Racial/ethnic disparities in the prevalence and awareness of Hepatitis B virus infection and immunity in the United States.

Hepatitis B virus (HBV) infection in the United States is the most common among Asians followed by non-Hispanic blacks. However, there have been few studies that describe HBV infection and immunity by racial group. Our study aimed to assess racial/ethnic disparities in the prevalence and awareness of HBV infection and immunity using nationally representative data. In the National Health and Nutrition Examination Survey 2011-2014, 14 722 persons had HBV serology testing. We estimated the prevalence of HBV infection, past exposure, and immunity by selected characteristics and calculated adjusted odds ratios using survey-weighted generalized logistic regression. Awareness of infection and vaccination history was also investigated. The overall prevalence of chronic HBV infection, past exposure and vaccine-induced immunity was 0.34% [95%CI 0.24-0.43], 4.30% [95%CI 3.80-4.81], and 24.4% [95%CI 23.4-25.4], respectively. The prevalence of chronic infection was 2.74% [95% CI 1.72-3.76] in Asians, 0.64% [95% CI 0.35-0.92] in non-Hispanic blacks, and 0.15% [95% CI 0.06-0.24] in non-Asian, non-blacks. Only 26.2% of those with chronic infection were aware of their infection. The prevalence of the past exposure was 21.5% [95%CI 19.3-23.7] in Asians, 8.92% [95%CI 7.84-9.99] in non-Hispanic blacks, 2.05% [95%CI 1.49-2.63] in non-Hispanic whites and 4.47% [95%CI 3.25-5.70] in Hispanics. Prevalence of vaccine-induced immunity by each race was 34.1% [95%CI: 32.0-36.2] in Asians, 25.5% [95%CI: 24.0-27.0] in non-Hispanic blacks, 24.0% [95%CI: 22.6-25.4] in non-Hispanic whites and 22.2% [95%CI: 21.3-23.3] in Hispanics. There are considerable racial/ethnic disparities in HBV infection, exposure and immunity. More active and sophisticated healthcare policies on HBV management may be warranted.

Role of active nitrogen molecules in progression of septic shock.

INTRODUCTION: Active nitrogen molecules are formed as a result of cell metabolism. They are essential for cell metabolism, but when produced in excess, they contribute to the pathogenesis of several disease processes. These nitrogen molecules play an important role in vascular instability of septic shock. This study was planned to detect the role of active nitrogen molecules in the progression of septic shock. MATERIALS AND METHODS: Blood samples were collected from 118 critically ill patients admitted in ICU and from 95 healthy relatives accompanying the patients. Patients were categorized into three groups: systemic inflammatory response syndrome (n = 54), sepsis (n = 35) and septic shock (n = 29). Plasma total nitrite (nitrites and nitrates), cytokines like tumour necrosis factor-α (TNF-α) and plasma lactate were measured to assess inflammatory activity and severity of septic shock. RESULTS: High plasma levels of nitrite and nitrate (No2-/No3-) were observed in critically ill patients (mean level 78.92 µmol/l in sepsis and 97.20 µmol/l in septic shock). Mean plasma TNF-α level in sepsis was 213.50 pg/ml and septic shock was 227.38 pg/ml. CONCLUSION: Plasma No2-/No3- and TNF-α levels were high in patients with sepsis and septic shock, which increased with severity of sepsis.

Internal podalic version for neglected shoulder presentation with fetal demise.

In modern obstetrics, the role of internal podalic version (IPV) is limited to delivery of the second twin. A retrospective study was conducted to assess the efficacy of IPV in singleton neglected shoulder presentation with fetal demise. Women with live fetuses, previous CS or contracted pelvis were excluded. The procedure involved repositioning the prolapsed hand under anaesthetic followed by breech extraction. 12 women were identified over a 19 month period and all underwent successful IPV. One woman had a postpartum haemorrhage. We conclude that, in singleton pregnancies with a transverse lie, IPV has a role to play in the delivery of dead fetuses.

Signet ring cell carcinoma of ampulla of Vater in a young adult.

