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Biomedical subjects

G Newton

Publications and source records attributed to G Newton.

At least 37 records · Page 2Linked to original sources
PubMed1992

Long-term results of the Manchester knee. Surface arthroplasty of the tibiofemoral joint.

Unicompartmental knee replacement is increasing in popularity. Long-term analysis of an early bi-compartment variety, the Manchester knee, therefore has relevance. One hundred fifty-six consecutive Manchester knee replacements were observed, 47 for longer than ten years. Using survivorship tables, the authors found that the annual failure rate did not increase during the ten-year period. The cumulative success rate was 73% for all knees and 69% for the osteoarthritic ones. The main cause of failure was subsidence. Correction of mechanical axis had no effect on the outcome. Polyethylene wear was not significant clinically or on measurement of retrieved specimens.

Adult↗
PubMed1991

In vivo assembly of the cytochrome d terminal oxidase complex of Escherichia coli from genes encoding the two subunits expressed on separate plasmids.

The cytochrome d terminal oxidase complex is a heterodimer located in the cytoplasmic membrane of Escherichia coli. Subunit II of the cytochrome d terminal oxidase complex was expressed independently of subunit I of the complex. It was found that the polypeptide is produced and is associated with the cytoplasmic membrane in the absence of subunit I, and is not associated with any of the three cytochrome components of the complex. Oxidase activity and heme binding are restored when the subunit I is expressed in the same cells using a second compatible plasmid. It has been previously demonstrated that subunit I, expressed in the absence of subunit II, contains cytochrome b-558, one of the three heme prosthetic groups found in the oxidase. Association of the two other heme moieties, cytochromes b-595 and d, apparently requires the association of the two subunits, and must be a late step in the assembly of the membrane-bound protein. It was also shown that under heme-deficient conditions, the two polypeptide subunits are expressed and are associated with the cytoplasmic membrane.

Cell Membrane↗
PubMed1991

Analysis of the topology of the cytochrome d terminal oxidase complex of Escherichia coli by alkaline phosphatase fusions.

The cytochrome d complex of Escherichia coli is a heterodimer located in the bacterial cytoplasmic membrane, where it functions as a terminal oxidase of the aerobic respiratory chain. The topology of each of the two subunits of the cytochrome d complex was analysed by the genetic method involving alkaline phosphatase gene fusions. These fusions were generated by both an in vivo method using the transposon TnphoA and an in vitro method of construction. A total of 48 unique fusions were isolated and the whole-cell alkaline phosphatase-specific activities were determined. Data from these fusions, in combination with information from other studies, provide the basis for two-dimensional models for each of the two subunits, defining the way in which the subunits fold in the inner membrane of E. coli.

Alkaline Phosphatase↗
PubMed1991

Radiographic sign of persistent soft-tissue imbalance after knee replacement.

We report on the radiological findings in a series of 871 consecutive primary condylar knee replacements followed up for an average of four years. A new radiological sign has been identified, consisting of a smoothly tapering wedge of cement visible beneath the horizontal portion of the tibial component on the anteroposterior radiograph. This was found in 25.4% of our cases and appears to indicate a persistent soft-tissue imbalance following condylar arthroplasty of the knee. The cement-wedge sign was associated with a highly significant increase in radiolucent lines at the tibial cement-bone interface.

Bone Cements↗
PubMed1991

Osteoclastoma of occipital bone.

Osteoclastoma of the calvarial bone of membranous origin is a rare entity. This paper presents a case of osteoclastoma of the occipital bone and a brief review of literature.

Child↗
PubMed1991

Cystic meningiomas in infancy.

A suprasellar meningioma with multiple intratumoral cysts in a 6-month-old boy is reported. A review of literature disclosed only 11 cases so far. They showed a characteristic predominance in males and predominance of fibroblastic type on pathological examination. Intratumoral cystes are less common than peritumoral cysts. The various hypothesis regarding cyst formation are discussed.

Cysts↗
PubMed1990

HIV and surgeons.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Cervical intramedullary neurofibroma.

Intramedullary spinal neurofibroma is extremely rare. A case of cervical intramedullary neurofibroma is presented in a 21-year-old man. Only 20 case have been previously reported in the literature. The site of origin is discussed with various hypotheses.

Adult↗
PubMed1989

Curved Kuntscher nail arthrodesis after failure of knee replacement.

We report the use of long curved Kuntscher nails to maintain stability during arthrodesis of nine infected and five uninfected failures of total knee replacement. The curvature of the nail helps positioning and avoids the need for cortical perforation. A single-stage operation was possible in most cases. Union rates are comparable with those of other series and even patients with delayed union have satisfactory function.

Adult↗
PubMed1988

The nucleotide sequence of the cyd locus encoding the two subunits of the cytochrome d terminal oxidase complex of Escherichia coli.

The cytochrome d terminal oxidase complex is one of two terminal oxidases in the aerobic respiratory chain of Escherichia coli. The enzyme is located in the cytoplasmic membrane where it oxidizes ubiquinol-8 in the bilayer and reduces oxygen to water. Enzyme turnover is coupled to the generation of a proton-motive force, resulting in electrogenic translocation across the membrane of one proton per electron passing through the system. The enzyme is an alpha beta heterodimer containing four hemes. The cyd locus, encoding both subunits, has previously been genetically mapped and cloned. This work describes an insertion and deletion analysis of cyd which indicates the direction of transcription, defines the coding regions, and suggests that cyd is an operon. In addition, the complete DNA sequence of the cyd gene is reported. Two open reading frames, separated by 18 base pairs, encode the two subunits of the oxidase complex. Hydropathy profiles of the deduced protein sequence indicate that subunits I and II are each likely to have multiple transmembrane elements. There are only 10 histidines in both subunits, several of which are likely to serve as heme axial ligands.

Amino Acid Sequence↗
PubMed1986

Medullary femoral nailing of pathological fractures using the Derby nail--a preliminary report of 22 cases.

A new medullary femoral nail is reported. The device provides dynamic compression, producing rigid stabilization with resistance to rotational stresses. We present 22 cases of pathological fractures of the femur treated by the Derby nail. Rigid fixation was achieved with no sepsis, loosening or implant failure at the latest follow-up or death. The mean time spent in hospital was 20 days and patients took full weight, on average, by the 9th postoperative day.

Aged↗
PubMed1986

The results and morbidity of varus osteotomy for Perthes' disease.

The results of varus proximal femoral osteotomy in 55 hips in 52 patients were analyzed by Harrison's radiologic autoassessment method. Excluding operations upon Catterall Grade 1 hips, 75.6% were either therapeutic successes or unchanged; 24.4% were therapeutic failures. These results are compared with and shown to be similar to those of patients treated conservatively by the Birmingham splint. In ten children with Catterall Grade 1 disease, seven were unchanged but three were therapeutic failures. Improved end results occurred in hips with greater surgical varus than those in which the end result worsened, but the statistical significance was questionable. The bone remodelling in response to surgical varus was unpredictable, but the greater the surgical varus the less the correction of the neck shaft angle at follow-up evaluation. Chronologic age cannot be used to predict such bone remodelling as may be impaired by the disease process. An analysis of the incidence and significance of leg shortening, limping, and abductor lurch is presented and some observations made on trochanteric overgrowth and the effect of surgery on the rate of femoral head reconstitution. New attempts to achieve containment of the hip by high-femoral osteotomy may determine the effects of a combination of varus and selective rotation osteotomy using ultrasound scans to measure femoral torsion before operation.

Child↗