Cloning and expression of a plasmid-linked pediocin determinant trait of Pediococcus acidilactici F

Plasmid DNA from Pediococcus acidilactici F was prepared by lysozyme-mutanolysin method and purified by cesium chloride-ethidium bromide (CsCl-EtBr) density gradient ultracentrifugation. Agarose gel electrophoresis of plasmid DNA and plasmid-curing experiments suggested that bacteriocin activity was harboured on a small plasmid of approximately 9.1 kb (kilobasepair) in Pediococcus acidilactici F. Plasmid encoding bacteriocin production in P. acidilactici F was examined for restriction enzyme cleavage patterns and its map has been constructed. An Escherichia coli strain transformed with the recombinant plasmid, pQE322, produced and, most probably, secreted pediocin F.     

Immunohistochemical staining properties of PCNA, Ki-67, p53, beta-hCG and HPL in trophoblastic disease

OBJECTIVE: In this study proliferating markers PCNA (proliferating cell nuclear antigen) Ki-67 and mutation of supressor gene p53 were investigated in gestational trophoblastic disease (GTL). These markers were tested by using immunostaining with beta subunits of human chorionic gonadotropin (hCG) and human placental lactogen (HPL). MATERIAL AND METHODS: Twenty curetting samples, 20 spontaneous abortions, 16 hydatidiform moles and two choriocarcinomas were studied and compared. Hydatidiform moles were subdivided into 10 complete and six partial moles by using flow cytometry analysis. All slides were stained with PCNA, Ki-67, p53, hCG, and HPL immunohistochemically. PCNA and Ki-67 stained slides were studied quantitatively to determine the PCNA and Ki-67 index. Other slides that were stained with p53, hCG, HPL were evaluated according to staining percentage and intensity. Staining properties of all groups were compared with each other. Variance analysis and the Mann Whitney U test were used for statistical analysis. Choriocarcinomas were not included in the statistical analysis. Ki-67 and the PCNA index in two choriocarcinoma cases found 81.4% and 41%, and 44% and 64%, respectively. One case was stained in 70% with (++) intensity by p53. While both were stained in 80% with (++) intensity by hCG, one was stained in 30% field (+) intensity by HPL. RESULTS: The four groups of complete and incomplete diagnosed hydatiform moles, spontaneous abortions and retention curettage were matched in pairs and evaluated according to the PCNA index. This index showed significant differences among the groups. The differences among the Ki-67 index, p53, hCG and HPL staining properties were not statistically significant. CONCLUSION: Our findings showed that PCNA is a significant and useful marker for trophoblastic diseases and can be used as a prognostic factor.     

Functional magnetic resonance imaging of visual object construction and shape discrimination : relations among task, hemispheric lateralization, and gender

We studied the brain activation patterns in two visual image processing tasks requiring judgements on object construction (FIT task) or object sameness (SAME task). Eight right-handed healthy human subjects (four women and four men) performed the two tasks in a randomized block design while 5-mm, multislice functional images of the whole brain were acquired using a 4-tesla system using blood oxygenation dependent (BOLD) activation. Pairs of objects were picked randomly from a set of 25 oriented fragments of a square and presented to the subjects approximately every 5 sec. In the FIT task, subjects had to indicate, by pushing one of two buttons, whether the two fragments could match to form a perfect square, whereas in the SAME task they had to decide whether they were the same or not. In a control task, preceding and following each of the two tasks above, a single square was presented at the same rate and subjects pushed any of the two keys at random. Functional activation maps were constructed based on a combination of conservative criteria. The areas with activated pixels were identified using Talairach coordinates and anatomical landmarks, and the number of activated pixels was determined for each area. Altogether, 379 pixels were activated. The counts of activated pixels did not differ significantly between the two tasks or between the two genders. However, there were significantly more activated pixels in the left (n = 218) than the right side of the brain (n = 161). Of the 379 activated pixels, 371 were located in the cerebral cortex. The Talairach coordinates of these pixels were analyzed with respect to their overall distribution in the two tasks. These distributions differed significantly between the two tasks. With respect to individual dimensions, the two tasks differed significantly in the anterior--posterior and superior--inferior distributions but not in the left--right (including mediolateral, within the left or right side) distribution. Specifically, the FIT distribution was, overall, more anterior and inferior than that of the SAME task. A detailed analysis of the counts and spatial distributions of activated pixels was carried out for 15 brain areas (all in the cerebral cortex) in which a consistent activation (in > or = 3 subjects) was observed (n = 323 activated pixels). We found the following. Except for the inferior temporal gyrus, which was activated exclusively in the FIT task, all other areas showed activation in both tasks but to different extents. Based on the extent of activation, areas fell within two distinct groups (FIT or SAME) depending on which pixel count (i.e., FIT or SAME) was greater. The FIT group consisted of the following areas, in decreasing FIT/SAME order (brackets indicate ties): GTi, GTs, GC, GFi, GFd, [GTm, GF], GO. The SAME group consisted of the following areas, in decreasing SAME/FIT order : GOi, LPs, Sca, GPrC, GPoC, [GFs, GFm]. These results indicate that there are distributed, graded, and partially overlapping patterns of activation during performance of the two tasks. We attribute these overlapping patterns of activation to the engagement of partially shared processes. Activated pixels clustered to three types of clusters : FIT-only (111 pixels), SAME-only (97 pixels), and FIT + SAME (115 pixels). Pixels contained in FIT-only and SAME-only clusters were distributed approximately equally between the left and right hemispheres, whereas pixels in the SAME + FIT clusters were located mostly in the left hemisphere. With respect to gender, the left-right distribution of activated pixels was very similar in women and men for the SAME-only and FIT + SAME clusters but differed for the FIT-only case in which there was a prominent left side preponderance for women, in contrast to a right side preponderance for men. We conclude that (a) cortical mechanisms common for processing visual object construction and discrimination involve mostly the left hemisphere, (b) cortical mechanisms specific for these tasks engage both hemispheres, and (c) in object construction only, men engage predominantly the right hemisphere whereas women show a left-hemisphere preponderance.     

