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C Wallace

Publications and source records attributed to C Wallace.

At least 253 records · Page 14Linked to original sources
PubMed1984

Non-random in vitro 7;14 translocations detected in a routine cytogenetic series. 12 examples and their possible significance.

This study describes 12 examples of translocations between chromosomes 7 and 14 in short-term peripheral blood lymphocyte cultures from 10 patients investigated in a routine cytogenetic series. Only one constant breakpoint was found on 14q, and chromosome 7 had two constant breakpoints, one on 7p and the other on 7q. The cause and true significance of such nonrandom in vitro chromosome translocations is not known at present, but one may speculate as to their possible indication of heterozygosity for a chromosome instability syndrome and thus a predilection for the development of lymphoid or other malignancy.

Adult↗
PubMed1984

The incidence, type, and subsequent evolution of 14 variant Ph1 translocations in 180 South African patients with Ph1-positive chronic myeloid leukemia.

A Philadelphia (Ph1) chromosome translocation was found in 180 of 198 cases of chronic myeloid leukemia (CML). A standard t(9;22) was present in 166 patients, 83 of whom were black, 79 white, and 4 of "mixed" ancestry; whereas a variant Ph1 translocation was detected in 14 patients (7.8%), 11 of whom were black and only 3 white. There was a higher frequency of a variant Ph1 among black patients compared with whites. The significantly higher frequency of a variant among our patients compared with surveys from elsewhere could be due to differing environmental agents. Simple variants were detected in four patients. Complex variants were found in eight cases; in one of these patients, only chromosomes #9 and #22 were involved, but a complex rearrangement of chromosome #9 had occurred. A "masked" Ph1 translocation was detected in two cases, both of which showed monosomy #22 because the Ph1 chromosome was incorporated or interchanged with chromosome #9. Karyotypic evolution of the Ph1-positive cell line was observed more frequently in the variant group (71.4%) than the standard group (29.5%). This difference was significant (p less than 0.005). There was no difference in the type of clonal changes seen in standard and variant groups. The majority of clonal changes were observed during the acute stage in both groups. In the variant group, there was no obvious correlation between the type of variant, type of clonal change, blast morphology, or survival. Their initial survival pattern resembled that of Ph1-negative cases, but those patients who survived longer than 1 year showed a survival trend similar to standard Ph1-positive cases. Possible explanations for the specificity of chromosome #22 involvement and the constancy of the 22q11 breakpoint in all these variant translocations are discussed.

Adult↗
PubMed1984

The effect of saralasin in the chronically cannulated ewe in the early puerperium.

The effects of angiotensin II receptor blockade with saralasin ((sar1) (ala8) angiotensin II) have been studied 1-3 days post partum in seven ewes with indwelling vascular cannulae. Control experiments were performed 48 h later in five of the same ewes. The infusion of saralasin at 1, 2, 4 and 8 micrograms kg-1 min-1 resulted in an initial small pressor response, followed by a depressor effect. A significant inverse correlation was demonstrated between log10 dose saralasin and the evoked change in diastolic blood pressure (r = -0.5891, P less than 0.005). A small and inconsistent depressor effect was found in the control experiments; there was no evidence for an association between dose and response (r = +0.0411, P greater than 0.85). These data were compared with those from a previously published study in which an identical infusion protocol for saralasin was used in ten chronically cannulated pregnant ewes. The slopes of the two dose-response curves were very similar (-14.9 +/- 4.3 post partum compared with -14.2 +/- 4.2) in the two groups. However, the average response was greater in the pregnant group, by 7.6 +/- 1.2 mmHg (P less than 0.005). Plasma renin concentration rose significantly during saralasin infusion (P less than 0.05) but was unchanged in control experiments, indicating blockade of the renin-angiotensin system by the removal of negative feed-back control by angiotensin II. Saralasin is known to exert an agonist effect when angiotensin II itself is not directly concerned in the regulation of arterial blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