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Biomedical subjects

R Cole

Publications and source records attributed to R Cole.

At least 109 records · Page 6Linked to original sources
PubMed1983

Neoplastic transformation of newborn rat oligodendrocytes in culture.

We have developed a model to study the neoplastic transformation of rat oligodendrocytes in culture. This procedure utilizes a technique previously developed by McCarthy and de Vellis which allows the preparation of 99% pure astrocyte and oligodendrocyte populations from 1- to 2-day-old rat cerebral cortices. Pregnant rats on the 19th day of gestation were given injections with either ethyl nitrosourea (10 micrograms/g body weight) in phosphate-buffered saline or phosphate-buffered saline, and oligodendrocyte cultures were prepared. Oligodendrocytes appear to be unstable in culture since transformation was observed with cells derived from either pups from pregnant rats either treated with nitrosourea or phosphate-buffered saline. Transformation required 78 to 108 days and 3 to 9 passages, at which time a marked increase in cellular proliferation was observed. The possibility that the transformed cells were derived from a nonoligodendroglial cell was excluded by the following evidence. Light and scanning electron micrographs of the transformed cells revealed cytological features essentially similar to those of primary oligodendroglial cultures. Furthermore, 2 biochemical oligodendroglial markers, the induction of lactate dehydrogenase by N6,O6-dibutyryl cyclic adenosine 3':5'-monophosphate and the presence of 2',3'-cyclic nucleotide 3' phosphohydrolase, were also retained. Conversely, another oligodendroglial marker, the hydrocortisone induction of glycerol phosphate dehydrogenase, was not found in any of the cell lines. These transformed cells grew as tumors when injected intracranially into 21-day-old rats. Histologically, these tumors did not appear as classical oligodendrogliomas, but their oligodendroglial origin was confirmed since the tumor tissue contained 2':3'-cyclic nucleotide 3'-phosphohydrolase activity, and the cells which grew from tumor explant cultures morphologically appeared similar to the parent cell line. The transformed cells were also characterized for in vitro properties which correlate with the expression of tumorigenicity. The transformed cells exhibited anchorage-independent growth and were agglutinated by concanavalin A treatment. Changes in fibrinolytic activity were not an exclusive property of transformed glial cells. This model should now allow us to study various mechanisms involved in the neoplastic transformation of oligodendrocytes.

Animals↗
PubMed1980

Ultrastructural differentiation and synaptogenesis in aggregating rotation cultures of rat cerebral cells.

Cerebral cortices from fetal rats were dissociated into single cells by either trypsinization or mechanical sieving. Then the cells were allowed to form aggregates in rotation cultures. At 7, 14, 21, 28, and 35 days, aggregates were processed for electron microscopic study of morphological differentiation with special emphasis on synaptogenesis. Whether the tissue was initially dissociated by trypsin treatment or by mechanical sieving, the aggregating cultures did not exhibit any apparent differences in ultrastructural differentiation and synaptogenesis. At day 7, most neurons were immature and the extracellular space was large. Cell processes had not yet branched extensively but did contain numerous microtubules. A few immature synapses were observed. Astrocytes and oligodendrocytes displayed many of their typical cytological features. At day 14, dendritic spines had developed, some of which formed axodendritic spinous synapses. Multilayered myelin sheaths were tightly wrapped around axons. At day 21, synapses appeared mature and their number per unit area was maximal. The extracellular space had greatly decreased. At this age, asymmetrical synapses had increased approximately sixfold, whereas symmetrical synapses increased only fourfold when compared with the 7-day-old aggregates. Multifocal degeneration became apparent at 28 days and was accompanied by a significant decline in the number of synapses.

Animals↗
PubMed1980

Distended left renal vein: CT/sonographic normal variant.

