Search

(1965). Lymnaea natalensis and fascioliasis in Ghana. Annals of Tropical Medicine & Parasitology: Vol. 59, No. 3, pp. 320-326.

Sprague–Dawley male rats fed Master Lab cubes (MLC) or a semipurified diet (T4F) were kept for periods of 1–2 weeks at six subsequent temperatures : 28 °C, 22 °C, 6 °C, 0 °C, −10 °C, and −20 °C. Caloric balance, growth, body temperature, and survival were measured. As previously observed under outdoor winter conditions, with constant laboratory conditions T4F diet was still found to be superior to MLC in allowing a greater degree of cold resistance. At temperatures below 0 °C, in spite of a lower gross energy uptake, T4F-fed rats maintained a faster growth and a higher body temperature than MLC-fed rats, which suggests a greater heat conservation in these animals. Failure of MLC-fed rats to raise their gross energy uptake at −10 °C to a higher level than at 0 °C, and death of most of these animals at −20 °C within the first 3 days strongly suggest a physical limitation in the quantity of high bulk MLC diet which can be consumed every day, hence a limitation in energy uptake increase. The ability of T4F-fed rats, on the other hand, to raise energy uptake in a continuous linear fashion as temperature is reduced, and their capacity to draw on energy reserves and to survive longer at −20 °C reflect greater metabolic potentials in this group than in MLC rats.

On October 30 , 1918, the war with Turkey ended, and on November 7, the French and British governments issued a joint Declaration: "The object aimed at by France and Great Britain in prosecuting the war in the East ... is the complete and definite emancipation of the peoples so long oppressed by the Turks, and the establishment of National Governments and Administrations deriving their authority from the initiative and free choice of the indigenous populations." This seemed to offer the Arabs, including those in Palestine, the prospect of independence which some of their leaders had long sought.

(1954). Schistosomiasis in the Gambia. Annals of Tropical Medicine & Parasitology: Vol. 48, No. 3, pp. 277-286.

(1965). A note on intestinal schistosomiasis and the snail hosts in Ghana. Annals of Tropical Medicine & Parasitology: Vol. 59, No. 3, pp. 312-319.

Previous studies have suggested that iron mucosal protein complexes, possibly related to a carrier substance, are involved in intestinal iron transport. Since there is evidence indicating that phenobarbital induces an increase in intestinal microsomal proteins and enzymes, it was postulated that phenobarbital might affect iron absorption by increasing the synthesis of a carrier protein for iron. This investigation describes studies carried out in the rat to determine the effect of phenobarbital on the absorption of inorganic and hemoglobin iron labeled with Fe 59 . In vivo the absorption of Fe 59 SO 4 was significantly increased in phenobarbital-treated rats compared to controls (20.4 ± 5.7 versus 9.8 ± 4.2%; P P P 0.001). In vitro, phenobarbital treatment resulted in a significant increase in mucosal transfer of Fe 59 SO 4 by everted duodenal gut sacs compared to controls (51.3 ± 8.8. versus 28.0 ± 5.9 mμmoles; P 59 SO 4 by jejunal gut sacs. It is postulated that the phenobarbital-mediated increase in absorption of inorganic iron is related to increased synthesis of a carrier substance that influences iron transport. Further, it is suggested that the increased absorption of hemoglobin iron resulting from phenobarbital treatment is due, at least in part, to increased mucosal heme-splitting enzyme acitivity.

On the basis of observations of school children described in Part I, a model for the infective process of S. haematobium in man in the Misungwi area of Tanzania is put forward. On the basis of steady challenge by cercariae, effective concomitant immunity, exponential death of worm pairs, the observed variance of egg output at age 10, and constant ranking by infection level in early life, the behaviour of egg output patterns with age in the community is predicted. Expected curves of output are compared with those observed in cross-sectional survey of over 4,000 people at Misungwi. Agreement is close. This provides additional evidence for the occurrence of concomitant immunity to S. haematobium in man and suggests that immunity cannot be disregarded in epidemiological models of the infection. It is suggested that there are 3 phases in an age-cohort's experience of endemic infection: acquisition and increase of infection, a phase of decreasing worm load combined with concomitant immunity, and a steady state phase, with loss of immunity and reinfection balancing, in later life. The need for better data on the nature of human immunity to schistosomiasis becomes apparent.

Biography, Autobiography, and Reminiscence, reviewed by The Editor Literary and Critical Studies, reviewed by The Editor and Others Books on Religion, reviewed by W. S. McCullough Canada: The Land and the People, reviewed by J. M. S. Careless Other Books, reviewed by The Editor and Others

IN TESTING EQUALITY OF MEANS OF TWO Normal populations, Student's t-test is not generally applicable when the variances of the two populations may be unequal and their ratio unknown. A procedure is considered whereby a preliminary test is performed to ascertain whether or not the variances may be regarded as equal. On the basis of the outcome of this preliminary test, one proceeds to test for equality of means. Tables of size and power are included to indicate the behavior of the proposed tests. (Author)

Summary A clinical examination of 1,675 children in three different locations in rural parts of Northern Rhodesia showed a high incidence of blindness and of other eye symptoms and skin changes generally ascribed to vitamin A deficiency. In order to verify this observation, plasmalevels of vitamin A and carotene were measured in 183 preschool and school children in these areas. Very low values of both vitamin A and carotene were found in a high proportion of unselected cases. It is our view, based on these observations, that lack of vitamin A is a significant health problem. It is thought to be a principal factor in the great number of eye diseases and blindness and is a factor in the poor general health status and in the high mortality rate (30 to 50 per cent) of these children by causing a lowered resistance to infectious diseases and parasitic infestations. Great improvements could accordingly beachieved by providing more carotene-containing foods in the diet such as red palm oil and by growing more vegetables rich in carotene. To change the diet and eating habits is not easy, but considerable success could be achieved by instruction of the children in the schools and by developing school gardens.

The author presents the results of some laboratory experiments carried out to determine the susceptibility of the snail vectors of bilharziasis in Ghana to local strains of Schistosoma haematobium, isolated from children living in two districts near Accra: the Ke district, where Bulinus (Bulinus) truncatus rohlfsi is the important snail vector, and the Pokoasi district, where Bulinus (Physopsis) globosus is the exclusive intermediate host.Each strain was found to be virtually specific in its ability to develop in one or other of the vector species. The "Ke strain" developed readily in B. (B.) truncatus rohlfsi but not in B. (P.) globosus, while the "Pokoasi strain" developed readily in the latter snail but not in the former.The author points out that these findings provide a possible explanation for some of the conflicting observations that have been reported by workers in other African territories, and may have an important bearing on the epidemiology of urinary bilharziasis in Africa as a whole. He stresses the need for further studies on the relationship between bulinid snails and schistosome strains in Africa.

IN recent years, detailed studies have been conducted on schistosomiasis and its snail vectors in the Gold Coast. The results of surveys throughout the territory show that although Schistosoma haematobium and S. mansoni are both endemic, the former infection, together with its snail hosts, Physopsis africana and Bulinus sp., sensu stricto, is considerably more widespread than the latter and its planorbid vector, Biomphalaria pfeifferi1.