Reagent integration and controlled release for multiplexed nucleic acid testing in disposable thermoplastic 2D microwell arrays.

The seamless integration of reagents into microfluidic devices can serve to significantly reduce assay complexity and cost for disposable diagnostics. In this work, the integration of multiplexed reagents into thermoplastic 2D microwell arrays is demonstrated using a scalable pin spotting technique. Using a simple and low-cost narrow-bore capillary spotting pin, high resolution deposition of concentrated reagents within the arrays of enclosed nanoliter-scale wells is achieved. The pin spotting method is further employed to encapsulate the deposited reagents with a chemically modified wax layer that serves to prevent disruption of the dried assay components during sample introduction through a shared microchannel, while also enabling temperature-controlled release after sample filling is complete. This approach supports the arbitrary patterning and release of different reagents within individual wells without crosstalk for multiplexed analyses. The performance of the in-well spotting technique is characterized using on-chip rolling circle amplification to evaluate its potential for nucleic acid-based diagnostics.

Pressure changes in the Kager fat pad at the extremes of ankle motion suggest a potential role in Achilles tendinopathy.

INTRODUCTION: The Kager fat pad is one of the largest soft tissue structures local to the ankle joint, yet it is poorly understood. It has been hypothesised to have a role in Achilles tendinopathy. This study aimed to investigate the pressure areas in the Kager fat pad adjacent to the Achilles tendon and to assess the anatomy and deformation of the Kager fat pad in cadavers. METHODS: Twelve fresh frozen cadaveric ankles (mean age 44 years, range 38-51) were mounted in a customized testing rig, enabling plantar flexion and dorsiflexion of the ankle, with the Achilles tendon loaded. A needle tipped pressure sensor was inserted in two areas of the Kager fat pad under ultrasound guidance (retrocalcaneal bursa and at 3 cm proximal from Achilles insertion). Pressure readings were recorded at different flexion angles. Following testing, the specimens were dissected to expose the Kager fat pad and retrieve it for analysis. MRI images were also taken from three healthy volunteers and the Kager fat pad deformation examined. RESULTS: Mean pressures significantly increased in all specimens at terminal ankle plantar and dorsi flexion in both regions (p < 0.05). The Kager fat pad was consistently adherent to the Achilles at its posterior aspect for a mean length of 7.7 cm (SD 0.27, 89% of KFP length). The most distal part of the Kager fat pad was the exception and it detached from the Achilles to give way to the retroalcaneal bursa for a mean length of 0.92 cm (SD 0.24, 11% of KFP length). The bursal space is partially occupied by a constant 'wedge' extension of Kager fat pad. The mean volume of the whole Kager fat pad was 10.6 ml (SD 3.37). Video and MRI demonstrated that the Kager fat pad undergoes significant deformation during plantar flexion as it is displaced superiorly by the Achilles, with the wedge being forced into the retrocalcaneal bursal space. CONCLUSION: The Kager fat pad does not remain static during ankle range of motion, but deforms and its pressure also changes. This observation supports the theory that it acts as a shock-absorber to the Achilles tendon and pathological changes to the fat pad may be clinically important in the development of Achilles tendinopathy.

Association of use of Chinese herbal medicines and the risk of fracture in patients with osteoporosis: a population-based cohort study.

