Use of paediatric donor tissue in Descemet stripping endothelial keratoplasty

AIMS

To evaluate the feasibility, efficacy and postoperative complications of Descemet stripping endothelial keratoplasty (DSEK) with paediatric donor tissue.

METHODS

Retrospective non-comparative interventional case series. Seven consecutive cases (seven eyes) of pseudophakic bullous keratopathy were treated with DSEK using paediatric donor tissue and followed up for 12 to 18 months. Data collected included best spectacle-corrected visual acuity, spherical equivalent refractive error, corneal astigmatism, corneal curvature and endothelial cell density.

RESULTS

DSEK was successfully performed in six out of seven eyes with paediatric donor graft; one paediatric donor graft perforated during dissection. All paediatric tissue was unfolded using the "hitch suture" technique and supported with plenty of air. No graft dislocation occurred. At 12 months postoperatively, the cornea was clear in all eyes; the best spectacle-corrected visual acuity ranged from 20/67 to 20/32; the average spherical equivalent refractive error was 1.9 (0.5) dioptres; the average corneal astigmatism was 2.2 (0.6) dioptres; the average corneal curvature was 45.2 (1.6) dioptres; and the average endothelial cell density was 2247.7 (74.3) cells/mm(2) (41.4 (3.7)% of endothelial cell loss).

CONCLUSION

With high postoperative endothelial cell counts, low graft dislocation rate and absence of high myopic shifts, paediatric donor tissue can be successfully used in DSEK.

CITATION ANALYSIS OF FIVE JOURNALS IN ANDROLOGY

AIM

To find out features in literature demand by researchers in the field of andrology and to offer advice on literature utilization and journal management.

METHODS

Five andrology journals indexed by Science Citation Index Expanded (SCI-E) (Andrologia, Archives of Andrology, Asian Journal of Andrology, International Journal of Andrology, and Journal of Andrology) were included in the study. Original articles, editorials, reviews, corrections and letters from these journals were analyzed with bibliometric method for document loading, citations, information absorbing ability, and geographical coverage.

RESULTS

The average number of references in each paper was 28.78. The main type of references was periodicals (94.32%), while books and other sources accounted for only 5.68%. Average Price index was 30.14%. The number of references in the first ranking 10 periodicals cited by the five journals made up 34.53% of the total references cited. Geographically, the five journals covered 6 continents with 42 countries or regions.

CONCLUSION

Andrology journals have a wide coverage of literatures, which are related to reproductive medicine, urology, endocrinology and biochemistry. References in andrology journals are mainly periodicals and are relatively old. US, China and Japan lead the world in andrology researches for the number of papers published.

On the difference between reference radiations used in radiobiology

PURPOSE

To add further support to the designation of hard gamma-rays, such as those emitted by (60)Co or (137)Cs, as the common reference radiation, as recommended by the International Commission on Radiological Protection (ICRP) Task Group 37 in the recent ICRP Publication 92.

MATERIALS AND METHODS

The study examined the microdosimetric properties of seven commonly used reference radiations and quantified differences in radiation quality among them. The principal tool is the proximity function, which is derived from the spatial distributions of energy deposits calculated by Monte Carlo simulations.

RESULTS

The microdosimetric properties of the seven commonly used reference radiations were significantly different. However, there were no significant differences in the spectra of energy deposition in microscopic regions between hard gamma-rays over a wide range of distances of biological interest.

CONCLUSIONS

From a microdosimetric point of view, gamma-rays from (60)Co or (137)Cs are the most suitable reference radiations for specification of the relative biological effectiveness.

Enhancer deletions of the SHOX gene as a frequent cause of short stature: the essential role of a 250 kb downstream regulatory domain

Background:

Mutations and deletions of the homeobox transcription factor gene SHOX are known to cause short stature. The authors have analysed SHOX enhancer regions in a large cohort of short stature patients to study the importance of regulatory regions in developmentally relevant genes like SHOX.

Methods:

The authors tested for the presence of copy number variations in the pseudoautosomal region of the sex chromosomes in 735 individuals with idiopathic short stature and compared the results to 58 cases with Leri–Weill syndrome and 100 normal height controls, using fluorescence in situ hybridisation (FISH), single nucleotide polymorphism (SNP), microsatellites, and multiplex ligand dependent probe amplification (MLPA) analysis.

Results:

A total of 31/735 (4.2%) microdeletions were identified in the pseudoautosomal region in patients with idiopathic short stature; eight of these microdeletions (8/31; 26%) involved only enhancer sequences residing a considerable distance away from the gene. In 58 Leri–Weill syndrome patients, a total of 29 microdeletions were identified; almost half of these (13/29; 45%) involve enhancer sequences and leave the SHOX gene intact. These deletions were absent in 100 control persons.

Conclusion:

The authors conclude that enhancer deletions in the SHOX gene region are a relatively frequent cause of growth failure in patients with idiopathic short stature and Leri–Weill syndrome. The data highlights the growing recognition that regulatory sequences are of crucial importance in the genome when diagnosing and understanding the aetiology of disease.

