Diagnosis of latent tuberculosis by ELISPOT assay and tuberculin skin test

OBJECTIVE

To determine the prevalence of latent tuberculosis infection (LTBI) in college students.

PATIENTS AND METHODS

Four hundred and twenty newly admitted college students were enrolled. The Enzyme-Linked ImmunoSpot assay (ELISPOT) was used. Overall, 171 students with ELISPOT assay+/TST+ were monitored for three years to detect active TB disease.

RESULTS

The overall positive rate of ELISPOT assay was 40.7% among TST+ students. The ELISPOT positive rates were 36.9%, 45.4%, and 64.3% in groups of TST induration of 10-14mm, 15-20mm, and ≥20mm, respectively, with a significant difference (χ(2)=10.136, P<0.01) but no significant difference between BCG scar and no scar (41.2% vs. 38.8%; P>0.05). None of the 171 untreated students contracted active TB within the three-year monitoring period.

CONCLUSION

The LTBI rate might be overestimated by TST compared with interferon-γ release assays. On the basis of a close monitoring, few students developed active TB despite a positive result to the TST and ELISPOT assay.

Fibrin Glue Injections: A Minimally Invasive and Cost-Effective Treatment for Post-Renal Transplant Lymphoceles and Lymph Fistulas

Pelvic lymphoceles/lymph fistulas are commonly observed after kidney allotransplantation, especially when the kidney is placed in a retroperitoneal position. While the majority are <5 cm in diameter and resolve without intervention, some may continue to enlarge, and cause local or systemic symptoms or graft dysfunction. Among 1662 recipients of both living and deceased donor kidney transplants between January 2003 and July 2014, we found 46 (2.7%) patients with symptomatic lymphoceles requiring intervention. We studied the clinical outcomes and charges for three treatment modalities including open surgical drainage (22), laparoscopic surgical drainage (11), and percutaneous fibrin glue injections into the drained lymphocele cavity (13). The patient demographics and clinical characteristics were comparable for each treatment group, although maintenance immunosuppressive drugs differed by era. We found fibrin glue injections resulted in significantly lower (p = 0.04) rates of recurrence (1; 7.7%) than either laparoscopic (6; 54%) or open surgical drainage (6; 27.3%). In addition, fibrin glue injections generated significantly (p < 0.001) lower median ($4559) charges compared to either laparoscopic ($26,330) or open surgical drainage ($23,758). Fibrin glue treatment has the advantage of being an outpatient procedure, performed with the patient under local anesthesia, and does not incur the expense of an operative procedure or hospital admission associated with laparoscopic or open surgery.

Observation of non-Hermitian degeneracies in a chaotic exciton-polariton billiard

Exciton-polaritons are hybrid light-matter quasiparticles formed by strongly interacting photons and excitons (electron-hole pairs) in semiconductor microcavities. They have emerged as a robust solid-state platform for next-generation optoelectronic applications as well as for fundamental studies of quantum many-body physics. Importantly, exciton-polaritons are a profoundly open (that is, non-Hermitian) quantum system, which requires constant pumping of energy and continuously decays, releasing coherent radiation. Thus, the exciton-polaritons always exist in a balanced potential landscape of gain and loss. However, the inherent non-Hermitian nature of this potential has so far been largely ignored in exciton-polariton physics. Here we demonstrate that non-Hermiticity dramatically modifies the structure of modes and spectral degeneracies in exciton-polariton systems, and, therefore, will affect their quantum transport, localization and dynamical properties. Using a spatially structured optical pump, we create a chaotic exciton-polariton billiard--a two-dimensional area enclosed by a curved potential barrier. Eigenmodes of this billiard exhibit multiple non-Hermitian spectral degeneracies, known as exceptional points. Such points can cause remarkable wave phenomena, such as unidirectional transport, anomalous lasing/absorption and chiral modes. By varying parameters of the billiard, we observe crossing and anti-crossing of energy levels and reveal the non-trivial topological modal structure exclusive to non-Hermitian systems. We also observe mode switching and a topological Berry phase for a parameter loop encircling the exceptional point. Our findings pave the way to studies of non-Hermitian quantum dynamics of exciton-polaritons, which may uncover novel operating principles for polariton-based devices.

