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Biomedical subjects

A Ward

Publications and source records attributed to A Ward.

At least 145 records · Page 8Linked to original sources
PubMed1989

Long-term results of aortoinnominate and aortocarotid polytetrafluoroethylene bypass grafting for atherosclerotic lesions.

Between January 1978 and December 1986, 69 polytetrafluoroethylene bypass grafts on the ascending aorta were placed in 53 patients with atherosclerotic occlusive disease of the innominate and left common carotid arteries. Thirty-six patients had symptoms predominantly of amaurosis fugax, verebrobasilar ischemia, and upper limb ischemia. The remaining 17 patients had no symptoms but had severe hemodynamically significant occlusive disease. All operations were accomplished via median sternotomy. One patient died after surgery (operative mortality rate 1.9%), and one patient had minor postoperative neurologic deficit that partially improved on long-term follow-up. Patency of the reconstruction was routinely assessed by a Doppler device combining (1) a continuous wave Doppler and (2) real-time mechanical sector B-mode imaging with frequencies of 3.5 MHz and 7.5 MHz. There were two early asymptomatic occlusions; one was related to a technical error that was successfully revised and the other to low systemic perfusion. The mean follow-up time was 50.5 months. Two patients were lost to follow-up and a further six patients died, for a cumulative 5-year survival rate of 84.9%. One patient had only partial improvement in symptoms and one patient sustained a late postoperative neurologic deficit after internal carotid occlusion distal to a patent aortocarotid bypass. The remaining patients were free of symptoms. There were no infective complications. All the patients underwent late assessment by Doppler ultrasonography and B-mode scanning. One asymptomatic occlusion was thereby identified to be a result of diminished runoff. The overall secondary patency rate at 5 years was 96.1%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Morbidity coding in general practice.

If research is to be of any use the phenomena being studied must be clearly defined. Almost 30 years ago the difficulty of classifying primary care problems using the International Classification of Diseases (ICD-8) was demonstrated. This led to the development of the International Classification of Health Problems in Primary Care-2-Defined which is based on ICD-9. Despite the work that has gone into the development of ICHPPC-2-Defined, relatively little work has been undertaken to assess the validity and reliability of its use. This paper describes the results of such a study conducted as a preliminary to the use of ICHPPC-2-Defined in a study of consulting patterns in general practice. The participating general practitioners were trained in the use of ICHPPC-2-Defined and then coded problems which they identified in a set of clinical vignettes. Following the coding exercise, a review session was held in which difficulties and errors in the use of ICHPPC-2-Defined were discussed. Subsequently, the general practitioners were required to code two more sets of vignettes, which included some problems repeated from the preceding sets. Comparisons were then made of changes in the validity and reliability of coding from one round to the next. The results of the study suggest that the reliability and validity of morbidity data collected using ICHPPC-2-Defined can be increased by training sessions for the coders which focus on the main sources of error in the use of ICHPPC-2-Defined.(ABSTRACT TRUNCATED AT 250 WORDS)

Australia↗
PubMed1989

Carboplatin. A preliminary review of its pharmacodynamic and pharmacokinetic properties and therapeutic efficacy in the treatment of cancer.

Carboplatin is a 'second-generation' platinum compound advocated for use in the treatment of patients with ovarian cancer and it has also shown promise in small cell lung cancer, squamous cell carcinomas of the head and neck, and seminomas. Overall, it would appear to have a similar qualitative spectrum of activity to cisplatin. There have been few comparative trials with carboplatin, either alone or in combination with other chemotherapeutic agents, but the limited data suggest comparable efficacy with cisplatin in ovarian cancer. Importantly, the toxicity profile of carboplatin is markedly different from that of cisplatin, with nephrotoxicity, neurotoxicity and ototoxicity occurring only infrequently with carboplatin. As with cisplatin, nausea and vomiting occur in many patients after carboplatin administration, but symptoms are usually delayed for several hours and are mild to moderate in severity - dose-limiting nausea and vomiting are infrequent with carboplatin. The dose-limiting toxicity of carboplatin is myelosuppression, with severe thrombocytopenia and less often leucopenia, which may be more severe in older patients or in those with renal impairment or those who have had previous chemotherapy. Thus, preliminary data suggest that carboplatin is a therapeutically equivalent alternative to cisplatin, but with a differing toxicity profile that should offer advantages over cisplatin in many patients.