After utilizing a large population-based claims database and the application of propensity score match approach to reduce the confounding effects, we found that the use of Chinese herbal medicines (CHMs) was related to the lower risk of sequent osteoporotic fracture by 27% among the individuals with osteoporosis. The predominant effect was observed in those receiving CHMs for more than two years. INTRODUCTION: Osteoporosis (OS) is a highly disabling condition that can lead to fragility fracture, thus posing greater burdens of functional limitations for the affected individuals. It is unclear if the use of Chinese herbal medicines (CHMs) could reduce the risk of fracture due to OS. This study aimed to investigate the association of CHMs and the subsequent osteoporotic fracture risk among OS patients. METHODS: This longitudinal cohort study used the Taiwanese National Health Insurance Research Database to identify 250,699 newly diagnosed OS patients aged 20 years or older between 1998 and 2010. We recruited 103,325 CHM users following the onset of OS (CHM users) and randomly selected 103,325 subjects without CHM usage as controls (non-CHM users) by propensity score matching according to the demographic characteristics and comorbidities at enrollment. All enrollees were followed until the end of 2012 to record the incidence of osteoporotic fracture. We applied the Cox proportional hazard regression model to compute the hazard ratio (HR) of the risk of osteoporotic fracture. RESULTS: During the 15-year follow-up period, 7208 CHM users and 11,453 non-CHM users sustained osteoporotic fracture, with an incidence rate of 9.26 and 12.96, respectively, per 1000 person-years. We found that CHM users had a significantly reduced risk of osteoporotic fracture compared to non-CHM users (adjusted HR 0.73; 95% confidence interval [CI] = 0.70-0.75). Those treated with CHMs for longer than 730 days had a lower fracture risk by 54%. Some commonly used CHMs, such as Yan hu suo (Rhizoma Corydalis), Huang Qin (Scutellaria Baicale), Jie Geng (Platycodon grandifloras), Xiang Fu (Cyperus rotundus), Hai Piao Xiao (Cuttlebone Sepium), Jia-Wei-Xiao-Yao-San, Ge-Gen-Tang, Shao-Yao-Gan-Cao-Tang, and Du-Huo-Ji-Sheng-Tang, are related to the lower risk of fracture. CONCLUSIONS: The use of CHMs was associated with lower risk of osteoporotic fracture for OS patients, suggesting that it could be integrated into conventional therapy to prevent subsequent bone fracture.

Fractures and the increased risk of suicide: a population-based case-control study.

Aims: A high rate of suicide has been reported in patients who sustain fractures, but the association remains uncertain in the context of other factors. The aim of this study was to examine the association between fractures and the risk of suicide in this contextual setting. Patients and Methods: We performed a case-control study of patients aged 40 years or older who died by suicide between 2000 and 2011. We included patients' demographics, physical and mental health problems, and socioeconomic factors. We performed conditional logistic regression to evaluate the associations between fractures and the risk of suicide. Results: We included a total of 34 794 patients who died by suicide and 139 176 control patients. We found that fractures as a homogenous group (adjusted odds ratios (aOR), 1.48; 95% confidence interval (CI) 1.43 to 1.53), and specifically pelvic (aOR 2.04; 95% CI 1.68 to 2.47) and spinal fractures (aOR 1.53; 95% CI 1.43 to 1.64), were associated with a higher risk of suicide. In addition, we found that patients who had a lower income, had never married, had lower levels of educational attainment, or had coexistent physical and mental conditions such as anxiety, mood disorders, and psychosis-related disorders had a higher risk of suicide. Conclusion: Fractures, specifically those of the hip and spine, were associated with an increased risk of suicide. The findings suggest that greater clinical attention should be given to this risk in patients with fractures, especially for those with additional risk factors. Cite this article: Bone Joint J 2018;100-B:780-6.

Anti-viral therapy is associated with improved survival but is underutilised in patients with hepatitis B virus-related hepatocellular carcinoma: real-world east and west experience.

BACKGROUND: Hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC) worldwide. It remains incompletely understood in the real world how anti-viral therapy affects survival after HCC diagnosis. METHODS: This was an international multicentre cohort study of 2518 HBV-related HCC cases diagnosed between 2000 and 2015. Cox proportional hazards models were utilised to estimate hazard ratios (HR) with 95% (CI) for anti-viral therapy and cirrhosis on patients' risk of death. RESULTS: Approximately, 48% of patients received anti-viral therapy at any time, but only 17% were on therapy at HCC diagnosis (38% at US centres, 11% at Asian centres). Anti-viral therapy would have been indicated for >60% of the patients not on anti-viral therapy based on American criteria. Patients with cirrhosis had lower 5-year survival (34% vs 46%; P < 0.001) while patients receiving anti-viral therapy had increased 5-year survival compared to untreated patients (42% vs 25% with cirrhosis and 58% vs 36% without cirrhosis; P < 0.001 for both). Similar findings were seen for other patient subgroups by cancer stages and cancer treatment types. Anti-viral therapy was associated with a decrease in risk of death, whether started before or after HCC diagnosis (adjusted HR 0.62 and 0.79, respectively; P < 0.001). CONCLUSIONS: Anti-viral therapy improved overall survival in patients with HBV-related HCC across cancer stages and treatment types but was underutilised at both US and Asia centres. Expanded use of anti-viral therapy in HBV-related HCC and better linkage-to-care for HBV patients are needed.