The clinical significance of QTc dispersion measurement for risk of syncope in patients with aortic stenosis

OBJECTIVES: (1) To evaluate the clinical usefulness of QTc dispersion determination in aortic stenosis and (2) to compare the effects of QTc dispersion on the occurrence risk of syncope in aortic stenosis. BACKGROUND: QT interval dispersion has long been known to be a marker of dispersion of ventricular repolarization and, hence, electrical instability. Additionally, it has been shown that these patients have a propensity to ventricular tachyarrhythmic syncope. METHODS: The study included 86 patients with aortic stenosis who underwent left-heart catheterization and coronary angiography during investigation of syncope, as well as 30 control subjects. The patients were characterized with regards to the presence or absence of a history of syncope and the severity of aortic stenosis (the degree of peak transvalvular gradient). In addition, QT dispersion measurements were corrected for heart rate according to Bazett's formula and both were measured. RESULTS: QTc dispersion was greater in patients with aortic stenosis than in the control subjects (60 +/- 13 msec vs 38 +/- 12 msec, P < 0.001). Similarly, QTc dispersion was greater in the patients with a history of syncope than in the patients with no history of syncope (68 +/- 12 msec vs 53 +/- 10 msec, P < 0.001). In addition, QTc dispersion values were greater in the patients with a high transvalvular gradient than in the patients with a low transvalvular gradient (65 +/- 12 msec vs 50 +/- 9 msec, P < 0.001). Multivariate logistic regression analysis showed that only an increased QTc dispersion had significant value for the risk of syncope in aortic stenosis. CONCLUSIONS: An increased QTc dispersion increases the occurrence risk for syncope in aortic stenosis. These results suggest that high values of QTc dispersion are a sensitive noninvasive marker for determining the risk for syncope in aortic stenosis.     

Mapping of the second Friedreich's ataxia (FRDA2) locus to chromosome 9p23-p11: evidence for further locus heterogeneity

Friedreich's ataxia (FRDA), the most-common form of autosomal recessive ataxia, is inherited in most cases by a large expansion of a GAA triplet repeat in the first intron of the frataxin (X25) gene. Genetic heterogeneity in FRDA has been previously reported in typical FRDA families that do not link to the FRDA locus on chromosome 9q13. We report localization of a second FRDA locus (FRDA2) to chromosome 9p23-9p11, and we provide evidence for further genetic heterogeneity of the disease, in a family with the classic FRDA phenotype.     

Tympanometry and acoustic reflectometry in ears with chronic retraction without effusion

