Search PubMed⌕ Search

Biomedical subjects

R J Ellis

Publications and source records attributed to R J Ellis.

At least 127 records · Page 7Linked to original sources
PubMed1981

Prophylaxis of varicella in high-risk children: dose-response effect of zoster immune globulin.

Immunodeficient patients who were presumed to be susceptible received zoster immune globulin prophylaxis after exposure to varicella. The highest clinical attack rate (35.9%) was seen in household contacts; the lowest attack rate (0%) was observed in children exposed at school. Among household contacts, 48 of 100 patients who received high titer ZIG (reciprocal complement fixation titer greater than or equal to 2,560) developed fourfold rises in serum CF antibody between pre- and 48-hour post-treatment specimens, compared to only one of 34 patients treated with lower titer ZIG lots (P less than 0.001). Patients who developed fourfold antibody rises were significantly less likely to contract clinical varicella (P less than 0.01). Patients who received high titer ZIG also had significantly lower risks of death (P = 0.025) and complications (P = 0.006). Among ZIG-treated patients who contracted clinical varicella, 80% developed mild disease (less than 100 pox), and the median incubation period was prolonged. Immunodeficient children exposed to varicella benefit from ZIG prophylaxis and higher titer ZIG is of greatest benefit.

Adolescent↗
PubMed1981

Rapidly progressive coronary artery bypass graft atherosclerosis. Report of a case documented by serial coronary arteriograms and pathologic examination.

Atherosclerosis occurred in a coronary artery saphenous vein bypass graft. Serial angiograms are presented documenting subtotal occlusion of this graft which occurred over a nine-month period. Pathologic examination of graft material obtained at surgery demonstrated ulcerating atherosclerotic plaque. The occurrence of early saphenous vein graft atherosclerosis is discussed with particular reference to the possible effects of hyperlipidemia, which was present in this patient.

Arteriosclerosis↗
PubMed1981

Light-stimulated accumulation of transcripts of nuclear and chloroplast genes for ribulosebisphosphate carboxylase.

The chloroplast enzyme, ribulosebisphosphate carboxylase, consists of large subunit polypeptides encoded in the chloroplast genome and small subunit polypeptides encoded in the nuclear genome. Cloned DNA complementary to the small subunit mRNA hybridizes to a single RNA species of 900-1000 nucleotides in both total and poly(A)-containing RNA from leaves of Pisum sativum, but does not hybridize to chloroplast RNA. Small subunit cDNA hybridizes to at least three RNA species from nuclei, two of which are of higher molecular weight than the mature mRNA. A cloned large subunit DNA sequence hybridizes to a single species of Pisum chloroplast RNA containing approximately 1700 nucleotides, but does not hybridize to nuclear RNA. The light-stimulation of carboxylase accumulation reflects increases in the amounts of transcripts for both subunits in total leaf RNA. Transcripts of the small subunit gene are more abundant in nuclear RNA from light-grown leaves than in that from dark-grown leaves. These results suggest that the stimulation of carboxylase accumulation by light is mediated at the level of either transcription or RNA turnover in both nucleus and chloroplast.

Carboxy-Lyases↗
PubMed1981

Protein transport across membranes: an introduction.

A characteristic feature of all cells is the transport of proteins across membranes. Biochemical studies with isolated subcellular components have revealed two types of proteins transport: co-translational, in which transport and synthesis are simultaneous, and post-translational, where transport occurs after the protein has been released form the ribosomes. Both types of transport involve interactions between particular regions of the protein and the membrane to be traversed. The details of this interaction are obscure. This review introduces the subject with emphasis on genetic studies with bacteria and biochemical studies with isolated chloroplasts.

Amino Acid Sequence↗
PubMed1981

Intraoperative anticoagulation in cardiovascular surgery.