Do stillbirth, miscarriage, and termination of pregnancy increase risks of attempted and completed suicide within a year? A population-based nested case-control study.

OBJECTIVE: To investigate the risks of attempted and completed suicide in women who experienced a stillbirth, miscarriage, or termination of pregnancy within 1 year postnatally and compare this risk with that in women who experienced a live birth. DESIGN: A nested case-control study. SETTING: Linking three nationwide population-based data sets in Taiwan: the National Health Insurance Research Database, the National Birth Registry and the National Death Registry. SAMPLE: In all, 485 and 350 cases of attempted and completed suicide, respectively, were identified during 2001-11; for each case, ten controls were randomly selected and matched to the cases according to the age and year of delivery. METHODS: Conditional logistic regression. MAIN OUTCOME MEASURES: Attempted and completed suicidal statuses were determined. RESULTS: The rates of attempted suicide increased in the women who experienced fetal loss. The risk of completed suicide was higher in women who experienced a stillbirth [adjusted odds ratio (aOR) 5.2; 95% CI 1.77-15.32], miscarriage (aOR 3.81; 95% CI 2.81-5.15), or termination of pregnancy (aOR 3.12; 95% CI 1.77-5.5) than in those who had a live birth. Furthermore, the risk of attempted suicide was significantly higher in women who experienced a miscarriage (aOR 2.1; 95% CI 1.66-2.65) or termination of pregnancy (aOR 2.5; 95% CI 1.63-3.82). In addition to marital and educational statuses, psychological illness increased the risk of suicidal behaviour. CONCLUSIONS: The risk of suicide might increase in women who experience fetal loss within 1 year postnatally. Healthcare professionals and family members should enhance their sensitivity to care for possible mental distress, particularly for women who have experienced a stillbirth. TWEETABLE ABSTRACT: Suicide risk increased in women who had a stillbirth, miscarriage, or termination of pregnancy within 1 year postnatally.

The relationship of the anterior articular capsule to the adjacent subscapularis: An anatomic and histological study.

INTRODUCTION: The purpose of this study was to delineate the anatomic relationship between the anterior articular capsule and the adjacent subscapularis by measuring the dimensions of the anterior articular capsule attachment and the subscapularis footprint on the humerus, as well as investigating the interface between the two structures. MATERIALS AND METHODS: Three shoulder specimens underwent histological analysis; for histological analysis, cross-sections through the subscapularis-capsule complex were harvested at the tendinous and muscular insertion sites. The dimensions of the anterior articular capsule attachment and the subscapularis footprint (including the tendinous and muscular insertions) were measured in thirteen cadaveric shoulder specimens. RESULTS: Histologically, the articular capsule has thin and loosely arranged collagen fibers with many interspersing fibroblast nuclei, whereas the outer layer of the articular capsule blends into a layer of more loosely spaced and less organized collagen fibers. This interface between the subscapularis and the underlying articular capsule is filled with more loosely spaced and less organized collagen fibers. The macroscopic evaluation showed that the minimum articular capsule width (4.2mm, SD 2.2mm) was located at its initiation 4.9mm (SD, 2.1mm) inferior to the superior margin of the subscapularis; the corresponding subscapularis footprint width measured 10.1mm (SD, 4.9mm). The maximum articular capsule width was11.1 mm (SD, 3.7mm) and was located 5mm distal to the inferior margin of the tendinous footprint. The maximum subscapularis footprint width was 15.8mm (SD, 2.9mm); the corresponding articular capsule attachment measured 5.2mm (SD, 1.8mm). CONCLUSIONS: Our results suggest that the anterior articular capsule attachment of the glenohumeral joint complements the footprint of the subscapularis and occupies a larger area of the lesser tubercle and metaphysis of the humerus than previously documented. The histological study confirms the presence of a demarcation between the subscapularis and articular capsule, specifically more significant at the region medial to the tendon insertion and at the muscular insertion of the subscapularis.

