Mutational spectrum of Korean patients with corneal dystrophy

Corneal dystrophy typically refers to a group of rare hereditary disorders with a heterogeneous genetic background. A comprehensive molecular genetic analysis was performed to characterize the genetic spectrum of corneal dystrophies in Korean patients. Patients with various corneal dystrophies underwent thorough ophthalmic examination, histopathologic examination, and Sanger sequencing. A total of 120 probands were included, with a mean age of 50 years (SD = 18 years) and 70% were female. A total of 26 mutations in five genes (14 clearly pathogenic and 12 likely pathogenic) were identified in 49 probands (41%). Epithelial-stromal TGFBI dystrophies, macular corneal dystrophy and Schnyder corneal dystrophy (SCD) showed 100% mutation detection rates, while endothelial corneal dystrophies showed lower detection rates of 3%. Twenty six non-duplicate mutations including eight novel mutations were identified and mutations associated with SCD were identified genetically for the first time in this population. This study provides a comprehensive characterization of the genetic aberrations in Korean patients and also highlights the diagnostic value of molecular genetic analysis in corneal dystrophies.

Distribution of Porcine Endogenous Retrovirus in Different Organs of the Hybrid of a Landrace and a Jeju Domestic Pig in Korea

Xenotransplantation offers a solution to the shortage of available organs for transplantation, and the pig represents an ideal source of such organs. However, porcine endogenous retrovirus (PERV), whose genome is integrated in pigs, has been suggested to pose a potential risk of xenotransmission. Expression of PERVs in different organs of pigs was carefully measured at DNA, mRNA, and protein levels, providing information valuable for the application of pig organs in xenotransplantation. An analysis of PERV DNA showed that a very similar number of PERV copies was present in the genome of all organs, whereas mRNA and protein levels of PERV varied depending on the organ, with kidney, liver, and spleen expressing high levels of both mRNA and protein. In contrast, mRNA and protein levels were dissimilar in the lung and brain, where mRNA levels were low but protein levels were high. This discrepancy indicates that mRNA levels are not always reflected in protein expression. In addition, the difference between mRNA and protein highlights the importance of choosing the proper analysis method for diagnosing viral infection. In summary, this study provides insight into the distribution of PERV in various organs at the DNA, mRNA, and protein levels, and also informs the proper selection of tissues or organs for future clinical xenotransplantation.

Initial experiences of laparoscopic intravesical detrusorraphy using the Politano-Leadbetter technique

INTRODUCTION

Minimally invasive laparoscopic surgical procedures are increasingly being used for the management of vesicoureteral reflux.

OBJECTIVE

We present our experience of the laparoscopic Politano-Leadbetter technique performed under pneumovesicum conditions, which allows an orthotopic ureteral location after vesicoureteral reflux correction. Our procedure recreates the new ureteric orifice in a normal anatomical position with potential less morbidity and better cosmesis.

STUDY DESIGN

Our series comprises ten cases. The three 5 mm ports were introduced through bladder wall under cystoscopic vision. A 5-0 monofilament traction suture was used and dissection was carried out. After the ureteral mobilization, the location of the new hiatus was selected in a straight line superior to the original orifice. Dissection of the submucosal tunnel was started from the new hiatus and advanced to the original hiatus and the ureter was gently drawn passed through the tunnel. The ureter was rolled up and muscle fibers were incised until ureter could freely move from the base of the new hiatus. Finally, after spatulation of the terminal part of the ureter, ureterovesical anastomosis was performed with intracorporeal suturing using 5-0 monofilament sutures.

RESULTS

The average operative time was 125 min, with an average of 93 min for unilateral and 133 min for bilateral reimplantation. Blood loss was minimal and drains were used selectively. Removal of urethral catheter was decided empirically after hematuria stopped. Mean catheterization time was 5.1 days. The mean postoperative hospital stay was 6.2 days.

DISCUSSION

This study had limitations: the small number of cases, follow-up period is relatively short and data on the pre-operative bladder capacity, catheter-related morbidity, pain control and cosmesis are lacking. But most cases showed positive clinical results including acceptable operating time and good resolution rate with minimal complication. Our Politano-Leadbetter transvesicoscopic ureteric reimplantation is safe and useful in the resolution of VUR, even though the laparoscopic ureteric reimplantation is technically demanding even for experienced pediatric surgeons. Considering the main advantages of endoscopic surgery, our new vesicoscopic technique could be an optional treatment to the open reimplantation and has merits because whole the procedure are performed within the bladder, so there is no risk of intraperitoneal organ injury.

