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Biomedical subjects

C C McDonald

Publications and source records attributed to C C McDonald.

At least 19 recordsLinked to original sources

A randomised, crossover, multicentre study to compare the performance of 0.1% (w/v) sodium hyaluronate with 1.4% (w/v) polyvinyl alcohol in the alleviation of symptoms associated with dry eye syndrome.

AIMS: To assess the safety and performance of a 0.1% (w/v) solution of sodium hyaluronate (HA, Fermavisc, in the alleviation of symptoms of severe dry eye in comparison with a 1.4% (w/v) solution of polyvinyl alcohol. METHODS: A randomised, crossover, multicentre study carried out at eight centres in the UK. Eligible patients giving written informed consent were randomised to the order in which they would receive the two study products. Each treatment period lasted for 4 weeks, then the patient crossed over to the other study product. Symptoms of burning and grittiness were assessed by visual analogue scale (VAS) at each study visit and other objective clinical assessments of ocular structure and function were carried out at baseline and the end of each treatment period. RESULTS: Thirty-nine patients were entered into the study and 32 completed both treatment periods and were included in the statistical analyses. A significant improvement in the patients' VAS assessment of burning was seen after treatment with HA (P = 0.03, 95% Confidence Interval: -23.5 to -1.1). This treatment also resulted in a significantly lower rose bengal staining score (P = 0.04, 95% Confidence Interval: -1.62 to -0.05 for the right eye). CONCLUSION: The results show a significant clinical benefit in terms of relief of the symptom of burning when HA is applied topically to the eye three or four times per day or as required. HA also appears to have a protective effect on the corneal epithelium, as shown by a reduction in the level of staining of corneal epithelial cells by rose bengal. This study confirms that Fermavisc is a safe and effective product for use in the alleviation of symptoms of severe dry eye syndrome.

Adult↗

Randomised comparison of 5 years of adjuvant tamoxifen with continuous therapy for operable breast cancer. The Scottish Cancer Trials Breast Group.

In 1985 a second randomisation was initiated for women in the treatment arm of the Scottish Tamoxifen Trial either to stop tamoxifen at 5 years or to continue indefinitely. A preliminary analysis of outcome in 342 patients at a median follow-up of 6 years suggests that a worthwhile gain in disease control from continuing adjuvant tamoxifen beyond 5 years is unlikely. [Hazard ratio for events (relapse or death without relapse) is 1.27, 95% CI = 0.87 - 1.85.] There is a suggestion that therapy for longer than 5 years may increase the risk of endometrial carcinoma (P = 0.064).

Adult↗

Cardiac and vascular morbidity in women receiving adjuvant tamoxifen for breast cancer in a randomised trial. The Scottish Cancer Trials Breast Group.

OBJECTIVE: To determine any cardiac or vascular morbidity associated with long term treatment with tamoxifen given after mastectomy for primary breast cancer. DESIGN: Cohort study using linkage between database of a randomised trial and statistics of Scottish hospital inpatients to identify episodes of cardiac and vascular morbidity. SETTING: NHS hospitals in Scotland. SUBJECTS: 1312 women who had undergone mastectomy for breast cancer and who were randomised either to a treatment group to receive adjuvant tamoxifen or to a control group to be given tamoxifen only on first relapse of disease. Maximum duration of tamoxifen treatment was 14 years. Total woman years of follow up were 9943. MAIN OUTCOME MEASURES: Randomised and observational comparisons of risk (expressed as hazard ratios) of myocardial infarction, other cardiac event, cerebrovascular disease, or thromboembolic event according to treatment allocated and between nonusers, former users, and current users of tamoxifen. RESULTS: Use of tamoxifen was associated with lower rates of myocardial infarction. Hazard ratio for women in control group was 1.92 (95% confidence interval 0.99 to 3.73) compared with women allocated to adjuvant treatment. The association was stronger for current use: hazard ratio for non-users was 3.49 (1.52 to 8.03) compared with current users. Current users of tamoxifen, however, had higher rates of thromboembolic events:hazard ratio for non-users was 0.40 (0.18 to 0.90) compared with current users. CONCLUSIONS: Our results provide further evidence that tamoxifen reduces the risk of myocardial infarction. Thromboembolic events should be carefully monitored in trials of tamoxifen, particularly those of prophylactic treatment, in which tamoxifen is given to healthy women.

Adult↗

The Edinburgh randomized trial of axillary sampling or clearance after mastectomy.

Between January 1980 and October 1983, 417 patients were randomized for mastectomy followed by axillary node sampling or full axillary clearance. The aim of the study was to determine whether a standard 'four-node' axillary sample, followed by careful dissection of removed tissue, could accurately indicate the extent of local treatment required. Axillary radiotherapy was given only to patients with histological involvement of sampled nodes and not to any having axillary clearance. The incidence of involved nodes was similar for both groups, as were distant relapse and survival rates. Currently 62.6 percent are alive after clearance and 65.0 percent after sampling. A non-significant increase in the rate of locoregional relapse was observed for those treated by axillary node clearance, this being due mainly to increased relapse on the unirradiated chest wall (clearance 21 percent versus sampling 12 percent in patients with node-positive disease). There was only a minor difference in axillary relapse, favouring axillary clearance (3.0 versus 5.4 percent). In patients with operable breast cancer, mastectomy with axillary node sampling gives equal control to mastectomy with axillary node clearance but, as morbidity is greater, surgical clearance of the axilla is the preferred option.

Adult↗

Delayed splenic hematoma rupture.