Use of NanoICE for Procurement Achieves Better Cooling of Liver Grafts.

BACKGROUND: Rapid cooling at procurement after cross-clamping has been the cornerstone of organ preservation. NanoICE is a new form of ice that has emerged in the food industry and is providing more efficient cooling and preservation than regular ice. We hypothesize that the use of NanoICE will accelerate the cooling process of the allograft and will be able to maintain a steady low temperature without causing any significant histologic damage. METHODS: In this randomized pilot study, 14 pigs were used to study the liver core/surface cooling in a non-survival organ procurement operation. Animals were randomly assigned to 1 of 2 groups, each arm involving 7 pigs: (1) crushed-iced normal saline cooling method (control group) and (2) NanoICE cooling method (study group). Surface and core temperatures were measured with temperature probes, and liver biopsies were obtained before cross-clamping and 15 hours after preservation to assess for any evidence and degree of freezing injury. RESULTS: NanoICE was able to reduce and sustain lower core temperatures at 30 minutes, 60 minutes, and 15 hours, compared with crushed ice. The degree of histologic damage (reflecting cold injury) at 15 hours after flushing was not significantly different between the 2 methods. CONCLUSIONS: NanoICE cools the deeper liver parenchyma more quickly and sustains a cooler temperature than regular crushed ice without causing significantly histologic damage. Future research should focus on whether the effect of NanoICE has any impact on graft function and survival.

Pressure drop of two-phase helium along long cryogenic flexible transfer lines to support a superconducting RF operation at its cryogenic test stand.

BACKGROUND: Establishing a stand-alone cryogenic test stand is of vital importance to ensure the highly reliable and available operation of superconducting radio-frequency module in a synchrotron light source. Operating a cryogenic test stand relies strongly on a capability to deliver two-phase helium along long cryogenic transfer lines. A newly constructed cryogenic test stand with flexible cryogenic transfer lines of length 220 m at National Synchrotron Radiation Research Center is required to support a superconducting radio-frequency module operated at 126.0 kPa with a 40-W dynamic load for a long-term reliability test over weeks. It is designed based on a simple analytical approach with the introduction of a so-called tolerance factor that serves to estimate the pressure drops in transferring a two-phase helium flow with a substantial transfer cryogenic heat load. Tolerance factor 1.5 is adopted based on safety factor 1.5 commonly applied in cryogenic designs to estimate the total mass flow rate of liquid helium demanded. A maximum 60-W dynamic load is verified with experiment measured with heater power 60 W instead after the cryogenic test stand has been installed. RESULTS: Aligning the modeled cryogenic accumulated static heat load with the results measured in situ, actual tolerance factor 1.287 is obtained. The feasibility and validity of our simple analytical approach with actual tolerance factor 1.287 have been scrutinized by using five test cases with varied operating conditions. Calculated results show the discrepancies of the pressure drops between the estimated and measured values for both liquid helium and cold gaseous helium transfer lines have an underestimate 0.11 kPa and an overestimate 0.09 kPa, respectively. A discrepancy is foreseen, but remains acceptable for engineering applications from a practical point of view. CONCLUSIONS: The simple analytical approach with the introduction of a tolerance factor can provide not only insight into optimizing the choice of each lossy cryogenic piping element of the transfer lines in the design phase but also firm guidance for upgrading the present cryogenic transfer lines for its subsequent application.

