Preparation of recombinant vaccinia virus for expression of small GTPases.
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Animals↗
Biomedical subjects
L Thomas
Publications and source records attributed to L Thomas.
Colorectal carcinomas show frequent allelic loss on the long arm of chromosome 17 with evidence for a specific target region.
Allelic loss is a common mechanism of inactivation of tumour-suppressor genes in colorectal carcinomas. A number of known or putative tumour-suppressor genes including NF1, BRCA1, NME1, NME2 and prohibitin are present on the long arm of chromosome 17, and this region has not been extensively analysed in colorectal tumours. In this study 72 colorectal carcinomas were examined for allelic loss at eight loci on chromosome 17. Allelic loss was frequent both at the p53 locus, which is known to be important in colorectal carcinoma, and also telomeric to p53 on 17p. Allelic loss continued to be present in more than 50% of cases in the pericentromeric region and on proximal 17q to the marker LEW101 (D17S40) at 17q22-23. The most telomeric markers on 17q showed lower rates of allelic loss. Analysis of cases with partial deletions which did not include the p53 locus showed a common region of overlap of the deletions centred on D17S40. This suggests the target of allelic loss on 17q is a tumour-suppressor gene in this region.
Alleles↗
Use of the CS-3000 Plus to prepare apheresed blood cells for immunomagnetic positive cell selection.
The Baxter CS-3000 Plus Blood Cell Separator was used to prepare progenitor cell components in a three-step process. The process was designed to remove platelets and plasma from a leukapheresis cell product before incubation with anti-CD34 monoclonal antibody (9C5) and to remove unbound monoclonal antibody after incubation. Fluorochrome-labeled cultured KG1a (CD34+) cells were added to the leukapheresis cell product (at 2% of total WBC) before CS-3000 processing to evaluate the CS-3000 process for preparing cells for immunomagnetic selection using the Isolex 300 (SA) Magnetic Separation system. Data were obtained using five leukapheresis products. Two percent of the nucleated cells were lost during the platelet reduction wash, and 67% of the platelets were removed. The amount of antibody initially added to the cells for incubation ranged from 3.9 to 7 mg (0.5 microgram/10(6) nucleated cells). The residual antibody in the cells after the antibody wash ranged from 11 to 40 micrograms. The antibody wash resulted in a 3% loss of nucleated cells and an additional 66% removal of platelets. The antibody-sensitized cells were then processed on the Isolex 300 (SA) system. The purity and yield of the Isolex KG1a cell product were 94% and 82%, respectively.
Antibodies, Monoclonal↗
Mycobacteria of Runyon groups I, II and IV do not play an aetiological role in Crohn's disease.
OBJECTIVE: In addition to Mycobacterium paratuberculosis, other slow-growing as well as rapid-growing mycobacteria were isolated from mucosa or full thickness samples of intestine from patients with Crohn's disease. The meaning of these data remained unclear. To investigate the possible aetiological role of these rapid- and slow-growing mycobacteria, serosa and mesenteric lymph nodes were also cultivated in the present study. DESIGN AND METHODS: Mucosa, lymph nodes and serosa of 23 patients with Crohn's disease and 23 patients with other intestinal afflictions were incubated at 37 degrees C on Löwenstein-Jensen medium and Herrold egg yolk medium. These methods allow the cultivation of most atypical mycobacteria, including Mycobacterium paratuberculosis. In addition, full thickness samples of some of these patients were analysed for mycobacterial DNA using polymerase chain reaction. RESULTS: Despite lack of decontamination of 60% of lymph nodes and serosa, no mycobacterial growth was observed over a long incubation period (an average of 718 days in Crohn's disease and 552 days in controls) on Löwenstein-Jensen medium. Polymerase chain reaction was based on the amplification of 16S ribosomal DNA sequences specific for mycobacteria of tissues derived from four patients with Crohn's disease and one control was negative. CONCLUSIONS: These findings suggest that mycobacteria, such as M. fortuitum and M. chelonei, which are widespread in the environment, are not involved in the aetiology of Crohn's disease but, rather, should be considered as environmental opportunists.
Adolescent↗
Ribozyme-mediated inhibition of expression of leukocyte-type 12-lipoxygenase in porcine aortic vascular smooth muscle cells.
