The in vitro replication phenotype of hepatitis B virus (HBV) splice variants Sp3 and Sp9 and their impact on wild-type HBV replication

Prior to nuclear export, the hepatitis B virus (HBV) pregenomic RNA may be spliced by the host cell spliceosome to form shorter RNA sequences known as splice variants. Due to deletions in the open reading frames, splice variants may encode novel fusion proteins. Although not essential for HBV replication, the role of splice variants and their novel fusion proteins largely remains unknown. Some splice variants and their encoded novel fusion proteins have been shown to impair or promote wild-type HBV replication in vitro, and although splice variants Sp3 and Sp9 are two of the most common splice variants identified to date, their in vitro replication phenotype and their impact on wild-type HBV replication are unclear. Here, we utilize greater than genome-length Sp3 and Sp9 constructs to investigate their replication phenotype in vitro, and their impact on wild-type HBV replication. We show that Sp3 and Sp9 were incapable of autonomous replication, which was rescued by providing the polymerase and core proteins in trans. Furthermore, we showed that Sp3 had no impact on wild-type HBV replication, whereas Sp9 strongly reduced wild-type HBV replication in co-transfection experiments. Knocking out Sp9 novel precore-surface and core-surface fusion protein partially restored replication, suggesting that these proteins contributed to suppression of wild-type HBV replication, providing further insights into factors regulating HBV replication in vitro.

IMPORTANCE

The role of hepatitis B virus (HBV) splice variants in HBV replication and pathogenesis currently remains largely unknown. However, HBV splice variants have been associated with the development of hepatocellular carcinoma, suggesting a role in HBV pathogenesis. Several in vitro co-transfection studies have shown that different splice variants have varying impacts on wild-type HBV replication, perhaps contributing to viral persistence. Furthermore, all splice variants are predicted to produce novel fusion proteins. Sp1 hepatitis B splice protein contributes to liver disease progression and apoptosis; however, the function of other HBV splice variant novel fusion proteins remains largely unknown. We show that Sp9 markedly impairs HBV replication in a cell culture co-transfection model, mediated by expression of Sp9 novel fusion proteins. In contrast, Sp3 had no effect on wild-type HBV replication. Together, these studies provide further insights into viral factors contributing to regulation of HBV replication.

CD8+ T cells specific for an immunodominant SARS-CoV-2 nucleocapsid epitope display high naive precursor frequency and TCR promiscuity

To better understand primary and recall T cell responses during coronavirus disease 2019 (COVID-19), it is important to examine unmanipulated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cells. By using peptide-human leukocyte antigen (HLA) tetramers for direct ex vivo analysis, we characterized CD8⁺ T cells specific for SARS-CoV-2 epitopes in COVID-19 patients and unexposed individuals. Unlike CD8⁺ T cells directed toward subdominant epitopes (B7/N₂₅₇, A2/S₂₆₉, and A24/S_1,208) CD8⁺ T cells specific for the immunodominant B7/N₁₀₅ epitope were detected at high frequencies in pre-pandemic samples and at increased frequencies during acute COVID-19 and convalescence. SARS-CoV-2-specific CD8⁺ T cells in pre-pandemic samples from children, adults, and elderly individuals predominantly displayed a naive phenotype, indicating a lack of previous cross-reactive exposures. T cell receptor (TCR) analyses revealed diverse TCRαβ repertoires and promiscuous αβ-TCR pairing within B7/N₁₀₅⁺CD8⁺ T cells. Our study demonstrates high naive precursor frequency and TCRαβ diversity within immunodominant B7/N₁₀₅-specific CD8⁺ T cells and provides insight into SARS-CoV-2-specific T cell origins and subsequent responses.