Spontaneous burrowing behavior as an outcome measure of the global impact of chronic pain in preclinical models of arthritis

Aims

Arthritis is the leading cause of chronic pain in European adults (painineurope.com). Arthritis-induced chronic pain is a major clinical problem that is frequently inadequately treated by current analgesics and results in significant reduction in the patient’s quality of life. Outcome measures used in pain research to assess injury-induced pain-like behaviours in preclinical models are often dependent on the assessment of withdrawal reflexes, typically evoked by mechanical or thermal stimuli.Advances inpre-dictive validity may be improved by assessing the global impact of pain and the reinstatement of innate behaviours suppressed by injury. Burrowing, an indicator of the global “wellbeing” of the animal can be objectively measured. We aimed to assess the impact of several preclinical modelsof arthritis onburrowing behaviour in mice.

Methods

The collagen antibody-induced arthritis (CAIA) pre-clinical model of rheumatoid arthritis, the complete Freund’s adjuvant (CFA), monosodium iodoacetate (MIA) and partial medial menisectomy (MMT) preclinical models of osteoarthritis were assessed in female and/or male C57/Black6J adult mice, comparing to control (salineorsham-operated) and naïve animals. Mechanical hypersensitivity using von Frey filaments and spontaneous burrowing behaviour were assessed over60days (CAIA), 14days (CFA), 28 days (MIA) and up to 200 days (MMT).

Results

We show the development of mechanical hypersen-sitivity in all preclinical models of arthritis, whereas spontaneous burrowing behaviour was altered differently between the preclin-ical models. A deficit in burrowing behaviour was observed in the preclinical models of osteoarthritis and a gain in burrowing behaviour noted in the preclinical model of rheumatoid arthritis, with no effect seen in the CFA model.

Conclusions

Burrowing behaviour appears more sensitive to detecting variation in preclinical models of arthritis when compared to mechanical hypersensitivity. Burrowing behaviour can detect both gain and deficits in the behaviour, which differs between preclinical models of rheumatoid and osteoarthritis.

Chronic urticaria in Chinese population: a hospital-based multicenter epidemiological study

BACKGROUND

The epidemiologic profiles of chronic urticaria (CU) vary considerably among regions, and few such data are available from China.

METHODS

We performed a multicenter open questionnaire investigation about the clinical and laboratory features of CU, defined as recurrent wheals with/without angioedema lasting for ≥6 weeks, among 3027 patients.

RESULTS

Female preponderance was observed (female/male ratio, 1.46 : 1). The mean age at diagnosis was 34.7 ± 13.8 years, and the mean disease duration was 18.5 ± 46.1 months (range, 1.5-127 months). Patients were classified as having chronic spontaneous urticaria (CSU, 61.0% of patients), physical urticaria (PU, 26.2%), or other urticaria types (OU, 2.3%). Nocturnal attacks were reported by 60% of cases. The Urticaria Activity Score (UAS) in patients with CSU was 3.8 ± 1.4. The mean Dermatology Life Quality Index was 7.3 ± 3.4 (range 0-30). Induction or exacerbation of wheals with alcohol drinking was reported by 55.7% of patients. Chronic hepatitis B was less prevalent in our CU patients compared with the general Chinese population (2.7% vs 7%). Positive autologous serum skin tests (ASSTs) were observed in 66.9% of patients. Patients with positive ASST had higher UAS, greater angioedema frequencies, longer disease durations, and poorer QoL compared with patients with negative ASST (P < 0.05).

CONCLUSION

In this Chinese population, CU usually affected youth, and CSU was the most common subtype. Autoreactivity and alcohol consumption were the top two triggers for CU, whereas latent infectious and chronic inflammatory diseases were not as common as in previous reports.

Envelope surface ultrastructure and specific gravity of artificially fertilized Pacific cod Gadus macrocephalus eggs

The envelope surface ultrastructure and specific gravity of artificially fertilized eggs of the Pacific cod Gadus macrocephalus were examined. The unfertilized, demersal and slightly adhesive eggs of G. macrocephalus were almost spherical and had no oil globules. Wrinkled envelope surface with elaborated hexagonal reticulated patterns and type I micropyle were observed under a scanning electron microscope. The adhesiveness of the eggs was lost at the blastodermal-cap stage after fertilization. The micropylar canal was sealed by secretion of the perivitelline fluid, and the entire surface became rough. Numerous bacilli were deposited at the micropyle and the outer envelope surface at the late germ-ring stage and at the embryo five-eighths around the yolk stage. The micropyle was completely deformed at the embryo seven-eighths around the yolk stage. The specific gravity of the fertilized G. macrocephalus eggs ranged from c. 1·0316 to 1·0454. These values, however, sharply decreased towards the end stages of egg development to produce pelagic larvae. The ultrastructural changes in the micropyle and envelope surface of the G. macrocephalus eggs protected the embryo from microorganism infections and mechanical stress during the long incubation period. The adhesiveness and specific gravity of the eggs influenced their dispersion potential.

