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Biomedical subjects

C H Swan

Publications and source records attributed to C H Swan.

At least 19 recordsLinked to original sources
PubMed2006

T-cell protection and enrichment through lentiviral CCR5 intrabody gene delivery.

CCR5 is the chemokine co-receptor for R5-tropic human immunodeficiency virus type 1 (HIV-1) isolates most often associated with primary infection. We have developed an HIV-1 self-inactivating vector, CAD-R5, containing a CCR5 single-chain antibody (intrabody) gene, which when expressed in T-cell lines and primary CD4+ T cells disrupts CCR5 cell surface expression and provides protection from R5-tropic isolate exposure. Furthermore, CAD-R5 intrabody expression in primary CD4+ T cells supports significant growth and enrichment over time during HIV-1-pulsed dendritic cell-T-cell interactions. These results indicate that CCR5 intrabody-expressing CD4+ T cells are refractory against this highly efficient primary route of infection. CD34+ cells transduced with the CAD-R5 vector gave rise to CD4+ and CD8+ thymocytes in non-obese diabetic (NOD)/ severely combined-immunodeficient (SCID)-human thymus/liver (hu thy/liv) mice, suggesting that CCR5 intrabody expression can be maintained throughout differentiation without obvious cellular effects. CD4+ T cells isolated from NOD/SCID-hu thy/liv mice were resistant to R5-tropic HIV-1 challenge demonstrating the maintenance of protection. Our findings demonstrate delivery of anti-HIV-1 activity through CCR5 intrabodies in primary CD4+ T cells and CD34+ cell-derived T-cell progeny. Thus, gene delivery strategies that provide a selective survival and growth advantage for T effector cells may provide a therapeutic benefit for HIV-1-infected individuals who have failed conventional therapies.

Animals↗
PubMed2006

Can gene delivery close the door to HIV-1 entry after escape?

BACKGROUND: Research efforts to prevent viral entry by developing small molecule inhibitors against HIV-1 chemokine coreceptors have yielded promising clinical results. However, resistance to some chemokine receptor inhibitors has been recently documented, and therefore, alternative methods of HIV-1 coreceptor disruption are needed. CONCLUSION: We will describe current HIV-1 vector-delivered genetic disruption mechanisms that target HIV-1 chemokine coreceptors, such as RNA interference, ribozymes, zinc fingers, intrakines, and intrabodies, and frame the use of these gene delivery chemokine receptor disruption mechanisms in the context of current small molecule blocker/antagonists of CCR5 and CXCR4. In addition, we will discuss the importance of evaluating HIV-1 vector-delivered viral entry prevention mechanisms in the rhesus macaque SIV non-human primate model in regard to pathogenesis and therapeutic efficacy.

Animals↗
PubMed1994

Persistent monoarthritis and occult coeliac disease.

Arthritis is a recognized complication of untreated coeliac disease. Symptoms and signs usually respond to the institution of a gluten-free diet. We report a case of occult coeliac disease presenting as a monoarthritis. Severe and progressive erosive damage has occurred in his talo-navicular joint despite a response to the institution of a gluten-free diet.

Adult↗
PubMed1993

Nature and standards of gastrointestinal and liver services in the United Kingdom.

1. Purpose of the working party: 1.1 To describe the scope of major digestive and liver disorders and identify changes in patterns of disease. 1.2 To identify diagnostic and therapeutic services required to manage these disorders in the United Kingdom. 1.3 To describe the facilities and staffing required to provide these services. 1.4 To examine the training requirements for medical, nursing, and other support staff. 1.5 To define the part that audit and research should play in the provision and maintenance of high quality gastrointestinal and liver services.

Education, Medical, Graduate↗
PubMed1992

Short report: comparison of two doses of balsalazide in maintaining ulcerative colitis in remission over 12 months.

In a four-centre prospective double-blind trial, 108 patients with ulcerative colitis in remission were randomized to receive balsalazide in doses of 3 g or 6 g/day for 12 months. The patients were assessed at 3-monthly intervals clinically, sigmoidoscopically and with routine haematology and biochemistry. Remission rates of 77% (3 g/day) and 68% (6 g/day) at 12 months were not significantly different. Intolerance reactions leading to withdrawal from the study occurred in only 9 patients (8%), all occurring in the first 7 weeks of the study. Balsalazide is therefore both highly effective in maintaining remission in ulcerative colitis and well tolerated in both conventional and high dosage (the latter equivalent to 5.5 g/day of sulphasalazine). In this study no distinct advantage in maintenance of remission has been found for the higher dose of balsalazide.

Adult↗
PubMed1991

Recommendations for standards of sedation and patient monitoring during gastrointestinal endoscopy.

