Process optimization of one-step direct transesterification and dual-step extraction-transesterification of the Chlorococcum-Nannochloropsis consortium for biodiesel production

In the present study, the efficacy of one-step direct transesterification (OSDT) and Dual-step extraction-transesterification (DSET) of Chlorococcum sp., Nannochloropsis sp., and their consortium was evaluated for fatty acid methyl ester (FAME) yield. Initially, the biomass yield and lipid content of the two strains and their consortium were estimated. Of the biomasses, the consortium showed a higher biomass yield of 1.41 g/L and lipid content of 30.2%, which is higher than the monocultures irrespective of the different biomass drying methods used. With regards to the FAME yield, OSDT and DSET have yielded almost similar quantities about 21 g/100g dried biomass. Of the different reaction conditions of OSDT tested, a higher FAME yield at 70-71% (based on lipid weight) was obtained at 75 °C reaction temperature, 3 h reaction time with a 2g sample size. Eventually, the fatty acid composition of consortium biomass revealed higher levels of saturated and monounsaturated fatty acids in the vicinity of 46 and 25%, respectively. Based on the results, it is concluded that OSDT is a promising method due to its low energy consumption, cost-effective and time-saving attributes for quality biodiesel production from the Chlorococcum-Nannochloropsis consortium.

Enhanced photocatalytic degradation of polycyclic aromatic hydrocarbon by graphitic carbonitride-nickel (g-C3N4-Ni) nanocomposite

The objective of the present study is to synthesize g-C3N4-Ni nanocomposites composed of graphitic carbon nitride and magnetic nickel nanoparticles for benzopyrene degradation, which is one of the most potent polycyclic aromatic hydrocarbons (PAH) molecules. The concocted g-C3N4-Ni nanocomposites contained confined nanospheres with a mean particle dimension of 22 nm. Batch adsorption studies revealed that a rise in adsorbent dosage elevates benzopyrene degradation percentage in both water and soil samples with respect to time. The increase in the benzopyrene concentration did not have much influence on the degradation efficiency, and hence, the minimal concentration of PAH molecule is essential for the effective adsorption by g-C3N4-Ni nanocomposites. The rise in pH tends to increase the degradation of Benzopyrene till 3 h of the incubation period, and beyond 3 h, the degradation percentage declines. With regard to the effect of light source, UV light has been shown to accelerate the degradation of benzopyrene by g-C3N4-Ni nanocomposites than sunlight. The adsorption kinetic and isotherm investigations have proven that the Pseudo-second order kinetic model and Freundlich isotherm model were appropriate for our study. Thus, the g-C3N4-Ni nanocomposites were found to be efficient as a photocatalyst for the adsorption of benzopyrene from environmental samples.

Urban-rural disparities in acceptance of human papillomavirus vaccination among women in Can Tho, Vietnam

Background

In Vietnam, cervical cancer is a significant public health concern for women. Unfortunately, despite the availability of the HPV vaccine, low vaccination rates persist.

Objectives

This study investigates the discrepancy between urban and rural areas in the willingness to receive HPV vaccination with or without fees.

Methods

A cross-sectional study was conducted on a sample of 648 women aged between 15 and 49, living in two urban and two rural Vietnamese districts of Can Tho, between May and December 2021.

Results

The overall vaccination rate was 4%, with urban women having a higher rate of 4.9% compared to rural women at 3.1%. Among unvaccinated women, those from rural areas expressed a significantly higher desire to receive the free vaccine (91.4%) than urban women (84.4%). However, the intention to vaccinate declined when rural women and urban women were advised to pay the cost (63.4% and 57.1%, respectively). A strong correlation was found between a positive attitude and intention for vaccination, irrespective of its price or free availability. Education and access to information about the HPV vaccine were also identified as the most significant factors influencing the intention to vaccination among urban and rural women.

Conclusion

The low HPV vaccination rates among women aged 15-49 living in both urban and rural regions of Vietnam are a notable public health concern. These outcomes emphasize the critical need for effective programs of vaccine laterization, as an introduction to the offer of affordable and accessible HPV vaccines for women in Can Tho, Vietnam.

The role of knowledge management in driving academic advancement: empirical examination from the lens of the social cognitive theory

Purpose

The purpose of this paper is to investigate the relationship between the attitudes, skills and knowledge-based researchers’ competencies (ASK-RC), academic affiliation (AA) and knowledge management (KM) and its effect on promoting the growth of scholarly international publications (SIPs).

Design/methodology/approach

This research takes a quantitative approach relying on primary data gathered through a questionnaire-based survey. The study’s target population includes lecturers, managers and researchers involved in research activities in educational institutions. To operationalize the research framework, this study used social cognitive theory (SCT) and the academic community served as an empirical field of study.

Findings

The primary findings of this research are twofold: ASK-RC and AA are positively and statistically significantly associated with SIP; KM moderates the influence of ASK-RC on SIP.

Originality/value

This research adds to the current body of literature on research productivity by providing new information and empirical evidence on improving research productivity and international publication. Moreover, this research offers a new approach to the existing literature stream by operationalizing an underexplored framework from the lens of SCT. This study explains why scientific research productivity is becoming increasingly important to academia and stakeholders. Because scientific works are motivated by the goal of addressing general socioeconomic and environmental concerns, it is possible to address this concern based on SCT. Therefore, this research offers theoretical and managerial implications that may interest academics, professionals and policymakers.

The COVID-19 pandemic's effects on SMEs and travel agencies: The critical role of corporate social responsibility

This study is based on the system resilience framework, which outlines the aspects of community behavior, employees, the environment, history, and corporate social responsibility. We used a partial least squares structural equation model to evaluate a sample of 300 Vietnamese SMEs and travel agencies. We discovered that SMEs' strategies positively influence performance and are co-created with corporate social responsibility. The dependability of internal integrity was then determined. The empirical results showed that the overall confidence index for all facilities ranged from 0.70 to 0.95, with values ranging from 0.809 to 0.931. Furthermore, the A and Cronbach's alpha reliability values ranged from 0.70 to 0.90. As a result, the reliability of internal consistency was established. The convergence validity of the configurations was assessed by comparing the extracted mean values of variance (AVE), which, for all configurations, exceeded the limit of 0.50. This approach emphasizes the impact of corporate social responsibility practices on communities, the environment, and heritage.

Linking big data, sustainable supply chain management and corporate performance: the moderating role of circular economy thinking

Purpose

This paper aims to assess how big data–driven supply chain management (BDSCM) influences sustainable supply chain management (SSCM) to achieve sustainable corporate performance (SCP) for small and medium-sized enterprises (SMEs) in an emerging economy such as Vietnam, besides exploring whether Circular Economy Thinking Application (CETA) moderates the relationship between BDSCM and SSCM.