Carboplatin↗
PubMed1989

Arterial complications of the thoracic outlet syndrome: fifty-five operative cases.

Between January 1, 1969, and December 31, 1984, 55 operative procedures were carried out in 47 patients to correct subclavian-axillary artery lesions resulting from compression at the thoracic outlet. The most common causes of compression were a long cervical rib (27) and an anomalous first rib (15). Presenting features included claudication, vasomotor phenomena, digital gangrene, and acute limb-threatening ischemia. A combined supraclavicular and infraclavicular approach was preferred. Decompression was best achieved by excision of the cervical rib and the first rib and division of all soft tissue elements. The most common methods of arterial repair were resection-anastomosis (23) and replacement of vein graft (11). Embolic occlusions were frequently present (35). Axillary emboli were amenable to direct revascularization at the time of subclavian artery repair. If possible, more-distal embolic occlusions were managed without recourse to embolectomy catheter manipulations. The mean follow-up was 5 years 8 months (range 4 months to 16 years). Patients were assessed clinically, and the arterial repair was monitored by Doppler ultrasonography, B-mode scanning, and digital subtraction angiography. Of the 39 patients available for follow-up, 35 had no symptoms and four had residual claudication. There were no amputations. In the remaining cases the subclavian-axillary artery segment showed no hemodynamic or anatomic abnormality.

Adolescent↗
PubMed1988

Walking for health and fitness.

Recent studies have linked regular physical activity with reduced likelihood of developing coronary heart disease. Even low- and moderate-intensity exercise such as walking, when carried out consistently, is associated with important cardiovascular health benefits. Walking has also been shown to reduce anxiety and tension and aid in weight loss. Regular walking may help improve cholesterol profile, help control hypertension, and slow the process of osteoporosis. Recent physiological studies have demonstrated that brisk walking provides strenuous enough exercise for cardiovascular training in most adults. A recently developed submaximal 1-mile walk test provides a simple and accurate means for estimating aerobic capacity and guiding exercise prescription. These new insights and tools will assist the clinician in the prescription of safe and effective walking programs.

Coronary Disease↗
PubMed1988

Expression of a bacterial gene in plants mediated by infectious geminivirus DNA.

A viable coat protein deletion mutant of cassava latent virus (CLV) DNA 1 has been isolated, suggesting that this geminivirus might be exploited as a gene replacement vector. An extensive deletion of 727 nucleotides within the coat protein gene renders DNA 1 non-infectious. Chimeric clones have been constructed in which the deleted coat protein open reading frame has been replaced by the coding region of the bacterial chloramphenicol acetyl transferase (CAT) gene. Infectivity is restored to DNA 1 when the CAT gene is inserted in either orientation, producing symptoms typical of CLV infection. The results demonstrate that the coat protein plays no essential role in virus spread throughout the host. Levels of CAT expression of 80 U/mg soluble protein occur in systemically infected Nicotiana benthamiana leaves when the CAT gene is fused in-frame to the amino terminus of the coat protein, providing a sensitive assay for viral DNA replication.

Journal Article↗
PubMed1988

Detection of specific IgM in varicella and herpes zoster by antibody-capture radioimmunoassay.

A simple and sensitive M antibody-capture radioimmunoassay (MACRIA) is described which utilizes crude commercial VZV antigen and a single monoclonal anti-VZV antibody. This was compared to the immunofluorescence (IF) test for IgM antibody and was used to study IgM responses in sera from 261 patients with varicella and 220 patients with herpes zoster. With MACRIA, IgM antibodies were detected in all patients with varicella. The IgM antibodies appeared shortly after onset of rash, reached peak levels between 1 and 4 weeks after onset and then declined to low or undetectable levels in most, though not all, patients after 3 months. IgM antibodies were also detected in 98.2% of patients with herpes zoster, but the levels of IgM were significantly lower than after varicella and there was wider individual variation both in magnitude and duration of the IgM responses, in some cases only lasting 2-3 weeks. Comparison between MACRIA and IF showed good agreement in the detection of IgM antibodies following varicella. Discordant results were obtained with 13% of sera, of which 81% were taken either early or late after onset of rash and contained very low IgM levels. In contrast, 62 (28%) of the 220 sera from patients with zoster gave discordant results in the two tests, all except five being MACRIA-positive but IF-negative. The largest proportion of discordant results were obtained with sera taken more than 3 months after onset of rash, but 18 (29%) contained high IgM levels and were taken during the period of peak IgM responses. The diagnostic applications of the VZV MACRIA are discussed.

