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Biomedical subjects

M Morrin

Publications and source records attributed to M Morrin.

10 recordsLinked to original sources
PubMed2002

CD44v6 is not relevant in colorectal tumour progression.

BACKGROUND AND AIMS: There is a lack of consensus regarding the role of CD44 variants in colorectal cancer, with conflicting reports regarding their expression and correlation with prognosis. We investigated the expression and prognostic significance of CD44v6 protein in our series of colorectal tumour specimens and then analysed the pattern of CD44 variant mRNA transcript expression in a smaller series of colorectal tumour/normal tissue specimens, thus assessing what our data contributes to this debate. METHODS: Immunohistochemistry was used to detect CD44v6 protein expression, while reverse transcriptase-polymerase chain reaction in combination with Southern blotting was used to analyse CD44 mRNA transcript expression. RESULTS: Similar levels of expression of CD44v6 protein were observed in each of the Dukes' stages, ranging from 50% to 67%, indicating no correlation with progression of disease or survival rates. CD44 variant mRNA expression was found in 85% of the tumours and 75% of the normal specimens. The majority of tumours expressed each of the variants. The pattern of variant expression was maintained in the corresponding normal tissue in nearly one-half (47%) of the tumour specimens. A sequential pattern of variant expression was observed in the majority of specimens. There was no association between CD44 variant mRNA expression and Dukes' stage, tumour differentiation or survival. CONCLUSIONS: The data reported here, along with those already in the literature, suggest that CD44v6 does not play a pivotal role in colorectal cancer progression. Moreover, due to the pattern of expression of contiguous blocks of variant transcripts it is unlikely that expression of any single variant can predict outcome in vivo.

Blotting, Southern↗
PubMed1999

Oxygen-enhanced magnetic resonance ventilation imaging of the human lung at 0.2 and 1.5 T.

Lung ventilation imaging using inhaled oxygen as a contrast medium was performed using both a 0.2 and a 1.5 T clinical magnetic resonance (MR) scanner in eight volunteers. Signal-to-noise-ratios (SNRs) of the ventilation images as well as T1 values of the lung acquired with inhalation of 100% oxygen and room air were calculated. The SNR was 9.7 +/- 3.0 on the 0.2 T MR system and 69.5 +/- 28.8 on the 1.5 T system (P < 0.001). The mean T1 value on the 0.2 T MR system with subjects breathing room air was 632 +/- 54 msec; with 100% oxygen, it was 586 +/- 41 msec (P < 0.01). At 1.5 T, the mean values were 904 +/- 99 msec and 790 +/- 114 msec, respectively (P < 0.0001). We conclude that MR oxygen-enhanced ventilation imaging of the lung is feasible with an open configured 0.2 T MR system.

Adult↗
PubMed1999

Virtual colonography: techniques and current clinical applications.

The advent of volumetric helical computed tomography (CT), coupled with the almost universal use of oral and intravenous contrast agents, has resulted in CT becoming the diagnostic and therapeutic cornerstone for alimentary tract disease. Recent technical advances, further enhanced by innovative software developments, now permit multiplanar and endoluminal projections of the entire abdomen, and have resulted in the development of novel diagnostic applications in the abdomen.

Journal Article↗
PubMed1998

Consumer behavior: a quadrennium.

Consumer behavior continued to attract additional researchers and publication outlets from 1993 through 1996. Both general interest and domain-specific scholarly contributions are discussed, along with limitations and suggested areas for future research. A concluding section observes that the integrity of consumer research is unnecessarily compromised by the failure of the major scholarly association in the field to develop and adopt a code of researcher ethics.

Journal Article↗
PubMed1997

Titanium mesh and bone dust calvarial patch during cranioplasty.

A technique of filling calvarial defects using bone dust reinforced with titanium Micro Mesh (Leibinger) was investigated using plain x-ray films and computed tomography (CT) in seven consecutive patients (age range, 7-21 years). The aim of our study was to assess whether, in the presence of the titanium, bone dust harvested with a power burr promotes persistent ossification that is comparable with adjacent bone. The mesh was localized by standard skull plain x-ray films, and orthogonal CT scans were obtained at between 9 and 18 months post-operatively. An ultrahigh-resolution algorithm was used to detect neoossification on either side of the Micro Mesh (1-mm collimation, 330-mA and 120 KV(p) at the center of 400 HU, and window width of 2000 Hu). The mesh induced minimal streak artifact. Virtually no new bone formation was seen. It appears that bone dust was completely reabsorbed in this patient group even in the presence of semi-rigid fixation.

Absorption↗
PubMed1994

Mutations of Ki-ras and p53 genes in colorectal cancer and their prognostic significance.

