Rabbit Retinal Neovascularization Induced by Latex Angiogenic-Derived Fraction: An Experimental Model

Purpose: To create a retinal neovascularization experimental model using intravitreal injection of microspheres loaded with latex-derived angiogenic fraction. Methods: Thirty-two albino New Zealand rabbits, divided in 4 groups of 8 animals, were enrolled in this study. Rabbits in groups I, II, and III received one intravitreal injection of PLGA (L-lactide-co-glycolide) microspheres with 10, 30, and 50 mu g of latex-derived angiogenic fraction into their right eyes, respectively, and group IV received 0.1 ml of microspheres without the angiogenic fraction. Weekly follow-up with ophthalmoscopy and fluorescein angiography was performed; the rabbits were sacrificed in the 4th week and their eyes processed for light microscopy. Results: All eyes from group I demonstrated increased retinal vascular tortuosity, observed from 14 days after injection and maintained for 28 days, otherwise without new vessels detection. All group II eyes showed vascular changes similar to group I. Fifty percent of the eyes from group II rabbits developed retinal neovascularization 21 days after injection. All eyes from group III demonstrated significant vascular tortuosity and retinal new vessels 2 weeks after injection, progressing to fibrovascular proliferation and tractional retinal detachment. No vascular changes or retinal new vessels were observed in group IV eyes. Light microscopy confirmed the existence of new vessels previously seen on fluorescein angiography, in retinal sections adjacent to the optic disc, not observed in sections at the same area in the control group. Conclusion: Thirty- and 50-mu g microspheres containing latex-derived angiogenic fraction injected into the vitreous cavity induced retinal neovascularization in rabbits.

BhSGAMP-1, a Gene That Encodes an Antimicrobial Peptide, Is Developmentally Regulated by the Direct Action of 20-OH Ecdysone in the Salivary Gland of Bradysia hygida (Diptera, Sciaridae)

Recently we have shown that BhSGAMP-1 is a developmentally regulated reiterated gene that encodes an antimicrobial peptide (AMP) and is expressed exclusively in the salivary glands, at the end of the larval stage. We show, for the first time, that a gene for an AMP is directly activated by 20-OH ecdysone. This control probably involves the participation of short-lived repressor(s). We also found that the promoter of BhSGAMP-1 is not equipped with elements that respond to infection, provoked by the injection of microorganisms, in the salivary glands or in the fat body. We produced polyclonal antibodies against the synthetic peptide and found that the BhSGAMP-1 peptide is secreted in the saliva. The BhSGAMP-1 gene was also activated during the third larval molt. These facts confirm our hypothesis that this preventive system of defense was selected to produce an environment free of harmful microorganisms in the insect`s immediate vicinity, during molts. genesis 47:847-857, 2009. (C) 2009 Wiley-Liss, Inc.

Synaptic transmission block by presynaptic injection of oligomeric amyloid beta

Early Alzheimer`s disease (AD) pathophysiology is characterized by synaptic changes induced by degradation products of amyloid precursor protein (APP). The exact mechanisms of such modulation are unknown. Here, we report that nanomolar concentrations of intraaxonal oligomeric (o)A beta 42, but not oA beta 40 or extracellular oA beta 42, acutely inhibited synaptic transmission at the squid giant synapse. Further characterization of this phenotype demonstrated that presynaptic calcium currents were unaffected. However, electron microscopy experiments revealed diminished docked synaptic vesicles in oA beta 42-microinjected terminals, without affecting clathrin-coated vesicles. The molecular events of this modulation involved casein kinase 2 and the synaptic vesicle rapid endocytosis pathway. These findings open the possibility of a new therapeutic target aimed at ameliorating synaptic dysfunction in AD.

