Short-term corneal endothelial changes after laser-assisted subepithelial keratectomy

To investigate the short-term effects of laser-assisted subepithelial keratectomy (LASEK) on the corneal endothelium, 10 patients undergoing LASEK for myopia without complications (20 eyes) were observed. Each eye was evaluated by slit-lamp biomicroscopy and non-contact specular microscopy pre-operatively, and at 15 min, 1 day and 1 week post-operatively. The decrease in endothelial cell density was statistically significant at 15 min post-operatively, and the difference between pre-operative and 15-min post-operative coefficient of variation of cell size was also statistically significant. The percentage of hexagonal cells was significantly different from baseline levels at 15 min and at 1 day post-operatively. All parameters at 1 week post-operatively were not statistically different from those observed pre-operatively. Immediate changes in endothelial cell number and morphology occurred following LASEK, but endothelial morphology returned to the pre-operative condition after 1 week. Long-term follow-up is needed to identify further consequences of this procedure.

Novel and recurrent TRPV4 mutations and their association with distinct phenotypes within the TRPV4 dysplasia family

BACKGROUND

Mutations in TRPV4, a gene that encodes a Ca(2+) permeable non-selective cation channel, have recently been found in a spectrum of skeletal dysplasias that includes brachyolmia, spondylometaphyseal dysplasia, Kozlowski type (SMDK) and metatropic dysplasia (MD). Only a total of seven missense mutations were detected, however. The full spectrum of TRPV4 mutations and their phenotypes remained unclear.

OBJECTIVES AND METHODS

To examine TRPV4 mutation spectrum and phenotype-genotype association, we searched for TRPV4 mutations by PCR-direct sequencing from genomic DNA in 22 MD and 20 SMDK probands.

RESULTS

TRPV4 mutations were found in all but one MD subject. In total, 19 different heterozygous mutations were identified in 41 subjects; two were recurrent and 17 were novel. In MD, a recurrent P799L mutation was identified in nine subjects, as well as 10 novel mutations including F471del, the first deletion mutation of TRPV4. In SMDK, a recurrent R594H mutation was identified in 12 subjects and seven novel mutations. An association between the position of mutations and the disease phenotype was also observed. Thus, P799 in exon 15 is a hot codon for MD mutations, as four different amino acid substitutions have been observed at this codon; while R594 in exon 11 is a hotspot for SMDK mutations.

CONCLUSION

The TRPV4 mutation spectrum in MD and SMDK, which showed genotype-phenotype correlation and potential functional significance of mutations that are non-randomly distributed over the gene, was presented in this study. The results would help diagnostic laboratories establish efficient screening strategies for genetic diagnosis of the TRPV4 dysplasia family diseases.

Aortic length changes during abdominal aortic aneurysm formation, expansion and stabilisation in a rat model

BACKGROUND

Determinants of extracellular matrix (ECM) destruction/reconstruction balance influencing abdominal aortic aneurysm (AAA) diameter may impact length.

OBJECTIVE

Document aortic lengthening, its correlation to diameter, and determine how treatments that impact diameter also affect length.

METHODS

Three hundred and fifty-five diameter and length measurements were performed in 308 rats during AAA formation, expansion and stabilisation in guinea pig aortas xenografted in rats. Impact of modulation of ECM destructive/reconstructive balance by endovascular Vascular Smooth Muscle Cell (VSMCs) seeding, TIMP-1, PAI-1 and TGF-beta1 overexpression on length has been assessed.

RESULTS

Length increased in correlation with diameter during formation (correlation coefficient (cc): 0.584, P<0.0001) and expansion (cc: 0.352, P=0.0055) of AAAs. Overexpression of TIMP-1 and PAI-1 decreased lengthening (P=0.02 and 0.014, respectively) demonstrating that elongation is driven by matrix metalloproteinases and their activation by the plasmin pathway. Overexpression of TGF-beta1 controlled length in formed AAAs (17.3 ± 9.6 vs. 5.9 ± 7.4mm, P=0.022), but not VSMC seeding, although both therapies efficiently prevented further diameter increase. Length and diameter correlation was lost after biotherapies.

CONCLUSION

Length increases in correlation with diameter during AAA formation and expansion, as a consequence of ECM injury driven by MMPs activated by the plasmin pathway. Correlation between length and diameter increases is not universally preserved.

Cleaved high molecular weight kininogen inhibits tube formation of endothelial progenitor cells via suppression of matrix metalloproteinase 2

BACKGROUND AND OBJECTIVE

Endothelial progenitor cells (EPCs) contribute to postnatal neovascularization, thus promoting wide interest in their therapeutic potential in vascular injury and prevention of their dysfunction in cardiovascular diseases. Cleaved high molecular weight kininogen (HKa), an activation product of the plasma kallikrein-kinin system (KKS), inhibits the functions of differentiated endothelial cells including in vitro and in vivo angiogenesis. In this study, our results provided the first evidence that HKa is able to target EPCs and inhibits their tube forming capacity.

