To investigate the differentiation of rat neural stem cells (rNSCs) into cells of retinal pigment epithelial (RPE) lineage both in vitro and in vivo, after subretinal transplantation into normal rats ...and in a sodium iodate (NaIO(3)) model of RPE loss.
rNSCs prepared from the cortex of embryonic day (E)14 Fisher F344 rats were cocultured with different concentrations of vasoactive intestinal peptide (VIP), adult rat RPE cells, or neurosensory retina (NSR) for 5 days. Cell morphology and expression of RPE-specific markers (cytokeratin, CD68, microphthalmia-inducing transcription factor MITF) were studied. Additional antibodies used to characterize the rNSCs were markers for stem cells (nestin), immature neurons (betaIII-tubulin), astrocytes (glial fibrillary acidic protein GFAP), and oligodendrocytes (Rip). In in vivo studies, 10(6) green fluorescent protein GFP-labeled rNSCs were injected subretinally in either normal adult Lewis rats or NaIO(3)-treated rats (70 mg/mL NaIO(3) administered intravenously 7 days before transplantation).
In vitro VIP-treated rNSCs changed from round cells to glia-like cells with processes that stained for both GFAP and nestin. In addition, small clusters of flattened, polygonal cells with an epithelial-cell-like shape that stained for cytokeratin and CD68 were observed. Coculture of rNSCs with RPE cells, but not with NSR, also led to cells of this phenotype. After transplantation, nestin(+) and GFP(+) rNSCs were visible subretinally as a transplant. In addition, more than 50% of transplanted rNSCs were cytokeratin(+) and CD68(+).
Very few rNSCs differentiate in vitro into epithelial-like cells that express RPE-specific markers. In vivo, this differentiation is remarkably enhanced after subretinal engraftment. Thus, transplantation of NSCs into the subretinal space may be a therapy for retinal diseases involving an RPE abnormality.
β-catenin mutations in sporadic fundic gland polyps SEKINE, Shigeki; SHIBATA, Tatsuhiro; YAMAUCHI, Yuko ...
Virchows Archiv : an international journal of pathology,
04/2002, Letnik:
440, Številka:
4
Journal Article
Recenzirano
Fundic gland polyp (FGP) is the most common gastric polyp. It occurs sporadically or in association with familial adenomatous polyposis (FAP). FAP patients carry germline mutations of the adenomatous ...polyposis coli (APC) gene, and previous studies have revealed frequent somatic mutations of the APC gene in FGPs associated with FAP. Although inactivation of the APC gene contributes to histogenesis of FGPs associated with FAP, this rarely happens in sporadic cases. Loss of the APC gene promotes abnormal accumulation of beta-catenin, and mutation of GSK-3 beta phosphorylation sites in the beta-catenin gene can have a similar effect. To elucidate the contribution of beta-catenin gene mutation to the histogenesis of sporadic FGP, we analyzed beta-catenin gene mutation in exon 3 in 45 FGP lesions obtained from 35 patients. Somatic mutations were found in 29 lesions: 28 were missense mutations and one was an in-frame deletion. All of the missense mutations were confined to the former two serine residues of the GSK-3 beta phosphorylation sites and their flanking residues (codons 32, 33, 34, 37). Analysis in cases with multiple FGPs revealed a different mutation in each lesion, indicating their multicentric origin. Therefore, a significant proportion of sporadic FGPs have genetic alterations involving beta-catenin stabilization, as did FAP-associated FGPs.
Recent research on macular diseases has prompted investigations into the condition of the intersection between the photoreceptor inner and outer segments (IS/OS) and the relationship with retinal ...photoreceptor abnormalities. Although the origin of the IS/OS in optical coherence tomography (OCT) images is unclear, it may be related to either the cellular activity of the photoreceptors or the structure of the OS disks. To address this question, we compared the IS/OS status in OCT images of rat retinas before and after euthanasia.
OCT images were taken before and after euthanasia in four eyes of two Brown Norway rats. After the OCT images were taken, the rats were used for histopathological studies to confirm that retinal structures were intact.
Before euthanasia, the IS/OS and external limiting membrane (ELM) line were clearly identifiable on the OCT images. However, after euthanasia, neither the IS/OS nor the ELM line was evident in three out of four eyes, and a faint IS/OS and an ELM line were identified in one eye. Histopathological analysis did not show any abnormalities in the retina in any of the four eyes.
The origin of the IS/OS identified in OCT images is likely related to the biological activities of the photoreceptor cells.
The intensity of metastable helium (He*) atoms which survive during the scattering from water- and benzene-adsorbed Cu(1
0
0) surfaces was measured. The survival probability (SP) of He* was found to ...be sensitive to the electronic states at around the Fermi level, which is derived from the adsorbate/metal hybridization and extend toward the vacuum. The SP is likely to depend largely on the kinetic energy of the He* atoms. The kinetic energy dependence can be understood on the basis of the He* decay mechanism. Metastable-atom deexcitation spectroscopy (MDS) and surface electronic structure calculation have been used for discussing the results for the He* SP.
Utilizing a commercially available helium-purging device and PEEK tubes for all tubing, especially for connection between the mobile phase and pump, high performance liquid chromatography with an ...electrochemical detector (ECD/HPLC) at the cathodic mode is a simple and precise method for the determination of p-nitrophenol (NP). Studies with cyclic and hydrodynamic voltammetry indicated that 25% aqueous MeOH containing 0.1% (v/v) CF3CO2H and −0.8 V vs. Ag/AgCl are the best mobile phase and detection potential for cathodic ECD/HPLC. With the present system, the limits of detection and determination were 0.2 and 0.25 μM, respectively, and up to 50 μM, a linear calibration curve was afforded. Within-day precisions for the analysis of 5 and 50 μM NP were 0.8 and 0.7% (n=6), respectively, and between-day precisions (n=6) for these samples were 3.5 and 2.2%, respectively. Compared with the commonly used Bessey–Lowry–Brock method, cathodic ECD/HPLC was useful for the assay of acid phosphatase in urine samples with p-nitrophenyl phosphate disodium salt as a substrate.
The golden hamster is a mammal in which microinjection of round spermatids into oocytes (ROSI) was first attempted. However, no live ROSI offspring have ever been obtained in this species. This is ...the first report of live hamster offspring obtained by round spermatid injection. Over 90% of oocytes, injected with round spermatids, were activated without any additional stimulation. The proportion of the oocytes that were fertilized normally and that developed to morulae and blastocysts was higher when the plasma membranes of the spermatids were broken before injection, as compared with when the membranes were left intact. Five percent of 57 ROSI morulae/blastocysts developed into live offspring after transfer to foster mothers.
We report a case in which endocardial radiofrequency (RF) ablation guided by unipolar intracoronary mapping using a guidewire was an effective therapy for treating VT originating from an epicardial ...site of the left ventricle. A 55‐year‐old man with dilated cardiomyopathy was referred for treatment of refractory sustained monomorphic VT. The earliest unipolar electrogram with a near‐perfect pace map was identified at segment #8 of the left anterior descending artery utilizing a guidewire through a microtube catheter during the VT. VT was terminated by an endocardial RF application at an upper midventricular septal site that did not have a good pacemap or the earliest electrogram, and that was the most adjacent anatomical endocardial site to the guidewire tip. No VT was clinically observed during a follow up period of 14 months.
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