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T Porter

Publications and source records attributed to T Porter.

41 records · Page 3Linked to original sources
PubMed1982

Characterization of Giemsa dark- and light-band DNA.

Using synchronized cultures of V79-8 Chinese hamster lung fibroblasts, we either alternately labeled early- and late-replicating DNA, or substituted one of these with bromodeoxyuridine to separate them in CsCl density gradients or to identify the bromodeoxyuridine-containing chromosome bands by fluorescence microscopy. The Giemsa light R bands were shown to replicate in the first half of S phase, and the dark G bands were shown to replicate in the last half of S phase. S phase was bimodal, with a distinct pause in the rate of DNA synthesis that separated the period of R-band DNA synthesis from that of G-band DNA synthesis. G-band DNA was found to be 3.2% richer in AT than R-band DNA. Surprisingly, G- and R-band DNA appeared equally transcriptionally active in that alternate labels in chromatin were digested with the same kinetics by DNAase I, and in reassociation experiments, total poly(A)+ RNA drove nick-translated G- and R-band DNA probes similarly. G- and R-band DNA also reassociated with identical kinetics, demonstrating that they contain equal proportions of all kinetic-complexity classes of sequences.

Animals↗
PubMed1979

Natural history of the dislocated hip in spastic cerebral palsy.

A review was made of 88 adult institutionalized patients with spastic cerebral palsy and contractural deformity of the hips. 21 were untreated for dislocated hip, and 11 of these suffered from hip pain. The degree of pain was directly related to neurological maturity and to the coexistence of athetosis and spasticity. Decubitus ulcers and perineal care problems were more associated with contractures than with dislocation alone. It is concluded that dislocation and subluxation should be prevented by surgical means, but that surgical treatment of the already dislocated hip should be reserved for the neurologically mature and athetoid patient.

Adult↗
PubMed1979

Dimensions and determinants of judgements of colour samples and a simulated interior space by architects and non-architects.

Architects and non-architects made Semantic Differential ratings of colour samples (chips) and a simulated interior space (a model). In analyses of the total samples' ratings (architects and non-architects) of (a) colour chips and (b) models, and individual sample analyses, (c) architects' chip judgements, (d) architects' model judgements, (e) non-architects' chip judgements, and (f) non-architects' model judgements, five factors occurred, though not necessarily all in any one analysis. These were: (i) dynamism; (ii) spatial quality; (iii) emotional tone; (iv) evaluation; (v) complexity. Linear correlations between parameters of the Munsell Color System and the above factors in the various analyses were calculated, while parallel analyses were carried out employing a graphical technique described by Sivik (1974a) involving isosemantic maps. In all analyses, linear correlations between the colour parameters and judgements were found for the dynamism factor, spatial quality factor, and emotional tone factor. They were associated respectively with chroma, value, and hue. Inspection of the isosemantic maps indicated subsidiary effects of the non-dominant dimensions of a non-linear sort, though the maps also exhibited the linear relations. Linear correlations were low or non-existent for the evaluation and complexity factors, and the complex nature of their determinants was clear from the isosemantic maps. The dterminants of judgements were similar for architects and non-architects, with the exception of evaluative judgements for the models in which markedly different determinants were noted. Comparability of the present findings with other studies carried out in a variety of countries over a 20 year period was high for dynamism, spatial quality, and emotional tone, and it is suggested that there may be something inherent in the response to colour in relation to such judgements. Recent physiological work is discussed, and its limitations in terms of colours sampled and an overconcentration on the hue dimension noted. In contrast, it is suggested that dimensions of judgement, such as evaluation or complexity, reflect to a greater extent culture or training, and are hence independent of the basic colour attributes.

Adult↗
PubMedDate not supplied

Comparable proximal and distal severity of intimal thickening and size of epicardial coronary arteries in transplant arteriopathy of human cardiac allografts.

Previous angiographic observations have characterized transplant atherosclerosis as a generally diffuse and more distally severe disease with obliteration of secondary branches. However, it has not been firmly established that the disease is structurally and biologically more severe distally. We evaluated this hypothesis with computer-based digitization of subserial segments of the entire perfusion-fixed left anterior descending coronary artery (100 mm Hg for 1 hour with 10% formaldehyde solution) in 25 allografts at autopsy or explant (19 male and 6 female patients; mean age = 50 years, range 16 to 66; mean implant duration = 490 days, range 3 to 1610). The area, thickness, circumference of the intima and media, and the relative and absolute luminal narrowing were evaluated in a mean of 10 left anterior descending coronary artery sections per allograft. The percentage of luminal narrowing (intimal area/[intimal area + luminal area] x 100) was similar between proximal and distal segments of the left anterior descending coronary artery (45% versus 41%, p > 0.05), and the mean absolute intimal thicknesses (in millimeters) of proximal and distal segments of the left anterior descending coronary artery also were not different (0.32 versus 0.22, p > 0.05). In addition, the 95% confidence intervals for intimal thicknesses of proximal and distal segments were comparable. Because the absolute arterial size of proximal segments is naturally larger than that of distal segments (external diameter 9.37 versus 6.79, p < 0.0001), an appearance of progressive tapering may be visualized angiographically, even though the biologic severity of the disease is geographically uniform. Similarly, observations of obliterated secondary branches in distal segments may result from naturally smaller distal luminal areas which may be occluded by less intimal thickening than would be required proximally. These data emphasize that transplant atherosclerosis is biologically uniform from proximal to distal locations. Etiologic and pathogenetic studies on proximal or distal segments should be equally informative.

Adolescent↗