Design/methodology/approach

This study collected survey data from 495 SMEs in the food supply chain sector. It employed the PLS-SEM (Partial Least-Squares Structural Equation Modeling) technique to evaluate the hypothesized relationships.

Findings

This study found that BDSCM positively, directly and indirectly, impacted SCP. SSCM partially mediated the correlation between BDSCM and SCP. Additionally, CETA moderated the relationship between BDSCM and SSCM. CETA had a direct and positive effect on SSCM.

Originality/value

The insights into how BDSCM influences SSCM to achieve SCP for SMEs in the food value chain in an emerging economy like Vietnam provides an original value. Moreover, the novelty of this study is further reinforced by the coverage of the newfound mechanism, where CETA moderates the relationship between BDSCM and SSCM, directly and positively enhancing SSCM. These contributions could interest business practitioners and academics.

The boosting of the total quality management on corporate green growth in emerging markets: the mediating roles of corporate social responsibility and customer loyalty

Purpose

The primary purpose of this research is to examine how total quality management (TQM) boosts corporate green growth (CGG) with the involvement of corporate social responsibility (CSR) and customer loyalty (CL) as mediators in the relationship between TQM and CGG for small- and medium-sized enterprises (SMEs) in an emerging economy.

Design/methodology/approach

This research adopts a quantitative approach. According to the scope of this study, constructs of TQM, CSR, CL and CGG and the conceptual relationships between them are established using a systematic literature review. This study uses enterprise-level primary data collected from a questionnaire-based survey. The respondents are those holding managerial positions in their enterprises. There were 424 valid responses obtained following the necessary screening steps to ensure the eligibility of the collected data for analysis using AMOS version 20.

Findings

This study reveals that TQM has a positive and significant relationship with CSR, CL and CGG. Amongst these direct connections, TQM has the most substantial influence on CGG, followed by CL and CSR. Furthermore, the findings assert that CSR positively and significantly affects CGG and CL. When comparing the weighting of these effects, the results show that the impact of CSR on CGG is stronger than that on CL. Furthermore, the results confirm that CSR and CL partially mediate the relationship between TQM and CGG, both independently and simultaneously. The article also discusses the theoretical and managerial implications based on the stated findings.

Originality/value

The originality of this study stems from its contribution to enriching the body of the current literature on TQM and its combined influence on corporate performance. In this respect, this study adds to the existing literature by providing additional empirical evidence on the mechanism by which TQM boosts CGG with the involvement of CSR and CL in mediating the stated relationship between TQM and CGG for SMEs in an emerging economy. To the best of the author’s knowledge, such holistic incorporation is rare in the current literature. Furthermore, this study sheds light on the TQM enabling factors that are extended beyond the quality or technical scope as previously assumed. The stated contributions deserve to be originally derived from the attempt of this scientific work that may be of interest to academics, professionals and business practitioners.

Role of corporate governance in quick response to Covid-19 to improve SMEs’ performance: evidence from an emerging market

This paper aims to evaluate the role of corporate governance on performance of the small and medium-sized enterprises by exploring the mediating role of social responsibility engagement and environmental responsibility engagement between corporate governance and firm performance in the context of an emerging market. The paper follows a quantitative approach. The study sample was composed of 495 responses covering top executives, managers, and experts. The Analysis of a moment structures (AMOS version 20) was used to analyze the small and medium-sized enterprises data in an emerging economy in Southeast Asia in the year 2021. Our findings revealed that corporate governance has a significant and positive relationship with firm performance, social responsibility engagement and environmental responsibility engagement. In addition, social responsibility engagement and environmental responsibility engagement are found to mediate the relationship between corporate governance and firm performance. To the best of our knowledge, this is the first research that explores the mediating role of social responsibility engagement and environmental responsibility engagement between corporate governance and firm performance for the small and medium-sized enterprises. This study has novel contributions by providing important insights into the effective corporate governance mechanism and how corporate governance contributes to improving firm performance towards sustainability through engaging in social and environmental responsibility. Additionally, its application to food the small and medium-sized enterprises in the current context of an emerging economy in Southeast Asia reinforces the originality of this study. This study contributions are of great interest to academics, experts, business practitioners, and policymakers.

Innovation Onset: A Moderated Mediation Model of High-Involvement Work Practices and Employees’ Innovative Work Behavior

Purpose

Based on the componential theory of creativity, this study examined the link between high-involvement work practices and employees’ innovative behavior by further investigating the moderating and mediating role of leadership humility and employees’ personal initiative.

Methodology

To test the hypothesized model, the data were gathered from 255-line staff and 119 supervisors working in the textile industry in Pakistan via the time lag technique. The proposed hypotheses were analyzed through partial least squares structural equation modeling using Smart-PLS software.

Findings

The results indicated that high-involvement work practices were significantly related to employees’ innovative work behaviors. Additionally, the moderation findings revealed that a higher level of leadership humility strengthens the relationship between high-involvement work practices and employees’ personal initiative. Furthermore, employees’ personal initiative mediates the relationship between high-involvement work practices and their innovative work behavior. The findings of the moderated mediation model indicated that a higher level of leadership humility leads to higher innovative behavior of employees in the presence of high-involvement work practices via employees’ personal initiative.

Practical Implications

This study’s findings are helpful for the management of organizations to understand the factors that enhance innovative work behaviors in high-involvement work practices. Moreover, managers should establish humble behaviors in their leadership style to influence employees’ personal initiative, which indirectly influences their innovative work behavior.

Originality/Value

The present study highlights the importance of leadership humility and employees’ personal initiative in the relationship between high-involvement work practices and innovative work behaviors of employees in the textile industry of Pakistan.

Two Decades of Research on Consumer Behaviour and Analytics

The present study is a systematic literature review that identifies the context of consumer behaviour and analytics in business to forecast the future of consumer behaviour with changing business trends through TCCM (theory, context, characteristics, method) guidelines. The authors identified that prior research used theories in different disciplines to explain the phenomenon in customer behaviour and analytics literature. When considering the theory, these phenomena often can be segregated based on the industry (e.g., marketing, advertising, sales, healthcare, human resource management, tourism), focusing on status-based mechanisms (e.g., cross-gaming predictive models), inertia-based mechanisms (e.g., theory of rational expectations and adaptive learning), or relationship-based mechanisms (e.g., theory of consumer engagement behaviour).

Echocardiographic global longitudinal strain as a marker of myocardial fibrosis predicts outcomes in aortic stenosis

Background

Left ventricular global longitudinal strain (LV-GLS) by speckle tracking echocardiography (STE) reflects intrinsic myocardial function, influenced by interstitial abnormalities. Cardiovascular magnetic resonance (CMR) detects myocardial fibrosis non-invasively, but it is limited for widespread use. We aim to establish LV-GLS as a marker of replacement myocardial fibrosis on CMR and validate the prognostic value of LV-GLS thresholds associated with fibrosis.