Consensus statements on the clinical usage and characteristics of aripiprazole for Hong Kong

Aripiprazole, a dopamine partial agonist, is a second-generation anti-psychotic that is widely used for the treatment of schizophrenia and other psychotic disorders. A group of psychiatric experts in Hong Kong developed a set of consensus statements, aiming to facilitate the understanding of clinical properties and usages of aripiprazole among local physicians. Of note, because aripiprazole long-acting injectable has been available locally not long before the establishment of the consensus panel, which limited the discussion on its use in the local context, the consensus statements were focused primarily on oral aripiprazole. To draft the consensus statements, the panellists discussed the published evidence and their clinical experience regarding aripiprazole in a series of meetings based on several areas. At the final meeting, each drafted statement was voted on anonymously by all panellists based on its practicability of recommendation in Hong Kong. A set of consensus statements on the characteristics and clinical use of aripiprazole was established and accepted by the panel. These statements serve to provide a practical reference for physicians in Hong Kong, and possibly other parts of the Asia-Pacific region, on the use of aripiprazole in people with schizophrenia spectrum disorders and other psychotic problems.

Consensus statements on adherence issues in schizophrenia for Hong Kong

AIM

In view of the clinical importance of the adherence issues in schizophrenia management, a consensus group of experienced local psychiatrists and nurse specialists gathered to outline a number of consensus statements for clinicians to consider enhancing adherence in their patients.

PROCESS

Prior to the consensus group meeting, three core members drafted eight statements on the issue of adherence in schizophrenia. Using a modified Delphi method, published literature and published guidelines regarding the management of schizophrenia were reviewed by the full panel during the group meeting. After discussion and reflection from each individual member of the consensus group, the eight statements were reworded and electronically voted on anonymously in two steps: acceptance on quality of evidence and practicability in implementation.

RESULTS

After modifications of the original statements, there was very high overall level of agreement and acceptance (reaching international standard) on all the five areas of adherence within the eight statements of the finalised statement.

CONCLUSIONS

The present consensus statements are the first in Hong Kong to address systematically adherence issues in schizophrenia management. They include areas on adherence assessment and definition, treatment strategies in enhancing adherence, and treatment considerations at specific phases of schizophrenia. They are tailored to be of practical utility in the local Hong Kong setting.

Dietary glycotoxins exacerbate progression of experimental fatty liver disease

BACKGROUND & AIMS

Advanced glycation end-products (AGEs) levels are high in western diets and contribute to tissue injury via activation of RAGE (receptor for AGEs) and generation of reactive oxygen species (ROS). Here, we determined if high dietary AGE intake worsens progression of non-alcoholic fatty liver disease (NAFLD).

METHODS

Male Sprague Dawley rats were fed a methionine choline deficient (MCD) diet for 6 weeks before 6 weeks of a high AGE MCD diet through baking. They were compared with animals on MCD diet or a methionine choline replete (MCR) diet alone for 12 weeks. Hepatic ROS, triglycerides, biochemistry, picro-sirius morphometry, hepatic mRNA expression and immunohistochemistry were determined. Primary hepatic stellate cells (HSCs) from both MCR and MCD animals were exposed to AGEs. ROS, proliferation and mRNA expression were determined.

RESULTS

The high AGE MCD diet increased hepatic AGE content and elevated triglycerides, NADPH dependent superoxide production, HNE adducts, steatosis, steatohepatitis (CD43, IL-6, TNF-α) and fibrosis (α-SMA, CTGF, COL1A, picrosirius) compared to MCD alone. In HSCs, AGEs significantly increased ROS production, bromodeoxyuridine proliferation and MCP-1, IL-6, α-SMA, and RAGE expression in HSCs from MCD but not MCR animals. These effects were abrogated by RAGE or NADPH oxidase blockade.

CONCLUSIONS

In the MCD model of NAFLD, high dietary AGEs increases hepatic AGE content and exacerbates liver injury, inflammation, and liver fibrosis via oxidative stress and RAGE dependent profibrotic effects of AGEs on activated HSCs. This suggests that pharmacological and dietary strategies targeting the AGE/RAGE pathway could slow the progression of NAFLD.