Activation of a leukocyte-type 12-lipoxygenase (12-LO) has been proposed to be an important mechanism for angiotensin II- and glucose-induced vascular smooth muscle cell growth. Currently, no specific pharmacological inhibitors for the leukocyte-type 12-LO are available to test this hypothesis. We have therefore designed a chimeric DNA-RNA hammerhead ribozyme to produce cleavage at the first GUC sequence at nucleotide 7 of porcine leukocyte 12-LO mRNA. The ribozyme was tested in vitro with a 206-base 12-LO mRNA as substrate. We observed that the ribozyme specifically and dose-dependently cleaved porcine leukocyte 12-LO mRNA at the predicted site under physiological temperature. Furthermore, we also efficiently delivered the ribozyme into porcine aortic vascular smooth muscle cells by transfection with cationic liposomes. The ribozyme caused a dose-dependent decrease in levels of porcine leukocyte-type 12-LO mRNA in these cells and was more potent than an antisense oligonucleotide directed against porcine leukocyte 12-LO. The 12-LO ribozyme also attenuated 12-LO protein levels in the cells. The action of the ribozyme was primarily a result of its catalytic activity, since a modified ribozyme that lacks catalytic activity showed reduced effects. This represents the first ribozyme directed against a mammalian LO pathway. These results demonstrate the potential utility of new ribozyme technology to generate novel agents for gene modulation experiments to modify the development or progression of vascular disease in humans.
Animals↗
Interleukin-1 beta regulates the expression of a leukocyte type of 12-lipoxygenase in rat islets and RIN m5F cells.
The leukocyte type of 12-lipoxygenase (12-LO) may play a role in inflammatory reactions in many cell types through the conversion of arachidonic acid to proinflammatory eicosanoids that include 12-hydroperoxyeicosatetraenoic acid and 12-hydroeicosatetraenoic acid. Previous studies demonstrating the presence of a functional 12-LO pathway in rat and human pancreatic beta-cells plus the recent cloning of a rat leukocyte type of 12-LO allowed us to evaluate whether inflammatory cytokines such as interleukin-1 beta (IL-1 beta) can regulate the beta-cell 12-LO enzyme pathway, thus providing a potential link between the cytotoxic effects of cytokines on pancreatic beta-cells and the proinflammatory effects of 12-LO products. We demonstrate that IL-1 beta induces 12-LO protein and messenger RNA (mRNA) expression in RIN m5F cells and 12-LO mRNA expression in rat islets. RIN m5F cells treated for 16 h with IL-1 beta (25, 50, and 100 ng/liter) showed a maximal 2-fold increase in the expression of a leukocyte form of 12-LO demonstrated by Western blots. A concomitant increase in 12-LO mRNA expression was seen at this time point using a highly sensitive competitive polymerase chain reaction assay. The increase in mRNA and protein expression was preceded by increased 12-LO pathway activity measured by a RIA for 12-S-HETE. Separate experiments using purified Sprague-Dawley rat islets also showed increased expression of 12-LO mRNA and enzyme activity in response to IL-1 beta. These results demonstrate that IL-1 beta can up-regulate 12-LO expression and activity in rat beta-cells.
12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
Prevention of thromboses in human patients with Bothrops lanceolatus envenoming in Martinique: failure of anticoagulants and efficacy of a monospecific antivenom. Research Group on Snake Bites in Martinique.
Envenomation by the Bothrops lanceolatus, a snake found only in Martinique, leads to swelling and pain, and occasionally to systemic signs and/or coagulopathy. Severe thromboses at some distance from the site of the bite may appear within 48 hr. Uncertainties as to the actual development of thrombotic complications in patients appearing to be suffering from moderate poisoning and as to the availability and the toxicity of a monospecific antivenom (AVS) initially led us to reserve antivenom for the most severe cases, and to use anticoagulants to prevent thromboses in all patients. This approach was modified after we observed serious thromboses in patients with moderate poisoning. Of 50 adult snake bite cases hospitalized between June 1991 and August 1994, 11 developed serious thrombotic complications at 36 /+- 27 hr (mean +/- SD) (range 12-96) following envenomation, despite early preventive anticoagulant therapy. Those included pulmonary embolism (two cases), cerebral infarction (six cases), myocardial infarction (one case), and cerebral and myocardial infarctions (two cases). Sixteen patients were not treated with AVS: 10 of these recovered without complications and six developed systemic thrombosis causing permanent disability in three cases. Thirty were treated with an intravenous infusion of 2-6 vials of AVS given 2-48 hr after the bite. Of these, three died of cerebral infarction that developed before the initiation of serotherapy. All others recovered. Among patients treated with AVS, three presented with mild anaphylactic reactions, while one developed serum sickness that responded to steroids. These data indicate that preventive anticoagulant therapy is of limited efficacy in Martinique.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Cytokine treatment of human bone marrow activates anti-leukaemia effector cells: monitoring of purging by polymerase chain reaction and DNA analysis.
