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Biomedical subjects

K Morrison

Publications and source records attributed to K Morrison.

At least 19 recordsLinked to original sources

Proximal loop jejunostomy is a useful adjunct in the management of multiple intestinal suture lines in the septic abdomen.

BACKGROUND: Bowel repair in the septic abdomen can be problematic. This study investigated the use of a proximal loop jejunostomy to protect injured or fistulated bowel that had been returned to the abdomen after repair and/or anastomosis. METHODS: Ten patients who underwent laparotomy for intra-abdominal sepsis and/or fistulation, followed by distal enteric repair and/or anastomosis and construction of a proximal defunctioning loop jejunostomy, were studied retrospectively. Seven patients had 21 intestinal suture lines returned to the peritoneal cavity in the presence of intra-abdominal sepsis (14 anastomoses, two enterotomy closures and five serotomy repairs). Two patients had a difficult relaparotomy for pelvic abscess (two distal anastomoses, one enterotomy closure and three serotomy repairs). The final patient had pelvic sepsis and radiation enteritis; the distal anastomosis was defunctioned by a loop jejunostomy. RESULTS: The median distance from the duodenojejunal flexure to the loop stoma was 80 (range 30-170) cm. All jejunostomies were closed via a local approach, a median of 11 (range 9-18) months after formation. There was no significant postoperative morbidity and no postoperative death. At a median follow-up of 7 (range 0.5-56) months eight patients had no requirement for nutritional support. CONCLUSION: Use of a loop jejunostomy to protect suture lines in the septic abdomen justifies consideration of this procedure in selected patients.

Abdomen↗

Fistuloclysis can successfully replace parenteral feeding in the nutritional support of patients with enterocutaneous fistula.

BACKGROUND: Use of total parenteral nutrition (TPN) in patients with acute intestinal failure due to enteric fistulation might be avoided if a simpler means of nutritional support was available. The aim of this study was to determine whether feeding via an intestinal fistula (fistuloclysis) would obviate the need for TPN. METHODS: Fistuloclysis was attempted in 12 patients with jejunocutaneous or ileocutaneous fistulas with mucocutaneous continuity. Feeding was achieved by inserting a gastrostomy feeding tube into the intestine distal to the fistula. Infusion of enteral feed was increased in a stepwise manner, without reinfusion of chyme, until predicted nutritional requirements could be met by a combination of fistuloclysis and regular diet, following which TPN was withdrawn. Energy requirements and nutritional status were assessed before starting fistuloclysis and at the time of reconstructive surgery. RESULTS: Fistuloclysis replaced TPN entirely in 11 of 12 patients. Nutritional status was maintained for a median of 155 (range 19-422) days until reconstructive surgery could be safely undertaken in nine patients. Two patients who did not undergo surgery remained nutritionally stable over at least 9 months. TPN had to be recommenced in one patient. There were no complications associated with fistuloclysis. CONCLUSION: Fistuloclysis appears to provide effective nutritional support in selected patients with enterocutaneous fistula.

Adult↗

TCR beta polymorphisms and multiple sclerosis.

A total of 267 families with two or more siblings with multiple sclerosis (MS) were genotyped with 14 restriction fragment length polymorphisms at the TCR beta locus. A nonparametric linkage analysis of the data showed no evidence for linkage to this locus (mlod=0.11). No significant allelic or haplotype transmissions were observed in the total sample of 565 patients. After stratification for the presence of HLA DRB1*15, an association was observed between the BV25S1*1-BV26S1*1-BV2S1*1 haplotype and MS (P=0.00089). This was not significant upon correction for multiple comparisons. It was also not significant when the haplotype frequency in affected individuals was compared to a normal control sample (P=0.77). Furthermore, the associated haplotype was followed-up in an independent sample of 97 nuclear families with a single DRB1*15-positive child with MS. The BV25S1*1-BV26S1*1-BV2S1*1 haplotype did not show significant evidence for transmission distortion but the same trend was seen (P=0.21). There were no significant associations observed in the DRB1*15-negative patients and no detectable difference was seen in the DRB1*15-positive BV25S1*1-BV26S1*1-BV2S1*1 association when comparing different subgroups based on clinical course of MS. These results show no evidence for linkage and fail to establish an association between MS susceptibility and the TCR beta locus.

Female↗

Cloning and characterization of an inversion breakpoint at 6q23.3 suggests a role for Map7 in sacral dysgenesis.

