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Item PCR based detection techniques and DNA finger printing by restriction fragment analysis of mycobacterium tuberculosis(University of Colombo: UC(MED)., 2001) MAGANAARACHCHI, DNIn Sri Lanka definitive diagnosis of tuberculosis depends on the culture of mycobacteria, but the slow growth of the organism delays the diagnosis. Examination of direct smears for acid fast bacilli is the widely used method for the detection of mycobacteria, but lacks the desired specificity and relatively large number of bacteria is needed for detection. The objective of the study was to develop a rapid method to detect Mycobacterium tuberculosis from clinical samples and the applicability of DNA amplification techniques to a developing country like Sri Lanka. In this study, the potential use of PCR was investigated using the primers Pt8-Pt9 based on the insertion sequence IS 6110 of the Mycobacterium tuberculosis complex (Kolk etal, 1992). The study focused mainly on extrapulmonary tuberculosis where a definitive diagnosis was difficult. In this study 465 clinical samples were tested using PCR and the results obtained indicates that this approach offers may advantages over conventional methods and could be used to detect Mycobacterium tuberculosis in clinical samples. The sensitivity of the PCR method is largely dependent on the efficiency of the DNA extraction procedure which, could probably be improved by modifications of the lysis technique. For the DNA extraction and purification from the clinical samples two methods, the standard phenol extraction procedure desctibed by Sambrook etal (1982) and the guanidinium thiocyanate method described by Boom et al(1990) were used. The Boom's method was preferred to phenol/chloroform extraction method as most or all of the inhibitory substances in clinical samples were effectively removed by this method. Based on this study PCR was found to be more sensitive than culture or microscopy in those with a final diagnosis of extra pulmonary tuberculosis. In conclution, DNA amplification is a rapid, reliable and accurate method with a high degree of sensitivity and specificity for the detection of Mycobacterium tuberculosis DNA sequences and it can replace the conventional culture method in the diagnosis of extra pulmonary tuberculosis and tuberculosis meningitis except in the situation when antibiotic sensitivity results are required. Since PCR is too expensive to use in routine laboratories in Sri Lanka, one center could function as a reference laboratory where clinical samples can be tested using Polymerase Chain Reaction. Typing of Mycobacterium tuberculosis isolates is of great potential value for basic and epidemiological studies on tuberculosis. Results obtained from Restriction fragment length polymorphism typing show that the mahority of circulating Mycobacterium tuberculosis strains in Sri Lanka belong to a limited number of families, but the degree of IS6160 DNA polymorphism among strains were high. Of the 20 strains isolated from prisoners, none of the strains displayed identical fingerprints. In bacterial isolates of prisoners and ex-prisoners from the general population, there were 2 strains, which had identical banding patterns, while there were clear similarities between several isolates. From the general population 5 sets of identical banding patterns were observed. More than 68 percent had less than 5 copies of the IS sequence suggesting that our local M.tuberculosis strains have a fewer number of copies compared to data shown in most countries. Among the strains tested there were two strains that lacked the IS 6110 element. Drug resistant M. tuberculosis strains were examined by RFLP typing to determine whether a significant association between specific RFLP types and drug resistance is present. There were no specific RFLP types that could be associated with a particular type of drug resistance. Incidentlly the acquired drug resistance was 51.2 percent and multi drug resistance (MDR-TB) was 3.5 percent. The prevalence of acquired drug resistance to individual drugs was comparatively lower in Sri Lanka compared to other countries except ethambutol resistance. Furthermore there were strains that were resistant to second line drugs without showing resistance to first line drugs. Wide variation in drugs sensitivity patterns in the study indicates the necessity to have an antibiotic sensitivity test before instituting treatment for recurrent TB patients.Item Development of a preliminary computerized simulation model to monitor and predict the pollution levels due to NPK fertilizer(University of Colombo: UC(SCI)., 2000) GUNASEKERA, LMNutrient leaching into waterbodies effects the quality of water and their inhabitants. One major source of nutrients is the excess NPK fertilizer applied in agricultural practices. Lake of monitoring facilities to measure the degree of interference, makes it difficult to know the of pollution. This study was a preliminary attempt to develop a computerized simulation model predict the pollution levels due to NPK fertilizer leaching into waterbodies. The level of pollution is measured by the algal growth which is given as a number of algal cells. The computerized simulation model is a computer software package which consists of