Parasitism, origins

Vesicular type (Fig. 10.5 (b)). A protoscolex swells and becomes vesicular , taking on a cottage-loaf profile. This type becomes rounded, eventually secreting a laminated membrane (313,791) and developing into a miniature hydatid cyst (Fig. 10.5 (e)). The laminated membrane is strongly periodic acid-Schiff (PAS) positive and is composed of a mucopolysaccharide (Chapter 4). The origin of this membrane was previously in doubt, but the fact that it is entirely of parasite origin is demonstrated by the fact that it develops in vitro, even in protoscoleces cultured in a (serum-free) defined medium (313). 

The continuous cultivation of P. faloiparum in human erythrocytes has been recently accomplished by Trager and Jensen.34 The parasite, originally derived from an infected Aotus trivirgatus monkey, propagated over 100 million times by the addition of human erythrocytes at 3 to 4-day intervals. 

Momen, FI. (1979). Biochemistry of intraerythrocytic parasites. I. Identification of enzymes of parasite origin by starch-gel electrophoresis. Ann. Trap. Med. Parasitol. 73,109-115. 

Simaroubaceae are broadly used against dermatological conditions from bacterial origin (furuncles, superinfected wounds, erysipelas, acne, abscesses), parasitic origin (leishmaniasis), related to the presence of dermatophytes (ringworm), to those described as warts or cancerous tumors of the skin, tropical ulcers, and... 

Eosinophilic pneumonias of parasitic origin and other infectious causes Allergic bronchopulmonary aspergillosis and related syndromes Iatrogenic and toxic agents-induced eosinophilic pneumonias Drugs... 

Parasitic ferromagnetism is a weak ferromagnetism that accompanies antiferromagnetism, eg, in a-ferric oxide [1309-37-1], a-Fe202. Possible causes include the presence of a smaU amount of ferromagnetic impurities, defects in the crystal, and slight deviations in the directions of the plus and minus spins from the original common axis. 

Lac is derived from lac resin, the hardened secretion of the lac insect, the only known resin of animal origin. The lac insect, Kerria lacca, formerly known as Laccifer lacca, is a natural parasite of a variety of trees in large areas of southern Asia. Three different products are derived from lac resin lac dye, lac wax, and shellac. To obtain the lac resin, twigs encrusted with the secretion of the insects are cut down from the trees, then the incrustation is separated from the twigs, washed with water, and filtered. The wax and shellac, which are insoluble in water, remain as a solid residue of the filtration, while the soluble red dye (lac) is obtained as a powder when the water from the filtered solution is evaporated. The coloring matter in lac dye is an organic compound known as laccaic acid. 

---