Here we report on a male patient with sacral dysgenesis (SD) and constitutional pericentric inversion of chromosome 6 (p11.2;q23.3). SD is a heterogeneous group of congenital anomalies with complex genetic etiology. Previously, a patient with sacral abnormalities and an interstitial deletion of 6q23-->q25 region has been described. We speculated that a susceptibility gene for SD lies in 6q23.3 region (disrupted in both patients), and therefore, cloning of the breakpoint in our patient would lead to the identification of the disrupted gene. We performed FISH analysis followed by Southern blot analysis and inverse PCR to clone the breakpoint. The 6p11.2 breakpoint mapped very close to the centromere, and the 6q23.3 breakpoint localized in the ninth intron of the MAP7 gene. We then evaluated the involvement of MAP7 in SD by further screening of the gene in several patients with a similar phenotype. Two nucleotide changes causing Ile257Asn and Glu571Ala substitutions in the protein, both affecting amino acid residues conserved in the mouse homolog, were identified in two patients. Both changes are either very rare polymorphisms or true mutations, since they were not detected in 167 normal individuals nor found in the SNP database. Therefore, our study suggests MAP7 as a candidate gene for SD. However, we were unable to detect any sacral defects in the MAP7 knockout mice.

Abnormalities, Multiple↗

Stakeholder involvement in water management: necessity or luxury?

Stakeholder involvement in water management is widely recognized as an important component of the design and implementation of sustainable water management initiatives. Despite this, there remains a deep-rooted resistance to the widespread implementation of programs to prioritize such involvement (as witnessed by, for example, the low priority given to the public involvement element of the European Union Water Framework Directive). This paper addresses the issue of stakeholder involvement by first confronting the fact that it is not a water issue, per se. Such diverse fields as economics, agriculture, public health, pollution prevention, business and education have also identified stakeholder involvement as a difficult but necessary component of successful action in their fields. For the water sector, the issue of stakeholder involvement as either a necessity for sustainable water management, or a luxury to be used to complement traditional approaches, is discussed.

Agriculture↗

5-HT1B-receptors and vascular reactivity in human isolated blood vessels: assessment of the potential craniovascular selectivity of sumatriptan.

AIMS: 5-HT1B-receptor mediated vasoconstriction of cranial arteries is a potential mechanism by which 5-HT1B/1D-receptor agonists such as sumatriptan produce their antimigraine effects. 5-HT1B-receptors exist in other blood vessels which may give rise to unwanted vascular effects. Therefore we examined the distribution of 5-HT1B-receptor immunoreactivity (i.r.) in human blood vessels (including target and nontarget vessels) and confirmed the functionality of this receptor protein, by comparing the vasoconstrictor effects of sumatriptan and 5-HT (the endogenous ligand) in isolated vessels. METHODS: Blood vessels (middle meningeal, pial, temporal and uterine arteries and saphenous veins) were obtained from surgical patients (with consent). Sections of the vessels were prepared for routine immunohistochemical studies using specific 5-HT1B- and 5-HT1D-receptor antibodies. For functional studies, ring segments of the vessels were mounted in organ baths for isometric tension recording. RESULTS: 5-HT1B-receptor i.r. was detected on the smooth muscle layer in middle meningeal, pial and uterine arteries and in saphenous vein and sumatriptan produced contractions in these vessels with potency values (mean pEC50) of 7.00, 7.08, 6.44 and 6.61, respectively, the magnitude of contraction was greatest in the cranial arteries with Emax values of 100.7, 60.3, 23.0 and 35.9%, respectively (expressed as a percentage of the reference agonist 45 mm KCl). 5-HT1B-receptor i.r. was not detected in temporal artery and sumatriptan had no effect in this artery. 5-HT1D-receptor i.r. was not detected in any of the vessels studied. CONCLUSIONS: Sumatriptan can evoke vasoconstriction in antimigraine target vessels and also in nontarget vessels through an action at 5-HT1B-rcceptors. Sumatriptan acts preferentially to cause contraction in human cranial arteries compared with the other blood vessels we examined and this effect is likely to be shared by other drugs of this class.

Cerebral Veins↗

The chimeric protein tyrosine kinase ETV6-NTRK3 requires both Ras-Erk1/2 and PI3-kinase-Akt signaling for fibroblast transformation.

