Expression of the glycoprotein E2 of the classical swine fever virus in Escherichia coli

The glycoprotein E2 sequences of classical swine fever virus (strain p97) were cloned, sequenced and expressed in E. coli. Result from SDS-polyacrylamide gel electrophoresis analysis of expressed proteins revealed the presence of a prominently stained band corresponding to a molecular mass of 61 kDa, which is in agreement with the predicted size from the DNA sequence. The recombinant E2 protein contained an aminoterminal tag of six histidines that could be used for purification by the nickel chelate affinity chromatography. The elution fractions of the expressed protein also contain additional bands of 40 and 35 kDa proteins, indicating proteolytic cleavages might occur. Our Western blotting result also supported that the expression of the recombinant E2 protein of the classical swine fever virus were accomplished.

Synchronicity of frequently sampled, 24-h concentrations of circulating leptin, luteinizing hormone, and estradiol in healthy women

Leptin, an adipocyte hormone, is a trophic factor for the reproductive system; however, it is still unknown whether there is a dynamic relation between fluctuations in circulating leptin and hypothalamic-pituitary-ovarian (HPO) axis hormones. To test the hypothesis that fluctuations in plasma leptin concentrations are related to the levels of luteinizing hormone (LH) and estradiol, we sampled plasma from six healthy women every 7 min for 24 h during days 8-11 of the menstrual cycle. Cross-correlation analysis throughout the 24-h cycle revealed a relation between release patterns of leptin and LH, with a lag of 42-84 min but no significant cross-correlation between LH and estradiol. The ultradian fluctuations in leptin levels showed pattern synchrony with those of both LH and estradiol as determined by cross-approximate entropy (cross-ApEn). At night, as leptin levels rose to their peak, the pulsatility profiles of LH changed significantly and became synchronous with those of leptin. LH pulses were fewer, of longer duration, higher amplitude, and larger area than during the day. Moreover, the synchronicity of LH and leptin occurred late at night, at which time estradiol and leptin also exhibited significantly stronger pattern coupling than during the day. We propose that leptin may regulate the minute-to-minute oscillations in the levels of LH and estradiol, and that the nocturnal rise in leptin may determine the change in nocturnal LH profile in the mid-to-late follicular phase that precedes ovulation. This may explain the disruption of hypothalamic-pituitary-ovarian function that is characteristic of states of low leptin release, such as anorexia nervosa and cachexia.

A needs assessment and proposal for HIV education among human resource managers in Singapore

AIM OF STUDY

To assess the educational needs of human resource managers in Singapore with regard to the management of HIV at the workplace. No such study has been described before in an Asian country.

METHOD

A self-administered questionnaire was mailed to all companies (with more than 100 employees) of a local employers federation (n = 368).

RESULTS

A response rate of 64.1% was achieved. Respondents' knowledge about HIV transmission was found to be good. However, their attitudes and practices towards infected workers were unfavourable on such issues as pre-employment screening, medical coverage and termination of employment. Possible reasons for this disparity include inadequate information specific to workplace needs, multiple determinants of attitudes (other than knowledge) and various environmental factors.

CONCLUSION

Strategies for an educational intervention are proposed to facilitate the development of a rational HIV management policy by local managers.

Assess workers' needs and preferences first before planning a physical fitness programme: findings from a polytechnic institute in Singapore

Workplace physical fitness programmes are usually poorly attended because the activities do not meet workers' needs. We investigated leisure-time physical activity and its relation to sociodemographic characteristics and cardiovascular risk factors in a polytechnic institute in Singapore before planning a physical fitness programme. Low leisure-time physical activity (defined as no activity or engaging in physical activity less than once per week) was more prevalent among older women, married workers, smokers and men with unhealthy dietary habits. The type of physical activity varied with age and gender, with a preference for walking by women and older men and jogging by younger men. Low physical activity was significantly associated with sickness absence and self-reported stress in women and higher values of triglycerides and low density lipoprotein cholesterol in men. This survey helps to identify target groups for physical fitness programmes and determine leisure-time physical activities specific to workers' preferences by age and gender.

The recombinant nucleocapsid protein of classical swine fever virus can act as a transcriptional regulator

The cDNA of the nucleocapsid (core) protein of classical swine fever virus (CSFV) was generated by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into a eukaryotic expression vector. The effect of the recombinant core protein on the transcriptional regulation of cellular as well as viral promoters was studied. Using transient transfection assay, our results demonstrated that the core protein can activate the promoter of human heat shock protein 70 gene, and suppressed the SV40 early promoter. These findings indicate that the core protein appears to function not only as a viral structural protein but also as a regulator of gene expression. The implications of core proteins on the viral maturation are discussed.