Methods

LV-GLS thresholds of replacement fibrosis were established in the derivation cohort: 151 patients (57±10 years; 58% males) with hypertension who underwent STE to measure LV-GLS and CMR for replacement myocardial fibrosis. Prognostic value of the thresholds was validated in a separate outcome cohort: 261 patients with moderate-severe aortic stenosis (AS; 71±12 years; 58% males; NYHA functional class I-II) and preserved LVEF ≥50%. Primary outcome was a composite of cardiovascular mortality, heart failure hospitalization, myocardial infarction and cerebrovascular events.

Results

In the derivation cohort, LV-GLS demonstrated good discrimination (c-statistics 0.74; 95% confidence interval: 0.66–0.83; P<0.001) and calibration (Hosmer-Lemeshow X2=6.37; P=0.605) for replacement fibrosis. In the outcome cohort, 52 events occurred over 16 [3.1, 42.0] months of follow-up. Patients with LV-GLS >−15.0% (corresponding to 95% specificity to rule-in myocardial fibrosis) had the worst outcomes compared to patients with LV-GLS <−21.0% (corresponding to 95% sensitivity to rule-out myocardial fibrosis) and those between −21.0 and −15.0% (log-rank P<0.001; Figure 1). Furthermore, LV-GLS offered independent prognostic value over clinical variables, AS severity, echocardiographic LVEF and E/e' (hazard ratio 1.18; 95% confidence interval: 1.07 to 1.30; P=0.001).

Conclusions

LV-GLS thresholds associated with replacement myocardial fibrosis is a novel approach to risk-stratify patients with AS and preserved LVEF (Figure 2).

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Medical Research Council Figure 1Figure 2

P962 The Remodeling Index risk stratifies patients with hypertensive left ventricular hypertrophy

Funding Acknowledgements

National Medical Research Council

BACKGROUND

Hypertensive left ventricular hypertrophy (LVH) is associated with increased cardiovascular events. The authors previously developed the Remodeling Index (RI) that incorporated LV volume and wall-thickness in a single measure of advanced hypertrophy in hypertensive patients.

PURPOSE

This study examined the mechanisms and prognostic potential of the RI in reference with current LVH classifications.

METHODS

Cardiovascular magnetic resonance (CMR) was performed in 400 asymptomatic hypertensive patients. The newly derived RI ([(EDV)^1/3]/t; where EDV is LV end-diastolic volume and t is the maximal wall thickness across 16 myocardial segments) stratified hypertensive patients into 3 groups: without LVH, LVH with normal RI (LVH_Normal-RI) and LVH with low RI (LVH_Low-RI). The primary outcome was a composite of all-cause mortality, acute coronary syndromes, strokes and decompensated heart failure.

RESULTS

LVH_Low-RI was associated with increased LV mass index, fibrosis burden, impaired myocardial function and elevated biochemical markers of myocardial injury and wall stress. Over 18.3 ± 7.0 months (601.3 patient-years), patients with LVH_Low-RI had more than a 5-fold increase in adverse events compared to those with LVH_Normal-RI (11.6 events/100patient-years versus 2.0 events/100 patient-years, respectively; log-rank P < 0.001; Figure A). The RI provided incremental prognostic value over and above a model consisting of clinical variables and LVH (P = 0.02). Conversely concentric and eccentric LVH were associated with adverse prognosis (4.5 events/100patient-years versus 6.0 events/100patient-years, respectively; log-rank P = 0.62) that was similar as the natural history of hypertensive LVH (5.1 events/100patient-years).

CONCLUSIONS

The RI provides mechanistic insights and prognostic value that improves risk-stratification of hypertensive LVH.

Abstract P962 Figure.

P1419 Sex-related differences in cardiac remodeling in health and hypertension

Funding Acknowledgements

National Medical Research Council

OnBehalf

National Heart Centre Singapore

BACKGROUND

Adverse cardiac remodelling is associated with worse cardiovascular outcomes. Development of left ventricular hypertrophy (defined as increased myocardial mass) is a complex process mediated by myocardial wall thickening and/or ventricular dilatation. Sex-related differences in the relationship between myocardial mass and wall thickening/ventricular dilatation have not been well-described.

PURPOSE

We examine differences in determinants and patterns of cardiac remodeling between males and females.

METHODS

Comprehensive cardiovascular magnetic resonance imaging was performed in 1006 participants: 316 healthy volunteers (50% males, 46 ± 14 years) and 690 asymptomatic hypertensive patients (60% males, 57 ± 11 years). Myocardial mass, ventricular volumes and maximal myocardial wall thickness (across 16 myocardial segments) were measured using standardized contouring techniques. Clinically relevant variables (age, weight, height, and adiposity) that demonstrated significant univariate association with myocardial mass (P < 0.05) were selected in the multivariable linear regression model using the forward approach.

RESULTS

Increased body weight, lower body fat composition and higher systolic blood pressures were independently associated with increased myocardial mass in healthy volunteers (males and females) and hypertensive females. In hypertensive males, only increased body weight and elevated systolic blood pressure were independently associated with increased myocardial mass.

The association between myocardial mass and ventricular volumes was almost identical between males and females (P = 0.65 for interaction; Figure). Conversely, there was a significant gender-related difference in the association between wall thickness and myocardial mass after adjusting for potential confounders (P < 0.001 for interaction). Concentric remodeling was initially more evident in males; but further with increase, myocardial mass was associated with greater concentric remodeling in females (Figure). Similar results were observed when analyses were performed separately in healthy volunteers and hypertensive patients.

CONCLUSION

There were sex-related differences in concentric remodeling at progressive stages of myocardial hypertrophy that may explain the higher prevalence of heart failure with preserved ejection fraction reported in females.

Abstract P1419 Figure

A new potassium-based intermediate and its role in the desorption properties of the K-Mg-N-H system

New insights into the reaction pathways of different potassium/magnesium amide-hydride based systems are discussed. In situ SR-PXD experiments were for the first time performed in order to reveal the evolution of the phases connected with the hydrogen releasing processes. Evidence of a new K-N-H intermediate is shown and discussed with particular focus on structural modification. Based on these results, a new reaction mechanism of amide-hydride anionic exchange is proposed.

Generation of a pair of independently binding DNA aptamers in a single round of selection using proximity ligation

The ability to rapidly generate a pair of aptamers that bind independently to a protein target would greatly extend their use as reagents for two site ('sandwich') assays. We describe here a method to achieve this through proximity ligation. Using lysozyme as a target we demonstrate that under optimal conditions such a pair of aptamers, with nanomolar affinities, can be generated in a single round.

