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Biomedical subjects

C M Evans

Publications and source records attributed to C M Evans.

At least 37 records · Page 2Linked to original sources
PubMed1989

Epidural versus general anaesthesia for elective caesarean section. Effect on Apgar score and acid-base status of the newborn.

Elective Caesarean section deliveries over a 5-year period were studied to compare the effect of epidural block with general anaesthesia on the condition of the infant at birth. The Apgar score and umbilical arterial acid-base status were used as determinants of the latter. Epidural block was used in 139 (22.8%) mothers while 471 (77.2%) were performed under general anaesthesia. No babies in the epidural group were severely depressed (Apgar less than 4), compared with 6.2% in the general anaesthesia group. Only 4.3% of the epidural sections were moderately depressed (Apgar 4-6), compared with 15.4% of the others. These differences remained highly significant when infants of less than 2500 g were excluded, and when matched groups were compared. Mean umbilical arterial pH was similar within the two groups (pH 7.28), and was not consistent with asphyxia in almost 90% of the depressed infants. The findings suggest that general anaesthesia, rather than asphyxia or aortocaval compression, is responsible for most of the depressed infants born by elective Caesarean section. This may involve over 20% of babies delivered in this manner, so greater use of epidural block for elective Caesarean section is recommended. Further investigations are required to improve results with general anaesthesia.

Acid-Base Equilibrium↗
PubMed1988

Amoxycillin-clavulanic acid (Augmentin) antibiotic prophylaxis against wound infections in renal failure patients.

A randomized, controlled trial of the use of amoxycillin with clavulanic acid (Augmentin) for prophylaxis against wound infections following major surgery, including transplantation, in patients with chronic renal failure, was undertaken. Six of 22 control patients developed wound infections (27%) whereas no patient in the treatment group (24) developed a wound infection (P less than 0.05). After the termination of this trial, the next 35 consecutive patients received prophylactic amoxycillin/clavulanate; of these only two developed wound infections associated with leakage from their pancreatic anastomoses. All the wound infections were shown to be caused by bacteria sensitive to amoxycillin/clavulanate. Pharmacokinetic studies in patients have shown that a bactericidal concentration of the drugs was present for up to 20 h post-operatively in patients on dialysis, and in recipients of non-functioning renal transplants. In patients with normal renal transplant function excretion of the drug within 12 h was observed.

Adult↗
PubMed1988

Bulbocavernosus reflex latency in the investigation of diabetic impotence.

Impotence in males is a well recognised complication of diabetes mellitus, commonly held to be due to an autonomic neuropathy. The aim of this study was to determine the incidence of periphero-conus neuropathy in diabetic impotence. Nineteen diabetic males seeking treatment for loss of potency had bulbocavernosus reflex latency (BCRL) and sacral reflex latencies (SRLs) performed. The conduction studies indicated that impotence in these cases was associated with peripheral neuropathy in 21% of patients and that BCRL and SRLs are sensitive and useful diagnostic tests.

Adult↗
PubMed1983

The importance of urodynamic investigation following spontaneous rupture of the bladder.

We report a case of spontaneous intraperitoneal rupture of the bladder. Followup urodynamic studies revealed unsuspected detrusor bladder neck dyssynergia that was treated by unilateral endoscopic bladder neck incision. The pathogenesis of spontaneous bladder rupture is discussed and we recommend urodynamic evaluation in all cases of spontaneous rupture.

Adult↗
PubMed1983

Response of the normal human ankle joint to imposed sinusoidal movements.

Ankle joints were subjected to sinusoidal movements at a range of amplitudes and frequencies. Records were made of electromyograms (e.m.g.s) in calf muscles, and of the forces at the joints. When the leg is relaxed, the ankle joint resists an imposed sinusoidal movement with a small approximately sinusoidal force. It is stiffer in its resistance to small movements than to large ones, and this resistance is greater when the joint is dorsiflexed than when it is plantarflexed. If the subject exerts a steady mean flexing force, the imposed sinusoidal movement generates reflex activity which may be recorded as a modulation of the gastrocnemius and soleus e.m.g.s. The e.m.g. response to the sinusoidal movement occurs later in cycles of movement at high than at low frequencies, as one could expect of a reflex pathway that involves a delay. The results suggest that this delay is between 50 and 60 ms, and we conclude that under these circumstances spinal stretch reflexes are playing the important part. The relation of the resisting force to the movement has been displayed as a vector. As the frequency changes, this vector describes the circular path that is characteristic of a system which includes delays or lags; this path enables one to draw conclusions about the amplitude and timing of the reflex resistance to the movement. When a subject exerts a moderate flexing force against the sinusoidal movement for some minutes, the reflex response becomes progressively potentiated. A subject whose reflex responses are normally slight may then exhibit a vigorous reflex response to the movement of that ankle. This enhancement of spinal reflex activity was accompanied by an increase in the myotatic reflex response at the ankle. Reflex responses to sinusoidal movement were most clearly seen when the subject exerted a mean flexing force that amounted to about one-fifth of his maximum. Very small movements (+/- 0.5 degrees) generated little or no reflex response. With large amplitudes of movement there was more reflex activity, but at some amplitude (which varied from subject to subject and from time to time) the reflex mechanism appeared to 'saturate', and further increases in amplitude were not accompanied by comparable increases in the reflex response. With movements at 10-15 Hz the e.m.g. response often became large in alternate cycles, with less activity in the intervening cycles.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1983

Administration of meptazinol to opiate-dependent patients.