Progression of Hepatic Adenoma to Carcinoma in the Setting of Hepatoportal Sclerosis in HIV Patient: Case Report and Review of the Literature.

We report a case of hepatic adenoma progression to carcinoma in the setting of hepatoportal sclerosis in an HIV+ patient and provide a review of the scarce literature regarding hepatoportal sclerosis in HIV patients. We describe the clinical presentation, diagnostic workup, and management. This is the first case report in the literature of progression of hepatic adenoma to carcinoma in hepatoportal sclerosis in an HIV patient. This case also highlights the broad differential diagnosis that should always be included in the study of any liver disease in this patient population, including the performance of invasive and aggressive tests to arrive at the final diagnosis.

Increased parenchymal damage and steatohepatitis in Caucasian non-alcoholic fatty liver disease patients with common IL1B and IL6 polymorphisms.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a complex, multifactorial disease affected by diet, lifestyle and genetics. Proinflammatory cytokines like IL-1ß and IL-6 have been shown to be elevated in non-alcoholic steatohepatitis (NASH). AIM: To investigate the relationship between IL1B and IL6 gene polymorphisms and histological features of NAFLD in the NASH CRN cohort. METHODS: A total of 604 adult (≥18 years) non-Hispanic Caucasians with biopsy-proven NAFLD were genotyped for the following SNPs: IL1B, rs16944, rs1143634; IL6, rs1800795, rs10499563. Logistic regression was used to examine the relationship between genotype and a definitive diagnosis and advanced histological features of NASH after controlling for the following variables selected a priori: age, sex, diabetes, obesity and HOMA-IR level. RESULTS: The IL6 rs10499563 C allele was independently associated with the presence of definitive NASH, and increased ballooning and Mallory bodies. The IL1B rs1143634 TT genotype was associated with advanced fibrosis and increased Mallory bodies. The IL6 rs1800795 C allele was associated with not only increased risk for severe steatosis, >66% but also decreased risk for advanced fibrosis and lobular inflammation and Mallory body formation. CONCLUSIONS: These results suggest that common variants in the IL6 and IL1B genes may increase susceptibility for NASH and confer a higher risk of hepatic parenchymal damage including increased ballooning, increased Mallory bodies, and bridging fibrosis or cirrhosis. In contrast, the IL6 rs1800795 C allele may confer a higher risk for steatosis, but less parenchymal damage. Our findings support the development of therapeutics aimed at IL-1ß and IL-6 suppression.

Prospective Validation of Two 4D-CT-Based Scoring Systems for Prediction of Multigland Disease in Primary Hyperparathyroidism.

BACKGROUND AND PURPOSE: Patients with multigland primary hyperparathyroidism are at higher risk for missed lesions on imaging and failed parathyroidectomy. The purpose of this study was to prospectively validate the ability of previously derived predictive score systems, the composite multigland disease score, and the multiphase multidetector contrast-enhanced CT (4D-CT) composite multigland disease score, to identify patients with a high likelihood of multigland disease. MATERIALS AND METHODS: This was a prospective study of 71 patients with primary hyperparathyroidism who underwent 4D-CT and successful parathyroidectomy. The size and number of lesions identified on 4D-CT, serum calcium levels, and parathyroid hormone levels were collected. A composite multigland disease score was calculated from 4D-CT imaging findings and the Wisconsin Index (the product of the serum calcium and parathyroid hormone levels). A 4D-CT multigland disease score was obtained by using the CT data alone. RESULTS: Twenty-eight patients with multigland disease were compared with 43 patients with single-gland disease. Patients with multigland disease had a significantly smaller lesion size (P < .01) and a higher likelihood of having either ≥2 or 0 lesions identified on 4D-CT (P < .01). Composite multigland disease scores of ≥4, ≥5, and 6 had specificities of 72%, 86%, and 100% for multigland disease, respectively. 4D-CT multigland disease scores of ≥3 and 4 had specificities of 74% and 88%. CONCLUSIONS: Predictive scoring systems based on 4D-CT data, with or without laboratory data, were able to identify a subgroup of patients with a high likelihood of multigland disease in a prospectively accrued population of patients with primary hyperparathyroidism. These scoring systems can aid in surgical planning.