There is increasing interest in the potential role of the NTRK family of neurotrophin receptors in human neoplasia. These receptor protein tyrosine kinases (PTKs) are well-known mediators of neuronal cell survival and differentiation, but altered NTRK signaling has also been implicated in mesenchymal, hematopoietic, and epithelial malignancies. We recently identified a novel gene fusion involving one of the neurotrophin receptor genes, NTRK3, in the pediatric solid tumor, congenital fibrosarcoma. In these tumors (and subsequently demonstrated in several other human malignancies), a t(12;15)(p13;q25) rearrangement fuses the 3' portion of the ETV6 gene with exons encoding the PTK domain of NTRK3. The resulting ETV6-NTRK3 fusion protein functions as a chimeric PTK with potent transforming activity. However, previous studies failed to detect interactions between ETV6-NTRK3 and molecules known to link wild-type NTRK3 to its two major effector pathways, namely the Ras-Raf1-Mek1-Erk1/2 mitogenic pathway or the phosphatidylinositol 3'-kinase pathway leading to activation of the AKT survival factor. Therefore, it remains unknown whether ETV6-NTRK3 transformation involves altered NTRK3 signaling. We now report that ETV6-NTRK3 expression in NIH3T3 cells leads to constitutive activation of Mek1 and Akt, as well as to constitutively high expression of cyclin D1. ETV6-NTRK3-induced soft agar colony formation was almost completely abolished by inhibition of either the Ras-Raf1-Mek1-Erk1/2 or the phosphatidylinositol 3'-kinase-Akt pathway. Moreover, this inhibition dramatically reduced expression of cyclin D1. Our results indicate that ETV6-NTRK3 transformation involves a link between known NTRK3 signaling pathways and aberrant cell cycle progression and that Mek1 and Akt activation act synergistically to mediate these effects.

3T3 Cells↗

Efficacy of adenoviral gene transfer with manganese superoxide dismutase and endothelial nitric oxide synthase in reducing ischemia and reperfusion injury.

OBJECTIVE: Both superoxide dismutase (SOD), a free radical scavenger, and nitric oxide (NO), a vasodilator with anti-inflammatory properties, have been shown to protect the myocardium from reperfusion injury. They are known to interact in vivo, the influence of which on myocardial protection has not been studied. METHODS: Four groups of rats (n=7, per group) were subjected to experimental infarction following injections into the anterior wall of the left ventricle with adenoviral vector encoding beta-galactosidase (group A), eNOS (group B), Mn-SOD (group C) and both eNOS and MnSOD (group D). Hearts were assessed for protein expression and size of infarction. RESULTS: Efficiency of gene up regulation was confirmed by immunostaining for eNOS and Mn-SOD, and X-gal staining for beta-gal respectively. In B and D, overexpression of eNOS was demonstrated in cardiac myocytes in addition to that in the endothelium, while in C and D, Mn-SOD was overexpressed in mainly cardiomyocytes. Infarct size was 49.7+/-4.8% in A, and was significantly reduced in the other groups (29.8+/-2.7%, 21.8+/-2.5% and 24.9+/-2.4% in B, C and D respectively). CONCLUSION: Adenoviral gene transfer of Mn-SOD was superior to eNOS in reducing the extent of in vivo ischemia-reperfusion injury in the rat heart in our model. The effect of combined application of Mn-SOD and eNOS was not different from their individual effect.

Adenoviridae↗

Impaired olfactory identification in relatives of patients with familial schizophrenia.

OBJECTIVE: Impaired olfactory identification ability has previously been demonstrated in patients with schizophrenia. This study assessed olfactory function in psychotic and nonpsychotic members of multigenerational families with familial schizophrenia to determine whether deficits were present in both groups. METHOD: The University of Pennsylvania Smell Identification Test was administered birhinally to three groups of subjects aged less than 65 years: 19 psychotic and 27 nonpsychotic members of families with familial schizophrenia and 43 age- and sex-matched healthy volunteers. RESULTS: Nonpsychotic family members had significantly higher mean University of Pennsylvania Smell Identification Test scores than psychotic family members but were impaired relative to the healthy volunteer group. These group differences could not be accounted for by age, sex, or smoking habit. Fifty-eight percent of the psychotic and 34% of the nonpsychotic family members performed in the microsmic (impaired) range, compared to 9% of the healthy volunteers. CONCLUSIONS: Impaired olfactory deficits may aggregate in families with schizophrenia and may be indicative of a genetic predisposition to psychosis.

Adult↗

Conventional pituitary irradiation is effective in normalising plasma IGF-I in patients with acromegaly.

