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Biomedical subjects

C Green

Publications and source records attributed to C Green.

At least 73 records · Page 4Linked to original sources
PubMed2000

Functional outcome after restorative panproctocolectomy for ulcerative colitis decreases an otherwise enhanced quality of life.

BACKGROUND: Restorative panproctocolectomy is a favoured operation for ulcerative colitis, but altered bowel habit may adversely affect overall quality of life. METHODS: Specific and generic quality of life questionnaires and an instrument to award money for continuing disability based on government guidelines were sent to 103 patients who had curative surgery for ulcerative colitis between 1995 and 1997. Seventy-one patients returned completed questionnaires: 30 with an ileostomy (representing incontinence and abnormal body image), 11 with a Koch pouch (representing continence and abnormal body image) and 30 with a pelvic pouch (representing continence and normal body image). RESULTS: Patients valued the disability of having an ileostomy similar to that for a Koch pouch or a pelvic pouch: pound 40 000, pound 30 000 and pound 40 000 respectively (P = 0. 97). There was no sex difference. Body image measured with a visual analogue scale (least = 1, worst = 10) was worst with the ileostomy and Koch pouch (8 each) and best with a pelvic pouch (5) (P = 0.06). However, pelvic pouches scored significantly worse than an ileostomy with regard to altered bowel emptying (pelvic pouch, 8; Koch pouch, 7; ileostomy, 5) (P = 0.01). CONCLUSION: Poor function after pelvic pouch surgery offsets any advantage in body image over an ileostomy. Thus, overall quality of life and perceived monetary damage were the same for the two operations. Improved pelvic pouch function is likely to be reflected in better quality of life after restorative panproctocolectomy.

Adult↗
PubMed2000

Experimental study of faecal continence and colostomy irrigation.

BACKGROUND: Colostomy irrigation is a useful method of achieving faecal continence in selected conditions, but remains largely underutilized because it is time consuming. This study investigated the effect of modifying irrigation technique (route, infusion regimen and pharmacological manipulation) on colonic emptying time in a porcine model. METHODS: An end-colostomy and caecostomy were fashioned in six pigs. Twenty markers were introduced into the caecum immediately before colonic irrigation. Irrigation route (antegrade or retrograde), infusion regimen (tap water, polyethylene glycol (PEG), 1.5 per cent glycine) and pharmacological agent (glyceryl trinitrate (GTN) 0.25 mg/kg, diltiazem 3.9 mg/kg, bisacodyl 0.25 mg/kg) were assigned to each animal at random. Colonic transit was assessed by quantifying cumulative expelled markers (CEM) and stool every hour for 12 h. RESULTS: Mean CEM at 6 h for bisacodyl, GTN and diltiazem were 18.17, 12.17 and zero respectively; all pairwise differences in means were significant (P < 0.001). The difference at 12 h between the two routes (P = 0.001) and three fluids (tap water 6.75, glycine 14.83, PEG 16.33; P < 0. 001) was significant, but not for PEG versus glycine and bisacodyl versus GTN. Cumulative output was significantly more with the antegrade than retrograde route using PEG, but the difference in mean cumulative output for bisacodyl and GTN at 12 h was not significant. CONCLUSION: Colonic emptying is more efficient with antegrade than retrograde irrigation. PEG and glycine enhance emptying similar to bisacodyl and GTN solution. These findings show promise for improved faecal continence by colostomy irrigation and may justify construction of a Malone conduit at the time of colostomy in selected patients who wish to irrigate. Presented in part to the British Society of Gastroenterology in Glasgow, UK, March 1999, and published in abstract form as Gut 1999; 44(Suppl 1): A135

Analysis of Variance↗
PubMed2000

Experimental model of anorectal transplantation.