three parts that are the main components of any simulation model, namely, a way of input data, internal processing of these data and the use of these processed data to make predictions as output. The computer simulation model was developed allowing input of any number of variables permitting future expansion of the model. However, the model was tested for only two such variables namely fertilizer concentration and temperature. The regression relationship for fertilizer concentration and temperature with algal growth was teated in the laboratory. Laboratory experiments were carried out to find the relationships between nutrient concentration verses algal growth and the temperature verses algae growth. The results indicated that the ....Item Electro transfer in DNA: electrochemical investigation of DNA single base mismatch detection(University of Colombo: UC(SCI)., 2004) PERERA, HDDA large number of genetic diseases and genetic disorders are simply caused by single based substitutions or small additions and deletions in the genome. Therefore developing efficient and cost effective techniques for routine detection of DNA mutations is of great importance. Different method involving gel elctrophoresis and polymerase Chain Reaction have been developed to identify altered DNA. Many of these are costly, time consuming and lack high throughput capability. Detection methods based on electrochemical techniques are becoming very popular and are critical in biosensor development. In this study, new strategies for single base mismatch detection were developed using electrochemical methods. MutS protein, a number of the mis-matched repair (MMR) system, Recognizes mispaired and unpaired bases in duplex DNA and initiates a mismatch repair. The natural specificity of MutS mismatch repair protein for single base mismatch recognition was exploited in this study. Particular focus was given to oligonucleotides with single G:T mismatches. This method involves modification of a gold electrode surface using a bi-functional succinimidyl compound, immobilization of MutS protein on the modified gold electrode surface through amide linkages, and application of a DNA probe for mismatch recognition. Electrochemical discrimination between mismatched and comple,emtary DNA strands was performed using redox properties of Tris-2,2'-dipyridylocobalt (III) Perchlorate Trihydrate. QCM and EMSA studies further supported the results from square wave voltammetry. Another strategy for single base mismatch detection is covalent DNA immobilization. Mismatches were detected via charge transduction through the DNA immobilization. Mismatches were detected via charge transduction through the DNA film. This method involves chemical modification by electrochemical reduction of 4-diazonium carboxylic acid tetrafluoroborate on a glassy carbon electrode and immobilization of DNA on the modified electrode surface through carbodiimide1 N-hydroxy succinimide coupling. Square wave and cyclic voltammograms for different types of redox active probes showed discrimination between complementary and mismatch DNA.Item Plasmodium vivax:asexual erythrocytic stage antigens(University of Colombo: UC(MED)., 1989) UDAGAMA, PVAB. : A panel of 34 monoclonal antibodies (Mabs) established against the asexual erythrocytic (AE) stages of Plasmodium vivax was used to identify and characterize the antigenic profile of this parasite stage. These Mabs allowed the characterization of at least 38 different antigenic polypeptides, their relative molecular weights ranging from 14 to 225 kDa as ascertained by Western blotting. Classification of 6 distinct immunofluorescence staining patterns obtained with these Mabs led to formulate assumptions on the probable localization of the corresponding antigenic determinants with respect to the parasite and the infected erythrocyte. Stage specificities of these Mabs were established and cross reactivities with AE stages of 3 other plasmodial species, viz. P. cynomolgi, P. falciparum and P. fragile were determined by the indirect immunofluorescence test (IFT). An antigen associated with the caveola-vesicle complexes which are associated with Schuffner's dots on the infected erythrocyte was identified and characterized using one of these Mabs. Another antigen GAM-1, common to both asexual and sexual stages of P. vivax which has now been designated as a potential transmission blocking vaccine candidate was also identified. The analogue in P. vivax of the class of high molecular weight polymorphic schizont surface antigen, PV200 was described. Reactivity of this battery of MAbs by the IFT with 50 different P. vivax primary isolates originating from 16 different geographical districts of Sri Lanka indicated a high degree of polymorphism among these antigens in natural parasite isolates. While 6 epitopes were found to be conserved among more than 80 percent of the isolates examined, the rest were found to be divetse to varying degrees. Both epitope and size polymorphism were demonstrated in these parasite antigens. Mabs against variant epitopes of PV200 were used to analyze the variety of serotypes (genetically distinct populations) in individual P. vivax infections in Sri Lanka, by the IFT. Individual parasites were typed with respect to their reactivity with 2 Mabs (of different isotype