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Biomedical subjects

M A Amin

Publications and source records attributed to M A Amin.

At least 37 records · Page 2Linked to original sources
PubMed1983

Marking snails with nail varnish as a field experimental technique.

The use of nail varnish to mark snails for release and recapture in aquatic habitats in the Gezira Irrigation Canals has been evaluated. The nail varnish withstood immersion in canal water and adhered to the snail shell. The recovery of marked snails from a backwater site in a slow moving canal was satisfactory and indicated the usefulness of the technique in predicting changing patterns of immigration and emigration of snails. The method may also indicate ecological changes which affect the stability and mobility of snail populations and yield data on growth rates and longevity.

Animal Identification Systems↗
PubMed1981

The role of field irrigation canals in the transmission of Schistosoma mansoni in the Gezira Scheme, Sudan.

This study was carried out to determine the importance of small field irrigation canals (abu eshreens)-of which there are over 22 000 in the Gezira Scheme- in the transmission of schistosomiasis. The observations were made during a 12-month period, November 1976-November 1977. The results indicated that during the 4-year crop rotation the abu eshreens supported snail populations in only two seasons, when they were irrigating crops of either, cotton or groundnuts. Thus, when agricultural labourers built temporary dwellings on the abu eshreen banks during these periods, the probability of finding infected snails was high. The maximum risk periods occurred during vegetable harvesting (including groundnuts) (October-December) and in the cotton picking season (January-April). Certain special situations lead to some abu eshreens playing an even greater and more predictable role in transmission. These occur when abu eshreens: (a) irrigate eucalyptus or fruit trees; (b) irrigate a block inspector's garden; or (c) are situated very close to permanent villages. Possible control measures to reduce the transmission potential of abu eshreens are discussed. These include improved maintenance and the use of either focally sprayed or slow-release molluscicides.

Agriculture↗
PubMed1981

An assessment of anti-schistosomal treatment on physical work capacity.

Acting as their own controls, village subjects from the Gezira are of the Sudan with relatively high levels of schistosomiasis infection were first tested in an exercise laboratory in Khartoum and the tests were then repeated after a period of about 1 yr during which time the subjects were treated with hycanthone and periodically monitored to ensure that they had remained free of the disease. In the meantime they were also given anti-malarial prophylaxis. Laboratory tests showed a significant improvement in physiological work capacity of up to 20% after treatment compared with untreated controls. An overall improvement in pulmonary function, particularly forced vital capacity, was observed as well as a significant increase in mean haemoglobin concentration by 1.1 g/100 ml of blood in the treated group. Apart from these improvements in physical working capacity, the treated subjects subjectively felt better after the exercise tests, as expressed by the disappearance of fatiguability.

Adolescent↗
PubMed1978

Studies on the enzyme linked immunosorbent assay (ELISA) test for Schistosoma mansoni infections.

Extensive studies of the use of the ELISA test for the detection of antibodies in Schistosoma mansoni infections are described. A method has been evolved for the determination of the optimum value for the reference serum endpoint. In chimpanzees infected with S. mansoni a crude egg antigen detected antibodies earlier in the infection than did a worm antigen and was generally more reactive. The ELISA test, using the egg antigen, has been applied to sera from populations infected with S. mansoni, with other human schistosomes, or with helminth infections other than schistosomiasis. The ELISA test was as sensitive as the IFAT and CFT, but more specific. However, many cross-reactions occurred in infections with other human (and with animal) schistosomes, although to a lesser extent with other helminths. In surveys in the Sudan the use of blood collected on absorbent paper was only slightly less sensitive for the detection of antibodies than sera, and this technique showed that the prevalence of infection was higher than that measured by stool examination alone. Possible future developments are discussed with a view to improving sensitivity and specificity both for clinical and epidemiological work.

Age Factors↗
PubMed1976

Comparison of the Bell technique, a modified Kato thick smear technique, and a digestion method for the field diagnosis of schistosomiasis mansoni.

A modification of the Kato thick smear technique, the Bell filtration technique, and a digestion method were investigated to determine the relative merits of each for the detection of schistosome eggs in human faecal samples. The modified Kato technique was the method of choice because it was sensitive, simple to perform, and suitable for field use. The Bell filtration technique was equally sensitive in detecting light infections, but was more tedious and more complicated to perform than the thick smear technique.

Feces↗
PubMed1976

Energy expenditure and physiological performance of Sudanese cane cutters.

The thermal and exercise tolerances of 165 Sudanese cane cutters were measured in the laboratory and related to work performance and productivity in the cane fields. The results showed that the amount of cane cut per minute in the field was significantly correlated with changes in body weight (r = +0-53) during the third hour of work, aerobic energy expenditure (r = + 0-43), and cardiac frequency during work. These variables in turn were associated with predicted maximal power output (VO2 max) measured in the laboratory. The average energy expenditure during cane cutting was 1-66 +/- 0-33 1/min-1 (34-9 kJ/min-1) which represents approximately 60% of the workers predicted VO2 max. This rate of energy expenditure was sustained in the cane fields for at least three hours without significant pauses for rest. The sweat losses measured in 32 cane cutters during the two and three hours of work averaged 637 +/- 221 and 770 +/- 282 g/h-1 respectively, while the mean urine temperature immediately on cessation of effort was 37-74 +/- 0-46 degrees C. Despite the additional environmental heat load of the tropics, it would seem that cane cutters performing a self-paced task demanding heavy physical effort, are able to sustain work levels well in excess of those recommended for most European factory workers without obvious signs of fatigue or heat stress.

