Spleen

ACS Symposium Series American Chemical Society Washington, DC, 1980. 

Still V5X higher than for [Pt(NH3)i,] (0.25%). The spread In Pt concentrations after 7 d Is nearly 40-fold. 

---

Splat cooling Spleen SPLENDA Splint Split peas... 

Pneumogstis carini pneumonia (PCP), the most common of the opportunistic infections, occurs in more than 80% of AIDS patients (13). Toxoplasmosis, a proto2oan infection of the central nervous system, is activated in AIDS patients when the 004 count drops and severe impairment of ceU-mediated immunity occurs. Typically, patients have a mass lesion(s) in the brain. These mass lesions usually respond well to therapy and can disappear completely. Fungal infections, such as CTyptococcalmeningitis, are extremely common in AIDS patients, and Histop/asma capsulatum appears when ceU-mediated immunity has been destroyed by the HIV vims, leading to widespread infection of the lungs, Hver, spleen, lymph nodes, and bone marrow. AIDS patients are particularly susceptible to bacteremia caused by nontyphoidal strains of Salmonella. Bacteremia may be cleared by using antibiotic therapy. 

Ling Zhi-8 (LZ-8) is an immunomodulatory protein (29,30) isolated from the mycelial extract of Ganoderma lucidium, that has been purified and shown to stimulate mouse spleen and human peripheral blood lymphocytes. LZ-8 is able to inhibit antibody production and prevent the development of autoimmune type I diabetes in NOD mice. 

Selenium. Selenium, thought to be widely distributed throughout body tissues, is present mostly as selenocysteine in selenoproteins or as selenomethionine (113,114). Animal experiments suggest that greater concentrations are in the kidney, Hver, and pancreas and lesser amounts are in the lungs, heart, spleen, skin, brain, and carcass (115). 

CB, was identified by radioligand binding techniques and subsequently cloned. A second receptor subclass, CB2, has been identified in human spleen and also has been cloned (34). Table 5 Hsts cannabinoid receptor ligands. 

Based on tests with laboratory animals, aniline may cause cancer. The National Cancer Institute (NCI) and the Chemical Industry Institute of Toxicology (CUT) conducted lifetime rodent feeding studies, and both studies found tumors of the spleen at high dosage (100 —300 mg/kg pet day of aniline chloride). CUT found no tumors at the 10—30 mg/kg per day feeding rates. The latter value is equivalent to a human 8-h inhalation level of 17—50 ppm aniline vapor. In a short term (10-d) inhalation toxicity test by Du Pont, a no-effect level of 17 ppm aniline vapor was found for rats. At high levels (47—87 ppm), there were blood-related effects which were largely reversible within a 13-d recovery period (70). 

A novel approach to the modification of aminoglycoside pharmacokinetics is under investigation (84). Administration of gentamicin encapsulated in egg phosphatidylcholine Hposomes has been found to lead to a longer half-life and much higher spleen and Hver levels for the gentamicin component. This formulation is undergoing clinical study (85). 

Florfenicol concentrations in tissues and body fluids of male veal calves were studied after 11 mg/kg intramuscular doses adininistered at 12-h intervals (42). Concentrations of florfenicol in the lungs, heart, skeletal muscle, synovia, spleen, pancreas, large intestine, and small intestine were similar to the corresponding semm concentrations indicating excellent penetration of florfenicol into these tissues. Because the florfenicol concentration in these tissues decreased over time as did the corresponding semm concentrations, it was deemed that florfenicol equiUbrated rapidly between these tissues and the blood. Thus semm concentrations of florfenicol can be used as an indicator of dmg concentrations in these tissues. 

Florfenicol has a wide tissue distribution, similar to that reported for chloramphenicol in calves and thiamphenicol in humans (43,44). Chloramphenicol attains concentrations higher than the corresponding plasma concentrations in bile and urine, as does florfenicol (43). Unlike florfenicol, chloramphenicol concentrations in the Hver, kidney, spleen, and lungs are less than corresponding plasma concentrations. However, chloramphenicol penetrates the brain and CSF much better than does florfenicol, reaching values equal to plasma concentrations in the brain. The distribution of thiamphenicol into the kidney, urine, and muscles of humans compared with corresponding plasma concentration is similar to what was observed for florfenicol in calves (44). The penetration of thiamphenicol into the CSF is much smaller than that of florfenicol in calves. 

Technetium-99m albumin coUoid is cleared by the reticuloendothehal (RE) cells and is used for visualization of the RE system of the Hver, spleen, and bone marrow. The product is formed by the addition of up to 2.8 GBq (75 mCi) of Tc pertechnetate. 

