Substance Info: (and synonyms)|
Paspalum has about 400 species. P. notatum is native to southern Brazil, Uruguay, the Chaco region of northern Argentina, and northwestern Paraguay, and is found in most Central and South American countries. It may also be native to the West Indies. It has been introduced as a turf and forage grass into East and West Africa, Australia, Japan, Mexico, and the southern and eastern United States. It is widely cultivated in low-altitude pastures of southwestern Japan and is a popular forage grass on the north coast of New South Wales and on the south coast of Queensland, Australia. One species is especially important in India for growing on barren hills because it is drought-resistant.
Paspalum notatum is a sod-forming, deep-rooted, warm-season perennial grass. It spreads by short, stout, woody runners and by seed. The runners have many large, fibrous roots which form dense, tough sods, even on drought-prone sandy soils. The leaf bases at the terminus of each rhizome usually have a purplish hue. The culms (stems) of P. notatum are ascending, usually ranging from 20 to 75cm tall, and the dark green leaves are 4 to 10mm wide and 6 to 25cm long.
The inflorescences have 2 to several spicate branches 4-12 cm long, and each branch (or raceme) has 2 rows of spikelets, either paired or positioned with one slightly below the other. Flowering is between June and November but may flower throughout the year in various locations. (Bahia grass ripens progressively over the summer in the United States and at no time is all the seed mature.) Besides vegetative spread, some varieties can reproduce asexually by unfertilized yet viable seeds; the sexually reproducing varieties are wind-pollinated. The plant seeds prolifically during the summer. The seed stalks are 30 to 75cm high, usually with 2 (sometimes 3) racemes, each about 6cm long. The seeds - oval, yellowish-green, glossy and 3mm in diameter - are typically dispersed by ruminants.
Pollen of Bahia grass (Paspalum notatum) represents a major cause of type I allergy in diverse geographical areas, particularly in the southeastern coastal plain area of the United States. (Ghobrial 2002 ref.6870 1)
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This article compares allergy to subtropical and temperate grass pollens in patients with allergic rhinitis from a subtropical region of Australia. Sensitization to pollen extracts of the subtropical Bahia grass (Paspalum notatum), Johnson grass (Sorghum halepense) and Bermuda grass (Cynodon dactylon) as well as the temperate Ryegrass (Lolium perenne) were measured by skin prick in 233 subjects from Brisbane. Patients with grass pollen allergy from a subtropical region showed higher skin prick diameters with subtropical Bahia grass and Bermuda grass pollens than with Johnson grass and Ryegrass pollens. IgE reactivity was higher with pollen of Bahia grass than Bermuda grass, Johnson grass and Ryegrass. Patients showed asymmetric cross-inhibition of IgE reactivity with subtropical grass pollens that was not blocked by temperate grass pollen allergens indicating the presence of species-specific IgE binding sites of subtropical grass pollen allergens that are not represented in temperate grass pollens. Subtropical grass pollens are more important allergen sources than temperate grass pollens for patients from a subtropical region. Targeting allergen-specific immunotherapy to subtropical grass pollen allergens in patients with allergic rhinitis in subtropical regions could improve treatment efficacy thereby reducing the burden of allergic rhinitis and asthma.
Davies JM, Li H, Green M, Towers M, Upham JW. Subtropical grass pollen allergens are important for allergic respiratory diseases in subtropical regions. Clin Transl Allergy 2012 Mar 5;2(1):4.
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In an Australian study evaluating recombinant Bahia grass allergen Pas n 1, 29 of 34 (85%) consecutive patients presenting with grass pollen allergy were skin prick test positive to Bahia grass pollen. All reported seasonal rhinitis and 6 seasonal asthma. Serum IgE varied from 0.51 kU/l to 38.5 kU/l. All were also sensitised to rye grass and bermuda grass pollen. A number of patients were also sensitised to cat dander and house dust mite. Recombinant Pas n 1 reacted with serum IgE in 47 of 55 (85%) Bahia grass pollen-allergic patients. (Davies 2008 ref.22840 0)
Davies JM, Mittag D, Dang TD, Symons K, Voskamp A, Rolland JM, O'Hehir RE. Molecular cloning, expression and immunological characterisation of Pas n 1, the major allergen of Bahia grass Paspalum notatum pollen. Mol Immunol 2008 Dec;46(2):286-293
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In this study in Northern New South Wales, Australia, 153 (74.3%) of 206 subjects were atopic and reacted to one or more aeroallergens. Seventy were SPT positive to ragweed, and 11 to Tibouchina. An association between Bahia grass and asthma in children, and between Bermuda grass and allergic rhinitis in adults was demonstrated. (Bass 2000 ref.5243 3)
Bass DJ, Delpech V, Beard J, Bass P, Walls RS. Late summer and fall (March-May) pollen allergy and respiratory disease in Northern New South Wales, Australia. Ann Allergy Asthma Immunol 2000;85(5):374-81
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In 100 Thai individuals who were diagnosed with allergic rhinitis by history and clinical presentation who underwent a prick skin test with 30 aeroallergens:TREES: acacia 19%, mango 16%, coconut 12%. GRASSES: bermuda 17%, johnson 21%, timothy 16%, bahia 16% orchard 18%. WEEDS: pigweed 16%, kochia 14%. MOLDS: alternaria 11%, cladosporium 11%, aspergillus 12%, penicillium 16%, helminthosporium 16%, botrytis 15%, rhodotorula 20%, fusarium 26%, curvularia 26%, smut mix 11%, rust 9%. EPIDERMALS: cat 29%, dog 28%, feathers 37%. INDOOR ALLERGENS: house dust 72%, D. pteronyssinus 76%, D. farinae 79%, American cockroach 60%, German cockroach 41%, kapok 30%. Eighty-five percent of patients sensitive to house dust mites were positive to both D. pteronyssinus and D. farinae. (Pumhirun 1997 ref.2256 8)
Pumhirun P, Towiwat P, Mahakit P. Aeroallergen sensitivity of Thai patients with allergic rhinitis. Asian Pac J Allergy Immunol 1997;15(4):183-5
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Intradermal skin test (Phillips 1989 ref.5415 6)
Serum specific IgE (Phillips 1989 ref.5415 6)
Nasal challenge (Phillips 1989 ref.5415 6)
Bronchial challenge (Phillips 1989 ref.5415 6)
In a Florida, USA, study, 38 subjects were challenged (25 nasal, 13 bronchial) with Bahia grass, Paspalum notatum, pollen extract. A positive Bahia intradermal skin test predicted a positive challenge to Bahia in all (11/11) of the nasal challenges and 75% (6/8) of the bronchial challenges. Specific IgE antibodies to Bahia pollen were detected by conventional RAST (greater than or equal to 2+) in 82% (14/17) of subjects with positive challenges and in 5% (1/20) of subjects with negative challenges. Bahia grass is a significant aeroallergen, which in some subjects can be demonstrated not to cross-react with Timothy grass. (Phillips 1989 ref.5415 6)
Phillips JW, Bucholtz GA, Fernandez-Caldas E, Bukantz SC, Lockey RF. Bahia grass pollen, a significant aeroallergen: evidence for the lack of clinical cross-reactivity with timothy grass pollen. Ann Allergy 1989;63(6 Pt 1):503-7
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