BACKGROUND: Anorectal transplantation with pudendal nerve anastomosis after rectal excision is a possible strategy that would avoid a colostomy and recreate potentially normal anorectal function. This study investigates the technical feasibility of anorectal transplantation with pudendal nerve and inferior mesenteric artery and vein anastomosis in a porcine model. METHODS: Four female pigs (22-42 kg) provided donor anorectum for four male recipients (29-39 kg) under standard general anaesthesia. The donor operation involved abdominoperineal excision of rectum (APR) taking the anal sphincter, pudendal neurovascular bundle and inferior mesenteric vessels. The recipient underwent APR, transperineal introduction of the donor graft, anastomoses of the rectum, inferior mesenteric vessels and pudendal neurovascular bundle, and perineal closure. Recorded variables were duration of each step of transplantation, ischaemic time, dimensions of anastomosed structures and postoperative graft viability. Animals were killed at 24 h, the state of the graft was noted and tissue was taken for confirmatory histology. RESULTS: Mean operation time was 372 (range 303-435)min. Mean ischaemic time was 118 (100-130)min. Before death, observation at laparotomy revealed two pink grafts, one slightly dusky but healthy graft and one outright failure, reflecting the state of the mesenteric vessels, which were patent in three and thrombosed in one. Histological examination showed no difference between control biopsies and the three cases with satisfactory mesenteric flow. Gross ischaemia was present histologically in the failed case. CONCLUSION: Anorectal transplantation is technically feasible in a pig model. Longer-term studies are now needed to assess return of function and overcome rejection issues.

Anal Canal↗
PubMed2000

Ethical issues in perianesthesia nursing.

Ethical issues have historically been a significant focus in perianesthesia nursing. Issues of safety, privacy, and informed consent are never far from the consciousness of the perianesthesia nurse. As the national organization that serves as a clearing ground for issues and goals of perianesthesia nursing practice, ASPAN has begun the process of developing a code of ethics for perianesthesia nursing practice. This report is designed to provide a brief review of the important definitions and principles that are used in the discussion of ethics, review the contemporary forces that mandate and justify the development of an ethical code, and explore how such a code may function to aid and guide nursing practice.

Ethics, Nursing↗
PubMed2000

The necrotic gene in Drosophila corresponds to one of a cluster of three serpin transcripts mapping at 43A1.2.

Mutants of the necrotic (nec) gene in Drosophila melanogaster die in the late pupal stage as pharate adults, or hatch as weak, but relatively normal-looking, flies. Adults develop black melanized spots on the body and leg joints, the abdomen swells with hemolymph, and flies die within 3 or 4 days of eclosion. The TOLL-mediated immune response to fungal infections is constitutively activated in nec mutants and pleiotropic phenotypes include melanization and cellular necrosis. These changes are consistent with activation of one or more proteolytic cascades. The nec gene corresponds to Spn43Ac, one of a cluster of three putative serine proteinase inhibitors at 43A1.2, on the right arm of chromosome 2. Although serpins have been implicated in the activation of many diverse pathways, lack of an individual serpin rarely causes a detectable phenotype. Absence of Spn43Ac, however, gives a clear phenotype, which will allow a mutational analysis of critical features of the molecular structure of serpins.

Amino Acid Sequence↗
PubMed2000

Altered splicing of the ATDC message in ataxia telangiectasia group D cells results in the absence of a functional protein.

The ATDC gene was cloned using functional complementation and complements the radiosensitivity of ataxia telangiectasia (AT) group D cells. Although a number of transcripts have been detected, only a 3.0 kb cDNA found in a HeLa cell cDNA library has been cloned. Since AT group D cells express only a 2.4 kb transcript, efforts were made to clone and sequence this transcript. Using a biotinylated oligonucleotide probe, mRNA preparations were enriched in ATDC-related sequences. After this enrichment, 2.4 kb clones were obtained from the resulting library. The 2.4 kb transcript appears to be untranslated, since no protein from this transcript has been detected in AT group D cells, and this transcript is probably non-functional, since a splicing variation has positioned part of intron 1 near the first methionine codon in exon 1, eliminating most of exon 1 and important functional regions from this transcript. This transcript now has a stop codon located 33 bp in front of the first methionine, which would stop translation after the eleventh amino acid. As a result of these changes, the AT group D cell line (AT5BI) expresses no functional ATDC protein.

Alleles↗
PubMed2000

The temperatures reached and the damage caused to hair follicles by the normal-mode ruby laser when used for depilation.