Temperature-mediated survival, development and hatching variation of Pacific cod Gadus macrocephalus eggs

Laboratory-validated data on the survival, development and hatching responses of fertilized Pacific cod Gadus macrocephalus eggs from the northern Japan stock were determined through an incubation experiment. The optimum temperature for survival until hatching ranged from 4 to 8°C. No significant difference in development rates was found between the populations from Mutsu Bay, Japan, and western Canadian coastal waters even though the samples may belong to different G. macrocephalus stocks. Gadus macrocephalus larvae hatched asynchronously from egg batches despite incubation under the same environment during their development. Both incubation temperature and temperature-mediated hatch rank affect size and yolk reserve. These data suggest that variations in water temperatures within an ecological range markedly influence the development rates, survival and hatching of the eggs, as well as the stage at hatch larvae of G. macrocephalus. Asynchronous hatching and the production of offspring with variable sizes and yolk reserves are considered evolutionary bet-hedging strategies that enable the species to maximize their likelihood of survival in an environment with variable temperatures.

Comparative study of photodynamic therapy with 5%, 10% and 20% aminolevulinic acid in the treatment of generalized recalcitrant facial verruca plana: a randomized clinical trial

BACKGROUND

Generalised recalcitrant facial verruca plana responds poorly to current therapeutic options, including cryotherapy, topical drugs and carbon dioxide (CO2 ) laser. Case reports and uncontrolled studies suggested that topical photodynamic therapy (PDT) is effective choice of treatment free from potential complications associated with invasive therapies.

AIMS

To investigate the efficacy and safety of PDT with different concentrations of photosensitiser in the treatment of verruca plana.

MATERIALS & METHODS

The two sides of a subject's face were separately randomized to receive aminolevulinic acid (ALA) of 5%, 10% or 20% concentration. All patients were irradiated with 633-nm red light for 339 J/cm(2) total dose. Complete response (CR) rate was assessed on Week 4, 8, and 16 respectively.

RESULTS

The mean overall clearance rate was 74.1%, 68.8%, and 64.6% on Week 4, 8, and 12, respectively, in the 110 treated sides. The CR rate was lower in the 5%-ALA group than in the 10%-ALA group (14.3% vs. 33.3%, p < 0.05) and 20%-ALA group (14.3% vs. 26.3%, p < 0.05) after 12 weeks. The mean severity of pain measured by visual analogue scale (VAS) scoring was 3.8 (range: 2 to 10, depending on the lesion location). The overall recurrence rate was 16.7% (4/24) on Week 12. Hyperpigmentation was observed in 61% (67/110) of all treated sides. On Week 4, 8, and 16, hyperpigmentation was more developed in the 20%-ALA group than in the other two groups (p < 0.05).

DISCUSSION

In terms of complete clearance rate, the 5% ALA-PDT group was significantly inferior to the 10% and 20% ALA-PDT groups at each follow-up. In contrast, the 20% ALA group showed a higher incidence rate of transient hyperpigmentation than the other two groups.

CONCLUSIONS

This randomised clinical trial suggests that PDT with ALA of 10% concentration offers better efficacy and safety than 5% or 20% concentration for generalised recalcitrant facial verruca plana.

mTORC1/2 targeted by n-3 polyunsaturated fatty acids in the prevention of mammary tumorigenesis and tumor progression