The aims of this study were to investigate the role of cytokines (tumour necrosis factor alpha (TNF alpha), interferon gamma (IFN gamma) and interleukin-2 (IL-2) in augmenting graft-versus-leukaemia (GVL). We have investigated the effector cells involved in GVL, by studying the role of these cells in purging of the cell line K562 in short-term bone marrow cultures. The effect of the addition in vitro of rGCSF was also studied. Monitoring of purging was achieved by cytotoxicity assays, DNA analysis and the use of the polymerase chain reaction for the detection of bcr/abl transcripts in the Philadelphia positive (Ph+) K562 cell line. Supernatants from IL-2-treated and non-treated bone marrow were tested for cytokine production (TNF alpha and IFN gamma). The results have shown that the main cytotoxic effector cells in the bone marrow generated by IL-2 have the CD56+ CD8+ phenotype. Overnight incubation of bone marrow was sufficient to generate cytotoxic cells as measured by Chromium51 (Cr51) release assays. Measurable levels of TNF alpha but not IFN gamma were also detected in supernatants. Addition of TNF alpha and IFN gamma to the IL-2 in the bone marrow cultures augmented the cytotoxicity but tended to inhibit progenitor cell growth as measured by granulocyte-macrophage colony-forming unit (GM-CFU) and erythroid blast-forming unit (BFU-e) assays. An estimate of the purging of the marrow could also be achieved by DNA analysis of K562 DNA in bone marrow. The bcr/abl transcript could still be detected by PCR analysis in marrow containing 1% K562 and treated with IL-2 for 24 h, but by 6 days of incubation the bcr/abl transcript was weak or undectable. The results suggest that although reduction in the proportion of leukaemia in contaminated marrow can be detected after incubation with IL-2 for 24 h, complete elimination of minimal residual disease requires longer incubation times.
Biomarkers, Tumor↗
[What are expected improvements in the follow-up and treatment of stage I melanoma?].
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Combined Modality Therapy↗
[Disseminated cutaneous neurilemmomatosis].
INTRODUCTION: Neurilemmomatosis is a rare, non-inherited disease which has several features similar to type I neurofibromatosis. CASE REPORT: A 30-year-old man had more than 300 cutaneomucosal tumours. Most were sessile and of firm consistency on normal coloured skin. Histology reported masses of fusiform dermal cells S100 protein (+), NSE (-), actin (-). The cells had a polygonal ultrastructure with fine ramifications. Neurilemmomatosis (schwannomatosis) was diagnosed. No neurological or systemic disorder could be detected. The most bothersome tumors were destroyed. DISCUSSION: This is a typical anatomoclinical presentation of cutaneous neurilemmomatosis. This exceptional state raises the problem of differential diagnosis and nosological distinction from von Recklinhausen's disease. A characteristic feature in this case was the total absence of any malformation or associated tumour, notably neurological tumours. To our knowledge, this is the only documented case of disseminated neurilemmomatosis strictly limited to the skin.
Adult↗
[Perforating verruciform collagenoma, an exogenous inclusion skin disease? Apropos of a case induced by calcium chloride].
INTRODUCTION: Perforating verruciform collagenoma, first described in 1963, designates papular and keratotic post-trauma lesions which show an aspect of epidermal perforation microscopically with large fragments of collagen issuing through fistulous chimneys, more or less pycnotic polynuclears and squamating or necrotic epidermal cells. Three publications have presented this diagnosis. CASE REPORT: We observed a patient with multiple lesions with macroscopic and microscopic presentations suggestive of perforating verruciform collagenoma. The lesions appeared after scratches and inoculation with calcium chloride. DISCUSSION: This case is similar to those observed after intradermal inoculation of calcium salts. In the 4 previous cases, perforating verruciform collagenoma was associated with trauma allowing the intradermal penetration of a particular foreign material (glass wool, vegetable debris, drugs or intravenous injections, wound caused by a metallic garbage bin). The exceptional nature of perforating verruciform collagenoma in highly frequent skin wounds would suggest that a very particular post-trauma process is occurring caused by the introduction of an exogenous substance within the derma: calcium chloride in our case, a non-specific material in the four previous cases.
Adult↗
Evaluation of whole abdominal irradiation in ovarian carcinoma with a four orthogonal fields technique.
