Prefrontal cortex involvement in selective letter generation: a functional magnetic resonance imaging study

Leech neurons exposed to salines containing inorganic Ca(2+)-channel blockers generate rhythmic bursts of impulses. According to an earlier model, these blockers unmask persistent Na+ currents that generate plateau-like depolarizations, each triggering a burst of impulses. The resulting increase in intracellular Na+ activates an outward Na+/K+ pump current that contributes to burst termination. We tested this model by examining systematically the effects of six transition metal ions (Co2+, Ni2+, Mn2+, Cd2+, La3+, and Zn2+) on the electrical activity of neurons in isolated leech ganglia. Each ion induced bursting activity, but the amplitude, form, and persistence of bursting differed with the ion used and its concentration relative to Ca2+. All ions tested suppressed chemical synaptic transmission between identified motor neurons, consistent with block of voltage-dependent Ca2+ currents in these cells. In addition, a strong correlation between suppression of synaptic transmission and burst amplitudes was obtained. Finally, burst duration was increased and the rate of repolarization decreased in reduced K+ saline, as expected for pump-dependent repolarization. These results provide further support for the hypothesis that a novel form of oscillatory electrical activity driven by persistent Na+ currents and the Na+/K+ pump occurs in leech ganglia exposed to Ca(2+)-channel blockers.     

Prognostic implications of proliferating cell nuclear antigen (PCNA), AgNORs and P53 in non-Hodgkin's lymphomas

We investigated the prognostic value of proliferating cell nuclear antigen (PCNA) and p53 oncoprotein expression and of nucleolar organiser region (NOR) scoring, in relation to classic clinicopathological parameters, in a series of non-Hodgkin's lymphomas (NHL). Paraffin embedded tissue from 91 patients with NHL was stained immunohistochemically with the monoclonal antibodies PC-10 (PCNA) and DO-1 (p53) and histochemically with the AgNOR technique. The median follow-up was 48 (4 to 193) months. The impact of PCNA and p53 expression and of AgNOR number on survival was tested using univariate as well as multivariate analysis, in order to circumvent the heterogeneity in histologic grade, type and therapy. Univariate analysis identified seven variables related to overall survival: histologic type and grade, clinical stage, chemotherapy, p53 labelling index (LI), PCNA LI and AgNOR score, whereas only one parameter i.e. histologic grade influenced disease-free survival. In multivariate analysis stage, PCNA LI and AgNOR score predicted independently overall survival. PCNA was also the only independent predictor of post-relapse survival and histologic grade the most important indicator of disease-free survival. In conclusion, PCNA expression and AgNOR number may be better predictors of overall and post-relapse survival than histologic grade. The latter remains the most valuable prognostic indicator of disease-free survival.     

Extracellular signal-regulated kinase-2, but not c-Jun NH2-terminal kinase, activation correlates with surface IgM-mediated apoptosis in the WEHI 231 B cell line

Both extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) have been implicated in mediating the signaling events that precede apoptosis. We studied the activation of these kinases during apoptosis of WEHI 231 B cells. Surface IgM ligation induces apoptosis of WEHI 231 cells. This effect is augmented by simultaneous engagement of CD95 and is inhibited by costimulation with either CD40 or IL-4R. We determined that surface IgM ligation activates ERK2 to a much greater level than JNK, and that IgM-mediated ERK2 activation is enhanced by costimulation with anti-CD95. Costimulation with either IL-4 or anti-CD40 interferes with anti-IgM-stimulated ERK2 activation. Transient expression of mitogen-activated protein kinase phosphatase-1 (MKP-1) inhibits both ERK2 activation and cell death following stimulation with anti-IgM and the combination of anti-IgM plus anti-CD95. CD40 engagement alone activates JNK, but IL-4 stimulation does not. N-acetyl-L-cysteine pretreatment, which blocks CD40-mediated JNK activation, does not affect the ability of CD40 to inhibit anti-IgM-mediated ERK2 activation and apoptosis. Together, these data suggest that JNK activation is not required for CD40 inhibition of surface IgM-induced cell death and that ERK2 plays an active role in mediating anti-IgM-induced apoptosis of WEHI 231 B cells.     