Effect of Prolonged Diarrhea in Renal Transplant Recipients at a Single Center in Taiwan.

OBJECTIVE: Post-renal transplantation diarrhea is a common complication; however, it is easily ignored. This study aimed to determine the factors influencing graft function for renal transplant recipients with diarrhea. METHODS: A single-center retrospective study with the use of the Hyperion data warehouse was conducted to search and evaluate for renal transplant recipients who came for medical care for diarrhea at our transplant center from January 2009 to August 2015. The clinical features of patients with diarrhea were compared with the features of recipients without diarrhea. The causes and risk factors of post-transplantation diarrhea were also evaluated. RESULTS: For the 67 patients collected for the study, infectious diarrhea (ID) was confirmed in 27 patients (40.3%), and the most common causes were cytomegalovirus and Clostridium difficile infection. A significant difference was found between ID and noninfectious (NID) groups for serum creatinine change (0.31 ± 0.51 vs 0.1 ± 0.27 mg/dL; P = .0319), revealing that the impact of diarrhea on renal function was greater for ID patients. When diarrhea of ≥10 days was used as a cutoff for serum creatinine change, the change of serum creatinine became greater when the diarrhea period was longer (<7 d vs >14 d: 0.07 ± 0.22 vs 0.55 ± 0.6 mg/mL; P = .0001). CONCLUSIONS: Infectious diarrhea does more damage to the kidney graft than NID in transplant recipients. If the period of diarrhea is lengthened to >10 days, the renal function of the graft would be impaired and irreversible graft loss would be expected.

Translation of the Diabetes Prevention Program for diabetes risk reduction in Chinese immigrants in New York City.

AIMS: To evaluate the effectiveness and feasibility of implementing a linguistically and culturally tailored Diabetes Prevention Program among Chinese immigrants with prediabetes living in New York City. METHODS: A total of 60 Chinese immigrants with prediabetes were randomized into either a Diabetes Prevention Program lifestyle intervention (n = 30) consisting of 12 bi-weekly core sessions and six monthly post-core sessions or the control intervention (n = 30), consisting of quarterly mailing of diabetes prevention information. Each Diabetes Prevention Program intervention session lasted 1.5-2 h and covered topics such as healthy eating, physical activity, stress reduction and problem-solving skills. Outcomes such as percent change in weight, BMI, and HbA1c concentration were assessed at baseline, 6 and 12 months. A mixed-effects linear regression was applied to test the intervention effect at months 6 and 12. Data were collected in the period 2012-2013 and analysed in 2014. RESULTS: The participant attrition rate was < 5% (2 out of 60) at 12 months. There was a significantly greater percent weight loss in the intervention group (-3.5 vs. -0.1%; P = 0.0001) at 6 months, which was largely maintained at 12 months (-3.3 vs. 0.3%; P = 0.0003). CONCLUSIONS: Participants in a Diabetes Prevention Program-based intervention achieved greater weight loss and improvements in HbA1c concentration than control participants. Evaluation of the Chinese Diabetes Prevention Program curriculum in a larger trial is warranted.

Predictors of Multigland Disease in Primary Hyperparathyroidism: A Scoring System with 4D-CT Imaging and Biochemical Markers.