Role of Rab27 in synaptic transmission at the squid giant synapse

Small GTPase Rab is a member of a large family of Ras-related proteins, highly conserved in eukaryotic cells, and thought to regulate specific type(s) and/or specific step(s) in intracellular membrane trafficking. Given our interest in synaptic transmission, we addressed the possibility that Rab27 (a close isoform of Rab3) could be involved in cytosolic synaptic vesicle mobilization. Indeed, preterminal injection of a specific antibody against squid Rab27 (anti-sqRab27 antibody) combined with confocal microscopy demonstrated that Rab27 is present on squid synaptic vesicles. Electrophysiological study of injected synapses showed that the anti-sqRab27 antibody inhibited synaptic release in a stimulation-dependent manner without affecting presynaptic action potentials or inward Ca2+ current. This result was confirmed in in vitro synaptosomes by using total internal reflection fluorescence microscopy. Thus, synaptosomal Ca2+-stimulated release of FM1-43 dye was greatly impaired by intraterminal anti-sqRab27 antibody. Ultrastructural analysis of the injected giant preterminal further showed a reduced number of docked synaptic vesicles and an increase in nondocked vesicular profiles distant from the active zone. These results, taken together, indicate that Rab27 is primarily involved in the maturation of recycled vesicles and/or their transport to the presynaptic active zone in the squid giant synapse.

Indirect immune detection of ecdysone receptor (EcR) during the formation of DNA puffs in Bradysia hygida (Diptera, Sciaridae)

Gene amplification occurs in Bradysia hygida salivary glands, at the end of the fourth larval instar. The hormone 20-hydroxyecdysone (20E) triggers this process, which results in DNA puff formation. Amplified genes are activated in two distinct groups. The activity of the first group is dependent on high levels of 20E, while the second group needs low hormone levels. Consequently, the salivary glands of B. hygida constitute an interesting biological model to study how 20E, and its receptors, affect gene amplification and activity. We produced polyclonal antibodies against B. hygida EcR (BhEcR). In western blots a polypeptide of about 66 kDa was detected in salivary gland extracts. The antibodies were also used for indirect immune-localization of BhEcR in polytene chromosomes. RNA-polymerase II was also immune-detected. We did not detect the receptor in chromosome C where the first and second groups of DNA puffs form during DNA puff anlage formation, but it was present during puff expansion. During the active phase of both groups of DNA puffs, RNA polymerase II co-localized with BhEcR. After puff regression, these antigens were not detected. Apparently, EcR plays a direct role in the transcription of amplified genes, but its role in gene amplification remains enigmatic.

Some results on holomorphic generalized functions

In this note, we present three independent results within generalized complex analysis (in the Colombeau sense). The first of them deals with non-removable singularities; we construct a generalized function u on an open subset Omega of C(n), which is not a holomorphic generalized function on Omega but it is a holomorphic generalized function on Omega\S, where S is a hypersurface contained in Omega. The second result shows the existence of a holomorphic generalized function with prescribed values in the zero-set of a classical holomorphic function. The last result states the existence of a compactly supported solution to the (partial derivative) over bar operator.

Tentorial meningiomas: follow-up review

Tentorial meningiomas comprise 3-5% of the intracranial meningiomas. Different locations and sinus invasion require special surgical skills. This study aimed to analyze factors influencing the outcome of 29 patients (30 tumors) with tentorial meningiomas surgically treated. The study included 22 female and seven male patients, with age of 18-76 years old, and a follow-up of 6-179 months. Eight tumors were located on the inner tentorial ring, 15 on the outer ring, four were falcotentorial, and three attached/invading the torcula. Outcome was analyzed using survival and recurrence-free survival (RFS) curves. Twenty-seven tumors were WHO grade I and three were grades II-III. Total and subtotal resections were reached in 87.5% and 12.5% of tumors. Survival was better for patients with grade I tumors and similar according to sex, location, size, and extent of resection. Recurrence/regrowing rate was 12.5%. RFS curves were better for patients with grade I or with radical resection and similar according to sex, location, and size. There was no operative mortality. Permanent postoperative cranial nerve deficits occurred in 9.7% (all inner ring tumors). Despite being many times large-sized, surgical treatment of tentorial meningiomas gives good results. Prognostic factors for recurrence were histopathologic grade III and subtotal resection. Radical resection allowed better results. Nevertheless, subtotal resection may be acceptable for cases with cranial nerves or sinuses invasions.

