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Biomedical subjects

R Strachan

Publications and source records attributed to R Strachan.

11 recordsLinked to original sources
PubMed1999

The popliteofibular ligament. An anatomical study of the posterolateral corner of the knee.

We designed an experimental study to prove the existence of the popliteofibular ligament (PFL) and to define its role in providing static stability of the knee. We also examined the contribution of the lateral collateral ligament (LCL). We found this ligament to be present in all eight human cadaver knees examined. These specimens were mounted on a specially designed rig and subjected to posterior, varus and external rotational forces. We used the technique of selective sectioning of ligaments and measured the displacement with a constant force applied, before and after its division. We recorded the displacement in primary posterior translation, coupled external rotation, primary varus angulation and primary external rotation. Statistical analysis using the standard error of the mean by plotting 95% confidence intervals, was used to evaluate the results. The PFL had a significant role in preventing excessive posterior translation and varus angulation, and in restricting excessive primary and coupled external rotation. Isolated section of the belly of popliteus did not cause significant posterolateral instability of the knee. The LCL was also seen to act as a primary restraint against varus angulation and secondary restraint against external rotation and posterior displacement. Our findings showed that in knees with isolated disruption of the PFL stability was restored when it was reconstructed. However in knees in which the LCL was also disrupted, isolated reconstruction of the PFL did not restore stability.

Aged↗
PubMed1996

Screening for colorectal cancer: a general-practice-based study.

BACKGROUND: A 2-year study was undertaken to determine the best way of setting up faecal occult blood screening for colorectal cancer in a single general practice in north Birmingham, a district with no pre-existing hospital-based screening programme for colorectal cancer. This programme was set up in close collaboration with the Departments of Surgery and Biochemistry at the local Good Hope Hospital Trust. This facilitated joint meetings between the staff of these hospital departments and the practice manager, who was responsible for organization of the study at the Hawthorns Surgery and also supervised the day-to-day running of the programme. Essentially, the study was organized and run by the practice manager and nurse. AIM: The study was undertaken to prepare the way for other general practices in north Birmingham to screen selected populations for colorectal cancer. METHOD: A Haemoccult test kit was posted to patients together with an explanatory letter. The design of the screening programme was similar to the design of the 'screened arm' of the Medical Research Council (MRC) colorectal screening trial in Nottingham. On completion of the programme, questionnaires were posted to 100 responders and 100 non-responders to assess the level of patient acceptability for the screening study. A total of 3509 patients (1599 men and 1910 women) were invited to take part in the screening. RESULTS: The response rate was 55.4%. Thirty-nine patients were referred from the screening study for further investigation. Colonoscopy identified nine adenomas in nine patients, and a further 12 patients were found to have colorectal carcinoma. CONCLUSIONS: The findings from the study suggest that this method could be used as a model for other general practices introducing colorectal screening using Haemoccult.

Aged↗
PubMed1995

Thrombosis of the straight sinus complicating hormone replacement therapy.

Oral contraceptives have been implicated in the pathogenesis of dural venous thrombosis. No similar association has been confirmed between postmenopausal hormone replacement therapy and cerebral venous thrombosis, although one previous report in the literature has identified such a case. We present a further case of thrombosis of the straight sinus in a patient on hormone replacement therapy (HRT) and suggest that dural sinus thrombosis is a rare, but dangerous complication of HRT.

Cerebral Angiography↗
PubMed1989

Will chromosome karyotyping of meningiomas aid prediction of tumour recurrence?

Cytogenetic studies over many years have established absence or deletion of chromosome 22 as a common finding in meningiomas. Enormous karyotypic variation is recognised: an abnormal hyperdiploid clone can occur in a histologically benign meningioma. The cytogenetic, histopathological and macroscopic findings in 13 meningiomas of a prospective study are presented. Where the neuropathologist reported the presence of malignant change, a cytogenetically abnormal clone was more common in short-term culture of the tumour tissue. Histologically benign meningiomas showed great cytogenetic variation, from normal chromosomes to hyperdiploid clones with extensive karyotypic abnormality indicating malignant change. We suggest the addition of cytogenetic findings to histopathological features in assessing 'malignancy' in meningiomas and the risk of recurrence or regrowth.