Antibody landscapes after influenza virus infection or vaccination

We introduce the antibody landscape, a method for the quantitative analysis of antibody-mediated immunity to antigenically variable pathogens, achieved by accounting for antigenic variation among pathogen strains. We generated antibody landscapes to study immune profiles covering 43 years of influenza A/H3N2 virus evolution for 69 individuals monitored for infection over 6 years and for 225 individuals pre- and postvaccination. Upon infection and vaccination, titers increased broadly, including previously encountered viruses far beyond the extent of cross-reactivity observed after a primary infection. We explored implications for vaccination and found that the use of an antigenically advanced virus had the dual benefit of inducing antibodies against both advanced and previous antigenic clusters. These results indicate that preemptive vaccine updates may improve influenza vaccine efficacy in previously exposed individuals.

Aptamer-based biosensors for the rapid visual detection of flu viruses

RNA aptamers showing affinity and specificity for different strains of human influenza virus were assembled onto gold nanoparticles that subsequently formed a gold nanoshell (AuNS) around the viral envelope. These shells could be visualised by transmission electron microscopy (TEM). Changes in size and structure of the AuNS coated virus can be used to detect the viruses. We show that sedimentation with a low cost centrifuge and visual determination can detect 3 × 10(8) viral particles.

Effects of orexin A on proliferation, survival, apoptosis and differentiation of 3T3-L1 preadipocytes into mature adipocytes

Metabolic activities of orexin A (OXA) in mature adipocytes are mediated via PI3K/PKB and PPARγ. However, the effects of OXA on preadipocytes are largely unknown. We report here that OXA stimulates the proliferation and viability of 3T3-L1 preadipocytes and protects them from apoptosis via ERK1/2, but not through PKB. OXA reduces proapoptotic activity of caspase-3 via ERK1/2. Inhibition of ERK1/2 prevents the differentiation of preadipocytes into adipocytes. Unlike insulin, neither short-term nor prolonged exposure of 3T3-L1 preadipocytes to OXA induces preadipocyte differentiation to adipocytes, despite increased ERK1/2 phosphorylation. Unlike insulin, OXA fails to activate PKB, which explains its inability to induce the differentiation of preadipocytes.

Stability of milk fat globule membrane proteins toward human enzymatic gastrointestinal digestion

The milk fat globule membrane (MFGM) fraction refers to the thin film of polar lipids and membrane proteins that surrounds fat globules in milk. It is its unique biochemical composition that renders MFGM with some beneficial biological activities, such as anti-adhesive effects toward pathogens. However, a prerequisite for the putative bioactivity of MFGM is its stability during gastrointestinal digestion. We, therefore, subjected MFGM material, isolated from raw milk, to an in vitro enzymatic gastrointestinal digestion. Sodium dodecyl sulfate PAGE, in combination with 2 staining methods, Coomassie Blue and periodic acid Schiff staining, was used to evaluate polypeptide patterns of the digest, whereas mass spectrometry was used to confirm the presence of specific MFGM proteins. Generally, it was observed that glycoproteins showed higher resistance to endogenous proteases compared with non-glycosylated proteins. Mucin 1 displayed the highest resistance to digestion and a considerable part of this protein was still detected at its original molecular weight after gastric and small intestine digestion. Cluster of differentiation 36 was also quite resistant to pepsin. A significant part of periodic acid Schiff 6/7 survived the gastric digestion, provided that the lipid moiety was not removed from the MFGM material. Overall, MFGM glycoproteins are generally more resistant to gastrointestinal digestion than serum milk proteins and the presence of lipids, besides glycosylation, may protect MFGM glycoproteins from gastrointestinal digestion. This gastrointestinal stability makes MFGM glycoproteins amenable to further studies in which their putative health-promoting effects can be explored.

An ex vivo co-culture model system to evaluate stromal-epithelial interactions in breast cancer

Breast cancer is the most commonly diagnosed cancer among women worldwide. High breast cancer incidence and mortality rates, especially in obese patients, emphasize the need for a better biological understanding of this disease. Previous studies provide substantial evidence for a vital role of the local extracellular environment in multiple steps of tumor progression, including proliferation and invasion. Current evidence supports the role of adipocytes as an endocrine organ, which produces steroid hormones, pro-inflammatory cytokines and adipokines, such as leptin. To further define the role of the mammary microenvironment on tumorigenesis, we have developed an adipose-tumor epithelial cell co-culture system designed to reproduce the in vivo mammary environment. We validate this model through use of coherent anti-Stokes Raman scattering (CARS) microscopy, a label-free vibrational imaging technique. CARS analysis demonstrates the sustained viability of the adipocytes, and that mammary cancer cell morphology parallels that of tumors in vivo. Also, characterized was the influence of mammary adipose tissue on tumor cell growth and migration. Adipose tissue co-cultured with mammary tumor epithelial cells, in the absence of any serum or supplemental growth factors, resulted in substantial increases in growth and migration of tumor cells. In conclusion, this novel co-culture system provides an ideal model to study epithelial-stromal interactions in the mammary gland. Understanding the relationship between adipose tissue, the most abundant and least studied component of the breast stroma and tumor epithelial cells is critical to clarifying the influence of obesity on the development, progression and prognosis of breast cancer.

Identification of venous signal on arterial spin labeling improves diagnosis of dural arteriovenous fistulas and small arteriovenous malformations

BACKGROUND AND PURPOSE

DAVFs and small AVMs are difficult to detect on conventional MR imaging/MRA or CTA examinations and often require DSA for definitive diagnosis. The purpose of this study was to assess the value of venous signal intensity on ASL imaging for making this diagnosis.

MATERIALS AND METHODS

Two neuroradiologists and 1 neurologist reviewed MR imaging studies in 26 patients, 15 of whom had DSA-proved DAVFs or small (<2 cm) AVMs. Pseudocontinuous ASL was performed at 1.5T with background-suppressed 3D-FSE readout. Using a 5-point scale, these readers assessed the likelihood of positive findings on a DSA study before and after reviewing the ASL findings. Agreement on imaging findings, including venous ASL signal intensity, was performed by using κ statistics. Logistic regression and ROC analysis were performed to determine which imaging findings improved diagnosis.

RESULTS

Venous ASL signal intensity was seen frequently in cases with positive findings on DSA. The sensitivity and specificity of venous ASL signal intensity for predicting positive findings on a DSA study were 78% and 85%, respectively. On ROC analysis, there was a significant increase in the AUC after review of the ASL images (AUC = 0.798 pre-ASL, AUC = 0.891 post-ASL; P = .02). Multivariate regression identified venous ASL signal intensity as the strongest predictor of positive findings on a DSA study, with an odds ratio of 17.3 (95% CI, 3.3-90.4).

