Phylogenetic, virological, and clinical characteristics of genotype C hepatitis B virus with TCC at codon 15 of the precore region

Hepatitis B virus (HBV) with T-1856 of the precore region is always associated with C-1858 (i.e., TCC at nucleotides 1856 to 1858), and it is reported only in genotype C HBV isolates. We aimed to investigate the phylogenetic, virological, and clinical characteristics of HBV isolates bearing TCC at nucleotides 1856 to 1858. We have previously reported on the presence of two major subgroups in genotype C HBV, namely, HBV genotype Cs (Southeast Asia) and HBV genotype Ce (Far East). We have designed a novel 5' nuclease technology based on the nucleotide polymorphism (C or A) at nucleotide 2733 to differentiate the two genotype C HBV subgroups. The mutations at the basal core promoter and precore regions were analyzed by direct sequencing. Among 214 genotype C HBV-infected patients, 31% had TCC, 37% had CCC, 3% had CTC, and 29% had CCT at nucleotides 1856 to 1858. All except one HBV strain with TCC at nucleotides 1856 to 1858 belonged to subgroup Cs, which has been reported only in Hong Kong; Guangzhou, China; and Vietnam. HBV with TCC at nucleotides 1856 to 1858 was associated with the G1898A mutation (64%). Patients infected with HBV harboring TCC had more liver cirrhosis than those infected with HBV harboring CCC (18% versus 5%; P = 0.008), and more of the patients infected with HBV harboring TCC were positive for HBeAg (58% versus 36%; P = 0.01) and had higher median alanine aminotransferase levels (65 IU/liter versus 49 IU/liter; P = 0.006); but similar proportions of patients infected with HBV harboring TCC and those infected with HBV harboring CCT had liver cirrhosis (18% versus 13%; P = 0.43). In summary, we report that HBV with TCC at nucleotides 1856 to 1858 of the precore region might represent a specific HBV strain associated with more aggressive liver disease than other genotype C HBV strains.     

The value of serum neopterin, interferon-gamma levels and interleukin-12B polymorphisms in predicting acute renal allograft rejection

Acute rejection remains a poor predictor of graft outcome. In this study, we measured serum levels of interferon (IFN)-gamma and neopterin by enzyme-linked immunosorbent assay and a single nucleotide polymorphism (SNP) within the 3' untranslated region of the interleukin (IL)-12 B gene (1188 A/C) to determine whether either of these factors could predict acute rejection in renal transplantation. Significantly higher early post-transplant neopterin levels (days 5-7; 35.7 versus 19.9 nmol/l) were observed in recipients who subsequently rejected their grafts. Post-transplant neopterin levels showed a strong positive correlation with 1-month creatinine levels (Spearman's correlation 0.62, P < 0.001), suggesting macrophage activation early after transplantation. Pretransplant neopterin and IFN-gamma levels and the IL-12B gene SNP did not predict acute rejection in this small retrospective study. The ability to predict acute rejection non-invasively early after transplantation could lead to individual tailoring of immunosuppressive regimens and perhaps lead eventually to longer graft survival.     

Hematopoietic stem cell-derived pericytic cells in brain tumor angio-architecture

Bone marrow-derived cells are recruited into tumor vasculature in response to angiogenic signals, and some of the cells within the newly forming tumor vessels are hematopoietic stem cells (HSCs) in origin. Previous studies suggest that bone marrow-derived pericytes are associated with newly formed vessels in tumors. In this study, we used an orthotopic rat glioma model (RT-2/RAG) to examine the contribution of long-term hematopoietic stem cell (LT-HSC)-derived pericytic cells to brain tumor angiogenesis. Mice (RAG-2/KO5.2) were lethally irradiated, and their hematopoietic cells were repopulated by transplantation of double fluorescence-activated cell-sorted LT-HSCs that express green fluorescent protein (GFP+). RT-2/RAG cells were then injected into the striatum of the chimeric mice 6 weeks post-transplantation. The animals were sacrificed 9 days after tumor implantation, and the incorporation and lineage-specific marker expression profile of the GFP+ cells within the growing tumor and tumor periphery were analyzed. LT-HSC-derived GFP+ cells were noted to incorporate onto the surface of tumor vessels within the perivascular space. LT-HSC-derived GFP+ cells express the pericyte progenitor marker, platelet-derived growth factor receptor-beta (PDGFR beta), as well as mature perictyte markers such as nerve/glial antigen 2 proteoglycan (NG2), alpha-smooth muscle actin (alpha SMA), and desmin. These LT-HSC-derived cells may represent a population of progenitor or committed pericytes within the neovascular tree and may play a role in shaping the angio-architecture in the vascular niche of brain tumors.     