Comparative in vitro cytotoxicity study on uncoated magnetic nanoparticles: effects on cell viability, cell morphology, and cellular uptake

Magnetic iron oxide nanoparticles (MIONPs) must be biocompatible, and a thorough knowledge on their potential cytotoxicity is crucial for their biomedical applications. However, the detailed study about the effects of iron oxide nanoparticles on cell viability, cell morphology, and cellular uptake of different mammalian cells is still insufficient. In this paper, comparative cytotoxicity study of uncoated magnetite nanoparticles at different concentrations was performed on human cervical cancer cell line (HeLa) and immortalized normal human retinal pigment epithelial cell line (RPE). The size, structure, and magnetic behavior of the MIONPs were characterized using transmission electron microscopy (TEM), X-ray diffractometry (XRD), and vibrating sample magnetometry (VSM) respectively. After 24-hour incubation with the MIONPs, the cell viability was determined by live/dead assay, the cell morphology at high magnification was observed under scanning electron microscopy (SEM), and the cellular uptake of MIONPs was measured under TEM and verified by energy-dispersive X-ray spectroscopy (EDX) analysis. Our results indicate that the uncoated MIONPs at a high concentration (0.40 mg/ml) were toxic to both HeLa and RPE cells. However, the cytotoxicity of uncoated MIONPs at low concentrations was cell-type specific, and RPE cells were more susceptible to these MIONPs than HeLa cells. The effects of the MIONPs on cell morphology and the nanoparticles uptake also showed different features between these two cell lines. Hence cell type should be taken into consideration in the in vitro cytotoxicity study of uncoated MIONPs. Additionally, it should be noticed that the cell morphological changes and the uptake of nanoparticles can take place even though no toxic effect of these MIONPs at low concentrations was reflected in the traditional cell viability assay.

Western mental health training for traditional Chinese medicine practitioners

OBJECTIVE

To investigate the impact of a Western mental health training course for Traditional Chinese Medicine (TCM) practitioners.

METHOD

  A combined qualitative and quantitative approach was applied to examine the changes in the TCM practitioners' clinical practice characteristics and attitudes. Focus groups and structured questionnaire surveys were conducted to compare their responses before and after the Course.

RESULTS

After a 10-week training course conducted by psychiatrists and family physicians, there were significant changes in confidence of the TCM practitioners for diagnosis (33% being confident before the Course vs. 76% after the Course) and management (24% vs. 55%) of common mental health problems. The causal effects of better classifications to recognition of mental health problems were explained by the qualitative responses. Proportion of TCM practitioners being confident of referring mental health patients to other healthcare professionals doubled from 25% to 50% after the Course. Nonetheless, there was no significant change in percentage of these patients being recommended to Western doctors owing to a lack of formal referral channel.

CONCLUSIONS

Western mental health training for TCM practitioners has positive impact on their clinical practice. However, the practical barriers in making referrals highlight the need of closer collaboration between conventional and traditional medicine.

What do primary care doctors get out of a year-long postgraduate course in community psychological medicine?

OBJECTIVE

There are increasing expectations on primary care doctors to care for patients with common mental health problems. This study examines the outcomes of a postgraduate training course in psychological medicine for primary care doctors.

METHODS

A questionnaire developed by the research team was sent to the Course graduates (year 2003-2007). A retrospective design was adopted to compare their clinical practice characteristics before and after the Course. Differences in the ratings by the respondents before and after the Course were analyzed using the nonparametric Wilcoxon signed rank test.

RESULTS

Sixty-nine graduates replied with a response rate of 58.5% (69/118). Most respondents were confident of diagnosing (96.9%) and managing (97.0%) common mental health problems after the Course, compared to 50.0% and 50.7%, respectively, before the Course. Most graduates had modified their approach, increased their attention and empathy to patients with mental health problems. The percentage of respondents having enough time to treat these patients had increased from 55.8% to 72.1%. The median number of patients with mental health problems seen per week was in the range of 3-6 before, and had increased to the range of 7-10 after the Course. The proportion of respondents being confident of making appropriate referrals had increased from 72.8% to 97.0%, while the number of referrals to psychiatrists had dropped significantly.