specificities) at a time, by double staining with isotype specific chromatophores, fluoresceine and rhodamine. This technique allowed the detection of minor subpopulations representing at least 5 percent of the total parasite population within an isolate. In 9 out of 10 isolates examined parasities of only a single serotypically distinct between isolates. In one isolate parasite populations of 3 distinct serotypes were identified. Thus most P. vivax infections appeared to consist of a single genetically homogeneous population of parasites within the limits of detection of the technique used.Item Immobilization and kinetic studies of alfa- amylase and glucoamylase(University of Colombo: UC(MED)., 1984) ARASARATNAM, VAlfa- amylase and glucoamylase were coupled to sepharose -4B which was activated by nucleophilic and electrophilic methods using cyanogen bromide. The activity of Alfa-amylase and glucoamylase immobilized to gel activated by nucleophilic method were 19.7 percent and 20.42 percent respectively (40 mg CNBr / g wet gel was used). The activity of Alfa-amylase and glucoamylase immobilized to gel activated by electrophilic method were 23.64 percent and 26 percent respectively. (25 mg CNBr/ g wet gel was used) CNBr concentration was directly proportional to the concentration of the enzyme protein coupled. When 120 mg CNBr / g wet gel was used for activation by electrophilic and nucleophilic mrhtods, the protein coupled was 70 percent and 19 percent respectively. The coupling was linear up to 10 min and reached maximum by 0.5 hr. When the enzyme concentration added for coupling was increased from 1 - 1000 mg then the percent activity of the immobilized enzyme was decreased and it was inversely proportional to the log of enzyme concentration added. The activity of both soluble and immobilized Alfa- amylase and glucoamylase was linear for 3 min and 10 min respectively. The apparent Km values for the immobilized Alfa- amylase and glucoamylase for starch were 1.33 percent and 0.72 percent respectively. The optimum pH for soluble Alfa- amylase compared with that of the immobilized enzyme shifted from 6.9 to 6.5 in 0.02M phosphate buffer. The shift in pH optima for immobilized glucoamylase with that of soluble glucoamylase was from 4.8 to 5.2 where 0.1M acetate buffer was used. There were no shift in ionic strength optima for both immobilized Alfa-amylase \& glucoamylase from that of their respective soluble anzymes and the optimal ionic strengths were 0.02M (phosphate buffer) and 0.01M (acetate buffer) for Alfa-amylase and glucoamylase respectively. The temperature optimum of immobilized Alfa- amylase compared with the soluble enzyme shifted from 45 0 C to 50 0 C and that for gluccamylase was from 55 0 C to 58 0 C. in the temperature range from 30 0 C to 60 0 C the immobilized Alfa- amylase was most stable at 45 0 C indicating that the immobilized enzyme has a slightly higher temperature stability. The glucoamylase, both soluble and immobilized were most stable at 4 0 C that at higher temperatures.Item Development of a field assay method for the determination of cholinesterase activity(University of Colombo: UC(MED)., 2003) MULLER, ACOraganophosphate insecticides are the commonest cause of poisoning in Sri Lanka. Oraganophosphates inhibit acetylcholinestertase and plasma cholinesterase (pseudocholinestertas). Available evidence suggests that there is a high probability of adverse health effects due to low level chronic exposure to Oraganophosphates. Low concentrations of cholinesterase are usually seen when liver function is diminished through liver disease or malnutrition. Genetic variants of plasma cholinesterase can also lead to low enzyme activity. Genetic variants can be identified by dibucaine inhibition. Assay methods used for plasma cholinesterase activity are the use of propionylthiocholine or butyrylthiocholine iodide as substrates and measuring the increase in absorbance using a spectrophotometer. Another method is the use of acetylcholine as the substrate and measurement of pH decrease using pH meter. These methods are expensive and require instruments which are difficult to maintain under field conditions. Therefore these methods are not suitable for large scale screening in Sri Lanka to detect chronic organophosphate poisoning. To overcome this problem we have developed a cheap reliable method to assay cholinesterase levels using the Lovibond comparator. When the cholinesterase activity was determined by measuring the decrease in pH using a pH meter and the Lovibond method the results obtained were different and the difference was significant to a 0.01 level according to the paired t-test. When the normal assay methods for plasma cholinesterase activity using propionylthiocholine (PTC) and butyrylthiocholine iodide (BTCI) was used, 367 school children and 64 pesticide sprayers were within the normal range. The normal range for propionylthiocholine is 1700-4100 U/L and for butyrylthiocholine iodide is 3500-8500 U/L. All the school children (367) and 64 pesticide sprayers had whole blood cholinesterase activity between 0.026?pH/min to 0.040?pH/min when assayed using the Lovibond method. The 40 pesticide sprayers who had low plasma cholinesterase activity as determined by propionylthiocholine(PTC) and butyrylthiocholine iodide (BTCI) methods had whole blood cholinesterase activity between 0.013?pH/min and 0.020?pH/min when assayed using the Lovibond method. This indicates that persons having low pseudo-cholinesterase activity will have 0.020?pH/min or lower values when whole blood cholinesterase activity is determined by the Lovibond method. These results indicated that the Lovibond method is suitable for identification or persons having low cholinesterase activity. There was no statistically significant correlation between plasma cholinesterase activity and Hemoglobin content and plasma cholinesterase activity and body mass index. Therefore the Lovibond method is a low cost assay, method to monitor chronic organophosphate toxicity under field conditions. In the Colombo district 20 per cent of male students and none of the female students were exposed to pesticides. The results for Anuradhapura and Matale districts were for male students 82 percent and 72 percent and for female students 75 per cent and 49 per cent. All school children tested were within the normal range for plasma cholinesterase activity. There was no statistically significant difference between plasma cholinesterase activities of school children who were exposed to pesticides and no exposed to pesticides.Item Spectrophotometric determination of salbutamol in salbutamol syrup(University of Colombo: UC(SCI)., 2001) KUMARA, SThere has been no separate analytical monograph for salbutamol syrup given in either British pharamacopoea (BP) or United State pharmacopea (USP). The conventional spectrophotometric method given in BP for salbutamol tablets cannot be employed for estimation of salbutamol in its liquid in its liquid dosage forms due to the interference from esters of hydroxybenzoic acid (preservative) and flavanoid constituents present in compounds used as flavours. The interference is due to the absorption of these compounds at 276 nm which is the wavelength recommended for spectrophotometric determination of salbutamol. Though there is a method of analysis in Indian pharmacopoeia for salbutamol syrup the cost of analysis is found to be comparatively high due to the use of very expensive complexing reagent. Apart from this, it is also found that the shelf-life of the commercial reagent is very short because of its instability due to liquification followed by degradation. This method was developed on the basis of a qualitative colorimetric method given in British phamacopoea Cordex (BPC) for both salbutamol and Salbutamol sulphate. The aim is to use it as a simple, rapid and reliable analytical method for a determination of sabutamol in sabutamol syrup. The formation of a purplish of a purplish red complex by the reaction between salbutamol and 4 - aminophenazone (complexing agent) in an alkaline borate buffer (pH=10) medium (above pH 8.5) in presence of potassium of potassium hexacynoferrate (III) is a qualitative test of identity. This coloured complex gives a sharp absorption peak in the visible range at 505nm. It was found that the system obeys Beer's law. The reagent concentrations were optimized using a fixed amount of salbutamol. The reaction conditions such as pH (8.5), temperature (25-30§C), equilibration time (20 minute)etc. were also optimized. The colour stability of the complex was studied by time scanning. Under the optimum conditions, the moral absorptivity was found to be 12,857 dm3 mol-1 cm1.Reproducibility and repeatability of results under optimim conditions were verified. The percentage of recovery was found to be 99.85 - 100.50 with SD 0.68 percent (n=5). The interference from preservatives and flavours was eliminated by extracting the sample acidified with 0.05 M H2SO4 to pH2, with several portions of diethyl ether. The validation of this method, was established by analyzing several brand products of slabutamol syrup available in the market for the content of salbutamol. The results obtained from this method were statistically well compared with those obtained with the use of the standard official method given in the Indian Pharmacopoeia.Item Lankawe balapacharin vashayen thindu karana lada aya ema thathwayata pathweema udesa balapana lada hethu pilibanda wimarashanayak(University of Colombo: UC(CEN.)., 1979) PERERA, GPItem Study on mineral contents in textured Vegetable Protein-TVP (Defatted) Manufactured in Sri Lanka(University of Colombo: UC(SCI)., 1998) GANEWATTE, STo study the mineral content in 50 Textured Vegetable Protein-TVP (defatted) manufactured in Sri Lanka. The objectives of the work reported in the present study were to find out the minerals magnesium, manganese, copper and zine. The specific objectives of the work reported in the present study wereto: 1. Provide a date base on the levels of magnesium, manganese, copper and zinc. 2. Provide a possible basis (based on 1.) for identifying a marker to assess the soya protein in meat products for future work. This study concentrated on the estimation of minerals (magnesium, Manganese, zine) in TVP (defattd), protein of the same TVP samples and the estimation of mineral (magnesium, manganese, copper, zine) in few samples of meat (chiken, mutton, fish) to see whether they differ sufficiently from those of TVP(defatted).Item Disorders of carbohydrate metabolism and developed analytical techniques in laboratory