RESUMEN
The importance of informatics training within a health sciences program is well recognized and is being implemented on an increasing scale. At Chicago Medical School (CMS), the Informatics program incorporates information technology at every stage of medical education. First-year students are offered an elective in computer topics that concentrate on basic computer literacy. Second-year students learn information management such as entry and information retrieval skills. For example, during the Introduction to Clinical Medicine course, the student is exposed to the Intelligent Medical Record-Entry (IMR-E), allowing the student to enter and organize information gathered from patient encounters. In the third year, students in the Internal Medicine rotation at Norwalk Hospital use Macintosh power books to enter and manage their patients. Patient data gathered by the student are stored in a local server in Norwalk Hospital. In the final year, we teach students the role of informatics in clinical decision making. The present senior class at CMS has been exposed to the power of medical informatics tools for several years. The use of these informatics tools at the point of care is stressed.
Asunto(s)
Educación de Pregrado en Medicina/métodos , Informática Médica/educación , Sistemas de Registros Médicos Computarizados , Actitud hacia los Computadores , Capacitación de Usuario de Computador , Curriculum , Diagnóstico por Computador , Illinois , Facultades de MedicinaRESUMEN
Entamoeba histolytica, axenically grown, were unable to incorporate 14C-glycine into extractable purines, even after 16 hours incubation in the presence of this compound. Similarly, amoebas did not incorporate 14C-sodium formate into purines. Such data indicate a total absence of a de novo purine biosynthetic pathway in this amoeba. When amoebas were incubated in the presence of 3H-adenine and 3H-adenosine for one hour, considerable radioactivity was associated with AMP, ADP and ATP; no appreciable radioactivity was recoverable in the various guanine residues. However, after 16 hours incubation, a small percentage of guanine derivatives were labelled. Amoebas incubated for similar time periods in medium containing 3H-guanosine yielded high levels of radioactive guanosine and guanine nucleotides after one hour, and 3H-guanosine was not converted to adenine derivatives; after 16 hours incubation some 3H-guanosine was converted to adenine derivatives.
Asunto(s)
Entamoeba histolytica/metabolismo , Nucleótidos de Purina/biosíntesis , Entamoeba histolytica/crecimiento & desarrollo , Factores de TiempoRESUMEN
The distribution of RNA (to a lesser extent DNA) in the nucleus of E. histolytica appeared to be the opposite of what one found in other eukaryotic cells (originally stated by Pan and Geiman in 1955). Autoradiographs of amebae labelled with 3H-thymidine revealed primarily randomly distributed DNA-3H (probably euchromatin) in interphase cells. This DNA was so low in amount in individual cells that it usually did not stain with the Feulgen procedure. A small amount of DNA-3H was also detected by autoradiography in the peripheral chromatin (= rDNA?; occasionally it was abundant) and endosome. Clumps of DNA-3H were also observed around the endosomal area in some amebae. This labelling pattern was not observed in 3H-uridine (for RNA) incorporation experiments. These data were consistent with the possibility that the endosome, which was sometimes Feulgen +, was a site of condensation of DNA prior to nuclear division. As detected by light and electron microscopy autoradiographic analysis of 3H-uridine incorporation, RNA was synthesized (or accumulated) primarily in the peripheral chromatin; lesser amounts were evenly distributed. Most of the peripherally located amebal nuclear RNA was probably rRNA and/or precursor rRNA. If this is the case, it is probable that the peripheral chromatin, although structurally unlike nucleoli, may be "functionally" comparable to nucleoli of eukaryotes.
Asunto(s)
Cromatina/metabolismo , Entamoeba histolytica/crecimiento & desarrollo , ADN Bacteriano/biosíntesis , Microscopía Electrónica , ARN Bacteriano/biosíntesisAsunto(s)
Entamoeba histolytica/metabolismo , Nucleósidos de Purina/metabolismo , Purinas/metabolismo , Adenina/metabolismo , Adenosina/metabolismo , Animales , Medios de Cultivo , Entamoeba histolytica/crecimiento & desarrollo , Guanina/metabolismo , Guanosina/metabolismo , Hipoxantinas/metabolismo , Inosina/metabolismoRESUMEN
This study was conducted to determine the mode(s) of uptake of selected pyrimidine bases and nucleosides by axenically grown Entamoeba histolytica. Two-minute uptake studies with 3H-labeled compounds showed the following: 1) uridine and cytidine are taken up, in part, by a carrier mediated system; 2) uracil, cytosine, thymine and thymidine enter amebae via passive diffusion; both cytidine and uridine are taken up by passive diffusion when present at exogenous concentration greater than 500 muM; 3) specific carrier sites are used for transport of uridine-cytidine and uridine-adenosine; 4) cytidine and uridine uptake is markedly inhibited by iodoacetate and N-ethylmalemide; 5) hypoxanthine (10mM) stimulates uptake of uridine; 6) ribose fails to inhibit uptake of cytidine and uridine; 7) cytidine uptake exceeds that of uridine (i.e., apparent Vmax for: a) cytidine = 10.0 nmoles/2 min/10(6) amebae; b) uridine = 3.0 nmoles/2 min/10(6) amebae); 8) Kt for: cytidine = 0.30 mM; uridine = 0.21 mM; 9) Q 10's at 35.5 C vs 25.5 C for: a) cytidine = 3.9; b) uridine = 2.6.