PURPOSE: The purpose of this study is to evaluate the toxicity and the results of abdominopelvic irradiation with a four orthogonal field's technique in patients with ovarian carcinoma. METHODS AND MATERIALS: Between May 1981 and December 1990, 167 patients with ovarian carcinoma have been treated with whole abdominal irradiation: 62 patients with no or minimal residual disease < 2 cm after initial surgery (group 1) and 105 patients with no residual disease or macroscopic residual disease < 2 cm assessed by second-look surgery after incomplete debulking surgery and cisplatin-based polychemotherapy (group 2). Irradiation was performed by a four orthogonal field's technique. Thirty grays were given with a 25 MV photon beam (1.5 Gy/fraction/day, 20 fractions over 30 days). Boosts were performed in 50 cases (median dose of 15 Gy). RESULTS: With a median follow-up of 68 months, the 5-year actuarial survival rate was 50% in the entire group, 67% in group 1, 40% in group 2, and 84% in T1, 61.5% in T2, 38% in T3. Five-year actuarial survival was analyzed according to the residuum: (a) after initial surgery (no residual disease: 70%, residual disease: 36.5%), (b) after second-look surgery: 76% in patients with a negative second look, 66% in patients with microscopic residual disease, 22% in patients with macroscopic residual disease and secondary surgical reduction, and 10% in patients with small unresectable nodules. Nine percent of the patients failed to complete irradiation acute side effects related. Five percent required surgery for bowel obstruction. CONCLUSION: The abdominopelvic irradiation with this four orthogonal field's technique was associated with tolerable acute toxicity and a low risk of serious late complications. Similar late results to have been reported whole abdominal irradiation with chemotherapy in patients with negative or microscopic residual disease after surgery. Randomized trials comparing these two adjuvant treatments are warranted.
Actuarial Analysis↗
Intracellular trafficking and activation of the furin proprotein convertase: localization to the TGN and recycling from the cell surface.
Furin is a membrane-associated endoprotease that efficiently cleaves precursor proteins on the C-terminal side of the consensus sequence, Arg-X-Lys/Arg-Arg1, and has been proposed to catalyze these reactions in both exocytic and endocytic compartments. To study its biosynthesis and routing, a furin construct (designated fur/f) containing the FLAG epitope tag inserted on the C-terminal side of the enzyme's autoproteolytic maturation site was used. Introduction of the epitope tag had no effect on the expression, proteolytic maturation or activity of furin. Analysis of the localization of fur/f by immunofluorescence microscopy showed that its staining pattern largely overlapped with those of several Golgi-associated markers. Treatment of cells with brefeldin A caused the fur/f distribution to collapse around the microtubule organizing center, indicating that furin is concentrated in the trans-Golgi network (TGN). Immunoelectron microscopy showed unequivocally that furin resides in the TGN where it colocalized with TGN38. In agreement with its proposed activity in multiple compartments, antibody uptake studies showed that fur/f cycles between the cell surface and TGN. Furthermore, targeting to the TGN requires sequences in the cytoplasmic tail of the enzyme. Pulse-chase and immunofluorescence analyses demonstrated that proregion removal occurs in the endoplasmic reticulum and that cleavage may be required for exist from this compartment. Finally, we show that proregion removal is necessary but not sufficient for enzyme activation.
Amino Acid Sequence↗
Depressive symptomatology and smoking among persons with diabetes.
The purpose of this study was to determine whether (a) symptoms of depression are more prevalent and severe among diabetic smokers than diabetic nonsmokers, (b) smoking is related to depressive symptomatology among diabetic patients, and (c) there is a positive relationship between number of cigarettes smoked and severity of depressive symptoms. Diabetic non-smokers (n = 103) and diabetic smokers (n = 83) were surveyed regarding symptoms of depression as measured by the Beck Depression Inventory (BDI). Depressive symptomatology was more prevalent and severe among smokers than nonsmokers. Smoking was significantly associated with depressive symptomatology. Among smokers, the number of cigarettes smoked per day was independently associated with cognitive symptoms of depression.
Adult↗
Biochemical properties, activities, and presence in biologic fluids of eosinophil granule major basic protein.