Signet ring cell carcinoma of the ampulla of Vater is extremely rare. The 7 cases reported earlier have been in older patients. We report a 32-year-old lady with this condition, who also had metastases in the bone marrow, vertebrae, lungs and liver.

Bronchial diseases and lung aeration in children.

Bronchial diseases are common in children, and are usually associated with disturbances of aeration. This article briefly summarizes the embryological development and respiratory physiology pertinent to pediatric bronchial diseases. Current diagnostic imaging tools are discussed, with an emphasis on CT, which can demonstrate bronchial pathology such as bronchial obstruction and bronchiectasis in larger bronchi, as well as indirectly show the peripheral physiologic consequences of bronchial disease, such as alterations in aeration. Computed tomography measurements of lung attenuation may aid in diagnosis in problematic cases. Diseases that affect the pediatric airways at different ages are reviewed. Knowledge of these entities is important for accurate interpretation of imaging studies.

Imaging of musculoskeletal infections.

Imaging studies play a critical role in the diagnosis and management of musculoskeletal infections in children. Conventional radiography is usually the first imaging study performed with other imaging modalities as needed. Ultrasound is helpful in detecting joint effusions and fluid collections in the soft tissue and subperiosteal regions, and may guide localization for aspiration or drainage. CT can demonstrate osseous and soft tissue abnormalities and is ideal for detecting gas in soft tissues. Nuclear scintigraphy and MR imaging are valuable because of their high sensitivity. Scintigraphy is particularly useful in identifying multifocal involvement, which is an important consideration in neonatal osteomyelitis and CRMO. MR imaging provides accurate information on both the soft tissues and bones and is our imaging study of choice for evaluating the local extent of musculoskeletal infections.

Induction of Tax i expression in MT-4 cells by 5-azacytidine leads to protein binding in the HTLV-1 LTR in vivo.

The Tax I trans-activator protein of the human T-cell leukemia virus I (HTLV-I) enhances viral gene expression through enhancer sequences in the viral LTR. These sequences consist of three imperfect 21-bp repeats (TRE-1) and a region between the promoter central and promoter proximal TRE-1 (known as TRE-2). We have previously described the in vivo footprint of the HTLV-I TRE-1s and TRE-2 in two HTLV-I-infected cell lines, MT-2 and MT-4. MT-2 is a high-level producer of virus and shows significant DNA-protein interactions within the TRE-1s and TRE-2. In contrast, the proviral DNA in MT-4 cells is heavily methylated and produces no detectable virus. In this report, we describe the footprints of the TRE-1s and TRE-2 in MT-4 cells that were induced to express high levels of viral proteins by treatment with 5-azacytidine, a potent inhibitor of methylation. The footprints of the TRE-1s in 5-azacytidine-treated MT-4 cells were virtually identical to those observed in MT-2 cells. In contrast, the footprints within the TRE-2 region of 5-azacytidine-treated MT-4 cells did not resemble those in either MT-2 or MT-4 cells.

Generation of replication-defective helper-free vectors based on simian immunodeficiency virus.

A systematic study on generating simian immunodeficiency virus (SIV)-based vectors was carried out. The goal was to generate helper-free, replication-defective SIVmac-based vectors at high titers. The general approach was to cotransfect into human 293T cells a plasmid carrying the vector construct along with two helper plasmids that together expressed the SIVmac virion proteins. Initial vectors carried the bacterial beta-galactosidase gene (beta-gal). These vectors had a technical difficulty: "pseudotransduction" of beta-gal protein produced during the 293T cell transfections. As a result, infection of cultures with these vector stocks also resulted in passive transfer into, and X-gal staining of, cells that had not actually been infected by the vector. A second generation of vectors expressing the enhanced jellyfish green fluorescence protein (EGFP) was not subject to this artifact. A systematic study of the SIVmac-based EGFP vectors was carried out. Helper-free vector stocks were obtained when helper plasmids lacking the SIVmac packaging signals were used. By employing envelope helper plasmids derived from different SIVmac isolates, it was possible to generate SIVmac-based vectors pseudotyped with envelope proteins of different cell tropism. Optimization of vector and helper plasmid structures, transfection conditions, and infection procedures ultimately yielded vector titers in excess of 10(6)/ml.