Structural elucidation of metabolites of ginkgolic acid in rat liver microsomes by ultra-performance liquid chromatography/electrospray ionization tandem mass spectrometry and hydrogen/deuterium exchange

Ginkgolic acids have been shown to possess allergenic as well as genotoxic and cytotoxic properties. The question arises whether the metabolism of ginkgolic acids in the liver could decrease or increase their toxicity. In this study, the in vitro metabolism of ginkgolic acid (15:1, GA), one component of ginkgo acids, was investigated as a model compound in Sprague-Dawley rat liver microsomes. The metabolites were analyzed by ultra-performance liquid chromatography coupled with photodiode array detector/negative-ion electrospray ionization tandem mass spectrometry (UPLC-PDA/ESI-MS/MS) and hydrogen/deuterium (H/D) exchange. The result showed that the benzene ring remained unchanged and the oxidations occurred at the side alkyl chain in rat liver microsomes. At least eight metabolites were found. Among them, six phase I metabolites were tentatively identified. This study might be useful for the investigation of toxicological mechanism of ginkgolic acids.

Apolipoprotein E deficiency abrogates insulin resistance in a mouse model of type 2 diabetes mellitus

AIMS/HYPOTHESIS

Although it is known that lipid metabolism plays a role in insulin resistance in type 2 diabetes and in obesity, the mechanism is still largely unknown. Apolipoprotein E (ApoE) regulates plasma lipid levels and also plays a role in the uptake of lipids into various tissues. To investigate whether the suppression of whole-particle lipoprotein uptake into tissues affects insulin responsiveness and the diabetic condition, we examined the effect of an ApoE (also known as Apoe) gene deletion in MKR mice, a mouse model of type 2 diabetes.

METHODS

ApoE ( -/- ), MKR, ApoE ( -/- )/MKR and control mice were placed on a high-fat, high-cholesterol diet for 16 weeks. Glucose tolerance, serum insulin, blood glucose, insulin tolerance, tissue triacylglycerol content and atherosclerotic lesions were assessed.

RESULTS

ApoE ( -/- )/MKR and ApoE ( -/- ) mice showed significantly improved blood glucose, glucose tolerance and insulin sensitivity. Reduced triacylglycerol content in liver and reduced fat accumulation in liver and adipose tissue were found in ApoE ( -/- )/MKR and ApoE ( -/- ) mice compared with control and MKR mice. ApoE ( -/- ) and ApoE ( -/- )/MKR mice demonstrated similarly large atherosclerotic lesions, whereas MKR and control mice had small atherosclerotic lesions.

CONCLUSIONS/INTERPRETATION

We demonstrated that ApoE deficiency abrogates insulin resistance in a mouse model of type 2 diabetes, suggesting that lipid accumulation in tissue is a major cause of insulin resistance in this mouse model.

Low genetic diversity in the masked palm civet Paguma larvata (Viverridae)

The masked palm civet is distributed through south-east Asia, China and the Himalayas. Because of its potential role in the severe acute respiratory syndrome (SARS) epidemic, it has become important to gather information on this species, and notably to provide a tool to determine the origin of farm and market animals. For this purpose, we studied the genetic variability and the phylogeographic pattern of the masked palm civet Paguma larvata. First, two portions of mitochondrial genes, cytochrome b and the control region, were sequenced for a total of 76 individuals sampled from China, the Indochinese region and the Sundaic region. Results indicated a low genetic variability and suggested a lack of a phylogeographic structure in this species, which do not allow inferring the geographic origin of samples of unknown origin, although it is possible to distinguish individuals from China and the Sundaic region. This low variation is in contrast to the well-marked morphological differentiation between the populations in the Sundaic and Chinese-Indochinese regions. We also used five microsatellite loci to genotype 149 samples from two wild and four farmed populations in China, where the masked palm civet is farmed and where the SARS coronavirus was isolated. These analyses also showed a reduced variability in Chinese civets and showed that farmed populations did not exhibit a lower genetic diversity than wild populations, suggesting frequent introductions of wild individuals into farms.

Increased expression of erythropoietin receptor in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine-induced Parkinsonian model

Erythropoietin (EPO), known for its role in erythroid differentiation, has been suggested to have a direct protective role against a variety of neurotoxic insults. In the present study, we investigated the expression of EPO receptor (EPOR) and the number of EPOR-positive cells in three encephalic regions (ventral mesencephalon, striatum, cortex) following lesion induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). C57BL/6 mice underwent intraperitoneal injection of MPTP at 24 h intervals for 5 days, and their brains were examined 1, 2, 4, 7, 14 or 21 days after the last injection. Western blot and immunohistochemistry analysis revealed that EPOR was dramatically up-regulated in the ventral mesencephalon, 4 days after MPTP insult until the day 21. In contrast, there was a baseline level of EPOR in the striatum and cortex. At subsequent time points after MPTP injury, the levels of EPOR in the two regions were not statistically different compared with those in normal animals. These results suggest that the regional specific up-regulation of EPOR at an early stage after MPTP stimulus may represent a pro-survival mechanism against neurotoxin injury in Parkinsonian model.