OBJECTIVE: Purpose of this study was to find out test accuracy and predictivity of tympanometry (TYMP) and parameters (reflectivity and curve angle) of acoustic reflectometry (AR) in the ears with prior clinic and otoscopic evidences of effusion in which no effusion was detected by myringotomy, by comparing with the data found in normal ears and in those with effusion. METHODS: While study group included 31 ears with chronic retraction in which no effusion was detected by myringotomy, control group included 150 fully normal ears and 150 ears with effusion confirmed by myringotomy. B tracings in TYMP, and values of reflectivity higher than 5 and curve angle lower than 75 degrees in AR were accepted as indicators of effusion; in the combined test, the ears with non-B tracings in which curve angle higher than 75 degrees were accepted as those without effusion. RESULTS: False positivity values of TYMP, reflectivity and curve angle and the combined test found in the ears with chronic retraction without effusion (29, 23, 19 and 35% respectively; chi(2)-test, P > 0.1) were significantly higher than normal ears (chi(2)-test, P < 0.001), but lowe than those of effusion (chi(2)-test, P<0.0001). Further, although negative predictivity values of TYMP, reflectivity and curve angle were found to be lower in these ear, compared to normal ears (chi(2)-test, P < 0.01), the combined test reached to a perfect negative predictivity, as much as in normal ears. On the other hand, positive predictivity values were decreased in the ears with chronic retraction without effusion by only reflectivity. CONCLUSIONS: By both TYMP and AR alone, it is more difficult to find out the ears without effusion among the ears clinically and otoscopically diagnosed as otitis media than to find out normal ears. Therefore, in clinical work, false positivity of these devices were higher, and their specificity and negative predictivity were lower; although the combined test solved problem of low negative predictivity, high number of false positive ears in clinical work, that is lower specificity, continues to be an unsolved problem by either TYMP or AR alone, or both together.     

Melanotic neuroectodermal tumor of infancy: report of two cases and review of literature

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare, distinctive neoplasm containing melanin; it primarily affects the maxilla of the infants during the first year of life. Approximately 150 instances of this tumor are reported in the medical literature. Genesis of the tumor is obscure and the diagnosis is challenging for the pathologist. Two cases operated by the first author are presented, and the diagnostic features and treatment alternatives of MNTI discussed.     

Associations between the eustachian tube and craniofacial skeleton

OBJECTIVE: Growth and development of the anatomic region where the Eustachian tube (ET) is located are associated with the parameters related to other parts of the craniofacial skeleton (CFS). It has been suggested that ET dysfunction is as an important factor in pathogenesis of otitis media in childhood which is associated with its postnatal growth and development process. The purpose of this study was to evaluate associations of length of the ET with various craniofacial parameters. METHODS: On lateral cephalometric radiographs of 50 Japanese adult (25 male and 25 female), the dimension of the region where the ET is located ('length of the ET') and 22 (15 linear and seven angular) craniofacial parameters were measured by using a digitiser and computer. Correlation and regression analyses were performed between this dimension and other craniofacial parameters. RESULTS: It was found that the dimension of the region in which the ET is located ('length of the ET') was associated with many craniofacial parameters belonging to different subunits of the CFS. However, the stepwise regression analysis showed that total cranial base length, posterior upper face height and maxillary depth had determinative effects on this dimension. CONCLUSION: Development of the ET was associated with development of the cranial base and nasomaxillary complex. Therefore, it could be hypothesised that any cessation or aberration in these parts of the CFS cause corresponding imbalances in the ET, which may predispose to otitis media.     

Synthesis of some 3,4-disubstituted-6,7-dihydro-imidazo[2,1-b][1,3]thiazole and 3,4-disubstituted-7,8-dihydro-6H-imidazo[2,1-b][1,3]thiazine derivatives and evaluation of their cytotoxicities against F2408 and 5RP7 cells

This article describes the synthesis of 3,4-disubstituted-6,7-dihydro-imidazo[2,1-b][1,3]thiazoles and 3,4-disubstituted-7,8-dihydro-6H-imidazo[2,1-b][1,3]thiazines, having substituted or nonsubstituted phenyl rings at the 5,6 and 2,3 positions, respectively, their cytotoxic effects through noncancer (F2408) and cancer (5RP7) cells, and their detailed ¹H- and ¹³C-nuclear magnetic resonance (NMR) spectral characterization. The title compounds were obtained by the cyclization of 4,5-diaryl-imidazole-2-thione and dihaloalkane (i.e., 1,2-dihaloethane or 1,3-dihalopropane), in the presence of potassium carbonate (K₂CO₃) in N,N-dimethyl formamide (DMF). 4,5-Diaryl-imidazole-2-thione was prepared by condensation of α-hydroxyketones (acyloins), which were obtained by treating aldehydes with cyanide, with thioureas in AcOH. The structure of imidazo[2,1-b][1,3]thiazole and imidazo[2,1-b][1,3]thiazine derivatives was confirmed by infrared (IR), ¹H-NMR, and ¹³C-NMR. The cytotoxicities of the synthesized compounds on both of noncancer (F2408) and cancer (5RP7) cells were measured by 3-(4,5-dimethyl-thiazollyl-2)-2,5-diphenyltetrazolium (MTT) assay. In the presence of only lower doses of compounds 9 and 11, bearing methyl or methoxy substituents on the phenyl ring of imidazo[2,1-b][1,3]thiazole scaffold, the cytotoxic effect was higher on 5RP7 cells than control cells after 24 h.