Proton imaging for medical applications

In order to demonstrate the potential advantages of proton imaging for medical use, a 205-MeV proton beam was developed using the Argonne National Laboratory Booster I synchrotron. Data were taken using a narrow scanning beam and an electronic detector system. The dose reduction and an improved mass resulution over the radiographs. The images also show significant differences in the proton stopping power of different tissues, thus demonstrating considerable potential in soft-tissue imaging. The development of a proton tomographic scan system is also briefly discussed.     

A stable haemagglutinating antigen for detecting toxoplasma antibodies

The production of a toxoplasma-sensitized cell preparation stable for at least one year at 5 degrees C and its performance in the diagnosis of toxoplasmosis is described.     

Quantitative cell fusion: derivation and application of theoretical models

Cell fusion experiments were made on ten cell lines representing seven mammalian species, using inactivated Sendai virus. The extent of fusion was determined microscopically and tabulated as frequencies of cells with different numbers of nuclei. Expected distributions were derived theoretically under certain assumptions concerning the fusion process. A random model was assumed according to which the tendency to fuse depends only on the cell size, expressed as the number of nuclei present in the cell. Three distributions were derived, which were referred to as the simple, additive, and multiplicative models. The additive model pertained to fusions made in cell suspensions and the multiplicative one mainly to fusions in fibroblast monolayers.     

Diurnal variations in plasma concentrations of cortisol, prolactin, growth hormone and glucose in the fetal sheep and pregnant ewe during late gestation

We have measured fetal and maternal plasma concentrations of cortisol, prolactin, GH and glucose in samples collected during a 24-h period in 14 animals between 127 and 142 days of gestation. There was a significant increase in both the mean daily plasma cortisol concentration and mean daily coefficient of variation (C.V.) of plasma cortisol concentrations after 135 days of gestation. There was also a significant variation in the fetal plasma cortisol concentrations with a peak occurring at 19.00 h. There was a significant sinusoidal diurnal rhythm in the plasma prolactin concentrations in both the fetal sheep and pregnant ewe and the maximal prolactin concentrations occurred between 19.00 and 23.00 h (fetal) and 21.00 and 01.00 h (maternal). Although no significant diurnal variation was detected in fetal plasma GH concentrations, there was a significant sinusoidal diurnal rhythm in the plasma GH concentrations of the pregnant ewe and the maximal maternal GH concentrations occurred between 21.00 and 01.00 h. Both the fetal and maternal plasma glucose concentrations showed a significant sinusoidal diurnal rhythm. The maximal maternal and fetal glucose concentrations were measured between 21.00 and 01.00 h and between 23.00 and 03.00 h respectively. We have therefore established that diurnal variations in plasma cortisol and prolactin concentrations exist prenatally. Whether the presence of such hormonal rhythms reflects the activity of an endogenous fetal circadian pacemaker remains to be established.     

Parent evaluation of community based rehabilitation in Jamaica.

Much may be gained by intervening early in the lives of disabled children. While children may benefit from making developmental progress, early intervention may also help improve parental understanding, acceptance, competence, parental understanding, acceptance, competence, parent-child interactions, and overall integration into community services. Advocates also indicate their preference for direct parental involvement in teaching in home-based programs. The nongovernmental organization, 3D Projects, offers community-based rehabilitation services to more than 300 disabled children in rural south-central Jamaica. The parents of all clients receiving home-based services were interviewed to help assess the projects' impact. Home visits were much appreciated, with respondents especially in favor of the semi-academic and physical exercises. Respondents felt that they were quite involved in the training of their children. 92% were able to say which disability afflicts their child. While no baseline data were taken for this study, this degree of knowledge is significantly higher than that found in samples of individuals from comparable studies. 50% desired additional information related to their child's schooling, behavior, and speech and learning problems. More parental education is therefore warranted. 67% stated that the program has increased their sensitivity and concern for their children, 76% felt that the condition of their child is improving, and 93% generally felt positive about the program and would recommend it to other parents.     

Service needs of children with disabilities in Jamaica.

We investigated the service needs of children attending a medical assessment as part of a two stage survey of 2 to 9-year-old children in mid and south Clarendon, Jamaica. Parents were asked about symptoms relating to six different disabilities: visual, hearing, speech, motor, cognitive and fits. Following medical and psychological assessment, a diagnosis of mild, moderate, severe or no disability was made. For children with disabilities, the frequencies of five possible types of intervention recommended by the physician were analysed and related to the prevalence of the six disabilities in the parish. To estimate the needs of the Jamaican child population the figures were extrapolated based on an estimate of 1 million children under the age of 15 years. These needs were then compared with places in existing services. Of the disabled children, 62% needed special education, 29.5% needed community-based services, 21% needed spectacles, 21% needed specialist referral, and 6% required medical treatment. Although the vast majority of these needs are not met, many more could be met in the community if existing health and education personnel are trained in basic techniques of screening and assessment.