The optimal heparin dose to prevent intraoperative thrombosis or excessive bleeding during the occlusive phase of cardiovascular operations has not been determined. Therefore, we studied the kinetics of heparin effect in 28 patient undergoing peripheral vascular and cardiac operations. The activated clotting time (ACT) was measured in seconds by an electronic clot timer. The maximum ACT after initial heparin administration, the time to reach maximum ACT, and the half-time of heparin effect (t1/2) were determined. The anticoagulant effect of a given dose of heparin varies greatly among patients. No correlation was found between the t1/2 and the dosage of heparin administered. Despite higher doses of heparin administered to cardiac patients, the t1/2 in cardiac and vascular patients was not significantly different. Four patients received the same dose of heparin preoperatively and intraoperatively in an effort to predict the intraoperative effect. The times to maximum effect were the same but t1/2 intraoperatively was longer. These results indicate: (1) maximum heparin effect occurs later than previously believed and is different for cardiac and peripheral vascular patients; (2) the recommendation to give more heparin based on the 5-minute ACT is not valid; (3) individual response to a standard dose of heparin is unpredictable, both in duration and maximum effect; and (4) intraoperative monitoring of the heparin effect is practical and is the only way that any consistent, specific and point of heparin can be achieved.

Aged↗
PubMed1980

Protein synthesis in chloroplasts. IX. Assembly of newly-synthesized large subunits into ribulose bisphosphate carboxylase in isolated intact pea chloroplasts.

Isolated pea (Pisum sativum) chloroplasts incorporate [35S]methionine into the large subunit of the chloroplast enzyme ribulose bisphosphate carboxylase. When chloroplasts are incubated in a medium containing KCl as osmoticum, newly-synthesised large subunits are not incorporated into the holoenzyme but can be separated from pre-existing enzyme by gel electrophoresis under non-denaturating conditions. Furthermore, newly-synthesised large subunits are not precipitated by antibodies which precipitate pre-existing holoenzyme and large subunit prepared from holoenzyme. When chloroplasts are incubated in a medium containing sorbitol as osmoticum, some of the newly-synthesised large subunits comigrate with holoenzyme on both 3% and 5% polyacrylamide non-denaturing gels. Such comigrating large subunits are precipitated by antibodies raised against the holoenzyme. These results indicate assembly of large subunits into ribulose bisphosphate carboxylase in the sorbitol medium. Time course experiments indicate that there is a time-lag of several minutes between onset of synthesis of large subunits and the onset of assembly. Newly-synthesised large subunits which do not comigrate with holoenzyme on both 3% and 5% polyacrylamide non-denaturing gels are associated with a protein of subunit molecular weight 60 000. This protein may be specifically combined with newly-synthesised large subunits, and the resulting aggregate be involved in the assembly of complete molecules of ribulose bisphosphate carboxylase.

Carboxy-Lyases↗
PubMed1980

Protein synthesis in chloroplasts. VIII. Differential synthesis of chloroplast proteins during spinach leaf development.

Excised primary leaves of spinach (Spinacia oleracea) incorporate [35S]-methionine into a number of chloroplast polypeptides. The ratio of incorporation of isotope into the large subunit of ribulose bisphosphate carboxylase relative to a thylakoid polypeptide (peak D) decreases during leaf development in whole leaves; this changing pattern of incorporation is also observed in isolated chloroplasts where these two polypeptides are the major products of protein synthesis. Chloroplast RNA prepared from developing leaves was translated in a reticulocyte lysate extract to yield full-length carboxylase large subunit and peak D polypeptides. The fidelity of translation of these two polypeptides was checked by partial protease digestion. Changes in the synthesis of the large subunit of the carboxylase and peak D in developing leaves are reflected in changes in the amount of translatable mRNA for these two polypeptides.

Animals↗
PubMed1980

The Absence of Protochlorophyll(ide) Accumulation in Algae with Inhibited Chlorophyll Synthesis.

Golenkinia, Chlorella protothecoides, and mutant C-2A' of Scenedesmus were grown in darkness and on media in which chlorophyll synthesis is reduced significantly. The pigments were analyzed by spectrophotometry or by paper chromatography and compared with similar extracts from light-grown algae and dark-grown beans. No protochlorophyll(ide) was present in the dark-grown algae indicating that chlorophyll synthesis is blocked by a mechanism other than feedback regulation of aminolevulinic acid synthesis by protochlorophyll(ide) which has been proposed for flowering plants.

