Occurrence pollen

Inflammation is characterized by the orderly occurrence of several processes initiation of the event by a foreign substance or physical injury, recruitment and chemoattraction of inflammatory cells, and activation of these cells to release inflammatory mediators capable of damaging or killing an invading microbe or tumor. In some instances, the inflammatory response is initiated by an otherwise harmless foreign material (e.g., pollen). Inflammation can also result from an autoimmune response to the host s own tissue, as occurs in rheumatoid arthritis. 

Juhlin-Dannfelt, C. (1948). About the occurrence of various forms of pollen allergy in Sweden. Acta Med. Scand., 26, 563-577. 

The occurrence of brassinosteroids in gymnosperms has been reported from conifers. Yokota ef al. isolated typhasterol ( 2-deoxycastasterone ) from pollen of Japanese black pine ( Pinus thunbergii ) (38) and identified castasterone and typhasterol from shoots of sitka spruce (Picea sitchensis ) (39). Kim ef al. also identified castasterone and brassinolide from cambial scrapings of Scots pine (Pinus silverstris ), using a modified dwarf rice lamina inclination assay which showed a synergistic response of brassinosteroids with indole-3-acetic acid (40). 

Since the first isolation and identification of brassinolide (BR) from rape pollen by Grove et al in 1978 (7), a wide occurrence in the plant kingdom of related steroidal compounds which are now collectively called brassinosteroids, as well as BR itself, has been confirmed (2). 

Hormonal properties on plants. The occurrence and distribution of the brassinosteroids in assorted plant tissues has been comprehensively discussed (2). They occur in immature seeds, leaves, stems, shoots, pollen, and fruit. Furthermore, they have been found in insect galls and the corresponding healthy tissues. Although the chemical species remained the same in both sets, only brassinolide occurred in galls, but not in healthy tissues. Again, these compounds... 

Palynology is concerned with studies of pollen and its occurrence in the environment. 

Occurrence other than in man The spectrum of A. in vertebrates is, in principle, qualitatively the same as that in humans although there may be quantitative differences and differences with regard to biosynthetic and metabolic details. A. have also occasionally been isolated from plants as metabolites of steroidal secondary substances, e.g., testosterone and androstenedione from pollen of Scottish pine Pinus sylvestris (Pin-aceae) and rubrosterone (2/3,3/S,14a-trihydroxy-5)8-androst-7-ene-6,17-dione), a biological degradation product of an ecdysteroid from Achyranthes rubro-fusca (Amaranthaceae). 

Fathipour, A Schlender, KK Sell, HM. The occurrence of fatty acid methyl esters in the pollen of Zea mays. Biochim. Biophys. Acta, 1967,144,476-478. 

Some determinations have been made of the occurrence of PAs by insects, which assimilate the alkaloids from toxic plants to use in their own defense or to produce pheromones. PAs have been extracted from insects, using acidic methanol, followed by limited clean-up [16]. There is also interest in the PA content of pollen, for which it has been shown that careful washing with cyclohexane and grinding with sand is necessary to obtain pure PAs quantitatively [17]. 

Fossil pollen was found worldwide, with the oldest occurrence being Calystegiapollis microechinatus from the early Eocene ( 55 my ago) of Africa (Martin 2001). The separation of Ipomoea nil (L.) Roth, imperial morning glory, and I. purpurea (L.) Roth, common morning glory, is assumed to be 8 my ago (late Miocene) (Durbin et al. 2001). 

Occurrence. Found in the milk of all mammals to the extent of approximately 5%. It has been reported that a methanol extract of the longstyled pollen of forsythia flowers contains lactose (61). 

Pollen deposition on milkweed leaves during 1999-2000 (5) is represented on a separate scale in a cinnulative fiequency occurrence curve. 

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