Stimulation of type I DNA topoisomerase gene expression by pseudorabies virus

Previous results from our laboratory have demonstrated that type I DNA topoisomerase activity is required for the replication and gene expression of pseudorabies virus (PRV). In the present report, we further analyzed the expression of topoisomerase I in PRV-infected cells, and the western blot result showed that the expression of topoisomerase I was increased after virus infection. The increase sustained to late time of infection when the cytopathic effect was obvious and the synthesis of most host proteins was shut off by PRV. From transient expression assay, it was also found that the promoter of cellular topoisomerase I gene could be stimulated by immediate-early protein (IE180) and viral early protein 0 (EP0), and these two regulatory proteins appeared to work synergistically. Collectively, these findings provide evidence that PRV can stimulate the expression of topoisomerase I and that the stimulation is mediated at least by IE180 and EP0 proteins of PRV at the transcriptional level.

Intradecidual sign: is it effective in diagnosis of an early intrauterine pregnancy?

PURPOSE

To determine if the intradecidual sign at sonography is effective in the diagnosis of early intrauterine pregnancy.

MATERIALS AND METHODS

In 102 pregnant patients, transvaginal sonography revealed an intrauterine fluid collection without a yolk sac or embryo. Four observers (experienced sonologist, body imaging fellow, 1st-year radiology resident, and premedical student) determined independently whether the intradecidual sign was absent, present, or indeterminate. Interpretations were limited to visualization of only the uterus.

RESULTS

Follow-up revealed intrauterine pregnancy in 91 patients (outcome normal in 48 and abnormal in 43) and ectopic pregnancy in 11 patients. Among the four reviewers, sensitivity for diagnosis of an intrauterine pregnancy was 34%-66%, specificity was 55%-73%, accuracy was 38%-65%, positive predictive value was 91%-93%, and negative predictive value was 12%-16%. Three to five ectopic pregnancies were categorized incorrectly as demonstrating the intradecidual sign, depending on the reviewer.

CONCLUSION

The intradecidual sign does not appear to be sensitive or specific in diagnosis of an early intrauterine pregnancy. When an intrauterine fluid collection is present without an embryo or yolk sac (with positive pregnancy test results), a follow-up sonogram should be obtained unless contraindicated clinically.

Endogenous interleukin-1 receptor antagonist is neuroprotective

Interleukin-1 (IL-1) has been implicated in chronic and acute cerebral neuropathologies. IL-1 receptor antagonist (IL-1ra), a naturally occurring protein that binds to IL-1 receptors without inducing signal transduction, blocks several actions of IL-1. IL-1ra acts at the local level and it also circulates in the bloodstream. We now report evidence for a biological function of IL-1ra in the brain as an endogenous neuroprotective molecule. Cerebral expression of IL-1ra mRNA is induced rapidly by focal cerebral ischemia in rats, and inhibition of the action of IL-1ra, by passive immuno-neutralization, markedly enhances ischemic damage. To our knowledge this is the first report of an action of endogenous IL-1ra in the brain. Control of IL-1ra expression or action may therefore provide a useful therapeutic strategy to limit acute neurodegeneration.

Human leptin levels are pulsatile and inversely related to pituitary-adrenal function

Leptin communicates nutritional status to regulatory centers in the brain. Because peripheral leptin influences the activity of the highly pulsatile adrenal and gonadal axes, we sought to determine whether leptin levels in the blood are pulsatile. We measured circulating leptin levels every 7 minutes for 24 hours, in six healthy men, and found that total circulating leptin levels exhibited a pattern indicative of pulsatile release, with 32.0 +/- 1.5 pulses every 24 hours and a pulse duration of 32.8 +/- 1.6 minutes. We also show an inverse relation between rapid fluctuations in plasma levels of leptin and those of adrenocorticotropic hormone (ACTH) and cortisol that could not be accounted for on the basis of glucocorticoid suppression of leptin. As leptin levels are pulsatile, we propose that a key function of the CNS is regulated by a peripheral pulsatile signal. In a separate pilot study we compared leptin pulsatility in 414 plasma samples collected every 7 minutes for 24 hours from one obese woman and one normal-weight woman. We found that high leptin levels in the obese subject were due solely to increased leptin pulse height; all concentration-independent pulsatility parameters were almost identical in the two women. Leptin pulsatility therefore can be preserved in the obese.