In vivo genomic footprinting of the human T-cell leukemia virus type 1 (HTLV-1) long terminal repeat enhancer sequences in HTLV-1-infected human T-cell lines with different levels of Tax I activity.

The Tax protein of human T-cell leukemia virus type 1 (HTLV-1) enhances viral gene expression through sequences in the U3 region of the viral long terminal repeat. These sequences consist of three imperfect 21-bp repeats (TRE-1s) and a region between the promoter-central and promoter-proximal 21-bp repeats (TRE-2). The TRE-1s contain a core cyclic AMP response element (CRE) motif and can be bound by CREB, ATF-1, ATF-2, and other members of the CREB-ATF superfamily of transcription factors. Tax enhances CREB binding to TRE-1 in vitro, and it promotes dimerization of CREB as well as other bZIP proteins. Using ligation-mediated PCR on in vivo dimethyl sulfate-treated HTLV-1-infected cell lines MT-2 and MT-4, we have compiled a profile of protein occupancy in the HTLV-1 enhancer sequences in the presence of high (MT-2) and low (MT-4) levels of biologically active Tax I. The in vivo footprinting showed that all three TRE-1s were bound by protein(s), but only in MT-2 cells. In MT-2 cells, all TRE-1s showed strong protection of the G residues in the central CRE, and the footprints extended to differing degrees into the GC-rich flanking sequences. This indicated Tax I-dependent loading of transcription factors onto the HTLV-1 TRE-1s in vivo. In vivo footprinting on TRE-2 indicated that this region was bound by proteins regardless of the Tax I status of the cell line. However, the presence of Tax I increased the extent and altered the profile of proteins binding TRE-2 in vivo.

Comparison of transformation by manganese sulfate and 5-azacytidine in Rat 6 cells overexpressing the c-myc oncogene.

Rat 6 cells are not transformed by treatment with the well-known carcinogens benzo[a]pyrene (BP) or N-methyl-N-nitro-N'-nitrosoguanidine (MNNG). Upon retroviral transduction of the mouse c-myc gene, Rat 6 cells showed mildly altered morphology and formed microcolonies in soft agar; furthermore, they could be transformed by BP and MNNG to form large colonies in agar (Hsiao et al. (1992) Mol. Carcinogenesis, 5, 140-154). In the current report, we tested the sensitivity of the c-myc-overexpressing cells (Rat 6/c-myc) to two additional chemicals: 5-azacytidine and MnSO4. These chemicals differ from the direct-acting mutagens tested previously. 5-Azacytidine, a potent DNA methylation inhibitor, induced growth of large colonies in soft agar cultures of Rat 6 or Rat 6/c-myc cells. On the other hand, MnSO4 only induced transformation in Rat 6/c-myc cells, but not the parental Rat 6 cells. Transformants induced by 5-azacytidine lost c-myc-induced apoptotic cell death, whereas MnSO4-induced transformants showed a higher degree of apoptosis than the parental Rat 6/c-myc cells. These results suggest that MnSO4 co-operates with overexpressed c-myc in inducing transformation, while 5-azacytidine transformation is independent of c-myc overexpression and may involve alterations in the regulation of apoptosis.

Light propagation in a two-component nonlinear composite medium.

The propagation of intense light through a two-component nonlinear heterogeneous medium is considered by treating the medium as a composite medium. Introduction of dispersion and Kerr-type nonlinear terms leads to a nonlinear Schrödinger-type scattering equation. The effect of nonlinear scattering loss on soliton propagation is studied numerically. The propagation of two oppositely traveling waves is also discussed.

Pulse propagation in a two-component relaxing nonlinear heterogeneous medium.

The propagation of an intense light pulse in a two-component relaxing heterogeneous nonlinear medium is considered within the single-flux approximation. The pulses are shown to be strongly distorted owing to the finite relaxation of the medium. In a weakly heterogeneous medium, the transient suppression of light scattering through the optical nonlinearity may lead to pulse shortening or to square-type pulses. These effects are consequences of the intensity autolimitation and laser-induced self-transparency that are expected in the stationary regime in these media.