CONCLUSIONS

Identifying venous ASL signal intensity improved detection of DAVFs and small AVMs. Attention to this finding may improve triage to DSA in patients with suspected small vascular malformations.

Orexin A stimulates glucose uptake, lipid accumulation and adiponectin secretion from 3T3-L1 adipocytes and isolated primary rat adipocytes

AIMS/HYPOTHESIS

Orexin A (OXA) modulates body weight, food intake and energy expenditure. In vitro, OXA increases PPARγ (also known as PPARG) expression and inhibits lipolysis, suggesting direct regulation of lipid metabolism. Here, we characterise the metabolic effects and mechanisms of OXA action in adipocytes.

METHODS

Isolated rat adipocytes and differentiated murine 3T3-L1 adipocytes were exposed to OXA in the presence or absence of phosphoinositide 3-kinase (PI3K) inhibitors. Pparγ expression was silenced using small interfering RNA. Glucose uptake, GLUT4 translocation, phosphatidylinositol (3,4,5)-trisphosphate production, lipogenesis, lipolysis, and adiponectin secretion were measured. Adiponectin plasma levels were determined in rats treated with OXA for 4 weeks.

RESULTS

OXA PI3K-dependently stimulated active glucose uptake by translocating the glucose transporter GLUT4 from cytoplasm into the plasma membrane. OXA increased cellular triacylglycerol content via PI3K. Cellular triacylglycerol accumulation resulted from increased lipogenesis as well as from a decrease of lipolysis. Adiponectin levels in chow- and high-fat diet-fed rats treated chronically with OXA were increased. OXA stimulated adiponectin expression and secretion in adipocytes. Both pharmacological blockade of peroxisome proliferator-activated receptor γ (PPARγ) activity or silencing Pparγ expression prevented OXA from stimulating triacylglycerol accumulation and adiponectin production.

CONCLUSIONS/INTERPRETATION

Our study demonstrates that OXA stimulates glucose uptake in adipocytes and that the evolved energy is stored as lipids. OXA increases lipogenesis, inhibits lipolysis and stimulates the secretion of adiponectin. These effects are conferred via PI3K and PPARγ2. Overall, OXA's effects on lipids and adiponectin secretion resemble that of insulin sensitisers, suggesting a potential relevance of this peptide in metabolic disorders.

SerpinB2 deficiency modulates Th1⁄Th2 responses after schistosome infection

SerpinB2, also known as plasminogen activator inhibitor type-2, is a major product of macrophages and is upregulated during many infections. Although SerpinB2 inhibits urokinase plasminogen activator in vitro, evidence that this represents its physiological role in vivo is not compelling. We have recently shown that SerpinB2-/-mice generate enhanced Th1 responses after immunization with a Th1 immunogen. Herein,we show that Schistosoma japonicum granulomas induced liver SerpinB2 mRNA expression by >600-fold in wild-type mice. In SerpinB2-/- mice, worm and egg burden, and granuloma number and volume were unaffected. However, granulomas in these mice were associated with reduced fibrosis (as determined by Sirius red staining and image analysis) and increased iNOS, IL-6, IL-10 and TNFa and decreased Arg 1 and IL-13 mRNA expression. SerpinB2-/- mice immunized with soluble egg antigen (SEA) also showed reduced levels of SEA-specific IgG1. SerpinB2 deficiency thus promoted certain Th1 and reduced certain Th2 responses in response to this Th2 immunogen.

A Kunjin replicon vector encoding granulocyte macrophage colony-stimulating factor for intra-tumoral gene therapy

We have recently developed a non-cytopathic RNA replicon-based viral vector system based on the flavivirus Kunjin. Here, we illustrate the utility of the Kunjin replicon system for gene therapy. Intra-tumoral injections of Kunjin replicon virus-like particles encoding granulocyte colony-stimulating factor were able to cure >50% of established subcutaneous CT26 colon carcinoma and B16-OVA melanomas. Regression of CT26 tumours correlated with the induction of anti-cancer CD8 T cells, and treatment of subcutaneous CT26 tumours also resulted in the regression of CT26 lung metastases. Only a few immune-based strategies are able to cure these aggressive tumours once they are of a reasonable size, illustrating the potential of this vector system for intra-tumoral gene therapy applications.

Asymptomatic primary Epstein-Barr virus infection occurs in the absence of blood T-cell repertoire perturbations despite high levels of systemic viral load

Primary infection with the human herpesvirus, Epstein-Barr virus (EBV), may result in subclinical seroconversion or may appear as infectious mononucleosis (IM), a lymphoproliferative disease of variable severity. Why primary infection manifests differently between patients is unknown, and, given the difficulties in identifying donors undergoing silent seroconversion, little information has been reported. However, a longstanding assumption has been held that IM represents an exaggerated form of the virologic and immunologic events of asymptomatic infection. T-cell receptor (TCR) repertoires of a unique cohort of subclinically infected patients undergoing silent infection were studied, and the results highlight a fundamental difference between the 2 forms of infection. In contrast to the massive T-cell expansions mobilized during the acute symptomatic phase of IM, asymptomatic donors largely maintain homeostatic T-cell control and peripheral blood repertoire diversity. This disparity cannot simply be linked to severity or spread of the infection because high levels of EBV DNA were found in the blood from both types of acute infection. The results suggest that large expansions of T cells within the blood during IM may not always be associated with the control of primary EBV infection and that they may represent an overreaction that exacerbates disease.

Cytotoxic T cell polyepitope vaccines delivered by ISCOMs

CD8 alphabeta cytotoxic T lymphocyte (CTL) polyepitope or polytope vaccines have traditionally been delivered using recombinant vector or DNA based delivery modalities. Here we show the delivery of polytope vaccines in the form of either synthetic polypeptides or recombinant polytope proteins by ImmunoStimulatory COMplexes (ISCOMs(R)). Induction of multiple protective CTL responses by these polytope-ISCOM formulations were comparable to viral vector or DNA based delivery modalities as assessed by IFNgamma ELISpot, chromium release and viral challenge assays. Measurement of CTL responses specific for the different epitopes revealed immunodominance patterns, which were largely independent of the vaccine vector or the order of the epitopes in the polytope. ISCOMs thus emerge as a viable human delivery modality for protein-based polytope vaccines.

Risk behaviours of young Indo-Chinese injecting drug users in Sydney and Melbourne

OBJECTIVE

To investigate patterns of drug use and injection-related risk behaviours among young Indo-Chinese injecting drug users (IDUs).