Chickenpox↗
PubMed1988

Ciprofloxacin. A review of its antibacterial activity, pharmacokinetic properties and therapeutic use.

Ciprofloxacin is one of a new generation of fluorinated quinolones structurally related to nalidixic acid. The primary mechanism of action of ciprofloxacin is inhibition of bacterial DNA gyrase. It is a broad spectrum antibacterial drug to which most Gram-negative bacteria are highly susceptible in vitro and many Gram-positive bacteria are susceptible or moderately susceptible. Unlike most broad spectrum antibacterial drugs, ciprofloxacin is effective after oral or intravenous administration. Ciprofloxacin has been most extensively studied following oral administration. It attains concentrations in most tissues and body fluids which are at least equivalent to the minimum inhibitory concentration designated as the breakpoint for bacterial susceptibility in vitro. The results of clinical trials with orally and intravenously administered ciprofloxacin have confirmed the potential for its use in a wide range of infections, which was suggested by its in vitro antibacterial and pharmacokinetic profiles. It has proven an effective treatment for many types of systemic infections as well as for both acute and chronic infections of the urinary tract. Ciprofloxacin generally appeared to be at least as effective as alternative orally administered antibacterial drugs in the indications in which they were compared, and in some indications, to parenterally administered antibacterial therapy. However, further studies are needed to fully clarify the comparative efficacy of ciprofloxacin and standard antibacterial therapies. Bacterial resistance to ciprofloxacin develops infrequently, both in vitro and clinically, except in the setting of pseudomonal respiratory tract infections in cystic fibrosis patients. The drug is also well tolerated. Thus, as an orally active, broad spectrum and potent antibacterial drug, ciprofloxacin offers a valuable alternative to broad spectrum parenterally administered antibacterial drugs for use in a wide range of clinical infections, including difficult infections due to multiresistant pathogens.

Animals↗
PubMed1988

Ceftriaxone. A reappraisal of its antibacterial activity and pharmacokinetic properties, and an update on its therapeutic use with particular reference to once-daily administration.

Since ceftriaxone was first reviewed in the Journal, further studies have confirmed its broad antibacterial spectrum in vitro and extended its clinical documentation in comparative studies with other widely used drugs in infections of the urinary and lower respiratory tract, meningitis in infants and children, uncomplicated gonorrhoea, perioperative prophylaxis in patients undergoing surgery, and in several other types of infection. As in earlier studies, which primarily used a twice-daily dosage regimen, few significant differences were found between therapeutic groups in comparative studies and results have demonstrated the efficacy of once-daily ceftriaxone in all but the most serious infections, such as sole antibiotic therapy in pseudomonal infections. Wider clinical experience has established that ceftriaxone is generally well tolerated. Thus, ceftriaxone now has a well-defined place as an appropriate alternative for the parenteral treatment of a variety of infections due to susceptible organisms, as well as for perioperative prophylaxis of surgery, and may offer advantages of greater convenience over other parenteral antibiotics which are administered more frequently.

Bacterial Infections↗
PubMed1988

Bromperidol. A preliminary review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy in psychoses.

Bromperidol is a close structural analogue of haloperidol. Both agents possess similar pharmacodynamic properties which are consistent with central antidopaminergic activity. The available clinical data from non-comparative and comparative trials have shown that bromperidol possesses antipsychotic activity. Its overall efficacy was slightly greater than chlorpromazine and perphenazine, and similar to or slightly better than haloperidol in a small number of comparative studies. Bromperidol frequently displayed a faster onset of action than these comparative agents and there have been reports of bromperidol causing an activating effect. However, extrapyramidal side effects occurred with similar frequency and severity after bromperidol compared with the 3 reference drugs. Data from additional controlled clinical trials are required to confirm the comparative antipsychotic efficacy of bromperidol and to assess whether it possesses any advantages in certain sub-types of schizophrenia.

Clinical Trials as Topic↗
PubMed1988

Milrinone. A preliminary review of its pharmacological properties and therapeutic use.