BACKGROUND AND PURPOSE: Multigland disease represents a challenging group of patients with primary hyperparathyroidism. Additional lesions may be missed on imaging because they are not considered or are too small to be seen. The aim of this is study was to identify 4D-CT imaging and biochemical predictors of multigland disease. MATERIALS AND METHODS: This was a retrospective study of 155 patients who underwent 4D-CT and successful surgery with a biochemical cure that compared patients with multigland and single-gland disease. Variables studied included the size of the largest lesion on 4D-CT, the number of lesions prospectively identified on 4D-CT, serum calcium levels, serum parathyroid hormone levels, and the Wisconsin Index (the product of serum calcium and parathyroid hormone levels). Imaging findings and the Wisconsin Index were used to calculate a composite multigland disease scoring system. We evaluated the predictive value of individual variables and the scoring system for multigland disease. RESULTS: Thirty-six patients with multigland disease were compared with 119 patients with single-gland disease. Patients with multigland disease had significantly lower Wisconsin Index scores, smaller lesion size, and a higher likelihood of having either multiple or zero lesions identified on 4D-CT (P ≤ .01). Size cutoff of <7 mm had 85% specificity for multigland disease, but including other variables in the composite multigland disease score improved the specificity. Scores of ≥4, ≥5, and 6 had specificities of 81%, 93%, and 98%, respectively. CONCLUSIONS: The composite multigland disease scoring system based on 4D-CT imaging findings and biochemical data can identify patients with a high likelihood of multigland disease. Communicating the suspicion for multigland disease in the radiology report could influence surgical decision-making, particularly when considering re-exploration in a previously operated neck or initial limited neck exploration.

Clonal expansion of hepatocytes with a selective advantage occurs during all stages of chronic hepatitis B virus infection.

Hepatocyte clone size was measured in liver samples of 21 patients in various stages of chronic hepatitis B virus (HBV) infection and from 21 to 76 years of age. Hepatocyte clones containing unique virus-cell DNA junctions formed by the integration of HBV DNA were detected using inverse nested PCR. The maximum hepatocyte clone size tended to increase with age, although there was considerable patient-to-patient variation in each age group. There was an upward trend in maximum clone size with increasing fibrosis, inflammatory activity and with seroconversion from HBV e-antigen (HBeAg)-positive to HBeAg-negative, but these differences did not reach statistical significance. Maximum hepatocyte clone size did not differ between patients with and without a coexisting hepatocellular carcinoma. Thus, large hepatocyte clones containing integrated HBV DNA were detected during all stages of chronic HBV infection. Using laser microdissection, no significant difference in clone size was observed between foci of HBV surface antigen (HBsAg)-positive and HBsAg-negative hepatocytes, suggesting that expression of HBsAg is not a significant factor in clonal expansion. Laser microdissection also revealed that hepatocytes with normal-appearing histology make up a major fraction of the cells undergoing clonal expansion. Thus, preneoplasia does not appear to be a factor in the clonal expansion detected in our assays. Computer simulations suggest that the large hepatocyte clones are not produced by random hepatocyte turnover but have an as-yet-unknown selective advantage that drives increased clonal expansion in the HBV-infected liver.

Increased carrier mobility in end-functionalized oligosilanes.

We show that a class of oligosilane-arene σ, π-hybrid materials exhibits distinct and enhanced solid-state electronic properties relative to its parent components. In the single crystal structure, the σ-conjugation axis of one molecule points towards the π-face of a neighboring molecule due to an unusual gauche conformation. This organization is hypothesized to be beneficial for charge transport. We show that solution-deposited crystalline films of the hybrid materials show up to a 100-fold increase in space-charge limited current (SCLC) mobility relative to literature reports of photoinduced hole transport in oligosilane films. The discovery that σ, π-hybrids are more than the sum of their parts offers a design opportunity for new materials.

TGF-ß signaling alters the pattern of liver tumorigenesis induced by Pten inactivation.