Although it is proposed that heat is the cause of follicular damage leading to depilation, this has never been proved. This study aims to determine the mode by which depilation is effected and, if heat is the mechanism, what temperatures are reached within treated follicles and if sufficient damage is produced therein. Two excised specimens of hair-bearing skin from 5 patients undergoing facelifts were dissected to reveal the hair bulbs/shafts on the deep surface. They were placed on a jig, and one pulse from a normal-mode ruby laser (NMRL) of 15 J per square centimeter was fired on the epidermal surface. A thermal imaging camera recorded dermal temperature changes on the deep surface in real time. Specimens were then examined histologically for the site and extent of cellular damage by immunohistochemical staining for a protein marker of cell damage (p53). The NMRL targeted hair follicles specifically. The most common follicular temperature increase ranged from 5 to 10 degrees C. In specimens from 1 patient the increase was more than 30 degrees C (p < 0.001). Heat dissipation into interfollicular tissue in all specimens occurred 2 seconds after exposure. Evidence of laser-induced damage to follicle-lining cells was found only in those follicles with damaged hair shafts. The changes were found to a greater depth (to the bulb) and greater extent (beyond the bulge) in those follicles reaching higher temperatures. These findings suggest that the NMRL should produce permanent depilation. The variability between follicles and between patients explains, perhaps, the uneven outcome regarding depilation using the NMRL. Success appears to depend on peak follicular temperatures achieved during laser exposure, which may result from the follicular characteristics of the individual patient.

Body Temperature↗
PubMed2000

Multiple sleep latency test and polysomnography in diagnosing Kleine-Levin syndrome and periodic hypersomnia.

Kleine-Levin syndrome and periodic hypersomnia are often misdiagnosed initially because there is no objective test for these conditions. To determine the value of the Multiple Sleep Latency Test and polysomnography in this respect, the authors studied four patients with Kleine-Levin syndrome or periodic hypersomnia who had taken the Multiple Sleep Latency Test and undergone polysomnography during the symptomatic episode and/or during the asymptomatic interval. During but not between symptomatic episodes, the Multiple Sleep Latency Test revealed abnormal sleep latencies in all patients, and polysomnography revealed increased rapid eye movement propensity in one patient and a reduction in delta-sleep in two patients. In conclusion, the Multiple Sleep Latency Test and polysomnography are useful in diagnosing Kleine-Levin syndrome and periodic hypersomnia, especially when administered in a standardized fashion during and after the symptomatic period. The authors recommend that polysomnography and the Multiple Sleep Latency Test be performed no earlier than the second night after the onset of a symptomatic episode and the following day to reveal maximal hypersomnolence, and more than 2 weeks after a symptomatic episode to represent the asymptomatic interval.

Adolescent↗
PubMed2000

p107 is active in the nucleolus in non-dividing human granulosa lutein cells.

Cells are maintained in a quiescent state by members of the retinoblastoma protein family, pRb and p130. Both are phosphoproteins and hypophosphorylated forms of pRb and p130 bind and repress the activity of E2F transcription factors, thereby preventing entry into the cell cycle. Mitogenic stimulation causes activation of cyclin dependent kinases (cdk) that phosphorylate both pRb and p130, thereby releasing E2F factors which stimulate the transcription of a number of genes that are required for DNA synthesis and for regulating the cell cycle. In non-dividing cells, cdks are maintained in an inactive state by cdk inhibitor proteins such as p27(Kip1). The aim of our study was to determine how E2F complexes are regulated during the differentiation of human primary granulosa lutein cells (GLC) of the corpus luteum (CL). The CL is formed in the ovary after ovulation at the terminal stage of folliculogenesis after completion of maturation and differentiation of Graafian follicles. As shown by flow cytometry GLC are not dividing, being predominantly in the G(0)/G(1) phase of the cell cycle and, consistent with this, they contain the cdk inhibitor protein, p27(Kip1), but not E2F-1 which is normally expressed only in proliferating cells. The GLC do express E2F-4, hypophosphorylated pRb, p130 forms 1 and 2 and, surprisingly, hypophosphorylated p107. p107 is normally present only in dividing cells where it regulates E2F activity during the cell cycle. These forms of pRb, p130 as well as p107, together with E2F-4 are all active in that they can bind an E2F DNA-binding site in a pull-down assay. Immunocytochemistry shows that these proteins are expressed in almost all GLC but have different sub-cellular distribution: p107 is concentrated in nucleoli, while p130 and E2F-4 show relatively even nuclear and cytoplasmic distributions. Both pRb and p130 have been implicated previously in repressing E2F activity in many different cell types during cell cycle arrest in G(0)/G(1). We conclude that p107 is active in human primary GLC but its nucleolar localisation would suggest that it represses ribosomal RNA synthesis rather than E2F activity.

