Positive Control Group (positive + control_group)

Distribution by Scientific Domains


Selected Abstracts


Clonally rearranged T-cell receptor , chain genes in HTLV-I carriers with abnormal, non-flower-like, lymphocytes

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 4 2005
Maria M. Sales
Abstract:,Background:,The diagnosis of Adult T-cell leukemia/lymphoma ATLL subtypes in human T-lymphotropic virus type I (HTLV-I) carriers based in morphology and immunophenotype of lymphocytes can be challenger. We propose that polymerase chain reaction (PCR) amplification of the rearranged TCR gene in HTLV-I healthy carriers would be a convenient method for establishing the nature of the circulating T lymphocytes in asymptomatic HTLV-I carriers, presenting only mild and inconclusive signals of deviation from normality. Methods:,Using PCR, we analyzed the genetic recombination pattern of the T-cell , -chain receptor gene (TCR - ,) in order to identify clonal expansion of peripheral blood T lymphocytes in 17 HTLV-I-positive healthy carriers and in nine normal HTLV-I-negative blood donors. To evaluate the performance of PCR in detection of clonality, we also analyzed 18 patients with post-thymic/mature T-cell malignancies presenting circulating abnormal lymphocytes. Results:,Seven of the 17 HTLV-I positive individuals presented circulating abnormal lymphocytes; monoclonal or oligoclonal expansion of T-cells was detected in five of the 17 HTLV-I-positive individuals, all of them presenting abnormal lymphocytes. Clonal expansion was not detected in any of the negative controls or in any of the 12 remaining healthy carriers. All patients in the positive control group tested positive by PCR and Southern blots. Southern blots were negative for all 17 healthy carriers. Conclusions:,PCR amplification of segments of rearranged TCR- , is reliable for allowing early detection of small populations of clonal T cells in blood samples from asymptomatic HTLV-I carriers, providing an additional alert in the follow-up of carriers with abnormal circulating lymphocytes. [source]


Microleakage along Glassix glass fibre posts cemented with three different materials assessed using a fluid transport system

INTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2006
-Barbi, M. Rogi
Abstract Aim, To evaluate the microleakage along Glassix fibre posts cemented with three different materials. Methodology, The root canals of maxillary central incisor teeth were filled and restored with Glassix posts (Harald Nordin sa, Chailly/Montreux, Switzerland) cemented with either a zinc-phosphate Harvard cement (Richter & Hoffmann, Harvard Dental GmbH, Berlin, Germany), Fuji PLUS cement (GC Corporation, Tokyo, Japan) or Variolink II cement (Vivadent, Schaan, Lichtenstein) in three groups of 15 canals each. Twenty unrestored canals served as a control group, 10 filled with gutta-percha and sealer (negative control group), the remaining 10 with gutta-percha only (positive control group). Coronal microleakage was evaluated using a fluid transport system. The movement of an air bubble in a capillary glass tube connected to the apex of the experimental root section was measured over 5-min periods. Measurements were performed four times for each specimen and the mean values recorded. anova and Duncan's test were performed. Results, The positive control group had the highest values of microleakage. Amongst experimental groups, the highest values of microleakage occurred in the group with the posts cemented with Harvard cement, followed by Fuji PLUS and Variolink II cements. Groups with Fuji PLUS, Variolink II and the negative control group had significantly (P < 0.00001) less microleakage compared with the Harvard cement group and the positive control group. Conclusion, Canals with Glassix posts cemented with Variolink II and Fuji PLUS cement had the least leakage when assessed using a fluid transport system. [source]


Effects of some pharmacological agents on the survival of unipedicled venous flaps: an experimental study

MICROSURGERY, Issue 8 2001
Ibrahim Askar M.D.
Clinical and experimental studies have been conducted to improve the survival of venous flaps. As a result of these studies, although various survival mechanisms were raised, none obtained satisfactory information. Venous stasis, and the resultant venous thrombosis, is a factor that decreases the survival of venous flaps. In this study, we evaluated the effects of two antiinflammatory agents, etodolac and etofenamate, on the survival of unipedicled venous flaps. In this study, 35 male New Zealand white rabbits (3,500,4,000 g) (70 ears) were used. Perichondrocutaneous flaps, 3 × 4.5 cm in size, were designed and raised, keeping the central veins intact in the middle of venous flap. Central arteries and nerves were ligated and transected both proximally and distally, to prepare unipedicled venous flaps. A silicone sheet was placed between the cartilage tissue and flap, to prevent blood flow and revascularization beneath. The subjects were divided into seven groups, consisting of five rabbits (10 ears). In the negative control group (group I), the single vascular pedicle of venous flaps, central veins were ligated and flaps sutured into their own place as the composite graft. In the positive control group (group II), after venous flaps were prepared, normal saline, 0.2 mL, was given subcutaneously. In the first of five experimental groups (group III), unfractionated heparin (100 U/day) was given subcutaneously. In the second experimental group (group IV), etodolac (5 mg/kg/day) was given subcutaneously. In the third experimental group (group V), etophenamate (5 mg/kg/day) was given orally through a feeding tube. In the fourth experimental group (group VI), parnaparin (5 anti-Xa U/kg/day) was given subcutaneously. In the fifth experimental group (group VII), nadroparin (5 anti-Xa U/kg/day) was given subcutaneously, about 7 days postoperatively. At the eighth postoperative day, surviving areas of venous flaps were measured, and the results were evaluated by Kruskal-Wallis ANOVA and Mann-Whitney U-test (P < 0.05). Biopsies were also taken from the flaps for histological evaluation of border of necrotic tissue. Surviving areas of unipedicled venous flaps were larger in experimental groups than those in negative and positive control group (P < 0.05). However, comparison of the experimental groups demonstrated no statistically significant difference (P > 0.05). We concluded that all pharmacological agents used in the experimental groups succeeded in increasing the survival of unipedicled venous flaps. Survival of the unipedicled venous flap was higher in venous flaps than that of composite graft, clearly showing the importance of the venous pedicle. © 2001 Wiley-Liss Inc. MICROSURGERY 21:350--356, 2001 [source]


