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Biomedical subjects

T J Ellis

Publications and source records attributed to T J Ellis.

11 recordsLinked to original sources
PubMed1999

Knee manipulation after total knee arthroplasty.

To determine if any factors are associated with knee stiffness after total knee arthroplasty (TKA), we retrospectively reviewed the medical records and radiographs of patients who had knee manipulation after total knee replacement at Scott & White Memorial Hospital from 1983 to 1993. Twenty-five patients who had knee manipulation after TKA were matched by surgeon, year of surgery, and age (+/- 5 years) with a study group of 25 patients who did not have knee manipulation after TKA. Patients in the manipulated group had decreased flexion at the time of discharge from the hospital after the knee arthroplasty and a decreased final flexion. The age of the patient, time from surgery to manipulation, and preoperative flexion did not correlate with final flexion attained in the manipulated group. Relative to the control study group, the manipulated group had an increase in postoperative anteroposterior femoral thickness. A decrease in patellar height was noted both in the manipulated group and in the control nonmanipulated group. There was no significant difference between groups for a change in patellar height.

Arthroplasty, Replacement, Knee↗
PubMed1995

Post-transcriptional regulation of the stanniocalcin gene by calcium.

Stanniocalcin (STC) is a Ca(2+)-regulating hormone produced by the corpuscles of Stannius in bony fish. Calcium has been shown to stimulate STC synthesis at multiple levels including the level of gene expression. The purpose of this study was to determine the effects of Ca2+ on STC mRNA stability. The half-life of STC mRNA was measured in primary cultured trout corpuscles of Stannius cells maintained in either normal (1.2 mM) or high (1.9 mM) levels of extracellular calcium and treated with the transcriptional inhibitor alpha-amanitin. In cells maintained in 1.2 mM Ca2+, STC mRNA levels decreased progressively over time with an estimated half-life of approximately 71 h. However, message levels remained unchanged for up to 4 days in cells maintained in 1.9 mM Ca2+, indicating that the transcript had been stabilized in response to Ca2+ stimulation. Blocking transcription prior to exposing cells to high Ca2+ did not alter the stabilizing effects of the cation, indicating that synthesis and processing of the mRNA transcript were not involved in message stabilization. Inhibiting protein synthesis with cycloheximide also had no influence on the stabilizing effects of high calcium. The experiments involving cycloheximide further suggested that the mechanism of mRNA stabilization involved protein-nucleic acid interactions in the cytoplasm, whereby the polysomal complex protected the mRNA from degradation. These data demonstrate that the stimulatory effect of Ca2+ on STC gene expression is due, in part, to mRNA stabilization.

Amanitins↗
PubMed1995

Phylogenetic relationships between Toxoplasma and Sarcocystis deduced from a comparison of 18S rDNA sequences.

The current taxonomy of parasites in the genus Sarcocystis is largely based on morphological characteristics as well as on host specificity and life-cycle structure. Recently, phylogenetic analyses of partial ribosomal RNA (rRNA) sequences provided support for paraphyly of Sarcocystis. We have tested the validity of this hypothesis by sequencing the complete 18S rRNA genes of Sarcocystis arieticanis, Sarcocystis gigantea and Sarcocystis tenella and comparing them with gene sequences derived from other taxa of the phylum Apicomplexa. The results obtained from this study do not reject the hypothesis of monophyly of Sarcocystis species, although the bootstrap data were inconclusive for some species.

Animals↗
PubMed1980

Automated measurement of peripheral nerve fibres in transverse section.

Transverse sections of rat tibial nerve were scanned with an automated flying-spot microscope and the pictures examined in a one bit (black-and-white) form. Computer programs have been developed, and are described briefly, to isolate individual nerve fibres in the field of view, and to measure axon area and myelin area, from which it is trivial to calculate average axon diameter and average myelin thickness if the axon is assumed to be circular in cross-section. At the magnification used, it was possible to measure 40-50 fibres per field and the time required to do this was 5-7 minutes. For each specimen, 7-8 fields were measured, providing data on 300-400 fibres. Measurements, made on nerves from rats between 3 and 38 weeks of age, show the rate at which nerve fibres grow and also show that the ratio between axon diameter and fibre diameter remains constant, within experimental error, over this period and is close to the predicted value.

Age Factors↗
PubMed1975

Hemoglobin function in stored blood. XIII. A citrate-adenine preservative with optimal pH to maintain red cell 2,3-DPG (function) and ATP (viability).

Increasing pH by a 0.5 increment over the commonly used preservative, acid-citrate-dextrose with adenine (ACD-Ad), results in a significant improvement in 2,3-DPG, with no significant loss in concentrations of ATP. The intermediate pH preservative, 6.0, also had ATP concentrations which equaled those of the low pH preservatives, 5.0 and 5.5, from the 21st to the 42nd day of storage. A citrate-adenine preservative, with a pH between 5.5 and 6.0, would seem to be optimal for maintenance of hemoglobin function and red cell viability, as determined by measurements of 2,3-DPG and ATP concentrations.

Adenosine Triphosphate↗
PubMedDate not supplied

Blood preservation XVI packed red cell storage in CPD-adenine.

Interest has been renewed in CPD-adenine as a long-term liquid blood preservative. The question of whether the metabolic product of adenine, 2,8-dioxyadenine was toxic to humans has apparently been resolved by extensive animal and human studies in favor of there being no potential toxicity in the amounts used in blood preservation. Sweden is adopting CPD-adenine (0.25 mM) as its national blood preservative after ten years of clinical experience in trials. They have shown that each additional week of storage time beyond the current three weeks with CPD results in a 50 per cent reduction of wasteage caused by outdating. They are adopting the 35-day time for regular use with 42 days for an emergency reserve supply. However, many units of blood in the U.S. are stored as packed red blood cells and the question has been raised as to whether there is sufficient glucose in the preservative to maintain red blood cell metabolism in the packed cell unit. The present investigation indicates that there is sufficient glucose for 35 days of packed cell storage in CPD-adenine (0.25 mM) but in some units this might be marginal at 42 days of storage.

Adenine↗