METHODS AND RESULTS

We determined the effect of HKa on EPCs using a three-dimensional vasculogenesis assay. Upon stimulation with vascular endothelial growth factor (VEGF) alone, EPCs formed vacuoles and tubes, and differentiated into capillary-like networks. As detected by gelatinolytic activity assay, VEGF stimulated secretion and activation of matrix metallopeptidase 2 (MMP-2), but not MMP-9, in the conditioned medium of 3D culture of EPCs. Specific inhibition or gene ablation of MMP-2, but not MMP-9, blocked the vacuole and tube formation by EPCs. Thus, MMP-2 is selectively required for EPC vasculogenesis. In a concentration-dependent manner, HKa significantly inhibited tube formation by EPCs and the conversion of pro-MMP-2 to MMP-2. Moreover, HKa completely blocked the association between pro-MMP-2 and alphavbeta3 integrin, and its inhibition of MMP-2 activation was dependent on the presence of alphavbeta3 integrin. In a purified system, HKa did not directly inhibit MMP-2 activity.

CONCLUSIONS

HKa inhibits tube forming capacity of EPCs by suppression of MMP-2 activation, which may constitute a novel link between activation of the KKS and EPC dysfunction.

Traumatic corneal flap displacement five years after laser in situ keratomileusis

Laser in Situ Keratomileusis (LASIK) is the most common surgical procedure for the correction of refractive deviations. LASIK has been ongoing lately in our country, exclusively in private settings. This is the reason for which our clinic has no experience with LASIK procedure and complications following it. We are presenting a case of a 23 year-old female with traumatic flap displacement on the left eye, 5 years after the original LASIK operation. She was presented to our clinic on the 6th posttraumatic day. The patient was immediately operated and the flap repositioned. The case we present, is the only one treated to our clinic with such a vision-threatening complication of LASIK procedure.

Cleaved high molecular weight kininogen inhibits tube formation of endothelial progenitor cells via suppression of matrix metalloproteinase 2

BACKGROUND AND OBJECTIVE

Endothelial progenitor cells (EPCs) contribute to postnatal neovascularization, thus promoting wide interest in their therapeutic potential in vascular injury and prevention of their dysfunction in cardiovascular diseases. Cleaved high molecular weight kininogen (HKa), an activation product of the plasma kallikrein-kinin system (KKS), inhibits the functions of differentiated endothelial cells including in vitro and in vivo angiogenesis. In this study, our results provided the first evidence that HKa is able to target EPCs and inhibits their tube forming capacity.

METHODS AND RESULTS

We determined the effect of HKa on EPCs using a three-dimensional vasculogenesis assay. Upon stimulation with vascular endothelial growth factor (VEGF) alone, EPCs formed vacuoles and tubes, and differentiated into capillary-like networks. As detected by gelatinolytic activity assay, VEGF stimulated secretion and activation of matrix metallopeptidase 2 (MMP-2), but not MMP-9, in the conditioned medium of 3D culture of EPCs. Specific inhibition or gene ablation of MMP-2, but not MMP-9, blocked the vacuole and tube formation by EPCs. Thus, MMP-2 is selectively required for EPC vasculogenesis. In a concentration-dependent manner, HKa significantly inhibited tube formation by EPCs and the conversion of pro-MMP-2 to MMP-2. Moreover, HKa completely blocked the association between pro-MMP-2 and alphavbeta3 integrin, and its inhibition of MMP-2 activation was dependent on the presence of alphavbeta3 integrin. In a purified system, HKa did not directly inhibit MMP-2 activity.

CONCLUSIONS

HKa inhibits tube forming capacity of EPCs by suppression of MMP-2 activation, which may constitute a novel link between activation of the KKS and EPC dysfunction.

Lux vs. wavelength in light treatment of Seasonal Affective Disorder

OBJECTIVE

Published dosing guidelines for treatment of Seasonal Affective Disorder (SAD) refer to photopic lux, which is not appropriate for short-wavelength light. Short wavelengths are most potent for many non-visual responses to light. If SAD therapy were similarly mediated, standards utilizing lux risk overestimating necessary dose. We investigated antidepressant responses to light using two light-emitting diode (LED) sources, each emitting substantial short-wavelength light, but <2500 lux.

METHOD

A randomized, double-blind trial investigated 3-week 45 min/day out-patient treatment with blue-appearing (goLITE) or blue-enriched white-appearing light in 18 moderately-depressed adults (12F, 49.1 +/- 9.5 years). Equivalent numbers of photons within the short-wavelength range were emitted, but the white source emitted twice as many photons overall and seven-fold more lux.

RESULTS

Depression ratings (SIGH-ADS; http://www.cet.org) decrease averaged 82% (SD = 17%) from baseline (P < 0.0001) in both white- and blue-light groups. Both sources were well tolerated.

CONCLUSION

Short-wavelength LED light sources may be effective in SAD treatment at fewer lux than traditional fluorescent sources.