Phenylethanoid glycosides from Digitalis purpurea and Penstemon linarioides with PKCalpha-inhibitory activity

In a continuation of our search for potential tumor inhibitors from plants, it was found that the CH2Cl2-MeOH (1:1) extracts from Digitalis purpurea and Penstemon linarioides both showed PKCalpha-inhibitory bioactivity. Bioassay-directed fractionation of the extract from D. purpurea yielded the new, weakly active phenylethanoid glycoside 2-(3-hydroxy-4-methoxy-phenyl)-ethyl-O-(alpha-L-rhamnosyl)-(1-->3) -O- (alpha-L-rhamnosyl)-(1-->6)-4-O-E-feruloyl-beta-D-glucopy ran oside (1) together with the four known compounds calceolarioside A (2), calceolarioside B (3), forsythiaside (4), and plantainoside D (5). The extract from P. linarioides yielded the three known glycosides leucosceptoside A (6), acteoside (7), and poliumoside (8), together with the iridoid plantarenaloside (9). All of the isolated compounds, except compound 9, showed inhibitory activity against PKCalpha with IC50 values (in microM) of 125 (1), 0.6 (2), 4.6 (3), 1.9 (4), 14.8 (5), 19.0 (6), 9.3 (7), and 24.4 (8).     

Factors associated with penile amputation in Thailand

PURPOSE: To evaluate the feasibility of using the grading algorithm utilized by the Advanced Glaucoma Intervention Study (AGIS) on a Humphrey Field Analyser with program 9 (76/30 degrees Threshold Grid) of a computerized perimeter DICON TKS 4000 and find whether the obtained score can be used to determine the stage of glaucoma. METHODS: Computerized perimetry was performed on 205 eyes with proven or suspected glaucoma. Visual field changes were assessed first subjectively, and then with the scoring method used in AGIS: the size, depth, and location of the visual field defects, and the nasal step were determined using a stencil and then the final score was calculated. RESULTS: Of 205 eyes examined 79 had perimetric changes. These were allocated subjectively into four groups corresponding to four stages of glaucoma: initial, evoluted, advanced and terminal. The mean scores for each group were calculated. There was a statistically significant correlation between the score and the stage of glaucoma. The mean scores for the first 3 stages differed significantly from each other. For stages 3 and 4 the difference was not statistically significant. CONCLUSION: The AGIS scoring method, developed originally for program 30-2 of the Humphrey Field Analyzer, can be applied with the 30 degrees Threshold Grid program of DICON TKS 4000 Perimeter for objective assessment of the glaucoma stage.     

In defense of a body mass index of 25 as the cut-off point for defining overweight

A dermoid cyst occurring within the parotid gland of a 37-year-old Chinese man is reported. The diagnostic difficulties, histopathological features and pathogenesis are considered.     

High-efficiency retrovirus-mediated gene transfer into the livers of mice

Recombinant retroviral vectors represent an attractive means of transferring genes into the liver because they integrate in the host cell genome and result in permanent gene expression. However, efficient gene transfer is limited by the requirement of active cell division for integration. Surgical partial hepatectomy has been the traditional method of inducing hepatocellular proliferation, but this invasive approach would be difficult to justify in clinical gene therapy. As an alternative, we used a recombinant adenovirus expressing a nonsecreted form of urokinase plaminogen activator (Ad.PGKmuPA), which results in liver regeneration over a period of 8 days. When a high-titer retroviral vector was continuously infused into the portal vein of mice during this period of hepatocyte proliferation, 33.5% of hepatocytes were stably transduced. In addition, high-level expression of a secreted transgene reporter was sustained for at least 48 weeks (length of experiment). We investigated the influence of vector titer on the in vivo transduction efficiency in our system, and found that the total number of infectious retroviral particles delivered per target cell is a critical factor. The results presented here demonstrate the ability to obtain a high gene transfer efficiency and long-term gene expression in hepatocytes in vivo without the need for surgical hepatectomy. The two-vector system described here may be of clinical relevance, as the level of hepatic gene transfer achieved has potential to be curative for a large number of genetic liver diseases.     