METHOD

Cross-sectional survey. A structured questionnaire was administered to 184 Indo-Chinese IDUs aged 15 to 24 in Sydney and Melbourne. Participants were recruited using snowball sampling techniques; measures included patterns of heroin and other drug use, injection-related risk behaviours, perceived susceptibility to HIV and HCV infection and access to services.

RESULTS

Despite perceived high availability of sterile injecting equipment, 36% had ever shared a needle and syringe and 22% had done so in the preceding month. Lifetime sharing was significantly associated with duration of injecting, history of incarceration and residence in Sydney. Sharing of injecting paraphernalia other than needles and syringes was also common, with young women and Sydney residents significantly more likely to report sharing equipment in the preceding month.

CONCLUSIONS

Young Indo-Chinese IDUs are at high risk of infection with hepatitis C and other blood-borne viruses. Results indicate an urgent need for culturally appropriate and sustainable risk reduction programs which specifically target this population.

IMPLICATIONS

Health services must respond swiftly to implement effective blood-borne virus prevention programs for young Indo-Chinese IDUs. Failure to do so may sustain the current epidemic of hepatitis C among IDUs.

Nuclear gems and Cajal (coiled) bodies in fetal tissues: nucleolar distribution of the spinal muscular atrophy protein, SMN

SMN, the affected protein in spinal muscular atrophy (SMA), is a cytoplasmic protein that also occurs in nuclear structures called "gems" and is involved in snRNP maturation. Coilin-p80 is a marker protein for nuclear Cajal bodies (coiled bodies; CBs) which are also involved in snRNP maturation, storage or transport. We now show that gems and CBs are present in all fetal tissues, even those that lack gems/CBs in the adult. Most gems and CBs occur as separate nuclear structures in fetal tissues, but their colocalization increases with fetal age and is almost complete in the adult. In adult tissues, up to half of all gems/CBs are inside the nucleolus, whereas in cultured cells they are almost exclusively nucleoplasmic. The nucleolar SMN is often more diffusely distributed, compared with nucleoplasmic gems. Up to 30% of cells in fetal tissues have SMN distributed throughout the nucleolus, instead of forming gems in the nucleoplasm. The results suggest a function for gems distinct from Cajal bodies in fetal nuclei and a nucleolar function for SMN. Spinal cord, the affected tissue in SMA, behaves differently in several respects. In both fetal and adult motor neurons, many gems/CBs occur as larger bodies closely associated with the nucleolar perimeter. Uniquely in motor neurons, gems/CBs are more numerous in adult than in fetal stages and colocalization of gems and CBs occurs earlier in development. These unusual features of motor neurons may relate to their special sensitivity to reduced SMN levels in SMA patients.

The exon 2b region of the spinal muscular atrophy protein, SMN, is involved in self-association and SIP1 binding

Spinal muscular atrophy (SMA) is caused by mutations in the SMN (survival of motor neurons) gene and there is a correlation between disease severity and levels of functional SMN protein. Studies of structure-function relationships in SMN protein may lead to a better understanding of SMA pathogenesis. Self-association of the spinal muscular atrophy protein, SMN, is important for its function in RNA splicing. Biomolecular interaction analysis core analysis now shows that SMN self-association occurs via SMN regions encoded by exons 2b and 6, that exon 2b encodes a binding site for SMN-interacting protein-1 and that interaction occurs between exon 2- and 4-encoded regions within the SMN monomer. The presence of two separate self-association sites suggests a novel mechanism by which linear oligomers or closed rings might be formed from SMN monomers.

The survival motor neuron (SMN) protein: effect of exon loss and mutation on protein localization

Spinal muscular atrophy (SMA) is caused by mutations in the telomeric copy of the survival motor neuron gene (SMN1) but not mutations in the centromeric copy (SMN2). The critical difference between the two genes is a nucleotide difference in exon 7 that affects splicing and causes this exon to be spliced out of most SMN2 transcripts. A majority of the SMN1 gene transcripts contain exon 7. To investigate the effect of exon loss or mutations in SMN on protein localization, 15 SMN constructs were prepared and transfected into COS-7 cells and fibroblasts derived from a type I SMA patient. Loss of exon 5 (Iso5-SMN), a putative nuclear localization signal in exon 2, and the G279V point mutation had little effect on SMN localization. Loss of both exons 5 and 7 (Iso57-SMN) resulted in low gem numbers and the localization of the majority of the SMN protein to the cytoplasm. Cells expressing constructs lacking only exon 7 (Iso7-SMN) did not produce large numbers of gems in general, although there were a few cells that had a staining pattern similar to cells transfected with a full-length (Full-SMN) construct. HeLa cells stably transfected with full-length SMN or Iso7-SMN did not overexpress SMN, and both constructs produced a similar localization of the protein, although Iso7-SMN formed gems less efficiently. Removal of the amino-terminus, deletion of the conserved domain in exon 2A, and the mutation Y272C all caused accumulation of SMN in the nucleus, sometimes in large aggregates. These findings suggest that the amino-terminal domain of SMN is essential for the correct cellular distribution of SMN, whereas Iso7-SMN is capable of forming gems, albeit at a reduced efficiency.

In vivo targeted repair of a point mutation in the canine dystrophin gene by a chimeric RNA/DNA oligonucleotide

In the canine model of Duchenne muscular dystrophy in golden retrievers (GRMD), a point mutation within the splice acceptor site of intron 6 leads to deletion of exon 7 from the dystrophin mRNA, and the consequent frameshift causes early termination of translation. We have designed a DNA and RNA chimeric oligonucleotide to induce host cell mismatch repair mechanisms and correct the chromosomal mutation to wild type. Direct skeletal muscle injection of the chimeric oligonucleotide into the cranial tibialis compartment of a six-week-old affected male dog, and subsequent analysis of biopsy and necropsy samples, demonstrated in vivo repair of the GRMD mutation that was sustained for 48 weeks. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of exons 5-10 demonstrated increasing levels of exon 7 inclusion with time. An isolated exon 7-specific dystrophin antibody confirmed synthesis of normal-sized dystrophin product and positive localization to the sarcolemma. Chromosomal repair in muscle tissue was confirmed by restriction fragment length polymorphism (RFLP)-PCR and sequencing the PCR product. This work provides evidence for the long-term repair of a specific dystrophin point mutation in muscle of a live animal using a chimeric oligonucleotide.