Chinese Herbal Medicines. Many traditional Chinese medicines have been screened for radioprotective activity in experimental animals. In one study of more than a thousand Chinese herbs, a number of agents increased the survival rate of dogs exposed to a lethal dose of y-rays by 30—40%, and some symptoms of radiation injury were ameHorated. These effects are potentially related to stimulation of the hemopoietic and immune systems (130). Extracts of five Chinese dmg plants, as weU as aspirin, effectively protected mice exposed to 7.5—8.0 Gy (750—800 rad) of y-radiation, and increased survival rates by 8—50% (131). Several Chinese traditional medicines, adininistered ip before or after irradiation, protected against Hpid peroxidation in a variety of mouse tissues, including BM, Hver, and spleen, as weU as in mouse Hver microsomal suspensions irradiated in vitro (132). 

The effects of lL-1 ki accelerating recovery of BM hemopoiesis ki mice have been characterized (172). Injection of lL-1 20 h prior to sublethal kradiation promotes an eadier CEU-S/CEU-GM recovery ki the BM and spleen, and markedly affects BM ceUularity and mobilization of progenitor cells (172). Differences have been found between strains and administration protocols, especially with respect to BM CEU-GM numbers. 

Metabolism. Absorption, distribution, metaboHsm, and excretion of thioglycolic acid have been reviewed (20). In summary,. -thioglycolic acid was absorbed significantly after appHcation to the skin of rabbits. After intravenous injection, the greatest counts of radioactivity were found in the kidneys, lungs, and spleen of monkey and in the small intestine and kidneys of rat. Most of the radioactivity was rapidly excreted in the urine in the form of inorganic sulfate and neutral sulfur. 

Thorotrast (colloidal Th02) was once used as a radiopaque agent in medicine (see Radiopaques). Its injection in a dose of 2.0—15.0 g caused rises in body temperature, nausea, and injury to tissues at the injection site, followed by anemia, leukopenia, and impairment of the reticuloendothehal system. After intravenous adrninistration, thorotrast particles are taken up by reticuloendothehal cells of the fiver and spleen. Thorotrast is virtually not eliminated from the body (91). Between 1947 and 1961, 33 cases of cancer of the fiver, larynx, and bronchi and sarcoma of the kidneys, developing from 6 to 24 years after thorotrast administering, have been described in the literature (92). 

The adrenal glands and pituitary glands have the highest tissue concentration of ascorbic acid. The brain, Hver, and spleen, however, represent the largest contribution to the body pool. Plasma and leukocyte ascorbic acid levels decrease with increasing age (152). Elderly people require higher ascorbic acid intakes than children to reach the same plasma and tissue concentration (153). 

Diethylcarbama2iae has limited antimicrofilarial activity against Onchocerca volvulus. Adults of W. bancrofti the filarial worm causiag elephantiasis, coil in the lymph system. Here females can attain a length of 10 cm. Over the years, tissue reactions result in obstmction to lymph return. Lymph nodes, lymph vessels, and the spleen become enlarged. The condition of elephantiasis is a late and unusual complication of filariasis, where the lower extremities of the body become edematous, enlarge, and over a period of time harden with a rough nodular skin. 

Toxicity. The toxicity of barium compounds depends on solubility (47—49). The free ion is readily absorbed from the lung and gastrointestinal tract. The mammalian intestinal mucosa is highly permeable to Ba " ions and is involved in the rapid flow of soluble barium salts into the blood. Barium is also deposited in the muscles where it remains for the first 30 h and then is slowly removed from the site (50). Very Httle is retained by the fiver, kidneys, or spleen and practically none by the brain, heart, and hair. 

The GI absorption of the dmg after po adrninistration is slow and variable with estimates ranging from 20—55%. Once absorbed, 96% of the dmg is bound to plasma proteins and other tissues on the body. Whereas peak plasma concentrations may be achieved in 3—7 h, the onset of antiarrhythmic action may occur in 2—3 days or more. This may result, in part, from distribution to and concentration of the dmg in adipose tissue, Hver, spleen, and lungs. Therapeutic plasma concentrations are 1—2 p.g/mL, although there appears to be no correlation between plasma concentration and antiarrhythmic activity. The plasma half-life after discontinuation of the dmg varies from 13—103 days. The dmg is metabolized in the Hver and the principal metaboHte is desethylamiodarone. The primary route of elimination is through the bile. Less than 1% of the unchanged dmg is excreted in the urine. The dmg can also be eliminated in breast milk and through the skin (1,2). 

Thymine was isolated from hydrolyzates of bovine thymus or spleen in 1893, several years before uracil, but it was not made synthetically until 1901. Unlike uracil, it comes not from ribonucleic but from deoxyribonucleic acids via thymidine (3-D-2 -deoxyribofuranosidothymine). 

---