Skin testing for immediate hypersensitivity to betalactams: comparison between two commercial kits

ALLERGY, Issue 8 2006
J. L. Rodríguez-Bada
Introduction:, Skin testing with major and minor determinants of benzylpenicillin is the recommended standard practice to evaluate subjects with immediate hypersensitivity to betalactams. The withdrawal of these products from the market has set us back to the early days, before the introduction of reagents for in vivo testing. Objectives:, To compare a recently released kit of benzylpenicillin conjugated to poly- l -lysine (PPL) and minor determinants mixture (MDM) with the previously existing kit in a positive control group of subjects sensitized to major and/or minor determinants of benzylpenicillin. Methods:, Skin tests with both kits were made in a group of positive subjects previously diagnosed with immediate hypersensitivity to penicillins and with positive results to PPL and/or MDM and in a negative control group. Radioallergosorbent test (RAST) inhibition assays with a pool of sera and individual samples were carried out to compare the inhibition capacity of PPL and MDM of both kits. Results:, Of 22 cases selected from our historical group, 14 were positive: eight to PPL, three to MDM and three to both. These results were equivalent for both kits. RAST inhibition studies showed similar potencies in the inhibition of PPL and MDM. Conclusions:, Both tests show similar results in terms of RAST inhibition assays and skin tests sensitivity and specificity in the groups selected. The new assay can be used for the same purpose and indications as the previous test. [source]


Preventive Effects of Quercetin against Benzo[a]pyrene-Induced DNA Damages and Pulmonary Precancerous Pathologic Changes in Mice

BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 6 2006
Nian-zu Jin
In this study, mice in quercetin-treated groups were given quercetin for 90 days. After one week of treatment, mice in the quercetin-treated groups and the positive control group received a single intraperitoneal dose of benzo[a]pyrene (100 mg/kg body weight). The results of single cell gel electrophoresis assay showed that the average lengths of the comet cell tail and DNA damage in the peripheral blood lymphocytes of mice induced by benzo[a]pyrene decreased significantly as a result of quercetin treatment dose-dependently. Light microscopic examination showed that the degrees of pulmonary precancerous pathologic changes in the quercetin-treated groups decreased significantly compared with those in the positive control group. Meanwhile, the cytochrome P4501A1-linked 7-ethoxyresorufin O-dealkylase activities in lung microsomes of mice decreased as the dose of quercetin increased. The results of this in vivo study revealed that quercetin had a significant preventive effect on benzo[a]pyrene-induced DNA damage, and had a potential chemopreventive effect on the carcinogenesis of lung cancer induced by benzo[a]pyrene. The mechanism of these effects of quercetin could be related to the inhibition of cytochrome P4501A1 activity. [source]


Determination of the time required for appropriate chemical de-epithelialization of an ileal segment for cystoplasty: an animal model

BJU INTERNATIONAL, Issue 6 2005
Jalal Bakhtiari
Another group of authors from Iran attempted experimentally to determine the required time for the appropriate enzymatic treatment of the ideal segment to complete de-epithelialization, thus reducing its absorptive function. They found that 25 min of enzymatic treatment of the ideal segment was adequate for this, and that it was recommended from their experimental study for cystoplasty. OBJECTIVES To determine the time required for the appropriate enzymatic treatment of an ileal segment to de-epithelialize its mucosa and to reduce its absorptive function for cystoplasty in dogs. MATERIALS AND METHODS Twenty-one adult female Persian mixed-breed dogs were divided into seven equal groups: group 1 (negative control group) had no ileocystoplasty; group 2 (positive control group) had a routine ileocystoplasty with no enzymatic treatment of the ileal segment; and groups 3,7 had an ileocystoplasty with 5, 10, 15, 20 or 25 min, respectively, of enzymatic treatment of the ileal segment with collagenase and trypsin. The seven groups were then compared for haematological, biochemical and histological changes, and glucose reabsorption assessed using a glucose-absorption test. RESULTS No dogs showed any signs of metabolic disturbances, biochemical and haematological changes. There were significant differences in blood glucose level (BGL) for the groups at different times after the glucose-absorption test, but a pair-wise comparison showed significant differences in BGL between group 1 and the other groups, except group 7. The degree of histopathological change was associated with the duration of enzymatic treatment, in that changes were more prominent in group 7. There was no shrinkage or collagen deposition. CONCLUSIONS In these conditions, 25 min of enzymatic treatment of the ileal segment is sufficient to remove the absorptive function of the augmented bladder, and is recommended for cystoplasty in dogs. [source]