AngleNav: MEMS Tracker to Facilitate CT-Guided Puncture

As a low-cost needle navigation system, AngleNav may be used to improve the accuracy, speed, and ease of CT-guided needle punctures. The AngleNav hardware includes a wireless device with a microelectromechanical (MEMS) tracker that can be attached to any standard needle. The physician defines the target, desired needle path and skin entry point on a CT slice image. The accuracy of AngleNav was first tested in a 3D-printed calibration platform in a benchtop setting. An abdominal phantom study was then performed in a CT scanner to validate the accuracy of the device’s angular measurement. Finally, an in vivo swine study was performed to guide the needle towards liver targets (n = 8). CT scans of the targets were used to quantify the angular errors and needle tip-to-targeting distance errors between the planned needle path and the final needle position. The MEMS tracker showed a mean angular error of 0.01° with a standard deviation (SD) of 0.62° in the benchtop setting. The abdominal phantom test showed a mean angular error of 0.87° with an SD of 1.19° and a mean tip-to-target distance error of 4.89 mm with an SD of 1.57 mm. The animal experiment resulted in a mean angular error of 6.6° with an SD of 1.9° and a mean tip-to-target distance error of 8.7 mm with an SD of 3.1 mm. These results demonstrated the feasibility of AngleNav for CT-guided interventional workflow. The angular and distance errors were reduced by 64.4 and 54.8% respectively if using AngleNav instead of freehand insertion, with a limited number of operators. AngleNav assisted the physicians to deliver accurate needle insertion during CT-guided intervention. The device could potentially reduce the learning curve for physicians to perform CT-guided needle targeting.     

Climacteric symptoms and knowledge about hormone replacement therapy among Hong Kong Chinese women aged 40-60 years

OBJECTIVES: To evaluate the use of hormone replacement therapy (HRT), the prevalence of climacteric symptoms, and the knowledge about HRT. METHODS: A prospective study was conducted by telephone interview among a randomly selected population-based sample of 978 Hong Kong Chinese women aged 40-60 years. RESULTS: Of 414 women with a history of either natural or surgical menopause, 22 (5.3%) and 17 (4.1%), respectively, were either past or current users of HRT. The climacteric symptom scores of premenopausal women were significantly lower than those of perimenopausal women, but were comparable with those of postmenopausal women. The commonest climacteric symptom was 'muscle and joint pains' which was reported in 553 (56.6%) women, while only 228 (23.3%) and 151 (15.4%) women reported hot flushes and night sweating, respectively. Moreover, only 230 (23.5%) women realized that HRT could relieve menopausal symptoms and only 33 (3.4%) women were aware that HRT was protective against osteoporosis. In general, women with more climacteric symptoms, who had ever used HRT, and those with higher education level and higher family income, had better knowledge about HRT. CONCLUSIONS: Postmenopausal Hong Kong Chinese women have a low HRT usage rate and the majority of them are lacking of the knowledge about HRT.     

Do men with normal testosterone–oestradiol ratios benefit from letrozole for the treatment of male infertility?

Research question

Previous studies of aromatase inhibitors on male infertility have focused on men with low testosterone–oestradiol ratio of less than 10. Can aromatase inhibitors improve spermatogenesis in men with idiopathic male infertility with normal testosterone–oestradiol ratio?

颅脑有限元模型演化规律及其生物力学研究进展

交通事故中头颈部损伤因其较高的致命性,已成为最严重的损伤类型。有限元模型在创伤性脑损伤生物力学机理研究中得到日益广泛应用。回顾头颈部有限元模型的生物力学研究历史和现状,并阐述车辆碰撞交通事故中人体颅脑典型交通伤演化规律和生物力学研究进展,探索头颈部损伤安全防护的方法,以期为车辆碰撞事故中人体颅脑损伤生物力学研究和相应的汽车安全防护装置研制提供理论依据。     

Corticotropin-releasing hormone peptide and human first-trimester placental growth

The aim of this study was to determine whether corticotropin-releasing hormone (CRH) regulates human trophoblast cell growth. The results showed that exogenous CRH significantly stimulated human trophoblast proliferation in first-trimester primary cultures. In vivo, CRH was strongly immunolocalised to cytotrophoblastic cells in proliferative cell columns and in chorionic villi. We postulate that CRH may have an important role in early placental development and successful pregnancy.     

Influence of Magnolol on the bystander effect induced by alpha-particle irradiation

In this work, the influence of Magnolol on the bystander effect in alpha-particle irradiated Chinese hamster ovary (CHO) cells was examined. The bystander effect was studied through medium transfer experiments. Cytokinesis-block micronucleus (CBMN) assay was performed to quantify the chromosome damage induced by alpha-particle irradiation. Our results showed that the alpha-particle induced micronuclei (MN) frequencies were suppressed with the presence of Magnolol.