The existence of a proform of MBP is predicted from the sequence of MBP cDNA clones. ProMBP has been purified from the supernatants of CHO cells transfected with cDNA encoding prepro MBP. Purification involved heparin-Sepharose affinity purification followed by two sequential size fractionation steps over Sephadex G-100 and yielded proMBP with a molecular mass of 33 kd. Recombinant proMBP from the heparin-Sepharose column was subjected to isoelectric focusing followed by SDS-PAGE and Western blot analysis. The results indicated that most of the 33 kd form of proMBP focused predominantly between pI 4.2 and 5.1, with a major peak at a pI of approximately 4.9. Analyses of the carbohydrates associated with the purified 33 kd form of recombinant proMBP indicated the addition of 4856 to 5150 Da by carbohydrates characteristic of the complex type. Consistent with the hypothesis that the function of the propiece is to neutralize MBP toxicity during granule processing, proMBP lacked MBP cytostimulatory properties and actually blocked the effect of MBP in two different systems, basophil histamine release and neutrophil activation. In addition, as a measure of toxicity, proMBP did not inhibit protein synthesis, whereas MBP markedly reduced protein synthesis. The mechanisms by which MBP exerts its actions both as a cytostimulant and as a toxin are not known; however, it is known that cationic MBP readily reacts with acidic lipids. Using artificial liposomes as targets, MBP caused a disordering of the lipid bilayer membrane, resulting in fusion and lysis. Therefore, MBP may act both as a cytostimulant and as a toxin because of its marked cationicity and its ability to disorder lipid membranes.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗
Intraoperative interstitial iridium brachytherapy in the management of soft tissue sarcomas: preliminary results of a feasibility phase II study.
Between May 1986 and June 1992, 48 patients with soft tissue sarcomas underwent 50 intraoperative interstitial implants in conjunction with conservative tumoral resections. Brachytherapy was part of the initial treatment in 27 cases and was done in 21 other previously treated patients. For the last ones brachytherapy was, in most of the cases, the only treatment in addition to surgery. The implant dose was 40-65 Gy. When combined with external irradiation the mean prescribed dose was 20 Gy (12-25 Gy). With a median follow-up of 33 months, the 3-year actuarial survival rate was 81% and the local disease-free survival 91.7%. Five local failures were observed only in patients with recurrent sarcomas: two were inside the treated volume and three outside (local failure 5/48 = 10.4%). Acute side-effects occurred in 11 patients (11/48 = 23%), with skin breakdown (two cases) infection and hematoma (one case), infection, lymphocele, secondary skin breakdown and vascular rupture (one case), infection and limited skin breakdown (two cases) and delayed healing (five cases). As a consequence, six patients required reoperation but no amputation was necessary. The functional results were good. Only three patients had a moderate limitation of movement. Late complications occurred in five patients: bone fracture (one case), leg oedemas not interfering with normal activity (three cases), peripheral neuropathy fibrosis related requiring surgery (one case). Therefore, this preliminary report shows that adjuvant intraoperative brachytherapy is feasible and is safe in treating soft tissue sarcomas, even in previously irradiated patients. However, further evaluation is needed to determine the real place of intraoperative implant in the management of soft tissue sarcomas.
Adolescent↗
pp60c-src enhances the acetylcholine receptor-dependent catecholamine release in vaccinia virus-infected bovine adrenal chromaffin cells.
Secretion of catecholamines by adrenal chromaffin cells is a highly regulated process that involves serine/threonine and tyrosine phosphorylations. The nonreceptor tyrosine kinase pp60c-src is expressed at high levels and localized to plasma membranes and secretory vesicle membranes in these cells, suggesting an interaction of this enzyme with components of the secretory process. To test the hypothesis that pp60c-src is involved in exocytosis, we transiently expressed exogenous c-src cDNA using a vaccinia virus vector in primary cultures of bovine adrenomedullary chromaffin cells. Chromaffin cells infected with a c-src recombinant virus restored the diminished secretory activity accompanying infection by wild type virus alone or a control recombinant virus. The level of enhanced catecholamine release correlated directly with the time and level of exogenous c-src expression. These results could not be attributed to differences in cytopathic effects of wild type versus recombinant viruses as assessed by cell viability assays, nor to differences in norepinephrine uptake or basal release, suggesting that pp60c-src is involved in stimulus-secretion coupling in infected cells. Surprisingly, exogenous expression of an enzymatically inactive mutant c-src also restored catecholamine release, indicating that regions of the introduced c-src protein other than the kinase domain may affect catecholamine release. Secretory activity was elevated by both forms of c-src in response to either nicotine or carbachol (which activate the nicotinic and the nicotinic/muscarinic receptors, respectively). In contrast, release of catecholamines upon membrane depolarization (as elicited by 55 mM K+) or by treatment with the calcium ionophore A23187 was unaffected by either vaccinia infection or increased levels of pp60c-src. These results suggest that pp60c-src affects secretory processes in vaccinia-infected cells that are activated through ligand-gated, but not voltage-gated, ion channels.
Adrenal Glands↗