Hepatocarcinogenesis results from the accumulation of genetic and epigenetic changes in liver cells. A common mechanism through which these alterations induce liver cancer is by deregulating signaling pathways. A number of signaling pathways, including the PI3K/PTEN/AKT and transforming growth factor ß (TGF-ß) pathways have been implicated in normal liver development as well as in cancer formation. In this study, we assessed the effect of the TGF-ß signaling pathway on liver tumors induced by phosphatase and tensin homolog (Pten) loss. Inactivation of only the TGF-ß receptor type II, Tgfbr2, in the mouse liver (Tgfbr2(LKO)) had no overt phenotype, while inactivation of Pten alone (Pten(LKO)), resulted in the formation of both hepatocellular carcinomas and cholangiocarcinomas (CC). Interestingly, deletion of both Pten and Tgfbr2 (Pten(LKO);Tgfbr2(LKO)) in the mouse liver resulted in a dramatic shift in tumor type to predominantly CC. Assessment of the PI3K/PTEN/AKT pathway revealed increased phosphorylation of AKT and glycogen synthase kinase 3 beta (GSK-3ß) in both the Pten(LKO) and Pten(LKO);Tgfbr2(LKO) mice, suggesting that this pathway is constitutively active regardless of the status of the TGF-ß signaling pathway. However, phosphorylation of p70 S6 kinase was observed in the liver of all three phenotypes (Tgfbr2(LKO), Pten(LKO), Pten(LKO);Tgfbr2(LKO)) indicating that the loss of Tgfbr2 and/or Pten leads to an increase in this signaling pathway. Analysis of markers of liver progenitor/stem cells revealed that the loss of TGF-ß signaling resulted in increased expression of c-Kit and CD133. Furthermore, in addition to increased c-Kit and CD133, Scf and EpCam expression were also increased in the double knock-out mice. These results suggest that the alteration in tumor types between the Pten(LKO) mice and Pten(LKO);Tgfbr2(LKO) mice is secondary to the altered regulation of stem-cell features induced by the loss of TGF-ß signaling.

Transplantation of autologous endothelial progenitor cells in porous PLGA scaffolds create a microenvironment for the regeneration of hyaline cartilage in rabbits.

OBJECTIVE: Repairing articular cartilage is clinically challenging. We investigated a simple, effective and clinically feasible cell-based therapeutic approach using a poly(lactide-co-glycolide) (PLGA) scaffold seeded with autologous endothelial progenitor cells (EPC) to repair a full-thickness osteochondral defect in rabbits using a one-step surgery. METHODS: EPC obtained by purifying a small amount of peripheral blood from rabbits were seeded into a highly porous, biocompatible PLGA scaffold, namely, EPC-PLGA, and implanted into the osteochondral defect in the medial femoral condyle. Twenty two rabbits were randomized into one of three groups: the empty defect group (ED), the PLGA-only group or the EPC-PLGA group. The defect sites were evaluated 4 and 12 weeks after implantation. RESULTS: At the end of testing, only the EPC-PLGA group showed the development of new cartilage tissue with a smooth, transparent and integrated articular surface. Moreover, histological analysis showed obvious differences in cartilage regeneration. At week 4, the EPC-PLGA group showed considerably higher TGF-ß2 and TGF-ß3 expression, a greater amount of synthesized glycosaminoglycan (GAG) content, and a higher degree of osteochondral angiogenesis in repaired tissues. At week 12, the EPC-PLGA group showed enhanced hyaline cartilage regeneration with a normal columnar chondrocyte arrangement, higher SOX9 expression, and greater GAG and collagen type II (COLII) content. Moreover, the EPC-PLGA group showed organized osteochondral integration, the formation of vessel-rich tubercular bone and significantly higher bone volume per tissue volume and trabecular thickness (Tb.Th). CONCLUSION: The present EPC-PLGA cell delivery system generates a suitable in situ microenvironment for osteochondral regeneration without the supplement of exogenous growth factors.

Controllable disorder in a hybrid nanoelectronic system: realization of a superconducting diode.

We have studied a hybrid nanoelectronic system which consists of an AlGaAs/GaAs two-dimensional electron gas (2DEG) in close proximity (~70 nm) to an Al superconducting nanofilm. By tuning the current through the Al film, we can change the conductance of the 2DEG and furthermore vary the effective disorder in the Al superconducting film in a controllable way. When a high current is injected into the film, screening which couples the Al film and the 2DEG results in a collapse of anti-symmetric behavior in the current-voltage characteristics, V(I) ~ -V(-I), which holds true in a conventional superconductor. Our results may open a new avenue of experimentally realizing a superconducting diode.