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Biomedical subjects

C Russell

Publications and source records attributed to C Russell.

At least 91 records · Page 5Linked to original sources
PubMed1991

Production of recombinant products in yeasts: a review.

This paper reviews the use of yeasts to produce heterologous proteins via the development of transformation systems. The ability to genetically engineer yeast cells has many advantages over prokaryotic systems. Yeasts are already well established in fermentation procedures, are able to secrete glycosylated and modified proteins to render the proteins biologically active, and yeasts do not secrete toxic chemicals. With the techniques available it is possible to explore yeasts as hosts for the expression and secretion of commercially-useful proteins.

Genetic Vectors↗
PubMed1991

Changing patterns in presentation and management of the Zollinger-Ellison syndrome in Northern Ireland, 1970-1988.

The clinical features, diagnostic methods, management and survival in 16 cases of Zollinger-Ellison syndrome encountered in Northern Ireland between the years 1970 and 1988 are described. While the majority of patients in the first decade of the study period had surgical treatment, those presenting in the latter period have been managed with medical therapy in the form of H2-receptor antagonists or omeprazole. The increasing use of these agents seems to be altering the severe clinical features of this condition, reducing the indications for surgery and maintaining patients, with or without evidence of metastatic disease, in clinical remission.

Adult↗
PubMed1990

Comparison of risk factor and left ventricular stroke work index as predictors of cardiac complications in vascular surgery.

The peak left ventricular stroke work index developed in response to rapid volume infusion was calculated in 34 patients undergoing either aorto-iliac or peripheral vascular surgery. The average preoperative maximum stroke work index in patients recovering without cardiac complication was 0.47 (+/- 0.2) J/m2 compared with a mean value of 0.28 (+/- 0.14) J/m2 in patients with perioperative cardiac complications. This difference was significant (P less than 0.01). Clinical cardiac risk analysis identified a group of high risk patients in which more than half developed cardiac complications and a low risk group in which no cardiac complications were observed. There was a significant difference in maximum stroke work indices in these two groups.

Aged↗
PubMed1989

Noninvasive monitoring of drug biodistribution and metabolism: studies with intraarterial Pt-195m-cisplatin in humans.

We have performed a comparative evaluation of systemic (i.v.) and intraarterial (i.a.) cisplatin by using a trace dose of the radiolabeled form of this drug [( 195mPt]cisplatin) to monitor the drug's biodistribution by dynamic scintigraphic imaging. We have analyzed the drug's metabolism using a compartmental model both following i.a. and i.v. administration in patients with gliomas. Significantly larger amounts of radioactivity (up to 10 times higher than in the uninvolved brain) were measured in tumors following i.a. administration, whereas the differential localization following i.v. drug administration was, at best, only twofold that of the uninvolved brain. On the other hand, no significant differences could be detected in the pharmacokinetics of either free cisplatin or platinated proteins in blood. The washout slope in tumors following i.a. administration may be an indicator of the higher local concentration of free cisplatin; no such washout could be observed in tumors following i.v. administration. The present noninvasive methods may help document the amount and the rate of (active) drug deposition at the desired target site. They may also assist in monitoring, prospectively and/or, on line, the probable effect of chemotherapy in an individual patient. In turn it may lead to novel methods for optimizing chemotherapeutic effectiveness at specific tumor-bearing sites and in defined treatment protocols.

Cisplatin↗
PubMed1988

Can past academic criteria predict students at risk of future failure?

A significant minority of medical and dental students fail their undergraduate courses. Early warning systems (EWSs) have been developed in some areas of higher education to predict 'at-risk' students at an early remedial stage. An attempt is made to develop an EWS to predict failure in the bacteriology component of the Batchelor of Dental Surgery course at Manchester Dental School. A system based on class tests and previous end-of-year performance is derived which is used to predict those students likely to fail or fall in the bottom 20-25% in their finals examination. The predictors are combined by a simple equal weights method, which is found to have the same predictive power as using multiple regression. Failure was correctly predicted in 60% of cases, at the expense of 71% false alarms. The high number of false alarms reflects the low failure rate rather than the lack of predictive information. The need for effective cross-validation of EWSs is discussed; many previous studies have not been tested on independent data.

Achievement↗
PubMed1988

Acute lymphoid leukemia in adolescents: clinical and biologic features predict a poor prognosis--a Pediatric Oncology Group Study.

Analysis of remission induction rates for 1,768 children (1.5 to 11 years) and 425 adolescents (greater than or equal to 11 years) with acute lymphoid leukemia (ALL), and of event-free survival times for 570 children and 147 adolescents, disclosed that adolescents fared significantly worse by both measures of treatment outcome (P = .0001). Adolescents with either T cell or non-T cell ALL entered remission significantly less often than did children (P = less than .02 and P = less than .001, respectively). Within each of the major immunophenotypes of ALL, adolescents had shorter duration of continuous complete remission: early pre-B (non-B, non pre-B, non-T) (P = .001), pre-B (P = .05), and T (P = .027). We compared the clinical characteristics of adolescents and children, and lymphoblast characteristics present at diagnosis to account for the inferior prognosis of adolescent patients. Adolescents had a higher incidence of T cell ALL (P = .0001) and thus a higher incidence of all T cell-associated characteristics. Adolescents with non-T, non-B ALL were more likely to be male (P = .044), and to have higher leukocyte counts (P = .002) and lower levels of IgG (P = .0003), IgA (P = .0001), and IgM (P = .002). Their leukemic cells had lower PAS scores (P = .0001), a higher incidence rate of L2 morphology by French-American-British (FAB) criteria (P = .001), common ALL antigen negativity (P = .0001), and hypodiploid or pseudodiploid karyotypes (P = .004). These findings clearly indicate an increased incidence of prognostically unfavorable clinical and biologic features in adolescents with ALL, providing a biologic explanation for their poor prognosis.