CONCLUSIONS

The Course is effective in improving graduates' confidence, attitude, and skills in treating patients with common mental health problems. There are significant increases in the number of mental health patients handled, increased confidence in making referrals to psychiatrists, and decreased percentage of patients being referred.

Removal and speciation of heavy metals along the treatment path of wastewater in subsurface-flow constructed wetlands

This study was conducted to: (1) evaluate the performance of constructed wetlands in removing Zn, Pb and Cd, respectively, and Zn, Pb, Cd and Cu in combination and (2) investigate the speciation patterns of the dissolved metals differentiated according to their detectability by anodic stripping voltammetry (ASV) and their lability towards Chelex resin along the treatment path of metal-containing wastewater in horizontal subsurface-flow constructed wetlands. Four laboratory scale wetland units planted with cattails (Typha latifolia) were operated outdoors for six months. Three of the units were, respectively, fed with primary-treated domestic wastewater spiked with Zn(II), Pb(II) and Cd(II) whilst the fourth was spiked with a combination of Zn(II), Pb(II), Cd(II) and Cu(II). The results demonstrate that a metal removal efficiency of over 99% was achievable for wetland units treating the metals singly or in combination provided the sorption capacity of the media was not exceeded. When treating the metals in combination, an antagonistic effect, more significantly for Pb and Cd, on the sorptive metal uptake by media was observed. Based on the metal speciation patterns, the wetland system seemed to be capable of maintaining the ASV-labile metal species at relatively low level (< 10%) before media exhaustion.

The effect of heavy metals on nitrogen and oxygen demand removal in constructed wetlands

The objective of this study is to investigate the respective effects of Zn, Pb and Cd as well as the combined effect of Zn, Pb, Cd and Cu on the removal of nitrogen and oxygen demand in constructed wetlands. Four laboratory-scale gravel-filled subsurface-flow constructed wetland units planted with cattails (Typha latifolia) were operated outdoors and fed with primary-treated domestic wastewater at a constant flow rate of 25 ml/min. After 6 months, three of the wetland units were fed with the same type of wastewater spiked with Zn(II), Pb(II) and Cd(II), respectively, at 20, 5 and 1 mg/l for a further 9 months. The remaining unit was fed with the same type of wastewater spiked with a combination of Zn(II), Pb(II), Cd(II) and Cu(II) at concentrations of 10, 2.5, 0.5 and 5 mg/l, respectively, over the same period. The chemical oxygen demand (COD) and ammoniacal nitrogen (AN) concentrations were monitored at the inlet, outlet and three additional locations along the length of the wetland units to assess the performance of the wetland units at various metal loadings. At the end of the study, all cattail plants were harvested for the determination of total Kjeldahl nitrogen and metal concentrations. The results showed that the COD removal efficiency was practically independent of increasing metal loading or a combination of metal loadings during the duration of the study. In contrast, the AN removal efficiency deteriorated progressively with increasing metal loading. The relative effect of the heavy metals was found to increase in the order: Zn<Pb<Cd and the synergistic effect of metals was not observed. The metals seem to exhibit some inhibitory effect on nitrogen uptake by cattail plants as indicated by lower nitrogen uptake rates in comparison to rates recorded in wetland systems treating domestic wastewater only.

The 15-year outcome of Chinese patients with schizophrenia in Hong Kong

OBJECTIVE

To explore the differential outcome of schizophrenia in developed and developing countries. The 15-year outcome of patients with schizophrenia in Hong Kong is reported.

METHOD

In a 15-year retrospective outcome study, 100 patients with first-onset schizophrenia in 1977-1978 were randomly selected for outcome assessment from a pool of 797 patient files. The patterns of outcome were assessed by the same set of instruments and methodology as in other centres, since Hong Kong is 1 of the World Health Organization (WHO) centres for the International Study of Schizophrenia (ISoS).