The relationship between SMN, the spinal muscular atrophy protein, and nuclear coiled bodies in differentiated tissues and cultured cells

The spinal muscular atrophy protein, SMN, is a cytoplasmic protein that is also found in distinct nuclear structures called "gems." Gems are closely associated with nuclear coiled bodies and both may have a direct role in snRNP maturation and pre-RNA splicing. There has been some controversy over whether gems and coiled bodies colocalize or form adjacent/independent structures in HeLa and other cultured cells. Using a new panel of antibodies against SMN and antibodies against coilin-p80, a systematic and quantitative study of adult differentiated tissues has shown that gems always colocalize with coiled bodies. In some tissues, a small proportion of coiled bodies (<10%) had no SMN, but independent or adjacent gems were not found. The most striking observation, however, was that many cell types appear to have neither gems nor coiled bodies (e.g., cardiac and smooth muscle, blood vessels, stomach, and spleen) and this expression pattern is conserved across human, rabbit, and pig species. This shows that assembly of distinct nuclear bodies is not essential for RNA splicing and supports the view that they may be storage sites for reserves of essential proteins and snRNPs. Overexpression of SMN in COS-7 cells produced supernumerary nuclear bodies, most of which also contained coilin-p80, confirming the close relationship between gems and coiled bodies. However, when SMN is reduced to very low levels in type I SMA fibroblasts, coiled bodies are still formed. Overall, the data suggest that gem/coiled body formation is not determined by high cytoplasmic SMN concentrations or high metabolic activity alone and that a differentiation-specific factor may control their formation.

Delineation of a minimal interval and identification of 9 candidates for a tumor suppressor gene in malignant myeloid disorders on 5q31

Interstitial deletion or loss of chromosome 5 is frequent in malignant myeloid disorders, including myelodysplasia (MDS) and acute myeloid leukemia (AML), suggesting the presence of a tumor suppressor gene. Loss of heterozygosity (LOH) analysis was used to define a minimal deletion interval for this gene. Polymorphic markers on 5q31 were identified using a high-resolution physical and radiation hybrid breakpoint map and applied to a patient with AML with a subcytogenetic deletion of 5q. By comparing the DNA from leukemic cells to buccal mucosa cells, LOH was detected with markers D5S476 and D5S1372 with retention of flanking markers D5S500 to D5S594. The D5S500-D5S594 interval, which covers approximately 700 kb, thus represents a minimal localization for the tumor suppressor gene. Further refinement of the physical map enabled the specification of 9 transcription units within the encompassing radiation hybrid bins and 7 in flanking bins. The 9 candidates include genes CDC25, HSPA9, EGR1, CTNNA1, and 5 unknown ESTs. Reverse-transcription polymerase chain reaction confirms that all of them are expressed in normal human bone marrow CD34(+) cells and in AML cell lines and thus represent likely candidates for the MDS-AML tumor suppressor gene at 5q31.

The human centromeric survival motor neuron gene (SMN2) rescues embryonic lethality in Smn(-/-) mice and results in a mouse with spinal muscular atrophy

Proximal spinal muscular atrophy (SMA) is a common motor neuron disease in humans and in its most severe form causes death by the age of 2 years. It is caused by defects in the telomeric survival motor neuron gene ( SMN1 ), but patients retain at least one copy of a highly homologous gene, centromeric SMN ( SMN2 ). Mice possess only one survival motor neuron gene ( Smn ) whose loss is embryonic lethal. Therefore, to obtain a mouse model of SMA we created transgenic mice that express human SMN2 and mated these onto the null Smn (-/-)background. We show that Smn (-/-); SMN2 mice carrying one or two copies of the transgene have normal numbers of motor neurons at birth, but vastly reduced numbers by postnatal day 5, and subsequently die. This closely resembles a severe type I SMA phenotype in humans and is the first report of an animal model of the disease. Eight copies of the transgene rescues this phenotype in the mice indicating that phenotypic severity can be modulated by SMN2 copy number. These results show that SMA is caused by insufficient SMN production by the SMN2 gene and that increased expression of the SMN2 gene may provide a strategy for treating SMA patients.

Analysis of mutations in the tudor domain of the survival motor neuron protein SMN

Autosomal recessive childhood onset spinal muscular atrophy (SMA) is a leading cause of infant mortality caused by mutations in the survival motor neuron (SMN) gene. The SMN protein is involved in RNA processing and is localised in structures called GEMs in the nucleus. Nothing is yet understood about why mutations in SMN gene result in the selective motor neuron loss observed in patients. The SMN protein domains conserved across several species may indicate functionally significant regions. Exon 3 of SMN contains homology to a tudor domain, where a Type I SMA patient has been reported to harbour a missense mutation. We have generated missense mutants in this region of SMN and have tested their ability to form GEMs when transfected into HeLa cells. Our results show such mutant SMN proteins still localise to GEMs. Furthermore, exon 7 deleted SMN protein appears to exert a dominant negative effect on localisation of endogenous SMN protein. However, exon 3 mutant protein and exon 5 deleted protein exert no such effect.

Spit tobacco intervention in dental practice: recommendations for clinicians

To address ST use effectively, awareness needs to be raised regarding its harmful affects and addictive nature. Clinicians can and should take a leadership role in the control of ST by addressing ST use with patients. The recommendations provide clinicians with practical tools and strategies for intervention with ST users and potential users. Although many of these strategies require training and time, it should be emphasized that even minimal intervention can be effective in combating ST use.

Prevalence of hepatitis B, hepatitis C, and GB virus C/hepatitis G virus infections in liver disease patients and inhabitants in Ho Chi Minh, Vietnam

The prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and GB virus C or hepatitis G virus (GBV-C/HGV) infections was determined in 289 patients with liver disease in Ho Chi Minh City and 890 healthy inhabitants of its rural area, Dalat City, Vietnam, respectively. Serum HCV RNA and GBV-C/HGV RNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). HBsAg, HCV antibodies, and GBV-C/HGV RNA were detected in 139 (47%), 69 (23%), and ten (3%) subjects, respectively, often accompanied by elevated serum levels of alanine aminotransferase. HBsAg and HCV antibodies or HCV antibodies and GBV-C/HGV RNA were detectable simultaneously in 8% and 2% of the patients, respectively. In the inhabitants, HBsAg, HCV antibodies, and GBV-C/HGV RNA were found in 51 (5.7%), nine (1.0%), and 11 (1.2%) subjects, respectively. Thus, the prevalence of HBsAg, HCV antibodies, and GBV-C/HGV RNA was significantly higher in liver disease patients than those in the general population. In the samples from 69 patients and nine inhabitants who were seropositive for HCV antibodies, HCV RNA was detectable in 42 (61%) and 4 (44%), respectively. In patients with liver disease, ten belonged to HCV genotype 1a, ten to HCV 1b, three to HCV 2a, four to HCV 2b, and two to HCV 3a by PCR with genotype-specific primers. Nine patients had mixed genotypes, and the remaining four were not classified. Of the GBV-C/HGV RNA-positive individuals, two patients and two inhabitants were positive for HBsAg, while none of the residents had HCV antibodies, although six HCV antibodies (60%) and four HCV RNA (40%) were found in patients. When a phylogenetic tree of GBV-C/HGV was constructed based on the nucleotide sequences, the 21 isolates were classified into at least two genotypes; four isolates belonged to G2, and 17 to G3. The results indicate that in Ho Chi Minh HCV infection prevails with broad distribution of genotypes together with HBV infection among patients with liver disease. This study suggests that GBV-C/HGV infection occurs independently in the two different districts in association with HCV infection.