Cell Cycle↗
PubMed2000

Valuing health-related quality of life. A review of health state valuation techniques.

Given the growing need to value health-related quality of life, a review of the literature relating to health state valuation techniques was undertaken to appraise the current theoretical and empirical evidence available to inform on the techniques, to identify consensus, identify disagreement and identify important areas for future research. A systematic search of the literature was conducted, covering standard gamble (SG), time trade-off (TTO), visual analogue scale (VAS), magnitude estimation (ME) and person trade-off (PTO) techniques. The basic concepts of practicality, reliability, theoretical validity and empirical validity formed the criteria for reviewing the performance of valuation techniques. In terms of practicality and reliability, we found little evidence relating to ME and PTO. SG, TTO and VAS have been shown to be practical on a range of populations. There is little difference between the reliability of SG, TTO and VAS, and present evidence does not offer a basis to differentiate between them. When considering the theoretical basis of techniques, we conclude that choice-based methods (i.e. SG, TTO and PTO) are best placed to reflect the strength of preference for health, with the choice between these techniques depending on the study characteristics and the perspective employed. Empirical evidence relating to the theoretical perspective of the techniques has shown that there are problems with all techniques in terms of descriptive validity.

Economics↗
PubMed2000

Epigenetic regulation of gene expression in cervical cancer cells by the tumor microenvironment.

Evidence is accumulating that the adverse tumor microenvironment both modifies the malignant progression of tumor cells and contributes to chemotherapy and radiation resistance. We hypothesized that some of the effects on malignant progression are mediated through the transcriptional regulation of genes responsive to the stresses of the microenvironment, such as low oxygen or low glucose conditions. To determine epigenetic changes in gene expression that were consistent with that hypothesis, we used an in vitro subtractive hybridization method, representational difference analysis, to identify hypoxia-induced cDNAs from cultured human cervical epithelial cells. We identified 12 induced genes: two novel genes (HIG1 and HIG2), three genes known to be hypoxia-inducible (tissue factor, GAPDH, thioredoxin), and seven genes not previously identified as hypoxia-inducible [HNRNP(a1), ribosomal L7, annexin V, lipocortin 2, Ku(70), PRPP synthase, and acetoacetyl-CoA thiolase]. In cultured cells, HIG1 and HIG2 expression is induced by hypoxia and by glucose deprivation, but their expression is not induced by serum deprivation, UV, or ionizing radiation. The putative HIG1 and HIG2 open reading frames are expressed in cells, as confirmed by epitope tagging. In addition, tumor xenografts derived from human cervical cancer cells display increased expression of HIG1 and HIG2 when they are deprived of oxygen. Taken together, these data suggest a coordinated transcriptional response of eukaryotic cells to microenvironmental stresses found in the solid tumor.

Amino Acid Sequence↗
PubMed2000

Expression of red cell surface antigens during erythropoiesis.

BACKGROUND AND OBJECTIVES: We have analysed the appearance and disappearance of cell surface markers during erythropoiesis, in vitro. MATERIALS AND METHODS: CD34+ haemopoietic progenitor cells were isolated from umbilical cord blood and cultured by three different methods, all in the presence of erythropoietin. The methods included two one-stage techniques, one serum-free, the other with serum present, and one serum-present two-stage method. RESULTS: The appearance of cell surface markers on the differentiating erythroid cells varied slightly from sample to sample, but differed more substantially between techniques, with the cells differentiating more rapidly in the culture media containing serum. The order of appearance of the markers, which was constant in the three methods, was as follows: glycophorin C, Kell, Rh-associated glycoprotein, glycophorin A, band 3, Rh proteins, and glycophorin B. CONCLUSION: Cell surface antigens can be used as markers for mapping the progress of erythroid differentiation during erythropoiesis.

Antigens, CD34↗