CONCLUSION

Though the role of this new technique in the treatment of VUR remains to be determined, the technique could be an optional treatment to replace other surgical methods as a less invasive and effective therapeutic method.

Mutational characteristics of ANK1 and SPTB genes in hereditary spherocytosis

The aim of this study was to describe the mutational characteristics in Korean hereditary spherocytosis (HS) patients. Relevant literatures including genetically confirmed cases with well-documented clinical summaries and relevant information were also reviewed to investigate the mutational gene- or domain-specific laboratory and clinical association. Twenty-five HS patients carried one heterozygous mutation of ANK1 (n = 13) or SPTB (n = 12) but not in SPTA1, SLC4A1, or EPB42. Deleterious mutations including frameshift, nonsense, and splice site mutations were identified in 91% (21/23), and non-hotspot mutations were dispersed across multiple exons. Genotype-phenotype correlation was clarified after combined analysis of the cases and the literature review; anemia was most severe in HS patients with mutations on the ANK1 spectrin-binding domain (p < 0.05), and SPTB mutations in HS patients spared the tetramerization domain in which mutations of hereditary elliptocytosis and pyropoikilocytosis are located. Splenectomy (17/75) was more frequent in ANK1 mutant HS (32%) than in HS with SPTB mutation (10%) (p = 0.028). Aplastic crisis occurred in 32.0% of the patients (8/25; 3 ANK1 and 5 SPTB), and parvovirus B19 was detected in 88%. The study clarifies ANK1 or SPTB mutational characteristics in HS Korean patients. The genetic association of laboratory and clinical aspects suggests comprehensive considerations for genetic-based management of HS.

GRP78 is required for cell proliferation and protection from apoptosis in chicken embryo fibroblast cells

Chicken serum has been suggested as a supplement to promote chicken cell proliferation and development. However, the molecular mechanisms by which chicken serum stimulates chicken cell proliferation remain unknown. Here, we evaluated the effects of chicken serum supplementation on chicken embryo fibroblast (CEF) and DF-1 cell proliferation. We also sought to elucidate the molecular pathways involved in mediating the effects of chicken serum on fibroblasts and DF-1 cells by overexpression of chicken 78 kDa glucose-regulated protein (chGRP78), which is important for cell growth and the prevention of apoptosis. Our data demonstrated that the addition of 5% chicken serum significantly enhanced fibroblast proliferation. Moreover, knockdown of chGRP78 using siRNA decreased fibroblast proliferation and increased apoptosis. Based on these results, we suggest that the chGRP78-mediated signaling pathway plays a critical role in chicken serum-stimulated fibroblast survival and anti-apoptosis. Therefore, our findings have important implications for the maintenance of chicken fibroblast cells through the inhibition of apoptosis and may lead to the development of new treatments for avian disease.

Significance of KIT exon 17 mutation depends on mutant level rather than positivity in core-binding factor acute myeloid leukemia

KIT exon 17 mutation is a poor prognostic factor in core-binding factor acute myeloid leukemia. However, the mutation detection method used for risk assessment is not assigned. It is necessary to verify the analytical and clinical performance before applying new methods. Herein, we firstly applied a highly sensitive allele-specific, real-time quantitative PCR (AS-qPCR) assay to analyze KIT mutations, which demonstrated excellent sensitivity and specificity. Much higher incidence of KIT mutations (62.2%, 69/111) and prevalence of multiple mutations (43.5%, 30/69) were observed using AS-qPCR, which meant the existence of multiple KIT mutant subclones. The relative KIT mutant level was variable (median, 0.3 per control allele 100 copies, 0.002–532.7) and was divided into two groups: high (⩾10, n=26) and low (<10) mutant level. Interestingly, rather than mutation positivity, mutant level was found to be associated with clinical outcome. High mutant level showed significantly inferior overall survival (P=0.005) and event-free survival (P=0.03), whereas low level did not influence the prognosis. The follow-up data showed that the mutant level were along with fusion transcripts in the majority (n=29), but moved separately in some cases, including the loss of mutations (n=5) and selective proliferation of minor clones (n=2) at relapse. This study highlighted that the KIT mutation should be analyzed using sensitive and quantitative techniques and set a cutoff level for identifying the risk group.