Patient education in the management of diabetes mellitus

AIM

A patient education programme in the management of diabetes mellitus (DM) was piloted in a government polyclinic. This study aimed to evaluate the effectiveness of the education programme in improving knowledge of DM and skills in self-care in order to achieve long term control of DM.

METHOD

The study was carried out on an intervention group of 183 diabetic patients who completed the education programme and a control group of 95 diabetic patients who attended the clinic during the period of the study. The patients were assessed on their knowledge of diabetes and their practice for good control of the disease (dietary practice, compliance, home monitoring) through a questionnaire. Long term control was assessed by their glycosylated haemoglobin levels. The education programme comprised individual counselling using a diabetes education guide, talks, videoshows and food displays.

RESULTS

The intervention group showed a significant and greater improvement in the knowledge of the disease and self-care and in the dietary practice (taking more unpolished rice/high fibre food, reducing calories intake and cutting down oily/fatty food) when compared to the control group. Compliance with medication and the mean HbA1c levels were also improved in the intervention group.

CONCLUSION

In this study the educational intervention was observed to have improved the diabetic patients' knowledge of the disease and self-care and the long term control of the disease. Patient education is thus an important component in the management of diabetes mellitus.

Interleukin 1 receptor antagonist gene expression in rat pituitary in the systemic inflammatory response syndrome: pathophysiological implications

The systemic inflammatory response syndrome (SIRS) is characterized by endothelial cell activation causing a generalized inflammatory response and cytokine-mediated pathophysiological alterations. The pathophysiology of SIRS involves changes in the functioning of several endocrine glands, including the pituitary. SIRS-induced alterations in pituitary function include activation of the hypothalamic-pituitary adrenal (HPA) axis causing hypercortisolemia, the euthyroid sick syndrome, and cessation of reproductive function. These changes are in part mediated by cytokines, such as tumor necrosis factor alpha (TNF-alpha) and interleukin 1 (IL-1). IL-1 function depends on the local ratio of bioactive IL-1 and IL-1 receptor antagonist. Here we review our studies on IL-1 beta and IL-1ra mRNA levels in the pituitary in a rat model of SIRS. We have found that IL-1 beta mRNA peaked at 2 h after lipopolysaccharide (LPS) administration, increasing twelvefold over control values in the posterior pituitary and fivefold over controls in the anterior pituitary. IL-1ra mRNA levels peaked at 6 h post-LPS administration, later than those of IL-1 beta mRNA. IL-1ra mRNA levels increased tenfold in the anterior pituitary, but were induced only threefold in the posterior pituitary. IL-1ra gene expression is profoundly induced in the pituitary in vivo during systemic inflammation and its induction follows that of IL-1 beta, but it is differentially regulated and tissue-specific, occurring predominantly in the anterior pituitary. Future studies of the effects of IL-1 in the pituitary should take into account the local levels of IL-1ra.

Two-year follow-up of a behavioural weight control programme for adolescents in Singapore: predictors of long-term weight loss

We followed up 112 obese adolescents enrolled in a weight control programme at a polytechnic institute in Singapore for two years. The programme used behavioural and environmental strategies to help students make sustained changes in their diet and physical activity pattern. Of these 112 students, 71.4% lost weight compared to 60% in a comparison group of 86 obese students not in the programme. About one-third (29.5%) had achieved normal weight [body mass index (BMI) < 25] with a mean weight loss of 3.3 kg among boys and 2.3 kg among girls. A stepwise multiple linear regression to determine the best combination of variables predictive of weight loss found three variables to be significantly associated with long-term weight loss: percent of weight loss in the initial 8-week intervention period; increase in exercise or physical activity following intervention, and income. These 3 variables accounted jointly for 59.5% of the variance in weight loss in males and 48% of weight loss in females. We recommend intensive efforts during the initial intervention phase to help students lose weight and strategies that can help students incorporate exercise or increased physical activity in their daily routine.