DNA, Neoplasm↗
PubMed1984

Efficient expression of cloned complementary DNAs for secretory proteins after injection into Xenopus oocytes.

Cloned complementary DNAs encoding chicken ovalbumin, chicken prelysozyme and calf preprochymosin, prochymosin and chymosin were inserted downstream from various viral promoters in modified recombinant "shuttle" vectors. Microinjection of the ovalbumin, prelysozyme and preprochymosin constructs into the nuclei of Xenopus laevis oocytes resulted in the synthesis, segregation in membranes and secretion into the extracellular medium of ovalbumin, lysozyme and prochymosin, respectively. Judging from molecular weight estimations, lysozyme and prochymosin were correctly proteolytically processed while ovalbumin, which lacks a cleavable signal sequence, was glycosylated. Injection of the DNA construct encoding prochymosin without its signal sequence resulted in synthesis of prochymosin protein that was localized exclusively in the oocyte cytoplasm. No immunospecific protein was detected after injection of the DNA encoding mature chymosin. In terms of protein expression in oocytes, the Herpes simplex thymidine kinase (TK) promoter was up to sevenfold more effective than the simian virus 40 (SV40) early promoter, and equally as effective as the Moloney murine sarcoma virus long terminal repeat element. Where tested, protein expression in oocytes was much reduced if DNA sequences encoding the SV40 small t intron and its flanking sequences were present in the constructs. S1 nuclease mapping of transcripts produced after injection of DNAs containing the TK promoter indicated that the majority of transcripts initiated at, or within, two bases of the known "cap" site. However, minor transcripts initiating upstream from this site were observed and one (or more) of these transcripts was responsible for the synthesis of an ovalbumin polypeptide containing a 51 amino acid N-terminal extension. This extended protein remained in the oocyte cytosol. When ovalbumin cDNA was inserted into the vectors with opposite polarity to the viral promoter, expression in oocytes resulted in the predominant synthesis and secretion of a variant ovalbumin with a 21 amino acid N-terminal extension, although some full-length ovalbumin was also synthesized and secreted. S1 mapping revealed the presence, in these oocytes, of transcripts of predicted polarity initiating 118 bases upstream from the wild type ovalbumin initiator ATG, at a previously unreported SV40 "promoter". No protein synthesis was detected after the injection of these reverse-orientation constructs into baby hamster kidney (BHK-21) cells.

Amino Acid Sequence↗
PubMed1984

Segregation of mutant ovalbumins and ovalbumin-globin fusion proteins in Xenopus oocytes. Identification of an ovalbumin signal sequence.

The intramolecular signals for chicken ovalbumin secretion were examined by producing mutant proteins in Xenopus oocytes. An ovalbumin complementary DNA clone was manipulated in vitro, and constructs containing altered protein-coding sequences and either the simian virus 40 (SV40) early promoter or Herpes simplex thymidine kinase promoter, were microinjected into Xenopus laevis oocytes. The removal of the eight extreme N-terminal amino acids of ovalbumin had no effect on the segregation of ovalbumin with oocyte membranes nor on its secretion. A protein lacking amino acids 2 to 21 was sequestered in the endoplasmic reticulum but remained strongly associated with the oocyte membranes rather than being secreted. Removal of amino acids 231 to 279, a region previously reported to have membrane-insertion function, resulted in a protein that also entered the endoplasmic reticulum but was not secreted. Hybrid proteins containing at their N terminus amino acids 9 to 41 or 22 to 41 of ovalbumin fused to the complete chimpanzee alpha-globin polypeptide were also sequestered by oocyte membranes. We conclude that the ovalbumin "signal" sequence is internally located within amino acids 22 to 41, and we speculate that amino acids 9 to 21 could be important for the completion of ovalbumin translocation through membranes.

Amino Acid Sequence↗
PubMedDate not supplied

Facilitating return to practice.

The government has recently announced its intention to recruit nurses back into the profession. In this article, the authors describe an initiative undertaken by their trust to facilitate return to practice programmes, outlining the programme objectives and outcomes to date.

Education, Nursing, Continuing↗