Predictive role of capsule endoscopy on the insertion route of double-balloon enteroscopy

BACKGROUND AND STUDY AIMS

Double-balloon enteroscopy (DBE) has been suggested to be more efficient if based on the results of screening video capsule endoscopy (VCE). We evaluated the utility of VCE for predicting the best insertion route of DBE for the evaluation and treatment of small-bowel lesions.

PATIENTS AND METHODS

Results of studies of patients with complete VCE examination of the small bowel and with findings confirmed by DBE are reported. A location index of lesions found on VCE was defined as the time from the pylorus to the lesion as a percentage of the time from the pylorus to the ileocecal valve. Based on our previous retrospective evaluation, a cut-off value of 0.6 was adopted, and the oral or anal approach was selected when the index was < or = 0.6 or > 0.6, respectively.

RESULTS

Data from 60 patients who underwent both VCE and DBE examinations and in whom the capsule reached the cecum were evaluated. Lesions shown on VCE were all reached by the first DBE procedures (41 orally and 19 anally). Based on the time index cut-off value of 0.6, the accuracy of selecting the insertion route of DBE was 100 %.

CONCLUSION

DBE is an effective approach for confirming VCE results. In patients with complete small-bowel investigation by VCE, the best insertion route for DBE can be reliably indicated using a time index based on the VCE records.

Osteopontin induces angiogenesis through activation of PI3K/AKT and ERK1/2 in endothelial cells

Angiogenesis is a key step in tumor growth and metastasis. The mechanism by which osteopontin (OPN) induces the angiogenesis of endothelial cells remains unclear. Here, we show that OPN confers cytoprotection through the activation of the PI3K/Akt pathway with subsequent upregulation of Bcl-xL and activation of nuclear factor-kappaB. OPN enhances the expression of vascular endothelial growth factor (VEGF) through the phosphorylation of AKT and extracellular signal-regulated kinase (ERK). In turn, OPN-induced VEGF activates PI3K/AKT and the ERK1/2 pathway as a positive feedback signal. Blocking the feedback signal by anti-VEGF antibody, PI3-kinase inhibitor or ERK inhibitor can partially inhibit the OPN-induced human umbilical vein endothelial cell (HUVEC) motility, proliferation and tube formation, while blocking the signal by anti-OPN or anti-alphavbeta3 antibody completely abrogates the biological effects of OPN on HUVECs. In addition, blood vessel formation is also investigated in vivo. The antiangiogenesis efficacy of anti-OPN antibody in vivo is more effective than that of anti-VEGF antibody, which only blocks the feedback signals. These data show that OPN enhances angiogenesis directly through PI3K/AKT- and ERK-mediated pathways with VEGF acting as a positive feedback signal. The results suggest that OPN might be a valuable target for developing novel antiangiogenesis therapy for treatment of cancer.

Ultrastructural changes of nucleoli in common wheat induced by actinomycin DPeople's Republic of China

Common wheat root tip meristematic cells were treated with low concentrations of actinomycin D (ActD), then stained whole by silver nitrate. We showed by transmission electron microscopy that the typical nucleolar structure did not form, but a granular and fibrillar network was exhibited in the nucleolar region. Our results support a correlation between nucleolar organization/assembly and the activation of RNA Polymerase I transcription. Furthermore, we speculate that the fibrillar network present in the nucleolar region of ActD treated cells may represent the basic skeletal structure required to support the nucleolus.

Using a minigene approach to characterize a novel splice site mutation in human F7 gene causing inherited factor VII deficiency in a Chinese pedigree

Factor VII deficiency which transmitted as an autosomal recessive disorder is a rare haemorrhagic condition. The aim of this study was to identify the molecular genetic defect and determine its functional consequences in a Chinese pedigree with FVII deficiency. The proband was diagnosed as inherited coagulation FVII deficiency by reduced plasma levels of FVII activity (4.4%) and antigen (38.5%). All nine exons and their flanking sequence of F7 gene were amplified by polymerase chain reaction (PCR) for the proband and the PCR products were directly sequenced. The compound heterozygous mutations of F7 (NM_000131.3) c.572-1G>A and F7 (NM_000131.3) c.1165T>G; p.Cys389Gly were identified in the proband's F7 gene. To investigate the splicing patterns associated with F7 c.572-1G>A, ectopic transcripts in leucocytes of the proband were analyzed. F7 minigenes, spanning from intron 4 to intron 7 and carrying either an A or a G at position -1 of intron 5, were constructed and transiently transfected into human embryonic kidney (HEK) 293T cells, followed by RT-PCR analysis. The aberrant transcripts from the F7 c.572-1G>A mutant allele were not detected by ectopic transcription study. Sequencing of the RT-PCR products from the mutant transfectant demonstrated the production of an erroneously spliced mRNA with exon 6 skipping, whereas a normal splicing occurred in the wide type transfectant. The aberrant mRNA produced from the F7 c.572-1G>A mutant allele is responsible for the factor VII deficiency in this pedigree.