A multistep, ATP-dependent pathway for assembly of human immunodeficiency virus capsids in a cell-free system

To understand the mechanism by which human immunodeficiency virus type 1 (HIV) capsids are formed, we have reconstituted the assembly of immature HIV capsids de novo in a cell-free system. Capsid authenticity is established by multiple biochemical and morphologic criteria. Known features of the assembly process are closely reproduced, indicating the fidelity of the cell-free reaction. Assembly is separated into co- and posttranslational phases, and three independent posttranslational requirements are demonstrated: (a) ATP, (b) a detergent-sensitive host factor, and (c) a detergent-insensitive host subcellular fraction that can be depleted and reconstituted. Assembly appears to proceed by way of multiple intermediates whose conversion to completed capsids can be blocked by either ATP depletion or treatment with nondenaturing detergent. Specific subsets of these intermediates accumulate upon expression of various assembly-defective Gag mutants in the cell-free system, suggesting that each mutant is blocked at a particular step in assembly. Furthermore, the accumulation of complexes of similar sizes in cells expressing the corresponding mutants suggests that comparable intermediates may exist in vivo. From these data, we propose a multi-step pathway for the biogenesis of HIV capsids, in which the assembly process can be disrupted at a number of discrete points.

Early closure of coronary cameral fistula in a 3.9 kg infant

Congenital communications between the coronary artery and cardiac chambers are rare. The majority of cases present in adulthood. We report a patient with a coronary cameral fistula in which surgical closure of the fistula was performed at 10 weeks of age at a weight of 3.9 kg. We recommend early closure of coronary cameral fistula in symptomatic patients. Low weight or young age at presentation should not be a limiting factor.

Interleukin (IL) 1beta, IL-1 receptor antagonist, IL-10, and IL-13 gene expression in the central nervous system and anterior pituitary during systemic inflammation: pathophysiological implications

The pathophysiology of systemic inflammation and sepsis involves peripheral organs, causing gastrointestinal, renal, and cardiovascular alterations, as well as the central nervous system (CNS), affecting sleep, temperature regulation, behavior, and neuroendocrine function. The molecular basis of the CNS effects of systemic inflammation are not fully elucidated. Here we show that the CNS responds to systemic inflammation with pronounced IL-1beta gene expression and limited IL-1 receptor antagonist (IL-1ra), IL-10, and IL-13 gene expression. This pattern occurs throughout the CNS, including areas such as the subfornical organ, pineal gland, neurohypophysis, and hypothalamus. In contrast, in the anterior pituitary, we found limited IL-1beta gene expression but marked induction of the mRNA encoding for the secreted isoform of IL-1ra, secreted IL-1ra. We conclude that the central manifestations of peripheral inflammation are mediated by endogenous brain IL-1beta synthesized during systemic inflammation in the context of limited central cytokine counter regulation of IL-1. As IL-1beta is a potent stimulus for inducible nitric oxide synthase expression and activity, these findings explain our previous observation that systemic inflammation promotes inducible nitric oxide synthase gene expression in the brain and the spillover of NO metabolites into cerebrospinal fluid. The CNS transcription of the HIV-1 replication factor IL-1beta in the context of limited transcription of the IL-1 replication inhibitors IL-1ra, IL-10, and IL-13 might help explain the negative impact of systemic inflammation on the clinical course of AIDS. In addition, we propose that IL-1ra may be secreted by the anterior pituitary as a systemic anti-inflammatory hormone that is released in response to IL-1beta originated from multiple sources.

Evolutionary program induction directed by logic grammars

Program induction generates a computer program that can produce the desired behavior for a given set of situations. Two of the approaches in program induction are inductive logic programming (ILP) and genetic programming (GP). Since their formalisms are so different, these two approaches cannot be integrated easily, although they share many common goals and functionalities. A unification will greatly enhance their problem-solving power. Moreover, they are restricted in the computer languages in which programs can be induced. In this paper, we present a flexible system called LOGENPRO (The LOgic gramar-based GENetic PROgramming system) that uses some of the techniques of GP and ILP. It is based on a formalism of logic grammars. The system applies logic grammars to control the evolution of programs in various programming languages and represent context-sensitive information and domain-dependent knowledge. Experiments have been performed to demonstrate that LOGENPRO can emulate GP and GP with automatically defined functions (ADFs). Moreover, LOGENPRO can employ knowledge such as argument types in a unified framework. The experiments show that LOGENPRO has superior performance to that of GP and GP with ADFs when more domain-dependent knowledge is available. We have applied LOGENPRO to evolve general recursive functions for the even-n-parity problem from noisy training examples. A number of experiments have been performed to determine the impact of domain-specific knowledge and noise in training examples on the speed of learning.

