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M R Feneley

Publications and source records attributed to M R Feneley.

41 records · Page 3Linked to original sources
PubMed1994

Screening for carcinoma of the prostate: a GP based study.

OBJECTIVE: To examine the feasibility and acceptability of screening for cancer of the prostate by digital rectal examination (DRE), prostate specific antigen (PSA) determination and subsequent transrectal ultrasound (TRUS) in selected patients in a single general practice in Hertfordshire. SUBJECTS AND METHODS: A total of 568 of 856 men aged 55 to 70 accepted an invitation for a health check which included screening for prostate cancer. Of these, 80 individuals with either a raised PSA level or an abnormal DRE underwent TRUS. In 29 individuals biopsies were taken, 11 of which confirmed the presence of adenocarcinoma of the prostate giving an overall detected prevalence of 2%. Of the 11 tumours identified by screening, two were T1M0, four were T2M0, two were T3M0 and three were T3M1. RESULTS: To assess the acceptability of the screening exercise a postal questionnaire was sent to all 568 participants: 83% replied and 69% reported no concern. Of the 67 individuals who had undergone TRUS, 69% reported discomfort. A total of 448 (95%) of respondents declared that they would be prepared to undergo the screening exercise again. CONCLUSION: Screening for prostate cancer would seem to be technically feasible and generally acceptable. However, there is a considerable false positive rate in the PSA range 4 ng/ml to 10 ng/ml, particularly among men with clinical evidence of benign prostatic hyperplasia. To establish the true benefit of screening a large-scale prospective controlled study will be necessary.

Adenocarcinoma↗
PubMed1992

Capillary volume fraction is the principal determinant of villous membrane thickness in the normal human placenta at term.

The thickness of the villous membrane is known to be an important factor in determining the morphometric diffusing capacity of the placenta at term. As yet it is not certain how areas of the villous membrane specialised for gaseous exchange, the vasculo-syncytial membranes, differentiate. One mechanism suggested is that they arise through obtrusion of the fetal capillaries contained within the stromal core. As a result the bulk of the overlying trophoblast is displaced laterally, reducing the thickness of the villous membrane to as little as 1-2 microns at these points. To test this hypothesis the relationship between the vascularity of the villi, as determined by the villous capillary volume fraction, and the mean thickness of the villous membrane was investigated. Data were taken from a recent study in which placental villi were biopsied from normal term placentae within 1 min of caesarean delivery and at 5, 10, 15 and 20 min thereafter. Since intuitively the membrane has both a maximum and a minimum thickness a sigmoid relationship was fitted to the data using least squares regression analysis. Estimates of arithmetic and harmonic mean thicknesses were then predicted from the capillary volume fraction for a large number of placentae using data from previous studies. These all employed similar stereological techniques but were performed over a number of years by several workers in this laboratory. The predicted values were tested against the measured values using paired 't' tests, but no significant differences (P greater than 0.05) were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Capillaries↗
PubMed1991

The role of Schwann cells in the regeneration of peripheral nerve axons through muscle basal lamina grafts.

Evacuated muscle is a possible substitute for nerve autografts in the repair of damaged peripheral nerves. Previous experiments have shown that killed or evacuated muscle grafts are as effective as nerve autografts for bridging gaps of up to 4 cm between proximal and distal nerve stumps. Evacuated muscle grafts are made of extracellular matrix components, which are good substrates for axon growth in vitro. However, experiments in vivo have generally demonstrated that live Schwann cells are essential for successful axon regeneration. In the present experiments we have used immunohistochemical techniques with anti-S100 and anti-neurofilament antibodies to visualize axon growth and Schwann cell migration into muscle grafts over the first 10 days following grafting. We only saw axons growing into grafts accompanied by Schwann cells, and most though not all Schwann cells were associated with axons. Schwann cell migration from the proximal stump in association with axons was much faster and more extensive than from the distal stump. We examined muscle grafts over the first 20 days after grafting by electron microscopy. Regenerating axons were always associated with Schwann cells, which were mostly in the basal lamina-lined tubes left by the evacuated myofibrils. A comparison between evacuated muscle grafts and grafts in which the muscle had been killed but not evacuated revealed that 7 days after grafting there were more than twice as many regenerated axons in and distal to the evacuated grafts, but that by 20 days the numbers of axons were similar in the two groups.

Animals↗
PubMedDate not supplied

Villous composition and membrane thickness in the human placenta at term: a stereological study using unbiased estimators and optimal fixation techniques.

The aim of this study was to obtain unbiased estimates of in vivo villous composition and membrane thickness in the human placenta at term. By taking biopsies of the placenta 1 min after separation during caesarean section, and at regular intervals thereafter, it was possible to extrapolate back to the time zero values. It was estimated that at term intermediate and terminal villi are composed of 25.3 per cent trophoblast, 36.2 per cent stromal core and 37.1 per cent fetal capillaries. The villous membrane, defined as the outer surface of the syncytiotrophoblast (excluding the microvilli) to the inner surface of the capillary endothelium, was estimated to have an arithmetic mean thickness of 4.53 microns and a harmonic mean thickness of 3.65 microns. Villous composition and membrane thickness were found to change rapidly after delivery, despite the umbilical cord remaining clamped, and these changes were believed to be predominantly due to leakage of fetal blood or plasma from sites of damage to the villous tree caused at the time of delivery. These estimates do not, and indeed cannot, take into account the fact that the villi sampled have been removed from their uterine environment, and thus from the influences of the maternal and fetal blood pressures. However, they are free from methodological errors that have detracted from previous studies, and thus allow the morphometric diffusing capacity of the placenta at term to be calculated more accurately. They also provide baseline data against which measurements obtained from pathological pregnancies can be compared.

Adult↗