RESULTS

Nineteen subjects were untraceable, and 10 subjects committed suicide. More than one-half of the subjects had a good symptomatic outcome, while about 20% of the subjects were rated as having a good psychosocial adjustment. Over the entire 15-year period, 96% of the subjects were maintained on medications, and 79% were living with family members.

CONCLUSION

Despite Hong Kong's developed economy, its schizophrenia outcome is similar to that in developing countries. The existence of good family support and active follow-up treatment may be important contributory factors to better outcome.

Clinical usefulness of an aftercare worker for psychotic patients discharged from half-way houses in Hong Kong

BACKGROUND

The aim was to assess the clinical usefulness and economic viability of an aftercare worker for psychotic patients discharged from half-way houses in Hong Kong.

METHOD

A sample of 32 chronic psychotic patients was provided with a full-time aftercare worker. A matched control group received no such service.

RESULTS

The experimental group was found to have greater and better employment prospects, better mental status with less hospitalisation and less law-breaking behaviour than the control group. Some of these benefits were converted into economic terms and the tangible costs incurred in the project were calculated.

CONCLUSIONS

The provision of an aftercare service is clinically useful and economically viable.

Attitudes towards mental patients in Hong Kong

The purpose of this survey was to understand how the people of Hong Kong perceive mental health, mental illness, mental patients and mental health facilities. In March 1994, a total of 1,043 successful telephone interviews were conducted out of 2,202 valid telephone numbers. The sample was found to be representative of the Hong Kong adult population in terms of sex ratio, age structure, educational achievement and economic status. It was found that the majority of people of Hong Kong were very concerned about their mental health. Their knowledge on mental health was fairly good. Their attitudes towards mental patients and mental health facilities were, however, quite negative. Unlike previous western findings, these views towards mental patients and their rehabilitation facilities were found to be weakly associated with socio-economic factors including age, educational level and household income.

Improving oral health through understanding the meaning of health and disease in a Chinese culture

Advances in modern technology have undoubtedly been of benefit to dentistry in its preventive and curative activities for populations worldwide. Studies, mainly from Western societies, show nonetheless that utilisation of services or adoption of preventive methods are not taken up at satisfactory levels. The focus of this paper is on the special problems in a Chinese society where major differences exist between the traditional lay health concepts and the modernised professional ones. Traditional Chinese health concepts comprise the balance between and interaction of 'Yin' and 'Yang', the vital forces in both the universe and in man's body, as the basis for maintaining health. To restore a disturbed equilibrium of vital forces, which will manifest itself as disease, a range of dietary products are available in Hong Kong, for example cooling herb tea to reduce fire from the stomach producing gum disease. Seeking dental treatment from dentists could be delayed or made 'unnecessary' due to reliance on home remedies. This could reduce the effectiveness of any planned health education activities and dental services available for improving the oral health status of the community according to prevailing Western concepts. An understanding of the cultural meaning of dental disease is fundamental to changing beliefs and attitudes of people in order to improve the oral health of the community.

The living conditions of psychiatric patients discharged from half-way houses in Hong Kong

This paper reports on a study of the living environment of 64 psychiatric patients discharged from half-way houses in Hong Kong. The majority were living in a deprived situation compared to that of their neighbours. They were leading a very monotonous life throughout the year; the walls of their homes were dirty and very plain; and some even ate scraps from a neighbouring bakery. Many did not have any social life at all, and their hobbies were smoking, watching television and gambling. Their neighbours, by comparison, had hobbies such as floriculture, birds and goldfish; decorated their walls with pictures and had newspapers and periodicals in their houses; more often had telephone facilities, wardrobes and sofas; used town gas rather than kerosene stoves; and were more likely to have electrical appliances, especially an iron, refrigerator and shaver. Judged by their income from employment or from public assistance, the 'quality of life' (QOL) of these patients should not have been in such a desperate state. They lacked guidance and instruction in their management of money, and the care of their homes. It is proposed that an aftercare worker might improve the QOL of these discharged psychiatric patients.