investigations(University of Colombo: UC(SCI)., 1998) KAMALASIRI, APLaboratory investigations are extremely important because the modem health care experts rely heavily on the results of chemical measurements of constotuents in the body fluids and tissue. This dissertation discusses about disorders of carbohydrate metabolism in human body and laboratory investigations in the diagnosis of disease. Work perfomance in the laboratory is always better when the laboratoryworker understands the principles, application and technique of the laboratory investigations. The chemical principles of the selected methods are discussed along with the physiological and biochemical changes for carbohydrate metabolism in normal and disease states. clinical interpretations are given to show the significance of the laboratory test results in the joint efforts of laboratory worker and physician in the diagnosis and the treatment of the disease. In few instances this dissertation only presents the principles of themethods because most users actually follow instrictions in their commercoal kitsor use automated methods.Item Dwithiyika pasal lamayinge dharana gatalu sambandhayen upadeshaka sevayakin lada haki pitiwahala pilibanda adhayanayak(University of Colombo: UC(ML)., 1994) GAMINITISSA, NKItem Study on some entomological parasitological and socioeconomic aspects of bancroftian filariasis in the Colombo municipal area(University of Colombo: UC(SCI)., 1998) DHARMASENA, AThe study was conducted to determine the present filarial situation inthree wards of Colombo Municipal council, Sri Lanka. The entomological parasitological and socio-economic aspects of bancroftian filariasis were investigated in three wards of Colombo city, namey Mahawatta, Grandpass South and Kollupitiya The resting densities of Cx. quinquefasciatus which is the main vectory of bancroftian filariasis in Sri Lanka were 188.25, 53.58 and 33.74 C/MH in Mahawatta, Grandpass South and Kollupitiya respectively. The infection rates and infective rates of Cx. quinquefasciatus were 1.96 and 0.05 in Mahawatta, 1.62 and o.2 in Grandpass South and o.00 in Kollupitiya respectively. The mean sex ratio(male:female) of Cx. quinquefasciatus ranged from 1:0.5 to 1:6.32, the average being 1:3.08. of all the resting female mosquitoes collected from all the three wards, 96.35 were Cx, quinquefasciatus. of the total beetding places of Cx. quinquefasciatus, 65.85 were from Mahawatta while 31.71 and 2.44 were located in Grandpass South and Kollupitiya respectively. Damaged septic pits comprised of 55.3 of the breeding places while 19.2 and 10.6 consisted of cement drains and earth drains respectively. The parasitological investigations which were conducted to detect microfilariae of wuchereria bancrofti in the human population showed that the mf rate for Mahawatta, Grandpass South and Kollupitiya were 3.03, o.94 and o.oo respectively....Item A Study to determine the prevalence of hyperlipidemia, hyperhomocystenemia in young adults with a family history of coronary heart disease(University of Colombo: UC(MED)., 2000) HEWAVITHARANA, HIKNMorbidity and mortality from coronary heart diseases (CHD) have been a major public health problem in Sri Lanka over the last two decades. Recent hospital data shows an increase prevalence among young adults. Changes in environmental factors such as, life style and food behaviour could change the lipid levels in individuals and its adverse effects are greater when genetic defects in lipid metabolism coexist. The aim of the present study was to establish whether abnormalities in lipid profile exist in subject with a family history of coronary heart disease but without clinical evidence of CHD, when compared with a control group of subjects without a history of CHD. Ninety five healthy adults were selected for the study and separated into two groups based on family history. All subjects included in the family history group had parents or siblings diagnosed with coronary heart disease. Data regarding their socioeconomic states, past medical history, physical activity, alcohol consumption and smoking habitis were obtained by means of an interviewer-administered questionnaire. Their food intakes were determined using the food frequency method. Weight, height and waist and hip circumference were also measured. Blood samples were collected from each subject after a 12-14 hour fast and serum was separated and used to determine the lipid profile and plasma was used to determine homocysteine and blood glucose levels. The mean total cholesterol, LDL cholesterol and triglyceride levels were similar in the family history group and control group. However, among subject in the age group less than 40 years, elevated total cholesterol levels (\>240 mg/dl) were noted in 18.5 percent of subjects with a family history while none of the subjects in the control group had elevated LDL cholesterol levels. Similarly in the age group \<40 years, the elevated LDL cholesterol \>130 mg/dl were noted in 43.4 percent of subjects with a family history while 27.5 percent subjects in the control group had elevated LDL cholesterol level and elevated triglyceride (\>180 mg/dl) were noted in 16.6 percent of subjects with a family history while 4.8 percent in the control group had elevated triglyceride levels. Further subjects