Journal Article↗
PubMed1979

The biosynthesis of ribulose bisphosphate carboxylase. Uncoupling of the synthesis of the large and small subunits in isolated soybean leaf cells.

Isolated leaf cells from soybean (Glycine max) incorporate [35S]methionine into protein at a linear rate for at least 5h. Analysis of the products of incorporation by one-dimensional and two-dimensional polyacrylamide gel electrophoresis shows that major products are the large and small subunits of the chloroplast enzyme, ribulose bisphosphate carboxylase. The large subunit is synthesized by chloroplast ribosomes and the small subunit by cytoplasmic ribosomes. Addition of chloramphenicol to the cells reduces incorporation into the large subunit without affecting incorporation into the products of cytoplasmic ribosomes. Addition of cycloheximide or 2-(4-methyl-2,6-dinitroanilino)-N-methylpropionamide stops incorporation into the small subunit, but large subunit continues to be made for at least 4 h. For accurate estimates of incorporation into the large subunit, it is essential to use two-dimensional gel electrophoresis, because the large subunit region on one-dimensional gels is contaminated with the products of cytoplasmic ribosomes. Newly synthesized large subunits continue to enter complete molecules of ribulose bisphosphate carboxylase in the absence of small subunit synthesis. These results suggest that, in contrast to the situation in algal cells, the synthesis of the two subunits of ribulose bisphosphate carboxylase in the different subcellular compartments of higher plant cells is not tightly coupled over short time periods, and that a pool of small subunits exists in these cells. The results are disucssed in relation to possible mechanisms for the integration of the synthesis of the large and small subunits of ribulose bisphosphate carboxylase.

Carboxy-Lyases↗
PubMed1979

An accessory fill-in flash for the Nikon photo-slit lamp.

High-quality slit lamp photographs require a balance between slit beam exposure and exposure of surrounding ocular structures. Proper exposure of surrounding ocular structure is difficult to obtain with the Nikon photo-slit lamp. The purpose of this research was to design an accessory fill-in flash for this slit lamp, which would provide proper exposure of over all ocular structures. In addition, this paper describes the procedures used to obtain proper exposure values and provides an exposure table for this accessory flash unit.

Eye↗
PubMed1979

Mild ventricular dysfunction following cold potassium cardioplegia.

The long-term effects of cold potassium cardioplegic arrest was examined in 40 patients who underwent myocardial revascularization. Comparisons between resting ejection fraction (EF), end diastolic volume (EDV), and segmental wall motion were made between the preoperative and postoperative catheterization (mean postoperative recatheterization, 6 months). A 2.93 graft per patient ratio was found in this group of patients, with 108/117 grafts visualized at the time of recatheterization. The EF was 60% +/- 3% before surgery and 62% +/- 3% after surgery. A correlation coefficient of 0.91 was determined for the entire series. The EDV was 151 +/- 16 cc before coronary artery bypass graft (CABG) and was unchanged post CABG at an end diastolic volume of 137 +/- 15 cc. Analysis of preoperative wall motion of 33 patients demonstrated 111 depressed segments, 68 normal, and 52 hypercontractile; at recathetrization, there were 100 depressed, 66 normal, and 65 hypercontractile segments. Although there was essentially no deterioration of myocardial function for 37 out of 40 patients, three demonstrated a reduction in EF, the largest reduction being 15%. These three patients had a cardioplegic arrest time greater than 70 minutes. An inverse relationship between percent change in EF and the length of cardioplegic arrest was observed, with an r value o - 0.57 (p less than 0.01). These data suggest that prolonged cardioplegic arrest times may be associated with mild dysfunction. Cold potassium cardioplegic arrest up to 70 minutes was associated with no change in EF, EDV, or wall motion in this series of patients.

Cardiac Catheterization↗