The diagnosis of splenic hematoma can be clinically challenging. A case of delayed rupture of an atraumatic splenic hematoma is described, illustrating how unusual the presentation of this entity can be.

Emergencies↗

Fatal myocardial infarction in the Scottish adjuvant tamoxifen trial. The Scottish Breast Cancer Committee.

OBJECTIVE: To investigate the incidence of fatal myocardial infarction in women in the two randomised arms of the Scottish adjuvant tamoxifen trial. DESIGN: Retrospective review of hospital notes to determine with the greatest possible certainty women who had died of an acute myocardial infarction. SETTING: Scottish Cancer Trials Office, the University of Edinburgh. PATIENTS: 1070 postmenopausal women with operable breast cancer who were randomised to receive either adjuvant tamoxifen for five years or until relapse (539 patients) or tamoxifen for at least six weeks on the confirmation of first recurrence (531 patients). MAIN OUTCOME MEASURES: Incidence of fatal myocardial infarction in women with no known or suspected systemic cancer. RESULTS: Of the 200 women who died in the adjuvant tamoxifen arm of the trial, 44 were free of cancer at death and 10 of these died of myocardial infarction. In the observation arm 251 women died, of whom 61 showed no evidence of systemic cancer and 25 had a fatal myocardial infarction. The incidence of fatal myocardial infarction in the two groups was significantly different (chi 2 = 6.88, p = 0.0087). CONCLUSION: Tamoxifen given for at least five years as adjuvant therapy for breast cancer seems to have a cardioprotective oestrogen-like effect in postmenopausal women.

Aged↗

Vicryl intestinal anastomosis. Analysis of 327 cases.

Reported are 305 patients undergoing 327 intestinal anastomoses with polyglactin 910(Vicryl, Ethicon) suture. The technique of one-layer interrupted absorbable suture anastomosis is discussed. A leak rate of 0.6 percent is recorded and indicates this method is acceptable.

Adolescent↗

Selective effects of buspirone and molindone on dopamine metabolism and function in the striatum and frontal cortex of the rat.

The hypothesis that the nerve endings of the dopamine projection of the frontal cortex lack autoreceptors for regulation of tyrosine hydroxylase was tested by using the preferential inhibitors of dopamine autoreceptors, molindole and buspirone. In contrast to haloperidol, which elevates dopamine metabolism in the striatum and frontal cortex, both molindone and buspirone elicited little change in dopamine metabolism in the frontal cortex at doses up to 3.0 mg/kg, which cause the same maximal response in the corpus striatum as does haloperidol. Thus, the lack of autoreceptors in the frontal cortex is of pharmacological importance. That preferential inhibition of striatal dopamine autoreceptors may reverse catalepsy by enhancing synthesis and release of dopamine was tested by first inducing catalepsy with different drugs and then administering molindone or buspirone. Only buspirone (1.0 mg/kg) reversed catalepsy. This effect does not require presynaptic dopamine as catalepsy was reversed by buspirone in the dopamine-depleted rat (with 2.0 mg/kg R04-1284) as well as after postsynaptic dopamine receptor blockade by haloperidol of cis-flupenthixol. Thus, the mechanism for the reversal of catalepsy appears to be located efferent from the dopamine neuron. Buspirone, a non-benzodiazepine anti-anxiety drug, may prove useful for treatment of extrapyramidal motor disorders of either iatrogenic or idiosyncratic origin.

3,4-Dihydroxyphenylacetic Acid↗

Permanent cell line expressing human factor VIII-related antigen established by hybridization.

A permanent human cell line, EA . hy 926, has been established that expresses at least one highly differentiated function of vascular endothelium, factor VIII-related antigen. This line was derived by fusing human umbilical vein endothelial cells with the permanent human cell line A549. Hybrid cells that survived in selective medium had more chromosomes than either progenitor cell type and included a marker chromosome from the A549 line. Factor VIII-related antigen can be identified intracellularly in the hybrids by immunofluorescence and accumulates in the culture fluid. Expression of factor VIII-related antigen by these hybrid cells has been maintained for more than 100 cumulative population doublings, including more than 50 passages and three cloning steps. This is evidence that EA . hy 926 represents a permanent line.

Antigens↗

Volvulus of the sigmoid colon.

A study of 37 patients with sigmoid volvulus is presented. Subsequent bouts of recurrent volvulus are very common after sigmoidoscopic intubation, and overall mortality rates are high. Surgical resection is the preferred method of treatment.

Adult↗

Proton magnetic resonance and magnetic susceptibility characterization of ferredoxin I from Bacillus polymyxa.

Magnetic susceptibility and proton magnetic resonance spectra are reported for the oxidized and reduced forms of the iron-sulfur protein Bacillus polymyxa ferredoxin I. The magnetic susceptibility of the oxidized form indicates antiferromagnetic exchange coupling between component iron atoms that is quantitatively similar to that observed for the clostridial ferredoxins and for the [(C(2)H(5))(4)N](2) [Fe(4)S(4)(SCH(2)C(6)H(5))(4)] analog. Contact-shifted resonances observed in the proton-magnetic-resonance spectra of oxidized and reduced forms of the B. polymyxa protein can be correlated with the contact-shifted resonances of corresponding redox forms of the clostridial ferredoxins. Characteristics of the contact-shifted resonances observed in partially reduced B. polymyxa ferredoxin I are compatible with a "slow" rate of electron exchange between redox forms, which suggests that the "fast" electron exchange earlier observed in the eight-iron clostridial ferredoxins may derive from an intramolecular component.

Bacillus↗