Development and application of ligand-based NMR screening assays for γ-butyrobetaine hydroxylase

A ¹H NMR based dual-reporter binding assay for γ-butyrobetaine hydroxylase (BBOX) reveals unexpected structure–activity relationships for isoquinoline-derived inhibitors.

The prevalence of causative organisms of community-acquired urethritis in an age group at high risk for sexually transmitted infections in Korean Soldiers

OBJECTIVES

This study was designed to evaluate the causative organisms in young male soldiers with clinical signs and symptoms after sexual contact that suggests a diagnosis of urethritis.

METHODS

Between June 2012 and January 2015, male patients with urethritis symptoms that had resulted from sexual contact within 3 months participated in this study. All patients were evaluated using urinalysis and were screened for Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), Ureaplasma urealyticum (UU), Mycoplasma genitalium (MG), Mycoplasma hominis (MH), herpes simplex virus (HSV) type II and Trichomonas vaginalis (TV) using multiplex PCR (mPCR) assay in order to detect sexually transmitted infections (STI) or pathogens.

RESULTS

A total of 436 male patients aged 18-28 years were included in the study. The median age was 22.0 years. The prevalence of STI pathogens were as follows: NG in 19.0%, CT in 36.6%, UU in 24.0%, MG in 21.5%, MH in 6.1%, HSV type II in 1.6%, TV in 0.2% and indeterminate STI pathogens in 9.4%. Coinfection of NG with non-NG was detected in 5.7% of the participants, while the coinfection rates for STI pathogens were: with CT in 3.4%, with UU in 2.7%, with MG in 0.2% and with MH in 0.2%.

CONCLUSIONS

CT was the most prevalent STI pathogen and coinfections of NG with non-NG appeared less frequently. The young male soldiers with urethritis should be administered suitable antibiotics for STI pathogens that were found by mPCR results, rather than an experimental combination of antibiotics for coinfections.

Genetic association between VEGF polymorphisms and BRONJ in the Korean population

OBJECTIVES

The purpose of this study was to evaluate the association between vascular endothelial growth factor (VEGF) polymorphisms and bisphosphonate-related osteonecrosis of the jaw (BRONJ) in the Korean population.

SUBJECTS AND METHODS

Forty-five individuals (2 men, 43 women; mean age: 68.7 ± 12.3 years) were recruited for this study. All visited the Yonsei University Dental Hospital for surgical intervention from January 2012 to January 2013 and had a history of bisphosphonate (BP) administration (oral and/or intravenous). Patients were allocated to case (n = 26) or control (n = 19) groups according to the patients' selection criteria. Association between three VEGF single nucleotide polymorphisms (rs699947 (-2578 C>A), rs2010963 (-634 G>C) and rs3025039 (+936 C>T)) and BRONJ were investigated using multiple logistic regression analysis and Fisher's exact test where appropriate (α = 0.05).

RESULTS

The CC homozygotes of rs2010963 and rs3025039 of VEGF gene were associated with an increased risk of BRONJ (P = 0.04, 0.03, respectively). In haplotype analysis, no differences in haplotype C-C (-2578/-634) and haplotype C-C-C (-2578/-634/+936) were observed.

CONCLUSION

The CC homozygotes of rs2010963 and rs3025039 polymorphisms in the VEGF gene were associated with an increased risk of BRONJ in the Korean population. Further epidemiological cohort studies with a larger sample size would be required to confirm the suggestive correlations.

COUP-TFII Stimulates Dentin Sialophosphoprotein Expression and Mineralization in Odontoblasts

Chicken ovalbumin upstream promoter transcription factor 2 (COUP-TFII), an orphan nuclear receptor belonging to the steroid-thyroid hormone receptor superfamily, plays an important role in cell fate determination of various tissues. However, the specific role of COUP-TFII in tooth development has not yet been elucidated. In the present study, we aimed to explore the role of COUP-TFII in dentin sialophosphoprotein (DSPP) expression and matrix mineralization in odontoblast-lineage cells. In primary human dental pulp cells (HDPCs) and murine dental papilla-derived cells (MDPC-23) cultured in a mineralizing medium, the expression of COUP-TFII was induced along with the increased odontoblast-specific dentin matrix protein-1 (DMP-1) and DSPP expression. Endogenous expression of COUP-TFII in maxillary second molar germs of rats showed an increasing tendency as development of the tooth progressed. Also, COUP-TFII protein was detected in greater quantity in the odontoblastic layer of second molar germs than in that of third molar germs of rats. Overexpression of COUP-TFII using an adenoviral system upregulated the expression of odontoblast-specific genes with increased alkaline phosphatase activity and matrix mineralization in odontoblast-lineage cells. In contrast, knockdown of COUP-TFII using small interfering RNA decreased the expression of odontoblast-specific genes, which reduced matrix mineralization. Mechanistic studies revealed that COUP-TFII increased DSPP transcription by direct binding on the DSPP promoter. In addition, COUP-TFII physically interacted with the homeodomain transcription factor Msx2 and antagonistically regulated the Msx2 effect on DSPP promoter activity. Taken together, these results suggest that COUP-TFII has a stimulatory role in DSPP expression and matrix mineralization in odontoblast-lineage cells.