Milrinone is a bipyridine derivative of amrinone, with approximately 10 to 75 times greater positive inotropic potency, and separate direct vasodilatory properties. As with amrinone, the relative importance of these properties to treatment of congestive heart failure still remain controversial. The mode of action of milrinone appears to be due in part to selective inhibition of a specific cardiac phosphodiesterase with a subsequent increase in intracellular cyclic adenosine monophosphate and alteration in intracellular and extracellular calcium transport. Clinical experience has involved both short and long term treatment of a limited number of patients with moderate to severe congestive heart failure refractory to conventional therapy. Milrinone has usually been administered as intravenous bolus doses (12.5 to 75 micrograms/kg) and/or continuous intravenous infusion (0.5 microgram/kg/min), or orally (30 to 40 mg/day in divided doses). Milrinone rapidly improves cardiac performance by enhancing myocardial contractility, and by decreasing systemic vascular resistance (afterload), left ventricular filling pressure (preload), and pulmonary arterial pressure. Exercise performance improvement occurs with enhancement of left ventricular performance but without a significant increase in myocardial oxygen consumption or significant decrease in mean arterial pressure. Milrinone has been compared with dobutamine, nitroprusside and captopril in preliminary short term studies in patients with severe congestive heart failure. Milrinone significantly increased stroke work index and decreased left ventricular filling pressure compared to nitroprusside. When compared with dobutamine, both drugs improved cardiac index (to a similar degree), but milrinone significantly reduced right atrial pressure, pulmonary capillary wedge pressure and left ventricular end-diastolic pressure. One small study suggests that short term effects of intravenous milrinone may be superior to those of oral captopril, and it appears that the addition of captopril to milrinone therapy may produce a synergistic haemodynamic effect. Preliminary long term studies suggest that tolerance to the haemodynamic effects of milrinone does not occur, and that the drug is well tolerated and without the thrombocytopenic effects, fever and gastrointestinal complications observed with amrinone. However, it has not been demonstrated that milrinone improves the prognosis of the disease or the overall mortality and its propensity to produce arrhythmias has not been fully agreed upon.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

Sufentanil. A review of its pharmacological properties and therapeutic use.

Sufentanil, an opioid analgesic, is an analogue of fentanyl, and has been used for the induction and maintenance of anaesthesia, and for postsurgical analgesia. It has shorter distribution and elimination half-lives, and is a more potent analgesic than fentanyl. In clinical practice, however, intravenously administered sufentanil produces essentially equivalent anaesthesia to fentanyl and is a better anaesthetic than morphine or pethidine (meperidine) for major surgery. It would appear to maintain haemodynamic stability during surgery better than other opioids or inhalational anaesthetics. Postoperative respiratory depression has been reported in a few patients. For outpatient surgery, intravenous sufentanil produces equivalent anaesthesia to isoflurane or fentanyl. Recovery tends to be more rapid after sufentanil and the requirement for postoperative analgesia is less. Initial clinical trials with sufentanil administered epidurally to relieve pain during labour have produced encouraging results, but further studies are required to establish the drug's role in this indication. Epidural sufentanil produces a more rapid onset and better initial quality of analgesia than morphine, buprenorphine or hydromorphine when administered postoperatively, but the duration of analgesia is shorter. Thus, sufentanil's primary place in therapy at this time would appear to be as high dose anaesthesia for major surgery such as cardiac surgery, and as low dose supplement to balanced anaesthesia in general surgery. In addition, low doses administered epidurally seem to have a potential role for analgesia during labour or after surgery although further studies are required to clarify this situation.

Analgesics, Opioid↗
PubMed1988

Gemfibrozil. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in dyslipidaemia.

Gemfibrozil is a lipid-regulating agent which is generically classified as a fibric acid derivative, but which exhibits different pharmacological effects from other such drugs. Published data indicate that in patients with all types of dyslipidaemia (except type I) gemfibrozil 800 to 1200 mg/day is particularly effective in reducing total plasma triglyceride concentrations. The reduction in total plasma cholesterol is statistically significant with the most pronounced response occurring in patients with severe hypercholesterolaemia. Gemfibrozil also effectively increases high density lipoprotein cholesterol. In a 5-year double-blind prospective placebo-controlled study in over 4000 male patients with types IIa, IIb and IV primary dyslipidaemia (but without coronary symptoms), gemfibrozil 600mg twice daily significantly reduced the incidence of cardiac events (by 34%) compared with placebo, although overall mortality was not affected. In comparative studies with clofibrate similar reductions in plasma lipid levels have been observed, although these changes tend to be more favorable overall with gemfibrozil. Gastrointestinal symptoms and rash are the only side effects produced more frequently with gemfibrozil than with placebo. Although gemfibrozil is hepatotoxic in male rats, drug-induced pathological liver changes have not been reported in humans. Thus, gemfibrozil is an effective drug indicated for the treatment of severe hypertriglyceridaemia, and in certain patients with severe hypercholesterolaemia who are unresponsive to other standard therapies. In addition, it would appear to reduce the risk of cardiac events in patients with dyslipidaemia, although its effects on overall mortality remain speculative.