An aqueous extract of the leaves of Chromolaena odorata (formerly Eupatorium odoratum) (Eupolin) inhibits hydrated collagen lattice contraction by normal human dermal fibroblasts

Chromolaena odorata (formerly Eupatorium odoratum) is used as a traditional medicine in Vietnam (Nghiem, 1992), where its Vietnamese common name is "co hoi." While it has been widely considered a weed by agriculturalists (Holm et al., 1991), the aqueous extract and the decoction from the leaves of this plant have been used throughout Vietnam for the treatment of soft tissue wounds, burn wounds, and skin infections. A number of clinical studies done by Vietnamese as well as foreign medical workers has demonstrated the efficacy of this extract on the wound-healing process. In this article, the effect of the Eupolin extract on hydrated collagen lattice contraction by human dermal fibroblasts, an in vitro model of wound contraction, is described. The significant inhibition of collagen gel contraction by Eupolin extract at 50 to 200 micrograms/ml is demonstrated in various concentrations of collagen. When the extract at 50 to 150 micrograms/ml was washed out of the lattices and replaced by fresh medium without Eupolin, the contraction of collagen by cells was resumed. The visualization of cells in the lattices by incubation in a tetrazolium salt for 2 h showed live cells at 50 to 150 micrograms/ml of extract. In contrast, all cells were killed in the higher extract doses of 300 or 400 micrograms/ml. These preliminary results showing the inhibitory effect of Eupolin extract on collagen contraction suggest that a clinical evaluation of its effect on wound contraction and scar quality should be made. This work illustrates that traditional remedies that are used by folk practitioners to improve healing can be examined in a scientific manner using in vitro wound-healing models. It could be that the synergistic properties of components of the natural extract contribute to the positive effects demonstrated on various wound-healing mechanisms.

The survival motor neuron protein in spinal muscular atrophy

The 38 kDa survival motor neuron (SMN) protein is encoded by two ubiquitously expressed genes: telomeric SMN (SMN(T)) and centromeric SMN (SMN(C)). Mutations in SMN(T), but not SMN(C), cause proximal spinal muscular atrophy (SMA), an autosomal recessive disorder that results in loss of motor neurons. SMN is found in the cytoplasm and nucleus. The nuclear form is located in structures termed gems. Using a panel of anti-SMN antibodies, we demonstrate that the SMN protein is expressed from both the SMN(T) and SMN(C) genes. Western blot analysis of fibroblasts from SMA patients with various clinical severities of SMA showed a moderate reduction in the amount of SMN protein, particularly in type I (most severe) patients. Immunocytochemical analysis of SMA patient fibroblasts indicates a significant reduction in the number of gems in type I SMA patients and a correlation of the number of gems with clinical severity. This correlation to phenotype using primary fibroblasts may serve as a useful diagnostic tool in an easily accessible tissue. SMN is expressed at high levels in brain, kidney and liver, moderate levels in skeletal and cardiac muscle, and low levels in fibroblasts and lymphocytes. In SMA patients, the SMN level was moderately reduced in muscle and lymphoblasts. In contrast, SMN was expressed at high levels in spinal cord from normals and non-SMA disease controls, but was reduced 100-fold in spinal cord from type I patients. The marked reduction of SMN in type I SMA spinal cords is consistent with the features of this motor neuron disease. We suggest that disruption of SMN(T) in type I patients results in loss of SMN from motor neurons, resulting in the degeneration of these neurons.

Randomised feasibility trial of pre-exposure rabies vaccination with DTP-IPV in infants

BACKGROUND

Pre-exposure vaccination against rabies generally simplifies treatment and could be especially beneficial to children in countries where the disease is enzootic. We studied the feasibility of administering to infants pre-exposure rabies vaccination with combined diphtheria, tetanus, whole-cell pertussis, and inactivated poliomyelitis vaccine (DTP-IPV).

METHODS

84 Vietnamese infants were randomly assigned to groups that received three doses of DTP-IPV vaccine at 2, 3, and 4 months of age alone (n = 43) or with two doses of purified Vero cell rabies vaccine (PVRV) at 2 and 4 months (n = 41). The safety and immunogenicity data of the groups were compared.

FINDINGS

All infants in both groups developed protective antibody concentrations against diphtheria, tetanus, pertussis, and polio. All infants who received the PVRV vaccine developed protective antibody concentrations against rabies. No serious adverse effects were reported, nor did systemic reactions differ between groups.

INTERPRETATION

Administration of PVRV with DTP-IPV proved safe, and elicited what are presumed to be protective antibody concentrations to all antigens in all 41 infants. Confirmation of these results could lead to integration of pre-exposure rabies vaccination into Expanded Programme on Immunisation (EPI) sessions in selected countries where rabies is enzootic.

Changes in various plasma lipid components, glucose, and insulin in Spermophilus lateralis during hibernation

This study evaluated fat mobilization as related to gluconeogenesis in two age groups of hibernating golden-mantled ground squirrels (Spermophilus lateralis). Our experimental group consisted of a total of 16 male and 15 female squirrels. Plasma samples were collected from selected animals being killed weekly from January to March, and the concentration of triglycerides, glycerol (GY), free fatty acids (FFA), total cholesterol, lipase activity, glucose, and insulin, were determined by biochemical assays and radioimmunoassay. Our results showed a mean FFA/GY ratio of five, which was higher than the predicted value of three, suggesting a significant depletion of GY and an enhanced rate of gluconeogenesis via GY to maintain glucose homeostasis in the hibernating animals. The factor of age did not significantly affect plasma lipid components. However, in the male group, plasma glucose levels were significantly higher for adults than for juveniles. Overall, females had significantly higher plasma glucose levels than males (150 +/- 11 vs. 110 +/- 8 mg%, P < 0.05). In the adult group, a gender influence was also seen on plasma insulin levels, with females' being higher than males' (66 +/- 13 vs. 25 +/- 3 microIU/ml, P < 0.01). We suggest that during hibernation, female squirrels may have a higher rate of lipolysis and gluconeogenesis along with a lower glucose utilization than their male counterparts. Additionally, adult females may exhibit a higher peripheral insulin resistance during hibernation than adult males, a possibility which merits further study.