in the age group \<40 years with a family history had a significantly higher mean serum triglyceride than in the control group. The mean fasting blood glucose levels were similar in the family history group. However, among subjects in the age group less than 40 years, elevated blood glucose levels (\>110 mg/dl) were noted in 11.1 percent of subjects with a family history while now of the subjects in the control group had elevated blood glucose levels. Elevated homocysteine levels were not a major problem in our study population and there was no significant difference in mean homocysteine levels between subjects with a family history and controls. It is important to note that five sunjects (16.12 percent) in the family history group and 3 subjects (13.63 percent) in the control had elevated homocysteine levels (\>15 umol/L). Our result suggest that although was no significant difference in serum total cholesterol, LDL and HDL cholesterol and triglyceride levels between subjects with a family history and controls, unfavorable lipid profiles could be detected at an earlier age (\<40 years) among subjects with a family history than in those without a family history.Item An Investigation in to the parasite reservoir of malaria including the study of asymptomatic infections in an endemic region of Sri Lanka and evaluation of parasightTM-F dipstick method(University of Colombo: UC(MED)., 1999) KODISINGHE, HMThe study was based on investigations into the parasite reservoir in a malaria endemic region in Sri Lanka, where unstable malaria occurs with 2 seasonal peaks coinciding with the two monosoons. The study also made an attempt to evaluate the role of asymptomatic infections in malaria transmission in the area. Three clusters of villages in the Gokarella Health Area in the Kurunegala District were selected. A newly developed dipstick antigen method known as parasight TMF was evaluated aginst blood film microscopy.Item A Study of the normal haematological indices and its variations in malaria in a Sri alankan population(University of Colombo: UC(MED)., 2001) DE SILVA, SWMalaria, is the world's second most important tropical parasitic disease, and kills more people than any other communicable disease. Malaria is endemic in the dry zone of Sri Lanka and is non endemic in the west zone and central hills of Sri Lanka. In malaria, anaemia is a common accompanying feature and it develops for to five days after the onset of symptoms. Many confounding factors for anaemia such as nutritional deficiencies, parasite infestations, infections, haemoglobinopathies and thalassaemias too are commonly seen in malaria endemic populations. The main objective of the study was to assess the normal haematological indices and its variations due to malaria in a malaria endemic and noneendemic population in Sri Lanka. The other objectives were to determine the proportion of anaemia caused purely by malaria, and by other aetiologies like iron , vitamin B12 an dfolate deficiency, contributing to the anaemia in this population; to characterize the anaemia due to malaria in an endemic population and a non endemic population; to characterize the anaemia in the acutely ill and the chronically ill malatia patients in endemic and non endemic areas and to assess if the anaemia correlated with the degree of severity of the illness; tp assess the degree of anaemia in malaria in relation to the type of Plasmodium parasite involved. A hospital and out patient clinic based descriptive cross sectional study was done on 256 malaria patients, and compared with an age, sex, and BMI comparable control population. The essential clinical, haematological and biochemical tests were performed and compared. In the present study, the nutritional status was considered using the hight, weight, body mass index, educational level and monthly income between the controls and malaria patients, and was found to be comparable (Tables 3.7 to 3.9). A subject deficient in iron/folate/vitamin B12 was supplemented with the deficient factors and assessed after one month. 131/256 (51.2 percent) of all malaria positive patients observed in this study were anaemic. 79/143 (55 percent) of P vivax malaria patients and 52/113 (46 percent) P falciparum positive malaria patients were anaemic. Among malaria patients 52/113 ( 46 percent) P falciparum positive malatia paients were anaemic. Among malaria patients 52/100 (52 percent) of the females and 79/156 51 percent) of the males were anaemic. There was no significant difference in the presence of anaemia between the male and female malaria patients in this study. When compairing the red cell indices between the anaemic malaria patients and controls from the endemic and non-endemic areas a significant depression in the red cell indices were seen confirming depression of erythroid bone marrow function. A significantly increased red cell distribution eidth indicats premature or early release of immature red cells to the circulation but the decreased reticulocyte count indicates a depressed response of the bone marrow to the decreased red cell mass. Comparing the white cell counts in malria patients a significant decrease was observed in the mean total white cell count, mean neutrophil count and the mean lymphocyte count confirming depression of granulopoiesis in the