The series of genetic changes leading to malignancy in colorectal cancer is well reported. This includes mutational activation of the proto-oncogene Ki-ras and mutation/deletion of the p53 tumour suppressor gene. The frequency of these mutations was investigated in a panel of 52 colorectal cancer patients using a combination of immunocytochemistry and non-radioactive, digoxigenin-labelled in situ hybridisation. Sixty two per cent (32 of 52) of the study population were positive for p53 overexpression and 36% (19 of 52) positive for Ki-ras mutation. Twenty seven per cent (14 of 52) of the patients expressed both mutations. Mutation of either the p53 or the Ki-ras gene did not correlate with Dukes's stage, tumour differentiation or 5 year survival rate of the patients. Most of the rectal carcinoma specimens (11 of 15) showed p53 over-expression but the significance of this was not supported statistically. Thus detection of molecular changes is becoming more amenable to incorporation into routine histological carcinoma assessment because of the advent of non-radioactive labelling in in situ hybridisation and antibodies suitable for paraffin wax embedded specimens. The significance of these mutations in disease prognosis, however, remains questionable.

Colonic Neoplasms↗
PubMed1993

Inhibition of the adherence of Pseudomonas aeruginosa to epithelial cells by IgG subclass antibodies.

A beneficial role of the antibody response to Pseudomonas aeruginosa seen in cystic fibrosis (CF) patients has not been established. We investigated a possible role for these antibodies as inhibitors of the adherence of P. aeruginosa to mammalian cells. An adhesion model system was used, employing buccal epithelial cells in an enzyme-labelled immunoassay procedure on microtitration plates. Total levels of IgG, IgA, IgM and the four IgG subclasses were estimated in 11 CF patients and 10 healthy controls. Most of the CF patients demonstrated increased levels of all these immunoglobulin types. Sera from seven patients with elevated serum IgG were observed to cause greater inhibition of the adherence of P. aeruginosa to buccal cells than were the sera from four CF patients with low serum IgG and from ten healthy controls. Nevertheless, the levels of individual anti-P. aeruginosa IgG subclass antibodies varied amongst the patients and did not correlate with the degree of inhibition of bacterial adherence. Negative affinity chromatography was used to obtain antibody fractions enriched for IgG1, IgG2 or IgG4 and protein A-sepharose chromatography was used to isolate IgG3 antibodies from CF patients. The IgG1-, IgG2-, or IgG4-enriched fractions similarly inhibited the adherence of P. aeruginosa in the test system, whereas three of five IgG3-enriched fractions from CF patients had no greater effect on adhesion than did IgG from control individuals.

Adolescent↗
PubMed1993

Role of IgG subclass response to outer-membrane proteins in inhibiting adhesion of Pseudomonas aeruginosa to epithelial cells.

The IgG subclass response to the major outer-membrane proteins (OMPs) of Pseudomonas aeruginosa was investigated in 11 cystic fibrosis (CF) patients and 10 healthy controls. Inhibition of adhesion of P. aeruginosa to buccal epithelial cells by the IgG serum fractions from the CF patients has been established previously. The CF patients demonstrated marked heterogeneity in their individual IgG subclass response to pseudomonal OMPs. The predominant IgG1 and IgG4 responses were directed towards OMPs F, H2 and, with IgG1 only, to protein I. Proteins of 42 and 46 kDa primarily elicited an IgG2 response but some patients produced IgG4 antibodies. The IgG3 response varied from very weak in some patients to a strong reaction with proteins D2, E, G and I in others. The range of antigen-specific IgG subclass responses was similar in CF patients whose IgG fractions strongly inhibited the adherence of P. aeruginosa to epithelial cells and in those whose fractions gave only weak inhibition of adherence. There was no indication that an antibody response towards any particular OMP was implicated in the inhibition of bacterial adherence. Thus, the IgG subclass response to OMPs did not exert a significant effect on adherence when investigated in isolation, but may possibly play some role in combination with other processes.

Adult↗
PubMed1992

The relationship between a nutritional index and acute physiology score in critical illness.

Prognostic indices derived from available physiological data (SAPS), complex nutritional and biochemical tests (PNI), grip strength and serum albumin were calculated in 16 critically ill patients receiving intravenous nutrition over a six week period. The aim was to compare these independently derived prognostic indices, to assess their response to feeding, and to determine suitability for use in Irish intensive care units. Mean SAPS (7.6 +/- 0.92), PNI (3.1 +/- 0.29), serum albumin (30.3 +/- 1.03 g/l) and grip strength (17.9 +/- 1.3%) were all suggestive of an "at risk" group. Significant associations were found between the accepted SAPS index and both PNI (r = 0.6, p < 0.001, n = 35) and grip strength (r = -0.68, p < 0.001, n = 44) but not with serum albumin. No consistent improvement was seen in response to feeding in any of the derived indices. The close correlation between prognostic indices derived from either physiological, nutritional or grip strength data in this study and the failure of prognostic indices to improve during hyperalimentation would support a common mechanism, e.g. endogenous mediators, for metabolic and physiological disturbance in critical illness. It suggests that the role of hyperalimentation is supportive rather than therapeutic and re-iterates the importance of managing underlying disease processes. Simple grip strength may be a useful alternative to complex nutritional indices.

Critical Illness↗