OBJECTIVE: For patients in whom acromegaly persists despite pituitary surgery, conventional pituitary irradiation represents an additional treatment option. A 30-60% cure rate is described in the literature, but these studies did not utilise strict rules of remission, such as "safe" GH levels <2.5 microg/l, and age-adjusted normal IGF-I levels. DESIGN AND METHODS: We report the outcome of 41 patients with acromegaly who received pituitary conventional external irradiation. The median follow-up time was 12.8 years (3.7-43.4 years) post-radiotherapy. RESULTS: The median pre-irradiation GH level was 31.0 microg/l (7.0-210 microg/l). Information on IGF-I levels was only available for 6 patients prior to therapy. Utilising strict rules of remission, one-third (14/41) of our patients had normal biochemical parameters, i.e. "safe" GH (0.5 microg/l (range 0.2-1.6 microg/l)) and normal age-adjusted IGF-I levels (multiple of upper limit of normal range (xULN); 0.45 (0.2-1.0)) at the end of the follow-up period. An additional 9 patients achieved normal levels with adjunctive drug therapy. Furthermore, disease activity was reduced in a considerable proportion of the 18 patients who did not achieve normal biochemical levels (GH: 3.6 microg/l (1.9-15.7 microg/l); xULN of IGF-I: 1.6 (0.9-2.6)). In retrospect, remission is unlikely in patients who had a GH level greater than 52 microg/l (mean+2 s.d. of cured patients) prior to radiotherapy. In addition to the 12 patients with pre-irradiation pituitary functional deficiency, another 11 patients developed symptoms of panhypopituitarism during the 3-year period following irradiation. Within a 6-year period, partial pituitary insufficiency was observed in a further 7 patients, thus necessitating hormone substitution treatment. CONCLUSION: Using strict rules of remission, in our cohort we found both a normalisation of IGF-I and safe GH levels in 34% of patients treated for acromegaly with conventional irradiation therapy.

Acromegaly↗

A multidimensional meta-analysis of treatments for depression, panic, and generalized anxiety disorder: an empirical examination of the status of empirically supported therapies.

The authors report a meta-analysis of high-quality studies published from 1990-1998 on the efficacy of manualized psychotherapies for depression, panic disorder, and generalized anxiety disorder (GAD) that bear on the clinical utility and external validity of empirically supported therapies. The results suggest that a substantial proportion of patients with panic improve and remain improved; that treatments for depression and GAD produce impressive short-term effects: that most patients in treatment for depression and GAD do not improve and remain improved at clinically meaningful follow-up intervals: and that screening procedures used in many studies raise questions about generalizability, particularly in light of a systematic relation across studies between exclusion rates and outcome. The data suggest the importance of reporting, in both clinical trials and meta-analyses, a range of outcome indices that provide a more comprehensive, multidimensional portrait of treatment effects and their generalizability. These include exclusion rates, percent improved, percent recovered, percent who remained improved or recovered at follow-up, percent seeking additional treatment at follow-up, and data on both completer and intent-to-treat samples.

Anxiety Disorders↗

A comparison of laparoscopic supracervical hysterectomy vs laparoscopically assisted vaginal hysterectomy.

BACKGROUND: We set out to compare the length of stay, costs, and morbidity associated with laparoscopic supracervical hysterectomy (LSH) with laparoscopically assisted vaginal hysterectomy (LAVH). METHODS: We performed a cohort analysis of consecutive patients at a university-based medical center from April 1997 through October 1999. RESULTS: A total of 145 patients were identified initially; however, 13 cases were excluded because of concomitant procedures (retropubic urethropexy, lymphadenectomy, paravaginal repair). Of the 132 patients included in the study, 27 underwent LSH and 105 underwent LAVH. The two groups were similar with respect to gravidity, parity, uterine weight, and preoperative diagnosis. Patients undergoing LSH had significantly shorter operating times (median, 181 vs 220 min, p = 0.007), briefer hospital stays (median, 1.0 vs 2.0 days, p = 0.0001), and less blood loss (median, 125 vs 400 ml, p = 0.0001). None of the patients submitted to LSH experienced morbidity, as compared with a 13% morbidity rate for LAVH (bladder injury, n = 3; blood loss >1000 ml, n = 7; vaginal cuff hematoma, n = 4; 0% vs 13%; p = 0.04). CONCLUSIONS: Patients undergoing laparoscopic supracervical hysterectomy had shorter operating times, shorter hospital stays, and less morbidity than those who underwent laparoscopically assisted vaginal hysterectomy. The practice of routine cervicectomy at laparoscopic hysterectomy should be reconsidered.

Case-Control Studies↗

Intragraft interleukin-4 mRNA expression after short-term CD154 blockade may trigger delayed development of transplant arteriosclerosis in the absence of CD8+ T cells.