Clinical predictors and time course of the improvement in β-cell function with short-term intensive insulin therapy in patients with Type 2 diabetes

AIMS

In patients with Type 2 diabetes, a short course of intensive insulin therapy can improve β-cell function and even induce transient remission of diabetes. However, not all patients respond to this therapy. Although the achievement of fasting glucose  < 7.0 mmol/l one day after stopping intensive insulin therapy can identify patients in whom β-cell function has improved, we sought to determine clinical predictors for the early identification of such responders and the time course of response.

METHODS

We pooled data from two studies in which 97 patients with Type 2 diabetes mellitus (median 3 years duration) and HbA1c 51 ± 8.7 mmol/mol (6.8 ± 0.8%) underwent 4-8 weeks of intensive insulin therapy, consisting of basal detemir and pre-meal insulin aspart. They were classified as responders (n = 74) or non-responders (n = 23), defined by the achievement of fasting glucose  < 7.0 mmol/l after stopping intensive insulin therapy.

RESULTS

On logistic regression analyses, duration of diabetes (odds ratio [OR] = 0.72, 95% confidence interval [CI] 0.56-0.92, P = 0.009) and baseline fasting glucose (OR = 0.40, 95% CI 0.24-0.68, P = 0.001) emerged as predictors of the likelihood of responding. Ninety per cent of patients with duration ≤ 4 years and fasting glucose ≤ 8.0 mmol/l responded to intensive insulin therapy. Despite having lower glucose levels during intensive insulin therapy, responders had less hypoglycaemia than non-responders (median 0.3 vs. 1.6 episodes/week, P < 0.0001), with rates of hypoglycaemia diverging sharply from the third week onwards.

CONCLUSION

At baseline, shorter duration of diabetes and lower fasting glucose can identify patients most likely to benefit from short-term intensive insulin therapy. Most importantly, during therapy, responders had less hypoglycaemia from the third week onwards, despite lower glycaemia, suggesting that 2 weeks of intensive insulin therapy may be needed to improve endogenous islet function.

Disruption of Tgfbr2 in Odontoblasts Leads to Aberrant Pulp Calcification

Transforming growth factor β (TGF-β) signaling has been implicated in dentin formation and repair; however, the molecular mechanisms underlying dentin formation remain unclear. To address the role of TGF-β signaling in dentin formation, we analyzed odontoblast-specific Tgfbr2 conditional knockout mice. The mutant mice had aberrant teeth with thin dysplastic dentin and pulpal obliteration, similar to teeth from human patients with dentinogenesis imperfecta type II and dentin dysplasia. In mutant, the odontoblasts lost their cellular polarity, and matrix secretion was disrupted after mantle dentin formation. As a consequence, the amount of predentin decreased significantly, and an ectopic fibrous matrix was formed below the odontoblast layer. This matrix gradually calcified and obliterated the pulp chamber with increasing age. Immunohistochemistry revealed decreased expression of alkaline phosphatase in mutant odontoblasts. In mutant dentin, Dsp expression was reduced, but Dmp1 expression increased significantly. Collagen type I, biglycan, and Dsp were expressed in the ectopic matrix. These results suggest that loss of responsiveness to TGF-β in odontoblasts results in impaired matrix formation and pulpal obliteration. Our study indicates that TGF-β signaling plays an important role in dentin formation and pulp protection. Furthermore, our findings may provide new insight into possible mechanisms underlying human hereditary dentin disorders and reparative dentin formation.