Vocal cord and pharyngeal weakness with autosomal dominant distal myopathy: clinical description and gene localization to 5q31

Distal myopathy refers to a heterogeneous group of disorders in which the initial manifestations are weakness and atrophy of the hands and feet. We report a family segregating an autosomal dominant distal myopathy, with multiple affected individuals in whom vocal cord and pharyngeal weakness may accompany the distal myopathy, without involvement of the ocular muscles. To our knowledge, this pedigree displays a distinct distal myopathy with the added features of pharyngeal and vocal cord dysfunction (VCPDM) that has not been previously reported. We mapped the MPD2 gene for VCPDM to chromosome 5q within a 12-cM linkage interval between markers D5S458 and D5S1972 in a large pedigree (a maximum LOD score of 12.94 at a recombination fraction of 0 for D5S393) and combined genome screening and DNA pooling successfully adapted to fluorescent markers. This technique provides for the possibility of fully automated genome scans.     

Blunt splenic trauma: characteristics of patients requiring urgent laparotomy

Arthrogryposis is a heterogeneous birth defect characterized by limitation of movement at multiple joints. One in 3,000 infants is born with arthrogryposis, and at least a third of these cases have a genetic cause. Four distinct types of X-linked arthrogryposis have been reported, and a severe lethal form recently was mapped to Xpll.3-qll.2. We now report an extended family affected with a novel variant of X-linked arthrogryposis that involves only the lower limbs. Linkage analysis with polymorphic DNA markers maps the disease locus in this unique family to the long arm of the human X chromosome between DXS1220 and DXS1205 in Xq23-27.     

Myocardial uptake and redistribution of 99mTc-N-NOET in dogs with either sustained coronary low flow or transient coronary occlusion: comparison with 201Tl and myocardial blood flow

BACKGROUND: 99mTc-N-NOET (NOET) is a new myocardial perfusion imaging agent that redistributes over time. We sought to better define the redistribution kinetics of NOET using open-chest canine models of sustained low coronary flow (protocol 1) and transient coronary occlusion followed by reflow (protocol 2). METHODS AND RESULTS: In protocol 1 (n=10), NOET and 201Tl were injected during low flow in the left anterior descending coronary artery (LAD) that was sustained for 2 hours. Protocol 2 dogs (n=6) were injected with NOET during 20 minutes of LAD occlusion followed by 2 hours of reflow. In both protocols, serial NOET planar images were acquired, and myocardial flow and 2-hour tracer activities were determined by gamma-well counting. Defect resolution was observed on images in both protocols. Initial defect count ratios, reflecting flow disparity at injection (0.66+/-0.03 and 0.57+/-0.04, respectively), increased over 2 hours (0.73+/-0.02 and 0.75+/-0.04, respectively; P<.001 versus initial). Quantitative imaging showed that NOET redistribution resulted from greater clearance from normal areas versus low-flow or transiently occluded areas. In protocol 1, 2-hour NOET and 201Tl stenotic-to-normal tissue activity ratios were similar (0.76+/-0.06 versus 0.73+/-0.04, P=NS) and higher than injection flow ratios (0.52+/-0.06 and 0.56+/-0.07, respectively, P<.001), consistent with tracer redistribution. In protocol 2, NOET redistributed to an even greater extent (injection flow ratio, 0.27+/-0.04; 2-hour tissue activity ratio, 0.84+/-0.03, P<.001). CONCLUSIONS: NOET is the first 99mTc-labeled myocardial imaging agent with kinetics similar to 201Tl in experimental models, permitting redistribution imaging. NOET appears to be a promising agent for assessing patients with coronary artery disease.