Adult↗
PubMed1976

Physiological performance and work capacity of Sudanese cane cutters with Schistosoma mansoni infection.

Physiological tests of work performance and measurement of field productivity were made in 194 Sudanese cane cutters in order to study the effect of Schistosoma mansoni infection. The cane cutters were selected from two age ranges (16-24 and 25-45 years) and subdivided into three clinical groups: not infected, infected with, and infected without clinical signs of hepatosplenomegaly. Men infected with Schistosoma haemotobium, malaria (blood film), or with hemoglobin levels less than 10 g/100 ml were excluded. There was a statistically significant (P less than 0.002) higher mean hemoglobin concentration in those not infected but the mean difference was less than 1 g/100 ml. Submaximal responses to exercise on a stationary bicycle ergometer, oxygen intake, ventilation, tidal volume, cardiac frequency and estimated maximal aerobic power output calculated both in absolute terms and relative to lean body mass and leg volume were similar in the six groups of cane cutters. No significant differences were found in physique, body composition or in thermoregulatory function tests. The cane cutters were found to have little natural acclimatization to heat in terms of sweating capacity when compared with a group of fully acclimatized Sudanese soldiers. The mean productivity (mean daily weight of cane cut per man) was significantly correlated with the individual's estimated maximum aerobic capacity determined in the laboratory, but not with the degree of S. mansoni infection. The noninfected group was less "efficient" (mean productivity:oxygen intake) during cutting than the infected groups but a larger proportion of the noninfected were in their first season of cutting. There was a positive correlation between the number of seasons' cutting experience and the individual's age, degree of infection and mean productivity. Cane cutters studied in this investigation were a relatively fit, active population from whom the more seriously ill were excluded. These results do not, therefore necessarily reflect the effects of S. mansoni on physiological work capacity and productivity of more static populations in areas of high endemicity.

Adolescent↗
PubMed1976

A large-scale snail control trial with trifenmorph in the Gezira irrigation scheme, Sudan.

A large-scale field trial was carried out during December 1973 to assess the effect of trifenmorph on Bulinus truncatus and Biomphalaria pfeifferi in 379 000 feddans ( approximately 159 000 ha) of the Gezira irrigation system in the Sudan. The commercial formulation used (Frescon) is an emulsifiable concentrate containing 16.5% trifenmorph. Five dispensers were used to add the commercial product to the water continuously for 7.5 days; 18 121 litres were used to treat 28.4 million m(3) of water. In addition, each minor canal was hand-sprayed from the tail to 300 m upstream of the last open field outlet pipe; 360 litres of the commercial formulation were used for this operation.A minimum concentration of 0.035 mg trifenmorph per litre of water was produced at the head of each minor canal. The use of caged snails showed that a concentration as low as 0.015 mg/litre was sufficient to produce 100% mortality in B. truncatus in 7.5 days; this is equivalent to a concentration x time product of 0.12 mg/litre days.

Animals↗
PubMed1976

A simple thick-smear technique for the diagnosis of Schistosoma mansoni infection.

A smear technique is described in which thick glass coverslips are substituted for cellulose acetate film soaked in glycerine as used in the Kato technique for stool examination. Estimates of the sensitivity and applicability of this technique for Schistosoma mansoni infections indicate that it compares favourably with the Kato technique, especially for field use.

Humans↗
PubMed1975

Aerial application of N-trityl morpholine to irrigation canals in Sudan.

Using a crop-spraying aircraft modified to give a coarse spray, the feasibility of aerial application of the molluscicide N-trityl morpholine to minor canals on the Gezira has been proved. In January 1973, seven canals were sprayed at dosages of 0-1 p.p.m., 0-2 p.p.m., 0-5 p.p.m. and 1-0 p.p.m. Chemical analysis indicated that about 70% of the chemical was present in the water 5-15 hours after the spray, and snail exposure to the sprayed canals indicated that all dosages applied were lethal to Biomphalaria snails. Bulinus snails, which are less susceptible to the molluscicide, were killed only by the 0-5 p.p.m. and 1-0 p.p.m. dosages. Sampling of the natural snail populations of the canals confirmed these results. In March 1973, an area of 464 sq km was treated by drip-feed of 0-1 p.p.m. N-trityl morpholine to kill snails in the main and major canals, and then by aerial spraying 56 of the 58 minor canals in the area. Despite the high winds which disrupted the spray timetable, the canals were successfully treated in 9-5 hours flying-time within seven days. A very high initial snail kill was indicated by both caged snail exposure and natural snail population sampling. However, in excellent snail breeding conditions the area was reinfested with snails within two months. The cost of the application was only 5% of the chemical cost, and aerial spraying in March and May will almost certainly be incorporated in an annual snail control programme.

Aircraft↗