bone marrow in both P vivax and P falciparum malaria patients. Comparison of the platelet indices of malaria patients there was a statistically significant depression of the patelet count and platelectcrit in these patients when compared with the controls. Tjese results confirm that malaria causes depression of erythroid, myeloid and megakaryocyte cell lines in the bone marrow. Since the malaria parasite is an intra-erythrocytic parasite red cells haemolyse earlier than normal red cells, a certain degree of haemolysis is expected to accompany every infection. The degree of the breakdown of red cells is known to be greater in P falciparum malaria since plasmodia are known to attach to the vascular endothelium and multiple infection of each erythrocyte is common in P falciparum infection. However in this study almost the same proportion of anaemia was observed in patients affected with P vivax and P falciparum malaria, 79/143 (55 percent) P vivax malaria patients and 52/113 (46 percent) P falciparum malaria patients (Figure 3.2)(X2=0.045, P\>0.005). It is commonly believed that P falciparum malaria is the more severe form of disease. The present study confirms that P vivax malaria too causes almost the same debility as P falciparum malaria as evidenced by the comparison of clinical features and red cell indices in both groups of patients (Figures 3.3-3.4). The severity of anaemia due tomalaria too is comparable in P vivax and P falciparum malaria as shown in table 3.37(X2-0.03,P\>0.05). The severity of anaemia was greater in the non endemic area compared to the endemic area among malaria patients (Table 3.21 a)(P\<0.01). All the anaemic patients (8/17) from the non endemic area had moderate to severe anaemia when compared with the anaemic patients from the endemic area of whom 51/7(72 percent) had only mild anaemia (Table 3.38)(P\<0.05). IN the endemic area people are exposed to malaria transmission from birth and this confers and disease or clinical immunity within them (Karunaweera et al. 1998). The immunity acquired causes a reduction in the severity of disease and a milder degree of depression of bone marrow function (Karunaweera et al., 1998). To determine the proportion of anaemia caused purely by malaria, the full blood count report and the blood picture of the patients were examined in conjunction with the biochemical tests. Considering the above data it was confirmed that there is iron deficiency anaemia occurring in conjunction with malaria in 13/79(16 percent) of P vivax and 8/52(15 percent) of P falciparum malaria patients. Anaemia of chronic disease was observed in 63/79(80 percent) of P vivax and 42/52(81 percent) of P falciparum malaria patients. Occurrence of vitamin B12 and folate deficiency, was seen in only 2.5 percent of P vivax and 2 percent of P falciparum malaria patients. Severe haemolysis was not a prominent feature in these anaemic malarial patients as has been observed in other studies. Defective iron utilization as indicated by sufficient iron stores, in adequate haemoglobinisation, reduced number of reticulocytes, and normal serum iron levels, with normal serum bilirubin all are seen in these chronic P falciparum malaria patients. This is compatible with the normocytic normochromic blood picture seen in anaemia of chronic disease. The normal red cell, white cell and platelet indices of males and females of the control population were derived and were lower than in the studies on Caucasian and Black populations. This confirms the need for a comprehensive survey to establish the normal haematological indices for Sri Lankans. The study assesses the normal haematological indices of the control population with automated blood cell counting , a new facility in Sri Lanka. The variations in the iron content and the iron stores of normal healthy adults indicate that there is wide variation in the serum ion, serum ferritin, the total iron binding capacity, the haematological indices, and blood picture. It is concluded that malaria produces anemaia through several mechanisms, which are divided into two broad groups of a) increased red cell destruction and b) dimilished red cell production. In this study diminished red cell production due to anaemia of chronic disease was the main cause for the anaemia in these malaria patients. The time and nature of onset of anaemia due to malaria, have varied in the different age groups in several parts of the world. Iron deficiency anaemia also occurs concurrently with malaria adding to the burden of morbidity in this population.Item Studies on the allelopathic potential of selected plant species and characterization of allelochemicals(University of Colombo: UC(SCI); UC(CEN)., 1994) HEMALAL, KDPThe work embodied in this thesis endeavours deeply to evaluate the allelopathic potential of selected plant species: VIZ Gliricidia maculate(H.B.K)steud, (gliricdia sepium (Jacq.) Steud)1 (Fabaceae) and Tithonia diversifolla (Hems1) Gray. (Asteraceae) After setablishing that Teachate and blended aqueous extracts of both species had considerable bioactivity (both stimilatory and inhibitory), the leaf matetial applied as surface mulches and/or soil- incorporated residues, was teated in field experiments as wellas inglass house based pot experiments for weed suppression ability and other effects. Field