A double blind comparison of the effect of intravenous meptazinol 100 mg and placebo was carried out on 8 opiate-dependent patients who were on a prolonged methadone withdrawal regime. Psychological and physiological measurements revealed no significant differences between meptazinol and placebo, and no patient reported pleasurable effects following meptazinol injection. These findings support the evidence from animal studies that meptazinol is unlikely to be abused by opiate addicts or to lead to dependence.

Adolescent↗
PubMed1982

Production of tolerance and physical dependence in the rat by simple administration of morphine in drinking water.

1 Rats are capable of consuming solutions of morphine sulphate in drinking water ad libitum in the absence of taste-masking chemicals and without the need for scheduled provision or prior parenteral administration of the drug. 2 The success of this method depends on the initial provision of a 0.1 mg/ml solution of morphine sulphate. 3 When the drug concentration is increased to 0.4 mg/ml, the rats achieve an average daily intake of 50 mg/kg body wt. each. 4 Daily intake of morphine may be increased by at least about three fold by increasing the drug concentration to 1.2 mg/ml. 5 Oral morphine administration causes only a moderate loss in body weight. 6 Rats whose daily intake of the drug is 50 mg/kg exhibit tolerance to the analgesic action of morphine and show a drastic loss in body weight at 24 h after withdrawal and most of the behavioural symptoms of the naloxone-precipitated withdrawal syndrome. 7 It is suggested that this simple method of morphine administration is suitable for further biochemical and behavioural studies of the actions of the drug.

Animals↗
PubMed1981

Critical evaluation of direct vision urethrotomy by urine flow measurement.

Fifty-two male patients were studied prospectively to assess the results of direct vision urethrotomy in the treatment of urethral strictures. The prognosis was found to be significantly worse in those patients who had received extensive previous treatment. A catheter is recommended for at least 3 days and for 4 weeks in patients who have had minimal previous treatment or who have impaired detrusor function. The use of a urine flowmeter is essential for determining the success of treatment and stricture recurrence. Measurement of the recurrence-free period is important for assessing progressive improvement following repeat urethrotomy and for determining which patients cannot be cured by direct vision urethrotomy.

Adolescent↗
PubMed1980

Inhibition of rat brain tryptophan metabolism by ethanol withdrawal and possible involvement of the enhanced liver tryptophan pyrrolase activity.

1. Chronic ethanol administration to rats was previously shown to enhance brain 5-hydroxytryptamine synthesis by increasing the availability of circulating tryptophan to the brain secondarily to the NAD(P)H-mediated inhibition of liver tryptophan pyrrolase activity. 2. At 24h after ethanol withdrawal, all the above effects were observed because liver [NAD(P)H] was still increased. By contrast, all aspects of liver and brain tryptophan metabolism were normal at 12 days after withdrawal. 3. At 7--9 days after withdrawal, brain 5-hydroxytryptamine synthesis was decreased, as was tryptophan availability to the brain. Liver tryptophan pyrrolase activity at these time-intervals was maximally enhanced. 4. Administration of nicotinamide during the withdrawal phase not only abolished the withdrawal-induced enhancement of tryptophan pyrrolase activity on day 8, but also maintained the inhibition previously caused by ethanol. Under these conditions, the withdrawal-induced decreases in brain 5-hydroxytryptamine synthesis and tryptophan availability to the brain were abolished, and both functions were enhanced. Nicotinamide alone exerted similar effects in control rats. 5. It is suggested that ethanol withdrawal inhibits brain 5-hydroxytryptamine synthesis by decreasing tryptophan availability to the brain secondarily to the enhanced liver tryptophan pyrrolase activity. 6. The results are discussed in relation to the possible involvement of 5-hydroxytryptamine in dependence on ethanol and other drugs.

Animals↗
PubMed1980

A controlled trial of different treatment regimens in patients with urinary tract infections after lower urinary tract surgery.

One hundred and four patients who developed urinary tract infections after catheterization for acute retention of urine and surgery of the bladder or urethra were randomly allocated to four treatment groups. Analysis of the results in 65 patients showed that co-trimoxazole and 1 g cephradine administered twice daily for 1 week were successful in eradicating the urinary tract infections in 93% and 88% of the patients, respectively. The same dose of cephradine administered 4-times a day eradicated 64% of the infections. In patients for whom no treatment was given, the original infection did not clear in 65%. Escherichia coli and coagulase-negative staphylococci were the commonest infecting organisms. The in vitro sensitivity testing of antibiotics did not correlate well with the successful eradication of the infecting organism.

Aged↗