BACKGROUND: It has recently been shown that, although anti-CD154 induces CD4+ T-cell tolerance, it is unable to prevent allograft rejection mediated by CD8+ T cells. We have also shown that anti-CD154 monotherapy does not protect the graft from the development of transplant arteriosclerosis even in the absence of CD8+ T cells. This study was designed to investigate and characterize possible mechanisms responsible for the development of transplant arteriosclerosis after CD154 blockade in the absence of CD8+ T cells. METHODS: C57BL/6 (H2b) recipients received a fully MHC-mismatched BALB/c donor aorta (H2d). Animals were either treated with anti-CD154 monoclonal antibody (mAb) in the presence or absence of CD8 T cells. Histology, morphometric measurements, immunohistochemistry, and the production of alloantibodies (IgM, IgG1, IgG2a) were analyzed on days 14, 30, and 50 after transplantation. Cytokine production within the graft was investigated by competitive reverse transcription-polymerase chain reaction on day 14. RESULTS: Combined treatment with anti-CD154 and a depleting CD8 mAb resulted in a delay in the development of transplant arteriosclerosis (intimal proliferation: 33+/-10% vs. 67+/-11% untreated control, day 30) but ultimately did not prevent its progression (intimal proliferation: 55+/-10% vs. 78+/-9% untreated control, day 50). Although there was a significant decrease in the number of CD4+, CD11b+, and CD40+ graft-infiltrating cells and a reduction in the formation of donor-specific IgG1 alloantibodies in recipients treated with anti-CD154 and anti-CD8 mAbs, mRNA for interleukin (IL)-4 was increased, suggesting a shift in the intragraft cytokine profile towards a Th2-like pattern. CONCLUSIONS: Our data provide evidence that short-term CD154 blockade is insufficient to prevent transplant arteriosclerosis, even in combination with CD8+ T-cell depletion. Moreover, the increased expression of the Th2 cytokine interleukin-4 within the graft may be responsible for the development of transplant arteriosclerosis in the long term.

Animals↗

CD8+ T cells contribute to the development of transplant arteriosclerosis despite CD154 blockade.

BACKGROUND: The CD40-CD154 receptor-ligand pair plays a critical role in allograft rejection by mediating the activation of endothelial cells, antigen-presenting cells, and T cells. Blockade of this interaction prevents acute allograft rejection and leads to prolonged allograft survival in numerous experimental models, but in most cases indefinite graft survival is not achieved due to evolving transplant arteriosclerosis. In this study, we have used a model of transplant arteriosclerosis to investigate whether CD4+ and CD8+ T cells are differentially affected by CD154 blockade. METHODS: BALB/c (H2d) aortic grafts were transplanted into C57BL/6 (H2b) recipients treated with anti-CD154 monoclonal antibody in the presence or absence of CD8+ T-cell depletion. Histology and morphometric measurements were performed on day 30 after transplantation. RESULTS: Only combined treatment with anti-CD154 and anti-CD8 monoclonal antibodies resulted in a significant reduction of intimal proliferation (33 +/-10% vs. 67+/-14%; untreated control). Administration of either antibody alone did not produce this effect. Thymectomy did not alter the degree of intimal proliferation observed in any of the treatment groups. CONCLUSIONS: Our data provide direct evidence that CD8+ T cells are not targeted effectively by CD154 blockade and that the transplant arteriosclerosis seen after CD154 blockade is not due to recent thymic emigrant T cells.

Animals↗

Mutation analysis and embryonic expression of the HLXB9 Currarino syndrome gene.

The HLXB9 homeobox gene was recently identified as a locus for autosomal dominant Currarino syndrome, also known as hereditary sacral agenesis (HSA). This gene specifies a 403-amino acid protein containing a homeodomain preceded by a very highly conserved 82-amino acid domain of unknown function; the remainder of the protein is not well conserved. Here we report an extensive mutation survey that has identified mutations in the HLXB9 gene in 20 of 21 patients tested with familial Currarino syndrome. Mutations were also detected in two of seven sporadic Currarino syndrome patients; the remainder could be explained by undetected mosaicism for an HLXB9 mutation or by genetic heterogeneity in the sporadic patients. Of the mutations identified in the 22 index patients, 19 were intragenic and included 11 mutations that could lead to the introduction of a premature termination codon. The other eight mutations were missense mutations that were significantly clustered in the homeodomain, resulting, in each patient, in nonconservative substitution of a highly conserved amino acid. All of the intragenic mutations were associated with comparable phenotypes. The only genotype-phenotype correlation appeared to be the occurrence of developmental delay in the case of three patients with microdeletions. HLXB9 expression was analyzed during early human development in a period spanning Carnegie stages 12-21. Signal was detected in the basal plate of the spinal cord and hindbrain and in the pharynx, esophagus, stomach, and pancreas. Significant spatial and temporal expression differences were evident when compared with expression of the mouse Hlxb9 gene, which may partly explain the significant human-mouse differences in mutant phenotype.

Abnormalities, Multiple↗