Browsing by Author "Ranasinghe, C.P."

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    Identification and characterization of dieback syndrome in Camelliasinensis (TRI 2025)
    (University of Kelaniya, 2005) Ranasinghe, C.P.; Balasuriya, A.; Jayaratne, D.L.
    The disease has been reported in the tea cultivar TRI 2025, grown in the upcountry since 1989 (Nethaniel, 1999). Preliminary observations from different locations where the disease has already been reported showed pathological affiliations instead of a physiological disorder or agronomical reasons. During the eight months under investigation in the Nuwara Eliya Estate, the affected area expandedby 129.75 m2. A distinctive increase in the rate of spread was observed during dry seasons. Asignificant relationship between the spread of the disease and climatic stress was found. The rate ofspread of the disease was higher with low relative humidity and rainfall. The expansion of the patch followed the direction of the wind with an indication of an airborne disease. Phylloplane microflora of TRI 2025 between healthy and diseased plants, the soils, which they are grown, collected from diseased and healthy areas found to have no significant difference. However, Pantoea agglomerans (Beijerinck) (Gavini et al., 1989), a Gram negative rod was solely and repeatedly isolated on nutrient agar, from the xylem sap of diseased plants. The sap of visually healthy plants, of the same cultivar upon prolonged incubation developed few colonies of the same bacterium. The bacterium was also isolated from dew collected from leaves of the diseased plants. The isolate was confirmed by the International Mycological Institute (IMI) in the United Kingdom (Offord, 2003). Four experimental sets of plants used to demonstrate Koch’s postulates, using mature tea bushes (Nuwara Eliya and St. Coomb’s), young plants and tomato seedlings. None of the sets met with conclusive results. Stem section analysis of the cultivar showed a significant xylem blocking in diseased plants, which increased in numbers with the severity of symptoms. P. agglomerans (Beijerinck) (Gavini et al., 1989), produce high-molecular-weight extra-cellular polysaccharides (Balows et al., 1992) and some strains are ice-nucleae active causing frost damage (Pajand,2005). Under the evidences the dieback in TRI 2025 can be classified as a stress driven relationship between a stressed plant and an opportunist.
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    Liquid gastric emptying and antral motility in adult asthmatics
    (University of Kelaniya, 2008) Amarasiri, W.A.D.L.; de Silva, H.J.; Ranasinghe, C.P.
    Introduction: Asthmatics have increased prevalence of gastro-oesophageal reflux disease (GERD). Gastric antral hypomotility may contribute to this. Gastric motility has been little studied in asthma. Objective: To study gastric emptying (GE) of a liquid meal in adult asthmatics and investigate association with GERD symptoms and autonomic functions. Method: GE response to 200mL of chicken soup (54kJ, 15% protein, 30% fat and 65% carbohydrate) was assessed by real time ultrasonography in 30 stable, mild asthmatics (diagnosed according to American Thoracic Society Criteria) and 30 healthy controls. Percentage emptying at 15 minutes (GER%) and antral motility index were measured. Symptomatic GERD was assessed by a validated questionnaire, and autonomic nervous function by blood pressure and heart rate response to standing and deep breathing and the Valsalva maneuver. Results: The asthmatics (15 males, age (mean ± SD) 34.7 ± 8.4) and controls were comparable in age, gender and body mass index. On autonomic function assessment, 3 asthmatics showed hypervagal response, 2 showed reduced vagal response but none showed a hyperadrenergic response. They were only on inhaled ��-agonists as required. Although, 20 asthmatics had symptomatic GERD, none had endoscopic gastric pathology. Compared to controls, asthmatics had significantly delayed GER% (mean ± SD 55.4±14.4 versus 64.0±13.5, p=0.036) and lower antral motility index (mean ± SD 4.9±1.5 versus 6.4±1.4, p=