Merging and scoring molecular interactions utilising existing community standards: tools, use-cases and a case study

The evidence that two molecules interact in a living cell is often inferred from multiple different experiments. Experimental data is captured in multiple repositories, but there is no simple way to assess the evidence of an interaction occurring in a cellular environment. Merging and scoring of data are commonly required operations after querying for the details of specific molecular interactions, to remove redundancy and assess the strength of accompanying experimental evidence. We have developed both a merging algorithm and a scoring system for molecular interactions based on the proteomics standard initiative–molecular interaction standards. In this manuscript, we introduce these two algorithms and provide community access to the tool suite, describe examples of how these tools are useful to selectively present molecular interaction data and demonstrate a case where the algorithms were successfully used to identify a systematic error in an existing dataset.

Two-year experience of using the measles, mumps and rubella vaccine as intralesional immunotherapy for warts

BACKGROUND

The currently available treatments for warts, including cryosurgery, laser surgery, electrosurgery, and topical keratolytic applications, are often very painful and can induce disfiguring scars. Recently, intralesional immunotherapy with skin test antigens and vaccines has been shown to be effective in the management of warts.

AIMS

To evaluate the efficacy of a new intralesional immunotherapy for warts, using the measles, mumps and rubella (MMR) vaccine.

METHODS

A retrospective study was performed, and we enrolled 136 patients with various types of warts into the study, which was for a duration of 2 years. Patients were treated for a total of six times at 2-week intervals. The treatment response was classified as one of three levels, based on reduction in the size and number of warts, and patients with complete response (CR) were checked for recurrence. Clinical evaluations were carried out using photographs and medical records.

RESULTS

Over half (51.5%) of patients experienced > 50% reduction in the size and number of warts, and 46.7% who had distant warts (in different locations) showed good response. Common warts showed significantly higher treatment response than other types of warts (P < 0.05). However, other clinical variables did not have any effect on efficacy. Almost all the patients reported mild pain during the injection, but other side effects were rarely observed. Only 5.6% of patients who experienced CR had recurrence of warts after 6 months.

CONCLUSIONS

We suggest that intralesional immunotherapy with MMR vaccine is a tolerable and effective method for patients who are sensitive to pain, concerned about side effects, or have common warts. Treatment response is improved by increasing the number of injections.

Cosmetic side effects of antiepileptic drugs in adults with epilepsy

OBJECTIVE

Cosmetic side effects (CSEs) such as weight gain and alopecia are common, undesirable effects associated with several AEDs. The objective of the study was to compare the CSE profiles in a large specialty practice-based sample of patients taking both older and newer AEDs.

METHODS

As part of the Columbia and Yale AED Database Project, we reviewed patient records including demographics, medical history, AED use, and side effects for 1903 adult patients (≥16years of age) newly started on an AED. Cosmetic side effects were determined by patient or physician report in the medical record and included acne, gingival hyperplasia, hair loss, hirsutism, and weight gain. We compared the overall rate of CSEs and intolerable CSEs (ICSEs-CSEs that led to dosage reduction or discontinuation) between different AEDs in both monotherapy and polytherapy.

RESULTS

Overall, CSEs occurred in 110/1903 (5.8%) patients and led to intolerability in 70/1903 (3.7%) patients. Weight gain was the most commonly reported CSE (68/1903, 3.6%) and led to intolerability in 63 (3.3%) patients. Alopecia was the second most common patient-reported CSE (36/1903, 1.9%) and was intolerable in 33/1903 (1.7%) patients. Risk factors for CSEs included female sex (7.0% vs. 4.3% in males; p<0.05) and any prior CSE (37% vs. 2.9% in patients without prior CSE; p<0.001). Significantly more CSEs were attributed to valproic acid (59/270; 21.9%; p<0.001) and pregabalin (14/143; 9.8%; p<0.001) than to all other AEDs. Significantly less CSEs were attributed to levetiracetam (7/524; 1.3%; p=0.002). Weight gain was most frequently associated with valproic acid (35/270; 13.0%; p<0.001) and pregabalin (12/143; 8.4%; p<0.001). Hair loss was most commonly reported among patients taking valproic acid (24/270; 8.9%; p<0.001). Finally, gingival hyperplasia was most commonly reported in patients taking phenytoin (10/404; 2.5%; p<0.001). Cosmetic side effects leading to dosage change or discontinuation occurred most frequently with pregabalin and valproic acid compared with all other AEDs (13.3 and 5.6% vs. 2.3%; p<0.001). For patients who had been on an AED in monotherapy (n=677), CSEs and ICSEs were still more likely to be attributed to valproic acid (30.2% and 17.1%, respectively) than to any other AED (both p<0.001).

