenocarcinomas. Administration of the vaccine results in high levels of killer T cells whose mission is tumor destruction. (Consumer Summary produced by Reliance Medical Information, Inc.)

Molecular biology, Tumors, Chemotherapy, Tumor antigens

---

Gene replacement therapy for hereditary emphysema?

Article Abstract:

Alpha 1-antitrypsin deficiency is a rare genetic disorder in which the victims typically experience an early onset of emphysema. Emphysema is a chronic lung disease characterized by the loss of elasticity in lung tissue and the subsequent progressive decrease in pulmonary capacity (the ability of the lungs to exchange adequate volumes of air). This disorder is considered the second most deadly genetic disease in the United States. The protein antitrypsin normally functions to protect the lungs from damage. In its absence the walls of the alveoli (very small sacks of lung tissue in which air exchange occurs) are attacked, leading to a progressive deterioration in pulmonary function. A recent forum sponsored by the American Lung Association discussed studies which indicate that gene therapy may provide a method for correcting this disorder in the near future. Current methods of treatment with infusions of purified antitrypsin from blood plasma are expensive, inconvenient and have potential negative side effects. One new method currently under investigation involves the use of the mobile liver approach to gene therapy which uses T cells that are activated with antigens as a means of transport to a selected cell sites. (Blood cells are activated with foreign proteins which then convey them to specific sites.) Although researchers believe a clinical application for use on humans is not ready, much success has been demonstrated in experiments using mice. Safety remains a consideration and the incorrect insert of a gene could result in malignancies. Also, sufficient quantities of human antitrypsin must be produced before human trials can be performed. These processes may not provide an immediate cure, but effective treatments may be available by 1992.

Care and treatment, Usage, Genetic aspects, Gene therapy, Genetic disorders, Emphysema, Pulmonary, Emphysema, Human chromosome abnormalities, Alpha 1-antitrypsin

Similar abstracts:

• Abstracts: Scientists stumped by test that promises tailored treatment
• Abstracts: Harmful genital care practices in children: a type of child abuse. Newborns killed or left to die by a parent: a population-based study
• Abstracts: Cytokine production in the rheumatoid joint: implications for treatment. Arthritis associated with adjuvant mycobacterial treatment for carcinoma of the bladder
• Abstracts: Intestinal electrolyte transport and diarrheal disease. Diarrheal disease during Operation Desert Shield
• Abstracts: Uremia and host defenses. Rubor, dolor, calor, tumor, and radionuclide scans. In-labeled nonspecific immunoglobulin scanning in the detection of focal infection

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