Adolescent↗
PubMed1987

Organisms isolated from severe odontogenic soft tissue infections: their sensitivities to cefotetan and seven other antibiotics, and implications for therapy and prophylaxis.

Cefotetan is a new cephamycin antibiotic characterised by excellent B-lactamase stability and anti-anaerobe activity, coupled with a long half life of 3-4 h which permits twice daily dosage. A clinical trial of cefotetan in the treatment of severe oro-facial infections is presented, together with a detailed analysis of the causative organisms and their sensitivities to eight antibiotics. 50/50 patients achieved clinical cure with a treatment regime comprising cefotetan therapy and incision and drainage, with patients being transferred to oral cephradine for the final phase of therapy. Side effects were minimal and there were no instances of relapse. Significant resistance among alpha-haemolytic streptococci and bacteroides organisms to penicillin was observed. The streptococci were resistant due to mechanisms other than beta-lactamase production. In the light of these findings and the reports of other workers it is suggested that penicillin V may no longer be the most appropriate drug for endocarditis prophylaxis, despite the most recent recommendations of the American Heart Association. Furthermore, if penicillin V is used for this purpose, a penicillin free interval of 6-8 weeks may be inadequate before this drug is used. Cefotetan is not suitable for prophylaxis against endocarditis.

Acute Disease↗
PubMed1987

The effect of sucrose on the colonization of acrylic by Candida albicans in pure and mixed culture in an artificial mouth.

The roles of sucrose and microbial interactions in the colonization of acrylic by Candida albicans in an artificial mouth were investigated. The acrylic was colonized by pure cultures of the organism but a visible plaque was not produced whether or not sucrose was present. Salivary bacteria had no effect in the absence of sucrose but when sucrose was present the numbers of C. albicans were significantly increased. It is suggested that this phenomenon is related to the production of extracellular polysaccharides by salivary streptococci in the presence of sucrose. In mixed culture of C. albicans and Streptococcus salivarius CJ2, growth of the latter was inhibited in the presence of sucrose. This inhibition was due to factors other than pH, although no such antagonism could be demonstrated on solid media.

Candida albicans↗
PubMed1987

Carcinoma of the duodenum.

We report two patients with primary adenocarcinoma of the duodenum who underwent successful pancreatico-duodenectomy (modified Whipple operation). One patient died from an unrelated cause three years following surgery whilst the other remains well and clinically free of disease 3 years after resection. An aggressive surgical policy in patients with this rare tumour seems justified.

Adenocarcinoma↗
PubMed1986

Comparative adhesion of seven species of streptococci isolated from the blood of patients with sub-acute bacterial endocarditis to fibrin-platelet clots in vitro.

The adhesion to fibrin-platelet clots in vitro of 21 strains of streptococci isolated from the blood of patients with sub-acute bacterial endocarditis (SABE) was measured. The species, in order of greatest adhesion, were Streptococcus faecalis, Streptococcus mutans, Streptococcus milleri, Streptococcus sanguis, dextran-positive Streptococcus mitior, dextran-negative Streptococcus mitior and Streptococcus salivarius. Individual strains within species, however, cannot be assumed to be representative of their species and may exhibit unusually high or low adhesion. Adhesion depended upon both bacterial concentration and period of contact. There was no simple relationship between ability to adhere and liability to cause endocarditis. Formation of dextran did not increase adhesion. The streptococci were more adhesive than strains of Escherichia coli and Neisseria sicca and less adhesive than strains of Staphylococcus aureus and Streptococcus pyogenes.

Adhesiveness↗
PubMed1985

Experimental oral candidal infection and carriage of oral bacteria in rats subjected to a carbohydrate-rich diet and tetracycline treatment.

Oral candidal infection and the carriage of oral bacteria in rats has been studied in animals on a high carbohydrate diet and treated with tetracycline. Candidal infection was not significantly enhanced by carbohydrate alone but was promoted by tetracycline; carbohydrate plus tetracycline was no more effective than tetracycline alone. Carriage of lactobacilli was enhanced by carbohydrate but streptococcal carriage was depressed; there was no effect on the number of rats carrying enterobacteria. Administration of tetracycline reduced the carriage of all three groups of bacteria but the isolation rate for enterobacteria increased towards the end of the experiment, becoming nearly the same as at the start. The prevalence of C. albicans did not vary with these changes in bacterial populations.

Animals↗
PubMed1985

Assessment of esophageal abnormalities in progressive systemic sclerosis using radionuclide transit.

Radionuclide transit (RT) is a noninvasive test of esophageal function with a sensitivity equivalent to manometry. Using RT, 34 patients with progressive systemic sclerosis (PSS), 15 with diffuse scleroderma and 18 with the CRST variant, were studied and compared to 22 patients with other connective tissue diseases and 20 normal volunteers. Abnormalities were present in 87% of patients with diffuse scleroderma, 72% with CRST, 38% with other connective tissue diseases and in none of the controls. The most frequent abnormality in PSS was that of adynamic transit. Abnormalities correlated with disease duration in the diffuse scleroderma group but not the CRST group. There was a positive association between abnormal RT and the presence of esophagitis in the PSS patients (p = 0.003).

Adolescent↗