(1) Safety and monitoring should be part of a quality assurance programme for endoscopy units. (2) Resuscitation equipment and drugs must be available in the endoscopy and recovery areas. (3) Staff of all grades and disciplines should be familiar with resuscitation methods and undergo periodic retraining. (4) Equipment and drugs necessary for the maintenance of airway, breathing, and circulation should be present in the endoscopy unit and recovery area (if outside the unit) and checked regularly. (5) A qualified nurse, trained in endoscopic techniques and adequately trained in resuscitation techniques, should monitor the patient's condition during procedures. (6) Before endoscopy, adverse risk factors should be identified. This may be aided by the use of a check list. (7) The dosage of all drugs should be kept to the minimum necessary. There is evidence that benzodiazepine/opioid mixtures are hazardous. (8) Specific antagonists for benzodiazepines and opioids exist and should be available in the event of emergency. (9) A cannula should be placed in a vein during endoscopy on 'at risk' patients. (10) Oxygen enriched air should be given to 'at risk' patients undergoing endoscopic procedures. (11) The endoscopist should ensure the well being and clinical observation of the patient undergoing endoscopy in conjunction with another individual. This individual should be a qualified nurse trained in endoscopic techniques or another medically qualified practitioner. (12) Monitoring techniques such as pulse oximetry are recommended. (13) Clinical monitoring of the patient must be continued into the recovery area. (14) Records of management and outcome should be collected and will provide data for appropriate audit.

Anesthesia Recovery Period↗
PubMed1990

Mucosal peptide hydrolase and brush-border marker enzyme activities in three regions of the small intestine of rats with experimental uraemia.

1. The activities of nine peptide hydrolases and three non-peptidase brush-border marker enzymes have been quantified in crude homogenates prepared from the proximal, mild and distal regions of small-intestinal mucosa for sham-operated (n = 9) and uraemic (n = 14) rats. Abnormalities in enzyme activities were observed in all regions studied in the uraemic group, although no reduction in food intake occurred. 2. The proximal region of the small intestine from uraemic rats showed a general fall in enzyme activities associated with the brush-border. This fall was combined with a decline in mucosal protein content. In contrast, the mid and distal regions showed increased activity against the dipeptide tyrosyl-glycine. 3. It is proposed that the fall in brush-border enzyme activities in the proximal small intestine of uraemic rats is a response to the increased water intake associated with this, and presumably other, rat models of uraemia. The increased enzyme activity against tyrosyl-glycine found in the mid and distal regions of the small intestine of uraemic rats may be caused by an increased small-intestinal transit rate, but could be an attempt to maximize tyrosine absorption in response to decreased plasma tyrosine levels. 4. This study casts doubt on specific activities being the most useful units of enzyme activity, when measured in crude homogenates prepared from the proximal small intestine of uraemic rats. It also demonstrates that enzyme activities measured at a single site in the small intestine of uraemic rats may not be representative of the enzymatic changes occurring in the small-intestinal mucosa as a whole.

Animals↗
PubMed1989

Experimental uraemia with associated plasma amino acid abnormalities but without retarded food intake and weight gain.

A rat model of moderate uraemia is described in which uraemic animals attain normal food intake and weight gain. Despite the low levels of the induced uraemia, which has been well defined, changes in plasma amino acid concentrations associated with experimental uraemia still occur. It appears from this study that a reduction in food intake is not a major factor in the aetiology of the plasma amino acid changes seen in uraemia and that the model may prove useful in future studies of experimental chronic renal failure.

Amino Acids↗
PubMed1984

Breakdown of gliadin peptides by intestinal brush borders from coeliac patients.

The 'missing peptidase' hypothesis to explain the aetiology of coeliac disease has never been satisfactorily resolved and recent reports suggest that coeliac brush borders may have depressed levels of specific peptidase enzymes. It has been inferred from these studies that the subsequent brush border digestion of gliadin peptides may therefore be defective. In this present study a sensitive fluorometric assay was used to measure the hydrolysis of a peptic-tryptic digest of gliadin by both normal and coeliac brush borders. The coeliac brush borders were as efficient as the normals in hydrolysing gliadin peptides and showed no depression of any specific peptidase activity.

Celiac Disease↗
PubMed1979

Prostaglandin synthetase activity in acute ulcerative colitis: effects of treatment with sulphasalazine, codeine phosphate and prednisolone.

Prostaglandin synthetase activity in rectal biopsy specimens from patients with ulcerative colitis has been shown to fall on treatment with sulphasalazine, local steroids, and codeine phosphate. In vitro studies have shown that sulphasalazine is an inhibitor of prostaglandin synthetase, although less potent than indomethacin, whereas prednisolone and codeine phosphate were inactive. It is suggested that the therapeutic action of sulphasalazine may be related in part to its action in inhibiting prostaglandin biosynthesis.

Codeine↗
PubMed1978

Determination of prostaglandin synthetase activity in rectal biopsy material and its significance in colonic disease.

A method is described for determining prostaglandin synthetase activity in milligram amounts of tissue. The procedure is based on the conversion of 14C-arachidonic acid to prostaglandin E2 and F2alpha-like substances. High levels of prostaglandin synthetase activity occurred in the inflamed mucosa of patients with ulcerative colitis and fell during successful drug therapy, but it is not yet known whether the cause of the inflammation first involves increased PG synthetase activity, or whether inflammation caused increase of PG synthetase.

Colitis, Ulcerative↗
PubMed1978

Venous prostaglandin-like activity in diarrhoeal states.

Prostaglandin E2-like activity was determined in peripheral venous blood of control subjects and in patients with acute gastroenteritis and active ulcerative colitis, using a bioassay method. No significant diurnal variations of prostaglandin levels were detected in the control group, while significantly raised venous plasma prostaglandin-like activity was detected in acute gastroenteritis and in active ulcerative colitis.

Acute Disease↗