Biomedical subjects
Publications and source records attributed to P Stanley.
Explore the source record for details and available documents.
Low levels of plasma-25-hydroxy-vitamin-D (25-OHD) (less than 16 nmol/1) were found in 33% of a group of pregnant women studied in South London. Non-White women in the last 10 weeks of pregnancy had significantly reduced levels compared with non-pregnant controls (P less than 0.02). Plasma-25-OHD was unrelated to dietary vitamin-D intake, age, parity, social class, plasma-calcium, and plasma-albumin. Reduction of plasma-25-OHD could contribute to the fall in plasma-calcium during pregnancy, and may result from enhanced maternal metabolism or increased utilisation of vitamin D by the fetus.
Chinese hamster ovary (CHO) cells previously selected in a single-step for resistance to one or two different lectins and assigned to individual phenotypic groups on the basis of their unique patterns of lectin resistance, have been examined for their lectin-binding abilites. The lectin-binding parameters of CHO cells were shown to be very complex in a detailes study of the binding of 125I-WGA to wild-type (WT) cells. On the basis of these results, standard assay conditions were established and comparative binding studies between the twenty-two WT and lectin-resistant (LecR) clones were performed. A general correlation of lectin resistance with decreased lectin-binding ability and of lectin sensitivity with increased lectin-binding ability was found, although several exceptions to this trend were observed.
Chinese hamster cell mutants resistant to the lectins PHA, WGA, RIC, LCA, and CON A were previously grouped into 8--10 distinct phenotypes on the basis of their unique patterns of lectin resistance and lectin-binding properties. All but one of these classes of lectin-resistant (LecR) mutants behave recessively in somatic cell hybrids. One ricin-resistant class (RicRII) behaves dominantly. Tests for complementation, by measuring the lectin-resistant properties of appropriate hybrids, show that seven distinct complimentation groups can be delineated among the phenotypically recessive mutants.
Significant macrofistulae between arteries and veins of congenital origin may result in the extremes of life-threatening hemorrhage or simply a cosmetically displeasing mass. The most helpful diagnostic aid is that of adequate arteriography both to determine the size, location, and extent of the fistulae. After adequate clinical and angiographic evaluation, therapy should be conservative enough to afford optimal function and radical enough to prevent death due to hemorrhage. This report includes eight patients who underwent angiographic evaluation and surgical therapy for arteriovenous malformation. Of the six living patients, five are known to have residual arteriovenous shunting.
The binding of 125I-labeled wheat germ agglutinin (WGA) to parental and three distinct WGA-resistant Chinese hamster ovary cell lines possessing modified cell surface carbohydrate structures has been examined over a 10(6)-fold range of WGA concentrations. The Scatchard plot for WGA binding to parental cells was complex and exhibited positively cooperative binding at the high affinity sites. One of the WGA-resistant mutants (WgaRIII) was apparently not altered in its WGA-binding ability compared with parental cells. However, two of the WGA-resistant lines (WgaRI and WgaRII) had distinct alterations in their WGA-binding properties specific to certain regions of the binding curve. Neither appeared to be affected in either the highest or lowest affinity regions of the binding curve. Thus, lectin-resistant cell mutants altered in specific lectin-binding sites at the cell surface provide a direct approach to analysis of the complex binding parameters that characterize the interaction of WGA with the plasma membrane.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In hepatic tumors seen in children, treatment and prognosis differ from tumor to tumor and thus accurate determination of their extent and characteristics is important. Evaluation by gray scale ultrasonography, radionuclide imaging and angiography has produced definable characteristics for the various tumor types and often allows distinction from other intrahepatic processes. In addition, chemotherapeutic treatment of initially unresectable malignant hepatic tumors can be followed by nuclear imaging, ultrasound and angiography to determine therapeutic response.
Explore the source record for details and available documents.
Six infants with either cavernous hemangiomas or hemangioendotheliomas of the liver are described. Typical clinical features include cardiac failure, hepatomegaly, and cutaneous hamangiomas. Prompt recognition will direct management to prevent lethal complications of cardiac failure, hyperconsumptive coagulopathy, and hepatic rupture. Dynamic and static hepatic scintigraphy will demonstrate the vascularity and size of the liver mass and provide distinction from other tumors, although in certain circumstances angiography is required.