SIGNIFICANCE

Weight gain and alopecia were the most common patient-reported CSEs in this study, and weight gain was the most likely cosmetic side effect to result in dosage adjustment or medication discontinuation. Particular attention should be paid to pregabalin, phenytoin, and valproic acid when considering cosmetic side effects. Female patients and patients who have had prior CSE(s) to AED(s) were more likely to report CSEs. Knowledge of specific CSE rates for each AED found in this study may be useful in clinical practice.

Identification of Creb3l4 as an essential negative regulator of adipogenesis

Understanding the molecular networks that regulate adipogenesis is crucial for combating obesity. However, the identity and molecular actions of negative regulators that regulate the early development of adipocytes remain poorly understood. In this study, we investigated the role of CREB3L4, a member of the CREB3-like family, in the regulation of adiposity. Constitutive overexpression of CREB3L4 resulted in the inhibition of adipocyte differentiation, whereas knockdown of Creb3l4 expression caused differentiation of preadipocytes into mature adipocytes, bypassing the mitotic clonal expansion step. In 3T3-L1 preadipocytes, Creb3l4 knockdown resulted in increased expression of peroxisome proliferator-activated receptor γ (PPARγ2) and CCAAT/enhancer binding protein (C/EBPα), either by increasing the protein stability of C/EBPβ or by decreasing the expression of GATA3, a negative regulator of PPARγ2 expression. Consequently, increased PPARγ2 and C/EBPα levels induced adipocyte differentiation, even in the presence of minimal hormonal inducer. Thus, it can be speculated that CREB3L4 has a role as gatekeeper, inhibiting adipogenesis in 3T3-L1 preadipocytes. Moreover, adipocytes of Creb3l4-knockout mice showed hyperplasia caused by increased adipogenesis, and exhibited improved glucose tolerance and insulin sensitivity, as compared with littermate wild-type mice. These results raise the possibility that Creb3l4 could be a useful therapeutic target in the fight against obesity and metabolic syndrome.

Maternal perceptions of sibling adaptation in Korean families of children with Down syndrome

BACKGROUND

It is estimated that more than 500 infants with Down syndrome (DS) are born each year in Korea. DS affects not only these individuals, but family members as well. Some siblings deal successfully with the challenges of living with a child with DS and adapt well while others struggle or fail to adapt. The aims of this descriptive study were to explore how Korean mothers of children with DS perceive the adaptation of their typically developing (TD) children aged 4 to 19 and how family variables contribute to sibling adaptation.

METHOD

This descriptive, cross-sectional study was conducted with 105 Korean mothers.

RESULTS

Most mothers indicated that their TD children were not experiencing psychological or behavioural problems; however, many described problems in the sibling relationship. It was found that family factors (i.e. condition management effort, condition management ability, child's daily life, parental mutuality, family hardiness and social support) were strong predictors of sibling psychological, behavioural and relational adaptation. Demographic characteristics of the child with DS, the mother and the family appeared to significantly influence sibling adaptation.

CONCLUSIONS

These findings highlight the importance of familial contexts in understanding sibling adaptation. Knowledge of family factors associated with better adaptation in Korean siblings of child with DS will facilitate the development of culturally appropriate interventions for these children and their families. In addition, an awareness of demographic characteristics associated with sibling adaptation will help health care professionals identify siblings who are at increased risk of experiencing difficulties in adapting.

Honeycomb-like Structured Film Regulates Mediator Release from Non-Tumor Mast Cells

We previously reported a honeycomb-like structured film (HCF) stimulates mast cell proliferation and multinucleated formation. In this study, we examined the role of HCF in regulating the release of mediators from cultured mast cells. We measured the release of histamine, substance P, tumor necrosis factor (TNF)-α, and leukotriene B4 (LTB-4) from NCL-2 cells (proliferative mouse non-tumor mast cells). After 7 days of culture, HCF selectively down-regulated the release of TNF-α, LTB-4, and (to a lesser extent) substance P, but not histamine. Mast cell attachment to HCF may have a greater effect on release of de novo synthesized molecules.