Influenza A virus matrix protein 1 interacts with hTFIIIC102-s, a short isoform of the polypeptide 3 subunit of human general transcription factor IIIC

Influenza A virus matrix protein 1 (M1) is a multifunctional protein that plays important roles during replication, assembly and budding of the virus. To search for intracellular protein components that interact with M1 protein and explore the potential roles of these interactions in the pathogenesis of influenza virus infection, 11 independent proteins, including hTFIIIC102-s protein, encoding a short isoform of the TFIIIC102 subunit of the human TFIIIC transcription factor, were screened from a human cell cDNA library using a yeast two-hybrid technique. The interaction between M1 protein and hTFIIIC102-s was studied in more detail. Mapping assays showed that the N-terminal globular region (amino acids 1-164) of the M1 protein and the five tandem tetratricopeptide repeats (TPR1-5, amino acids 149-362) in hTFIIIC102-s were necessary for the interaction. The interaction was confirmed by both glutathione-S-transferase (GST) pull-down assays and coimmunoprecipitation assays. In addition, coexpression of hTFIIIC102-s with M1 in HeLa cells inhibited the translocation of M1 into the nucleus. Taken together, the present data indicate that hTFIIIC102-s can interact with the structural M1 protein of the influenza virus, which provides a novel clue toward further understanding of the roles of M1 protein in the interactions between influenza virus and host cells.

Automatic system for continuously monitoring digging volume of red imported fire ants (Hymenoptera: Formicidae) in the laboratory

In studying the dynamics of ant nest excavation, the nest volume has to be continuously monitored. In many laboratory studies, the excavated substrate, such as sand, was collected, and the volume of excavation was calculated by converting the weight of the collected sand into the volume. The excavated sand can be manually collected and weighed; however, manual collection is tedious, particularly when frequent collections have to be performed for a period of several days. Manual collection may also introduce disturbance to the ants. The volume of excavation can also be monitored using a video system by transferring images into volume data. Unfortunately, it requires sophisticated software customization. A simple automatic system for continuously collecting and weighing the excavated sand is described. This system does not disturb the ants while collecting data and requires no software customization. It can display the digging curves while it is still collecting data.

The feasibility and reliability of using circular electrode for sphincter of Oddi electromyography in anaesthetised rabbits

Sphincter of Oddi manometry (SOM) is the gold standard for assessing sphincter of Oddi dysfunction (SOD), but is considered a diagnostic sensitivity of 30-80% and associated with significant complications of pancreatitis. Electromyography (EMG) of sphincter of Oddi (SO) using a circular electrode (CE) may be useful in improving diagnostic accuracy and reducing complications. To evaluate the feasibility and reliability of the CE, we record myoelectric activity of SO in rabbits using the CE to compare with the traditional needle electrode (NE). The CE was prepared using a double-channel biogel catheter with two silver rings at the head of the catheter. The CE was then inserted into the lumen of the SO through the duodenal papilla, and myoelectric activity was recorded in the SO in 30 rabbits. An EMG recorded using an NE was performed at the same time, when the SO was in basal state, after injection of cholecystokinin and N-butylscopolamine bromide. Electromyographs recorded by the two methods were then evaluated. Satisfactory SO EMGs were acquired using the CE without any injury. Simultaneous recording revealed a very similar traces and one-to-one correspondence of SO spike bursts (SOSB). Linear regression analysis showed a significant direct correlation between the two methods for SOSB duration and amplitude. The results suggested that CE was comparable with NE in terms of recording efficacy. The CE also has advantages of easy fixation, accurate localisation, broad applicability and ease of achieving satisfactory outcomes without trauma, compared with the NE.

Pim-1 plays a pivotal role in hypoxia-induced chemoresistance

Hypoxia changes the responses of cancer cells to many chemotherapy agents, resulting in chemoresistance. The underlying molecular mechanism of hypoxia-induced drug resistance remains unclear. Pim-1 is a survival kinase, which phosphorylates Bad at serine 112 to antagonize drug-induced apoptosis. Here we show that hypoxia increases Pim-1 in a hypoxia-inducible factor-1alpha-independent manner. Inhibition of Pim-1 function by dominant-negative Pim-1 dramatically restores the drug sensitivity to apoptosis induced by chemotherapy under hypoxic conditions in both in vitro and in vivo tumor models. Introduction of siRNAs for Pim-1 also resensitizes cancer cells to chemotherapy drugs under hypoxic conditions, whereas forced overexpression of Pim-1 endows solid tumor cells with resistance to cisplatin, even under normoxia. Dominant-negative Pim-1 prevents a decrease in mitochondrial transmembrane potential in solid tumor cells, which is normally induced by cisplatin (CDDP), followed by the reduced activity of Caspase-3 and Caspase-9, indicating that Pim-1 participates in hypoxia-induced drug resistance through the stabilization of mitochondrial transmembrane potential. Our results demonstrate that Pim-1 is a pivotal regulator involved in hypoxia-induced chemoresistance. Targeting Pim-1 may improve the chemotherapeutic strategy for solid tumors.