Identification of hypothalamic transcripts upregulated by antidepressants

Identification of quantitative changes in gene expression that occur in the brain after antidepressant treatment can yield novel molecular markers that may be useful in the diagnosis and treatment of major depression. Using a modification of the differential display polymerase chain reaction, we describe the isolation of two transcripts that are differentially expressed in the brain after an 8-week course of antidepressant administration, compared to saline-treated control animals.

Dysthymia in neurological disorders

Dysthymia is characterized by long-lasting periods of lowered mood. Epidemiological studies in the USA and Europe have demonstrated that the prevalence of dysthymia is at least 3% of the general population. Its pervasive occurrence makes dysthymia a public health problem worldwide. One feature of this disorder is its co-occurrence with medical and neurological disorders. A World Health Organization meeting on dysthymia in neurological disorders was held in Geneva, 1-3 July 1996 to address this topic. Some of the major goals of this meeting were to clarify the definition of dysthymia in the presence of neurological disorders and to evaluate current research in the field, to point out new areas for investigation, and to discuss current psychological and pharmacological treatments for dysthymia in neurological disorders. The potential roles of neuroendocrine and molecular mechanisms in dysthymia were identified through specific problems related to dysthymia occurring in disorders such as Parkinson's disease, Alzheimer's disease, stroke, multiple sclerosis and epilepsy. This meeting provided direction and opportunity for future studies in the under-recognized and under-investigated relationship between dysthymia and neurological disorders.

IL-1 beta, IL-1 receptor type I and iNOS gene expression in rat brain vasculature and perivascular areas

The mechanism by which IL-1 beta exerts its actions in the brain during systemic inflammation is not fully understood, as neither IL-1 receptor gene expression nor IL-1 binding have been identified in significant levels in key areas that respond to IL-1 beta. Having hypothesized that perivascular nitric oxide (NO) might modulate the effects of systemic IL-1 beta in the brain, we studied the expression of the genes encoding for IL-1 beta, the signal-transducing IL-1 receptor type I (IL-1RI) and inducible NO synthase (iNOS) constitutively and during systemic inflammation in vascular and perivascular regions of the rat brain. Our results show that IL-1RI is constitutively expressed at the interface of the vascular wall and perivascular glia. During systemic inflammation there is induction of IL-1 beta gene expression in the vascular wall, accompanied by perivascular induction of iNOS mRNA. We conclude that during systemic inflammation vascular IL-1 beta, binding to vascular and perivascular IL-1RI receptors, may induce perivascular iNOS gene expression, leading to the production of NO and modulation of the effects of IL-1 beta in the brain. We propose that the vascular and peri-vascular induction of iNOS mRNA by IL-1 beta might represent a mechanism for the modulation of the central nervous system effects of peripheral inflammatory mediators.

Localization of urocortin messenger RNA in rat brain and pituitary

Pituitary function is regulated by hypothalamic releasing hormones secreted into hypophyseal-portal blood. A new hypothesis is that pituitary function might also be regulated at the local level by releasing hormones synthesized within the pituitary. Here we show that the pituitary expresses high levels of the gene encoding for urocortin. We suggest that urocortin synthesized by the pituitary may modulate pituitary function, and that adrenocorticotropic hormone (ACTH) secretion is dependent on input not only from the hypothalamus as previously described, but it may also be regulated by urocortin synthesized locally. Urocortin binds to the corticotropin-releasing hormone (CRH) receptor type 1 (CRH-R1) with high affinity and potently stimulates pituitary-adrenal function. Our group and others have previously localized high levels of CRH-R1 mRNA in the pituitary. Using a 35S-labeled rat urocortin riboprobe we have now localized urocortin mRNA in rat brain and pituitary. The finding of urocortin gene expression in the pituitary may help explain why proopiomelanocortin (POMC) mRNA levels are not decreased during hypothalamo-pituitary disconnection, and also describes a new level of complexity in the regulation of hypothalamo-pituitary function. Future studies should consider the possibility that pituitary function might be regulated at the local level by urocortin.

Videothoracoscopic ligation of patent ductus arteriosus--a case report

Video-assisted thoracoscopic surgical interruption (VTSI) of patent ductus arteriosus (PDA) is a relatively new technique when compared to surgical closure and transcatheter endovascular closure. Besides its minimally invasive nature, VTSI is the best option for neonates. Surgical approach may lead to late scoliosis in neonates and the vessels of neonates are too small for the transcatheter approach. VTSI potentially may prove to have lower morbidity and mortality than classic surgical closure of PDA. This article reviews the successful videothoracoscopic ligation of PDA in a 13-year-old girl.