The left renal vein frequently demonstrates a marked variation in caliber between the part distal to the aorta and the part directly in front of the aorta. This is well seen on both computed tomography (CT) and sonography. This variation in caliber or distention is believed to be secondary to a "nutcracker " effect formed by the aorta posteriorly and the superior mesenteric artery anteriorly. The third part of the duodenum may also add to the pincer effect on the left renal vein. A series of 72 patients was examined for this variation and the relation of the caliber of the left renal vein to the anatomy of the aorta, superior vena cava, and duodenum. These patients were also evaluated for any possible relation between the presence of a distended left renal vein and a varicocele.

Adolescent↗
PubMed1979

The effect of deinstitutionalization on a general hospital's inpatient psychiatric service.

As a result of the deinstitutionalization movement, increasing numbers of former state hospital patients are being rehospitalized in general hospital psychiatric units. Because of this change in patient population, the general hospital has had to adjust its treatment strategy to emphasize meticulous review of previous psychiatric history, including medications; plans for meeting the patients' posthospital housing, vocational, and social needs; and development of plans with community care-givers for continuing care. General hospital staff members have to be educated to develop competence in working with the new patient population and a tolerance for chronicity; that can be done through several forums ranging from large staff meetings to individual supervision.

Adult↗
PubMed1979

The understanding of medical terminology used in printed health education materials.

Self-administered, multiple-choice questionnaires were completed by 120 patients and students in order to assess their medical vocabulary knowledge. The fifteen test words were taken from printed health education materials. It was apparent that many respondents had problems with the words, in particular, those of low social status or low educational achievement. The scores of students, however, were not significantly higher than those of the patients. It is suggested that all health education materials be carefully screened for medical words, although they may have high readability scores. Even seemingly simple medical words should be explained in simple terms, or should be included in a glossary. This practice should increase understanding and recall.

Language Tests↗
PubMed1979

Biosynthesis of glycosylated hemoglobins in the monkey.

We have investigated the in vivo biosynthesis of the minor hemoglobin components in the rhesus monkey. The elution profile of rhesus hemolysate on BioRex 70 cation exchange resin was analogous to that of human hemolysate. The rhesus Hb Alc peak was identified with the TBA test, which revealed a carbohydrate content identical to that of human Hb A1c. A rhesus monkey was injected with autologous 55Fe-bound transferrin, and the specific activity of each of the minor and major components was followed for over 70 days. As previously shown in man, rhesus Hb alc accumulated specific activity almost linearly over the erythrocyte life-span, indicative of slow and continuous conversion of Hb A0 to Hb Alc. This study revealed two new findings. (1) The specific activity of rhesus Hb Alb was always significantly less than that of Hb Alc. This result suggested that HB Alb is made by further posttranslational modification of Hb Alc. (2) The first portion of rhesus Hb A0 to be eluted on BioRex 70 contained a significant amount of carbohydrate and lower initial specific radioactivity than did the latter portion. This unexpected heterogeneity in the major hemoglobin component reflects slow, nonenzymatic glycosylation at sites other than at the N-terminus of the beta-chain.

Animals↗
PubMed1977

Further studies on the cardiolipin phosphodiesterase of Escherichia coli.

The cardiolipin phosphodiesterase of Escherichia coli was further characterized. This enzyme has a pH optimum of 7.0 and is Mg2+ dependent. Mn2+ and Co2+ could replace Mg2+ but other divalent cations were inhibitory or without effect. The enzyme is not periplasmic and does not appear to be associated with membrane fractions prepared by different methods. It is recovered as a soluble protein in the cytosol fraction but could not be readily purified because of its instability. With cell-free systems, a requirement for ATP or ADP could be shown under certain defined conditions. Other nucleotides were less effective or ineffective in stimulating the phosphodiesterase. The cells displayed the highest activity during the middle to late exponential stage but no marked requirement for ATP was apparent when the phosphodiesterase was obtained from such freshly grown cells. If, however, cells were starved for several hours in saline medium, the cardiolipin phosphodiesterase level fell and a requirement for added ATP could be shown. The cardiolipin phosphodiesterase is an enzyme distinct from cardiolipin synthase. The assay conditions are quite different from each of these enzymes as are their subcellular distributions.

Adenosine Diphosphate↗