Gemfibrozil↗
PubMed1988

Nimesulide. A preliminary review of its pharmacological properties and therapeutic efficacy in inflammation and pain states.

Nimesulide is a new non-steroidal anti-inflammatory analgesic agent given orally or rectally on a twice daily basis in a number of inflammatory and pain states. Although still at an early stage of clinical assessment, preliminary evidence suggests that nimesulide 200 to 400mg daily is significantly more effective than placebo in reducing the pain, fever and inflammatory symptoms of chronic rheumatoid arthritis or osteoarthritis, respiratory tract infections, otorhinolaryngological diseases, soft tissue and oral cavity inflammation, dysmenorrhoea, phlebitis/thrombosis, urogenital disease and postoperative pain states. In a number of comparative studies, nimesulide has also been shown to be more effective than piroxicam (in osteoarthritis), paracetamol (acetaminophen) [in respiratory tract inflammation], benzydamine or naproxen (in otorhinolaryngological disease), phenylprenazone (in laryngotracheitis/bronchitis, respiratory inflammation and otorhinolaryngological disease), Serratia peptidases (in postoperative or dental pain, trauma and phlebitis), ketoprofen (in postoperative dental pain) and mefenamic acid (in dysmenorrhoea). In addition, the efficacy of nimesulide has been observed to be comparable with that of aspirin, with or without vitamin C, and mefenamic acid (in respiratory tract infection), ibuprofen (in soft tissue disease), naproxen (in respiratory tract inflammation, dysmenorrhoea and postoperative pain states), suprofen and paracetamol (in postoperative pain states), benzydamine (in genitourinary tract inflammation) and dipyrone, paracetamol or diclofenac (in fever). The safety profile of nimesulide has yet to be fully established, although initial evidence suggests the usual adverse effects associated with non-steroidal anti-inflammatory drugs occur, possibly with a lower incidence of gastrointestinal problems than with other members in its therapeutic class. Nimesulide, therefore, appears to offer a useful alternative to other non-steroidal anti-inflammatory drugs in the treatment of patients with inflammatory conditions and/or pain and fever states. However, further definition of its efficacy and tolerability is clearly required, particularly in comparison with established or other new drugs in its therapeutic class.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1987

Relative displacements in muscle and tendon during human arm movements.

1. X-ray, cine and video recordings were made of the movement of radio-opaque markers injected into the musculo-tendinous junctions of biceps brachii muscle. 2. In strong isometric contractions, the distal tendon of the long head of biceps lengthened by about 2% of its estimated rest length. 3. During voluntary isotonic elbow flexion-extension movements at frequencies up to 5.5 Hz there was no detectable phase shift between intramuscular and joint displacements. 4. In the fastest alternating movements (5.5-6.7 Hz) small phase advances developed in the muscle. 5. We conclude that human tendons do stretch during muscle contraction, but not enough to cause intramuscular phase reversals in rapid unloaded movements. This in turn means that muscle spindles shorten and lengthen virtually in phase with joint movements under most conditions.

Arm↗
PubMed1987

Efficacy of varicella vaccine in patients with solid tumours.

Thirty nine children with malignant disease and without antibodies to varicella zoster virus were immunised with a live Oka strain varicella vaccine. Seroconversion was shown in 24 of those who were vaccinated but five of 18 who responded to the vaccine who were followed up for over six months subsequently lost their antibodies. Of 10 children who were revaccinated, nine responded to the second dose but three lost their antibodies within six months to two years. Four children developed reactions related to the vaccine, one local and three generalised, but all these were transitory and of no clinical concern. Nine of those who were vaccinated, including four who did not respond to the vaccine, have subsequently had close exposure to varicella but none has developed the disease.

Antibodies, Viral↗