Quantitative and qualitative comparison of 3.0 T and 1.5 T MR imaging of the liver in patients with diffuse parenchymal liver disease

Purpose: The purpose of our study was to compare signal characteristics and image qualities of MR imaging at 3.0 T and 1.5 T in patients with diffuse parenchymal liver disease. Materials and methods: 25 consecutive patients with diffuse parenchymal liver disease underwent abdominal MR imaging at both 3.0 T and 1.5 T within a 6-month interval. A retrospective study was conducted to obtain quantitative and qualitative data from both 3.0 T and 1.5 T MRI. Quantitative image analysis was performed by measuring the signal-to-noise ratios (SNRs) and the contrast-to-noise ratios (CNRs) by the Students t-test. Qualitative image analysis was assessed by grading each sequence on a 3- and 4-point scale, regarding the presence of artifacts and image quality, respectively. Statistical analysis consisted of the Wilcoxon signed-rank test. Results: the mean SNRs and CNRs of the liver parenchyma and the portal vein were significantly higher at 3.0 T than at 1.5 T on portal and equilibrium phases of volumetric interpolated breath-hold examination (VIBE) images (P < 0.05). The mean SNRs were significantly higher at 3.0 T than at 1.5 T on T1-weighted spoiled gradient echo (SGE) images (P < 0.05). However, there were no significantly differences on T2-weighted short-inversion-time inversion recovery (STIR) images. Overall image qualities of the 1.5 T noncontrast T1- and T2-weighted sequences were significantly better than 3.0 T (P < 0.01). In contrast, overall image quality of the 3.0 T post-gadolinium VIBE sequence was significantly better than 1.5 T (P< 0.01). Conclusions: MR imaging of post-gadolinium VIBE sequence at 3.0 T has quantitative and qualitative advantages of evaluating for diffuse parenchymal liver disease. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Role of Ulnar Nerve Sonography in Leprosy Neuropathy With Electrophysiologic Correlation

Objective. The purpose of this study was to evaluate the diagnostic usefulness of ulnar nerve sonography in leprosy neuropathy with electrophysiologic correlation. Methods. Twenty-one consecutive patients with leprosy (12 men and 9 women; mean age +/- SD, 47.7 +/- 17.2 years) and 20 control participants (14 men and 6 women; mean age, 46.5 +/- 16.2 years) were evaluated with sonography. Leprosy diagnosis was established on the basis of clinical, bacteriologic, and histopathologic criteria. The reference standard for ulnar neuropathy in this study was clinical symptoms in patients with proven leprosy The sonographic cross-sectional areas (CSAs) of the ulnar nerve in 3 different regions were obtained. Statistical analyses included Student t tests and receiver operating characteristic curve analysis. Results. The CSAs of the ulnar nerve were significantly larger in the leprosy group than the control group for all regions (P < .01). Sonographic abnormalities in leprosy nerves included focal thickening (90.5%), hypoechoic areas (81%), loss of the fascicular pattern (33.3%), and focal hyperechoic areas (4.7%). Receiver operating characteristic curve analysis showed that a maximum CSA cutoff value of 9.8 mm(2) was the best discriminator (sensitivity, 0.91; specificity, 0.90). Three patients with normal electrophysiologic findings had abnormal sonographic findings. Two patients had normal sonographic findings, of which 1 had abnormal electrophysiologic findings, and the other refused electrophysiologic testing. Conclusions. Sonography and electrophysiology were complementary for identifying ulnar nerve neuropathy in patients with leprosy, with clinical symptoms as the reference standard. This reinforces the role of sonography in the investigation of leprosy ulnar neuropathy.

3q27 Aberrations in a Childhood Ovary Teratoma With Associated Malignant Germ Cell Component

Cytogenetic Studies of childhood ovary tumors have been poorly described. in the present article, the cytogenetic findings of an ovarian teratoma with malignant germ cell (yolk-sac) component occurring in an 8-year-old female are detailed. GTG-banding showed a karyotype of 46,XX, t(3;20)(q27;q13.3) [4]/46,XX, del3q27 [3]/46,XX [30]. Previous Studies have demonstrated common sites of loss of heterozygosity at 3q27-q28 region in different types of cancer, suggesting the presence of tumor Suppressor genes within this region. Pediatr Blood Cancer 2009;52:398-401. (C) 2008 Wiley-Liss, Inc.