studies as well as pot experiments the growth of crops (Tomato, Brinjar, Chilli), whilst controlling weeds in the treated plots very significantly, generally at rates of 2 or 4kg/m In these studies, the promotion of growth of the theee field crops caused by both types of residues was quite spectacular. Pot experiments clearly established that surface applied residues, as well as incorporated residues stimulated the growth of crop species, and caused significant inhibition of seed germination and seedling growth of weed species. surface placed residues were more effective than incorporated residues when the effect of timee of decomosition on the phytotoxicity of the residues was studied, evidence was obtained that Gliricidia residues were bioactive (stimulating the growth of crop species)....Item A Study antimicrobial properties of soap containing Coscinium fenestratum (Wenival)(University of Colombo: UC(SCI)., 2003) PERERA, PAVNA study was undertaken to assess antimicrobial properties of soap containing stem bark of Coscinium fenestratum (Menispermacea) inorder to establish the possibility of using in cosmetic formulations as antiseptic substance. The methanolic extract of C.fenestratum and the major alkaloid isolated as berberine hydrochlorid were tested for antimicrobial activities against staphylococcus aureus, Closteridium sporogenes, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Trichophyton rubrum, Trichophyton metegrophytes and Microsporum gypseum in vitro by the agar diffusion method. MICs were determined for the bacterial and fungi species using agar dilution method. Three soap formulas were prepared incorporating 10, 5 and 2 powdered stemof C.fenestratum and investigated antimicrobial properties against bacterial and fungi species.The methanol extract of C.fenestratum and its alkaloid berberine (hydrochloride) revealed selective inhibitory action on aerobic bacteria. The anerobic bacteria of Clostridium sporogenes showed strong inhibitory effect with MICs of 0.10 mg/ml and 0.22 mg/ml for the methanol extract and berberine hydreochloride respectively and these values were significantly lower than that obtained for the other aerobic organisms tested. The MIC of berberine hydrochloride was 0.21 mg/mll for the gram positive aerobic bacterium of staphylococcus aureus.Item Gamma spectroscopy measurements for estimating the thermoluminescence dates of a terracotta site at Rajanganaya(University of Colombo: UC(SCI)., 2000) FERNANDO, WKPKTerracotta and pottery samples collected from an ancient site at Rajanganaya were dated by thermoluminescence in this study. The natural radioactivity of these objects and of their surrounding was measured using insitu and laboratory gamma spectrometry. With gamma apectrometry the comparison of 238U (deduced from 234Th gamma emission) and that of 226Ra (deduced from 214Pb and 214Bi gamma emissions in equilibrium with 222Rn) shows a significant disequilibrium of the U series. The activity ratio 238U/226Ra, which is greater than unity in the present study is interpreted as a result of either uranium enrichment orradium impoverishment which had occurred before the burial of the terracotta. The effects of the changes in radiochemical composition on the annual dose are discussed and various determinations of the annual dose are analysed according to different hypothesis of disequilibrium which could be due to either a permanent state or occurrence. The Thermoliminescence age estimates 1292+73, 1257+59 obtained for thepottery and terracotta respectivily are consistent with the radiocarbon dates obtained from charcola collected at the same location which are 1215+125, 1135+105, 1175+105 AD. Except for the age estimates obtained for terracotta (sample No544) which indicates an older age to this cultural phase. Radiocarbon dating is considered stoll to be one of the best methods....Item The Psycho-social dimensions of the problem of child abuse and neglect within the family/gurdoamship in Sri Lanka- some case profiles(University of Colombo: UC(CEN.)., 1995) GUNAWARDENA, MPItem A Investigation of faceal pollution in water used for domestic purposes in two highly congested areas in and around the municipal limits of Colombo.(University of Colombo: UC(SCI)., 1982) FERNANDO, RVAn Investigation of faecal poiiution of water used for domestic purposes,in two highly congested areas, was carried at Kelaniya and Mattakuliya. The Henamulla Camp at Thotalanga (below the old Kelaniya bridge) is a highly condested tenement area. The Camp is of two settlements one being situated in close Proxmity to a very extensive Land reclamation site,which is filled with decomposing "Rubbish" There is also a large sewage drain believed to have been built more than forty years age. This drain carries inadequately treated domestic sewage from a very poorly functioning sevage treatment plant. which is about half a mile away from this area. The second settlement is more congested, and is clearly demarcated from the first, by a bund that runs acrose the marshy land that lies between the two schemes. "Kakkaduwa" (Crow Island) is a highty inhabited area in Mattakkuliya, situated behind the Mattakuliya Bus depot, and stretching towards the mounh of the Kelani River. This area provides a fair portion of habitable land for many fisher folk.