Biomedical subjects
Publications and source records attributed to D A Harvey.
Collections of nonredundant, full-length complementary DNA (cDNA) clones for each of the model organisms and humans will be important resources for studies of gene structure and function. We describe a general strategy for producing such collections and its implementation, which so far has generated a set of cDNAs corresponding to over 40% of the genes in the fruit fly Drosophila melanogaster.
Apicomplexan protozoan parasites have complex life cycles that involve phases of asexual and sexual reproduction. Some genera have intermediate insect hosts, for example, Plasmodium spp. (the cause of malaria), but related genera such as Eimeria spp. (causative agents of coccidiosis in poultry) have a direct life cycle occurring in only a single host. Mechanisms that regulate the life cycles of apicomplexan parasites are unknown, but the intracellular growth of avian Eimeria spp. is easily shortened by serial selection for the first parasites to complete the transition from asexual to sexual reproduction (to yield so-called precocious lines). To investigate the genetic basis of such an abbreviated life cycle, we have used the species E. tenella and analyzed the inheritance of 443 polymorphic DNA markers in 22 recombinant cloned progeny derived from a cross between parents that had selectable phenotypes of precocious development or resistance to an anticoccidial drug. The markers were placed in 16 linkage groups (which defined 12 chromosomes) and a further 57 unlinked groups. Two linkage groups showed an association (P =.0105) with the traits of precocious development or drug-resistance and were mapped to chromosome 2 (ca 1.2 Mbp) and chromosome 1 (ca 1.0 Mbp), respectively. The map provides a framework for further studies on the identification of genetic loci implicated in the regulation of the life cycle of an important protozoan parasite and a representative of a major taxonomic group. [A table with the segregation data is available as an online supplement at http://www.genome.org.]
Two genetically defined parents of Eimeria tenella, each characterized by a selectable phenotype, were mated to provide "recombinant' oocysts for an analysis of the inheritance of DNA markers into the sporocyst stage of the life-cycle. A total of 23 populations was established from infection with a putative single sporocyst and their inheritance of DNA markers provided compelling evidence that the 2 sporozoites within each sporocyst are genetically identical. EAch of the 5 polymorphic DNA markers used segregated independently within the "recombinant' parasites and only 1 of the parental forms was inherited in 22 of the populations aimed to have been established from a single sporocyst.
A mating was made between two populations of Eimeria tenella possessing the complementary traits of normal development (virulence) + resistance to the anticoccidial drug arprinocid or precocious development (attenuation) + drug-sensitivity. A small number of "recombinant" oocysts was recovered. The inheritance of markers from both parents into 22 cloned lines derived from the recombinant oocysts was confirmed by analyses of restriction fragment length polymorphisms of four repetitive DNA sequences.
Much misunderstanding and confusion exist about the meaning and nature of activities in health promotion. This article examines how our evolving beliefs and concepts about health have led to a new public health, namely health promotion. Health promotion is operationalized using Achieving Health for All: A Framework for Health Promotion.
The dissolution of solid gold sodium thiomalate (GSTM) in water results in loss of yellow color. We studied the initial reaction on dissolution. It was associated with the disappearance of 2 absorption peaks on ultraviolet spectrum, one a well defined peak at 335 nm and the other a shoulder at 370 nm. This solution caused platelet aggregation and on transmission electron microscopy, dense gold containing particles measuring 125 nm are seen. Within 10 min of onset of dissolution, no gold containing particulate matter was detectable on electron microscopy. By 20 min, fibrillar particles measuring 40-150 nm appear. These resembled in general morphology and element composition the particles seen within aurosomes in platelets treated with Myochrysine (GSTM) and in synovium and other tissues by other workers. Our data elaborate on previous physical and chemical studies and correlate with morphological variations of gold containing particles at different phases. These variations in GSTM may be due to polymer size and/or structural change within the polymer. The biochemical significance of our data should provide better understanding of the biological effects of these gold thiol compounds in vivo.
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Isosorbide mixture containing 50% w/v isosorbide and 5% w/v sorbitol is used in the treatment of hydrocephalus. The G.L.C. analysis of the mixture is described and its antimicrobial properties investigated. Results for the determination of lead in the mixture are given and the significance of the levels discussed with relevance to the treatment of infants.
Spindle cell lipoma is a specific type of lipoma that is easily mistaken for a liposarcoma. An analysis of 114 cases of this tumor from the files of the Armed Forces Institute of Pathology reveals that is occurs chiefly in male patients between 45 and 70 years of age and affects the regions of the shoulder and posterior neck almost exclusively. Microscopically, it consists of an intricate mixture of lipocytes and uniform spindle cells within a matrix of mucinous material traversed by a varying number of birefringent collagen fibers. Ultrastructural studies in one case support the fibroblastic nature of the spindle cells. Followup information obtained in 63 patients with this lesion revealed a uniformly favorable clinical course, indicating that local excision is the treatment of choice, and that there is no need or reason for radical surgical procedures.
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