3.0-T MRI evaluation of patients with chronic liver diseases: initial observations

Purpose: To describe the use of 3.0-T magnetic resonance imaging (MRI) for the evaluation of chronic liver diseases. Materials and Methods: Two groups of patients who had chronic liver diseases and underwent 3.0-T MRI for evaluation of the liver were included in the study. The first group of patients included 66 consecutive patients (33 male, 33 female; mean age +/- standard deviation, 56 +/- 11). The second group of patients included 30 consecutive patients (18 males, 12 females; mean age +/- standard deviation, 53 +/- 10) in whom Variable-Rate Selective Excitation (VERSE) pulses and improved adjustments procedure were used during the acquisitions. Imaging findings of chronic liver diseases, predetermined artifacts and image quality of all individual sequences in the first group and predetermined artifacts and image quality of T2-weighted sequences in the second group were reviewed retrospectively and independently by two reviewers. chi-Square tests were used to compare the findings between two groups of patients and individual sequences. Kappa statistics were used to determine the extent of agreement between the reviewers. Results: Fifteen dysplastic nodules in 6 of 66 (9%) patients and 12 hepatocellular carcinomas in 11 of 66 (17%) patients were detected. Excluding motion artifacts, three-dimensional (313) T1-weighted gradient-echo (GE) sequence was the least affected sequence by the artifacts. Image quality of T1-weighted 3D-GE sequences was excellent in 43 of 66 (65%) patients. In-phase and out-of-phase T1-weighted spoiled GE (SGE) images were fair in 62 of 66 (94%) and 61 of 66 (92%) patients, respectively. The image quality of short tau inversion recovery (STIR) and half-Fourier rapid acquisition with relaxation enhancement (RARE) sequences were fair in 31 of 66 (47%) and 53 of 66 (80%) patients. STIR and half-Fourier RARE sequences in the second group demonstrated significantly better image quality (P=.03 and P<.0001). Conclusion: 3.0-T MRI allows the acquisition of very high quality postgadolinium 3D-GE sequence, which permitted the detection and characterization of lesions in the setting of chronic liver diseases. The use of VERSE pulses and improved adjustments procedure improved the image quality of T2-weighted sequences. In-phase/out-of-phase SGE sequences are at present of fair quality. (C) 2008 Elsevier Inc. All rights reserved.

Water excitation MPRAGE: An alternative sequence for postcontrast imaging of the abdomen in noncooperative patients at 1.5 Tesla and 3.0 Tesla MRI

Purpose: To evaluate the diagnostic image quality of post-gadolinium water excitation-magnetization-prepared rapid gradient-echo (WE-MPRAGE) sequence in abdominal examinations of noncooperative patients at 1.5 Tesla (T) and 3.0T MRI. Materials and Methods: Eighty-nine consecutive patients (48 males and 41 females; mean age +/- standard deviation, 54.6 +/- 16.6 years) who had MRI examinations including postgadolinium WE-MPRAGE were included in the study. Of 89 patients, 33 underwent noncooperative protocol at 1.5T. 10 under-went noncooperative protocol at 3.0T, and 46 underwent cooperative protocol at 3.0T. Postgadolinium WE-MPRAGE, MPRAGE, and three-dimensional gradient-echo sequences of these three different groups were qualitatively evaluated for image quality, extent of artifacts, lesion conspicuity, and homogeneity of fat-attenuation by two reviewers retrospectively, independently, and blindly. The results were compared using Wilcoxon signed rank and Mann-Whitney U tests. Kappa statistics were used to measure the extent of agreement between the reviewers. Results: The average scores indicated that the images were diagnostic for WE-MPRAGE at 1.5T and 3.0T in noncooperative patients. WE-MPRAGE achieved homogenous fat-attenuation in 31/33 (94%) of noncooperative patients at 1.5T and 10/10 (100%) of noncooperative patients at 3.0T. WE-MPRAGE at 3.0T had better results for image quality, extent of artifacts, lesion conspicuity and homogeneity of fat-attenuation compared with WE-MPRAGE at 1.5T. in noncooperative patients (P = 0.0008, 0.0006, 0.0024, and 0.0042: respectively). Kappa statistics varied between 0.76 and 1.00, representing good to excellent agreement. Conclusion: WE-MPRAGE may be used as a T1-weighted postgadolinium fat-attenuated sequence in noncooperative patients, particularly at 3.0T MRI.