The follow-up of 44 patients with simple d-transposition of the great arteries is presented. All had balloon atrial septotomy shortly after birth. If an operation was needed at or before one year of age, atrial septectomy was carried out. Correction was done between the ages of 19 and 64 months. Of the 44 patients, 34 (77 per cent) are living and doing well (27 after the Mustard procedure), 3 (7 per cent) are lost to follow-up, and 7 (16 per cent) are dead. Death was due to technical problems during initial catheterization and balloon septotomy in 2 patients, occurred after septectomy in one (3 per cent), and after the Mustard procedure in one (4 per cent). There was one sudden inexplicable death in a 1 1/2-month-old patient, and 2 patients died with pulmonary vascular obstructive disease. Because of the relatively low over-all mortality and morbidity and the low surgical mortality rate for both palliation and correction, we believe that two-stage surgical correction of transposition of the great arteries is preferable to early one-stage correction in the infant.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Chinese hamster ovary (CHO) cells selected in a single step for resistance to the cytotoxicity of the lectin from red kidney beans (PHA) behave as authentic somatic cell mutants. The PHA-resistant (Phar) phenotype is stable in the absence of selection; its frequency in a sensitive-population is increased several-fold by mutagenesis; and it behaves recessively in somatic cell hybrids. The activity of a specific glycosyl transferase which transfers N-acetylglucosamine (GlcNAc) to terminal alpha-mannose residues is dramatically reduced (less than or equal to 5% of the activity detected in wild-type CHO cells) in several independent PhaR clones. These clones also exhibit (a) a decreased ability to bind [125I]-PHA; (b) a marked resistance to the cytotoxicity of wheat germ agglutinin (WGA), Ricin (RIC) and Lens culinaris agglutinin (LCA); (c) a 4- to 5-fold increased sensitivity to the cytoxocity of concanavalin A (Con A); (d) an increased ability to bind 125I-Con A; and (e) decreased surface galactose residues - all properties consistent with the specific loss of the GlcNAc transferase activity. The lectins WGA, RIC, LCA and Con A have also been used to select, in a single step, resistance closes from each of two complementary CHO auxitrophic lines. These lectin-resistant clones have been characterized by their ability to survive cytotoxic doses of PHA, Con A, WGA, RIC, or LCA, and 4-5 "lectin-resistance" phenotypes have been demonstrated. Complementation data is being sought by somatic cell hybridization. Preliminary results show that two phenotypically-distinct Con AR mutants are complementary in that hybrid cells formed between them exhibit wild-type sensitivity to Con A.
Nine children with partial anomalous pulmonary venous drainage into the superior vena cava were operated upon. The technique consisted essentially of partitioning and enlargement of the superior vena cava. The partitioning was done in all but one patient, with a longitudinal suture starting above the highest pulmonary vein directing the pulmonary venous flow through the enlarged atrial septal defect into the left atrium. The anterior cavo-auricular tunnel was enlarged with a right atrial appendage-superior vena cava angioplasty. Follow-up studies were done between 1 and 3 years after surgery. The hemodynamic data were normal in 7 patients. In 8 children, the superior vena cava was unobstructed and its diameter was normal as demonstrated by cavograms. In all patients, the angiographic evaluation of the pulmonary venous return was normal. These results are encouraging and indicate that this new approach is superior to those which have previously been reported.
The object of this investigation was to demonstrate the hemodynamic features of cardiac rejection. The postoperative functional evolution of a homogeneous group of unmodified homografts was compared with that of a group of autografts studied by the same protocol. On the 4th postoperative day, a significant decrease was observed initially in the maximum systolic output, the maximum systolic rate index, the mean systolic ejection rate and also in the strength, work and, especially, acceleration of the left ventricles of the homografts. In the terminal phase, the abnormalities already present in these parameters worsened; there was a large decrease in cardiac output, in the stroke volume, in the voltage of the electrocardiogram, and a slowdown in cardiac emptying. During terminal heart failure, the aortic pressure became depressed and the central venous pressure increased rapidly. The hemodynamic reaction following the homoplastic graft was totally different after the 4th day. The comparison of the results obtained from these two experimental groups established that the functional cardiac failure described for the homoplastic transplant represents the hemodynamic expression of acute rejection.