Although epidemiological and preclinical studies have shown the preventative effects of n-3 polyunsaturated fatty acids (PUFAs) on breast cancer, inconsistencies still remain in the data and the underlying mechanisms remain unclear. In this study, we identified mammalian target of rapamycin (mTOR) signaling, which plays an essential role in cell proliferation and breast tumorigenesis, as a target of n-3 PUFAs. In breast cancer cell lines, n-3 PUFAs rapidly and efficiently suppress both mTOR complex 1 (mTORC1) and mTORC2 and their downstream signaling, and subsequently inhibit cell proliferation and angiogenesis while promoting apoptosis. Further study indicates that stabilization of the mTOR-raptor complex by n-3 PUFAs may contribute to their inhibitory effect on mTORC1. Importantly, four complementary and well-controlled animal models were utilized to identify the role and molecular target of n-3 PUFAs in the prevention of breast carcinogenesis and progression, namely: (1) chemically induced mammary tumor rats with a high dietary intake of n-3 PUFAs; (2) nude mice implanted with mammary tumor cell lines stably expressing fat-1, a desaturase that catalyzes the conversion of n-6 to n-3 PUFAs and produces n-3 PUFAs endogenously; (3) fat-1 transgenic severe combined immune deficiency mice implanted with breast tumor cells; and (4) the fat-1 transgenic mouse mammary tumor virus-polyoma virus middle T oncogene double-hybrid mice, a model of aggressive breast cancer. In summary, dietary and endogenous n-3 PUFAs abrogate the activity of mTORC1/2 pathways in vitro and in vivo and prevent breast carcinogenesis, tumor growth and metastasis. Taken together, our findings convincingly clarify the causal relationship between n-3 PUFAs and breast cancer prevention and establish mTORC1/2 as a target of n-3 PUFAs.

Population genetic structure and geographical differentiation of burbot (Lota lota) in China

The burbot (Lota lota Linnaeus, 1758) is the only freshwater species of the family Gadidae. There is a long-standing controversy about taxonomic status of the burbot from the Amur River basin. It is necessary to investigate population genetic structure and geographical differentiation among burbot populations from the Irtysh River basin and Amur River basin by mitochondrial DNA nucleotide sequence analysis. A 572 bp segment of cytochrome b and 425 bp segment of control region gene were sequenced from 4 populations. The results showed that there was lower genetic diversity of burbot in China and highly significant genetic difference between populations in the Amur Riverbasin (P < 0.01). Demographic analysis indicated that the burbot from the Amur River basin experienced population expansion (Cytb: F(s) = -0.912 (P = 0.287), D = -0.399 (P = 0.375); CR: F(s) = -4.771 (P = 0.015), D = -1.523 (P = 0.03 )). The data of 4 populations in China combining with the published data representing the Eurasian and North American burbot, revealed three distinct phylogenetic lineages (labelled EB, NA, Amur).

H19 DMR methylation correlates to the progression of esophageal squamous cell carcinoma through IGF2 imprinting pathway

BACKGROUND

H19 gene has been proved to be essential for human tumor growth which contains CpG rich regions. Imprinted gene expression in many cancers is usually associated with the function of methylation. We performed this study to better understand wether H19 DMR methylation correlates to the progression of esophageal squamous cell carcinoma through IGF2 imprinting pathway.

METHODS

LOI of IGF2 was detected in 276 samples, which were determined as heterozygote with ApaI polymorphism in exon 9 of IGF2 by PCR-RFLP and RT-PCR-RFLP. Methylation status of H19 DMR in informative samples was analyzed by bisulfite sequencing PCR. IGF2 expression was examined by real-time PCR and IHC.

RESULTS

208 ESCC patients were informative for ApaI polymorphism. 92 tumor and 30 normal tissues showed IGF2 LOI. Methylation status of H19 CBS6 was higher in patients with IGF2 LOI compared to patients with IGF2 MOI (p < 0.05). IGF2 expression in patients with IGF2 LOI was higher than patients with IGF2 MOI (p < 0.05) which was correlated with lymph node involvement, neoplastic grade and metastasis (p < 0.05).

CONCLUSIONS

Our results suggested that H19 CBS6 hypermethylation is related to the LOI of IGF2 which usually leads to an overexpression of IGF2, playing important roles in the occurrence, development as well as metastasis of ESCC. Therefore, H19 CBS6 methylation potentially represents a novel clinically relevant epigenetic marker to identify individuals at increased risk for the occurrence, progression and prognosis of ESCC.

Graphene-coated atomic force microscope tips for reliable nanoscale electrical characterization

Graphene single-layer films are grown by chemical vapor deposition and transferred onto commercially available conductive tips for atomic force microscopy. Graphene-coated tips are much more resistant to both high currents and frictions than commercially available, metal-varnished, conductive atomic force microscopy tips, leading to much larger lifetimes and more reliable imaging due to a lower tip-sample interaction.