Working channel endoscope in lumbar spine surgery

Percutaneous endoscopic lumbar discectomy (PELD) is a well established modality in the treatment of patients with herniated lumbar discs. Since the time of its inception towards the end of 20th century, this technique has undergone significant modifications. With better understanding of the patho-anatomy and development of instrumentation the indications for PELD are on the rise. In the modern era of knowledge exchange there have been considerable variations among different endoscopic surgeons about classical indications and the implications of a particular technique pertaining to those indications. During last 15 years of experience in practicing endoscopic surgery, Choi has published many articles, regarding the techniques of PELD, across many scientific journals. In our practice there has been considerable shift from central debulking to discectomy to selective fragmentectomy. With further advancements the span of this technique is definitely on the rise. Here, we wish to share all the published data along with my current practice trends in more precise manner to help newer endoscopic spine surgeons understand the implications and limitations of a working channel endoscope in lumbar spine pathologies.

Enhanced aneurysmal flow diversion using a dynamic push-pull technique: an experimental and modeling study

BACKGROUND AND PURPOSE

Neurovascular flow diverters are flexible, braided stent-meshes for intracranial aneurysm treatment. We applied the dynamic push-pull technique to manipulate the flow-diverter mesh density at the aneurysm orifice to maximize flow diversion. This study investigated the hemodynamic impact of the dynamic push-pull technique on patient-specific aneurysms by using the developed high-fidelity virtual-stenting computational modeling technique combined with computational fluid dynamics.

MATERIALS AND METHODS

We deployed 2 Pipeline Embolization Devices into 2 identical sidewall anterior cerebral artery aneurysm phantoms by using the dynamic push-pull technique with different delivery-wire advancements. We then numerically simulated these deployment processes and validated the simulated mesh geometry. Computational fluid dynamics analysis was performed to evaluate detailed hemodynamic changes by deployed flow diverters in the sidewall aneurysm and a fusiform basilar trunk aneurysm (deployments implemented previously). Images of manipulated flow diverter mesh from sample clinical cases were also evaluated.

RESULTS

The flow diverters deployed in silico accurately replicated in vitro geometries. Increased delivery wire advancement (21 versus 11 mm) by using a dynamic push-pull technique produced a higher mesh compaction at the aneurysm orifice (50% metal coverage versus 36%), which led to more effective aneurysmal inflow reduction (62% versus 50% in the sidewall aneurysm; 57% versus 36% in the fusiform aneurysm). The dynamic push-pull technique also caused relatively lower metal coverage along the parent vessel due to elongation of the flow diverter. High and low mesh compactions were also achieved for 2 real patients by using the dynamic push-pull technique.

CONCLUSIONS

The described dynamic push-pull technique increases metal coverage of pure braided flow diverters over the aneurysm orifice, thereby enhancing the intended flow diversion, while reducing metal coverage along the parent vessel to prevent flow reduction in nearby perforators.

Transcriptional factor ATF6 is involved in odontoblastic differentiation

ATF6 is an endoplasmic reticulum (ER) membrane-bound transcription factor that regulates various cellular functions. The purpose of this study was to investigate the role of ATF6 in odontoblast differentiation. Rat tooth germs were isolated, changes in gene expression were evaluated over time, and localization of ATF6 was determined by immunohistochemistry. Human dental pulp cells (HDPCs) were cultured with 50 µg/mL ascorbic acid and 5 mmol/L β-glycerophosphate or 100 ng/mL bone morphogenetic protein 2 to induce differentiation. Translocation of ATF6 was observed by immunofluorescence and confocal microscopy. Overexpression of ATF6 was performed with an adenoviral vector. Matrix mineralization was evaluated by alizarin red staining. Immunoreactivity to anti-ATF6 was observed in the odontoblastic layer of the molar tooth germ, and expressions of ATF6, dentin sialophosphoprotein (DSPP) and dentin matrix protein 1 (DMP1) increased gradually during tooth germ development. When HDPCs were cultured in differentiation media, ATF6, DSPP, and DMP1 expression increased with the expression of unfolded protein response (UPR) markers, BiP and CHOP. Immunofluorescence results showed that ATF6 protein moved from cytoplasm to nucleus when cells were exposed to differentiation media. Notably, overexpression of ATF6 increased DSPP and DMP1 expression, alkaline phosphatase (ALP) activity, and matrix mineralization in HDPC cultures. Inhibition of ATF6 decreased ALP activity and mineralization. These results suggest that ER membrane-bound transcriptional factor ATF6 may be involved in odontoblastic differentiation.