Manipulators Of The Developing Immune System

The immune system matures according to developmental pathways but also in response to the environment. Four manipulators impact many facets of the immune system and deserve attention. First and foremost, nutrition plays a vital role in the ability of the body to defend against pathogens (Bardare et al. 1993 Devereux et al. 2002). The majority of immunocompromised individuals in the world simply lack nourishment (Janeway Jr. et al. 1997a). Studies implicate maternal diet in development of atopic...

Pyrethroid Insecticides Cypermethrin

Cypermethrin is a widely used synthetic type II pyrethroid insecticide due to its high insect toxicity, low mammalian toxicity, and rapid metabolism (Crawford et al. 1981 Rhodes et al. 1984). Cypermethrin is primarily considered to be a sodium channel toxin. At high concentrations, pyrethroids induce a long-lasting depolarization and block nerve conduction. However, other secondary mechanisms of action are also involved in their toxicity, including antagonism of GABA inhibitory action,...

Alcohol

A number of studies have shown that consumption of alcohol inhibits immune function in both adult humans and animals (Jerrells et al. 1986). In adults, ethanol is immunosuppressive, decreasing both the cellularity of the thymus and spleen and interfering directly with B and T-lymphocyte responses. Additionally, alcohol suppresses the phagocytic activity of macrophages and reduces NK cell activity (Seelig et al. 1996). Ethanol consumption alters cytokine production, including IL-2, IL-5, IL-6,...

Current Assessment Of The Immune System In Epa Guideline Studies

A number of guideline toxicity studies utilized in the regulation of pesticides, industrial chemicals, and environmental pollutants include assessments of immune system structure and or function. The majority of these studies are performed in adult animals. Although they were not developed to assess the developing immune system, they can provide valuable information that could indicate the necessity for further testing to evaluate effects on the immune system following developmental exposure....

Signaling Pathways and Transcription Factors Involved in Asthma Pathogenesis

Soluble mediators may play important roles in the sensitization and triggering of asthmatic responses, but they only do so by acting through specific receptors. Binding to a specific receptor by any cognate ligand normally transduces a signal to the nucleus to transcribe, or block the transcription of, a gene or genes via one or more intracellular biochemical pathways. Steps along a pathway are referred to as pathway intermediates, and those intermediates directly responsible for binding to DNA...

Asthmatic Inflammation

Asthma is a chronic inflammatory disease of the airways. Asthmatic inflammation involves complex interactions between the cytokines and signaling pathways of many cell types. In adults and children, T cells are known to be integrally involved in this process (Azzawi et al. 1990 Corrigan and Kay 1990 Wardlaw et al. 1988). The maintenance of airway inflammation is attributed, in adults, to chronically activated memory T cells sensitized against a variety of allergens (Corrigan and Kay 1990) and,...

Ochratoxin A

Ochratoxin A is a mycotoxin produced by Aspergillus ochraceus and Penicillium verrucosum and is found worldwide as a food contaminant. It is known to cause porcine nephropathy and may be associated with a human kidney disease endemic to the Balkan region Bondy and Pestka 2000 . Mice and rats exposed to ochratoxin A in utero had altered immune responses compared to controls. A single dose of och-ratoxin A 10 to 500 mg kg to pregnant mice decreased thymic CD4 and increased thymic CD4 CD8...

Therapeutic Immunosuppressant Levels In Mammary Gland Secretions

Many of the immunosuppressive drugs used during pregnancy are also found in breast milk. Currently, the American Academy of Pediatrics AAP provides guidelines for breastfeeding based on the excretion rate and potential teratogenic effects of each drug Tendron et al. 2002 . For example, limited concentrations lt 10 of prednisone and prednisolone have been measured in breast milk, levels perceived by the AAP as nonthreatening to the breastfed infant Coulam et al. 1982 Ost et al. 1985 . Thus,...

The Pigs Intestinal Immune System During Postnatal Development

The early postnatal development of the gut immune system is important for effective immunological responses towards nutritional and microbial antigens in the intestinal lumen. Adaptation to the commensal flora, defense against pathogens, and the development of oral tolerance to food components are essential immunological processes. Depending on the food composition and on the presence of oral food components, the morphology of both the intestinal mucosa and the intestinal immune cells changes...

Diazepam Valium

Diazepam DZP is a benzodiazepine BDZ with central nervous system CNS -depressant properties. It has anxiolytic, sedative hypnotic, muscle relaxant, and anticonvulsant effects. DZP is used in humans for the short-term relief of symptoms related to anxiety disorders the treatment of agitation, tremors, delirium, seizures, and hallucinations as a result of alcohol withdrawal the relief of muscle spasms in certain neurological diseases and the control of active seizures Costa and Guidotti 1979 ....

Proposed Content Of A Developmental Immunotoxicity Study

Although the need for developmental immunotoxicity testing has long been recognized by the scientific and regulatory communities NRC 1993b USEPA 1999, 2002b , there is currently no formal EPA testing guideline protocol for this study. Studies have, however, been conducted in numerous laboratories to assess the developmental immunotoxic potential for a myriad of pharmaceuticals, pesticides, and environmental pollutants. Additionally, the National Toxicology Program NTP has devised an...