Turbulent blood flow plays an essential localizing role in the development of atherosclerotic lesions in experimentally induced hypercholesterolaemia in rats

Taking into account that atherosclerosis is a focal disease and high levels of plasma cholesterol are closely correlated with its pathogenesis, it is a challenge to explain how equal concentrations of cholesterol bathing the endothelium can produce local, rather than global, effects on arteries. The focal distribution of atherosclerotic lesions has been considered to be dependent, at least in part, on hydrodynamic factors. The present study was carried out to further test the hypothesis that these forces are an important localizing factor in rats feeding a hypercholesterolaemic diet and submitted to infra-diaphragmatic aortic constriction. These animals develop a normotensive prestenotic region with laminar blood flow that serves as control for a normotensive poststenotic region with turbulent blood flow. Our findings clearly demonstrated that the combination of turbulent blood flow and low wall shear stress (WSS) in the presence of hypercholesterolaemia and oxidative stress creates conditions to the formation of focally distributed incipient atherosclerotic lesions observed in the poststenotic segment. In contrast, only diffuse fatty streaks could be observed in the normotensive prestenotic segment with laminar blood flow and normal WSS in the presence of hypercholesterolaemia and oxidative stress. Although haemodynamic forces are not by themselves responsible for the pathogenesis of atherosclerosis, they prime the local vascular wall in which the lesion develop. Further studies are required to establish how haemodynamic forces are detected and transduced into chemical signalling by the cells of the artery wall and then converted into pathophysiologically relevant phenotypic changes.

Acute alterations in anorectal manometry induced by proximal and distal sphincterotomy. Experimental studies on piglets

Anal incontinence causes psychological, social and adaptive troubles prejudicial to the quality of life both in children and adults. Therefore, the detailed knowledge of its causes and the improvement of diagnostic and therapeutic methods increase the possibilities of a more adequate social life to patients with congenital anomalies or sphincteric lesions or degenerations. In this work, a manometric study was developed through an experimental model so as to analyze alterations in behavior of muscle groups responsible for the anorectal sphincteric mechanism, previous to and after proximal and distal lesions. Twenty-two pigs aged between 25 and 30 days, weighing 5-7 kg, were randomly divided into two groups. They were submitted to lesions of different levels in the anorectal muscle. The animals were studied by anorectal manometry (rectoanal inhibitory reflex and vector volume) before and after the lesions. The Student t test and the Wilcoxon test were applied for the statistical analyses, considered p <= 0.05. The proximal lesion preserved sphincter relaxation, retarding its closure [speed of relaxation recovery 4.35 +/- 2.10 vs. 2.70 +/- 1.32 mm/s (p = 0.001)], but it reduced the maximum pressure [62.45 +/- 20.02 vs. 40.36 +/- 12.59 mmHg (p = 0.004)] and vector volume [2,749 +/- 921 vs. 1,591 +/- 1,379 mmHg(2)cm (p = 0.005)]. There was an increment in the high-pressure zone [5.09 +/- 1.04 vs. 6.36 +/- 1.50 mm (p = 0.005)], but the asymmetry percentage and the sphincter length were maintained. The distal lesion did not alter the rectoanal inhibitory reflex, the high-pressure zone length, the asymmetry percentage, or the vector volume. Nevertheless, the sphincter length increased [11.82 +/- 2.82 vs. 14.09 +/- 2.39 mm (p = 0.022)] and the maximum pressure decreased [60.55 +/- 22.05 vs. 40.91 +/- 13.41 mmHg (p = 0.004)]. The alterations observed due to proximal lesion of the anorectal sphincter suggest a direct and more important interference of the levator ani muscle in the function of the sphincteric musculature than that caused by the distal lesion.

Mucoepidermoid Carcinoma of the Lung Arising at the Primary Site of A Bronchogenic Cyst: Clinical, Cytogenetic, and Molecular Findings

Primary lung tumors are rare in children, and mucoepidermoid carcinoma (MEC) represents less than 10% of them. Additionally, MEC arising from bronchogenic cysts (BC) is particularly unusual. We describe the clinical and genetic findings on a MEC occurring within a previous location of a BC in an adolescent. This particular association has not been previously reported. The lesion revealed normal karyotype without the typical t(11;19)(q21;p13) translocation. Cyclin D1 overexpression (165-fold increase) was demonstrated by real-time PCR although FISH assessment showed normal hybridization at 11q13. Information on these unusual clinical presentations may present relevant insight on tumorigenesis of infrequent pediatric pulmonary tumors. Pediatr Blood Cancer 2011;56:311-313. (C) 2010 Wiley-Liss, Inc.