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Hiroi N, Wong ML, Licinio J, Park C, Young M, Gold PW, Chrousos GP, Bornstein SR. Expression of corticotropin releasing hormone receptors type I and type II mRNA in suicide victims and controls. Mol Psychiatry 2001; 6:540-6. [PMID: 11526468 DOI: 10.1038/sj.mp.4000908] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2001] [Revised: 02/22/2001] [Accepted: 02/22/2001] [Indexed: 12/13/2022]
Abstract
Corticotropin-releasing hormone (CRH) is a key neuroendocrine factor implementing endocrine, immune and behavioral responses to stress. CRH exerts its action through two major receptors, CRH-R1 and CRH-R2. Recently novel non-peptidic antagonists directed against CRH-R1 or CRH-R2 have been proposed as promising agents in the treatment of depression, anxiety and eating disorder. However, so far the CRH-receptor system has not been widely studied in humans. Therefore, we employed quantitative TaqMan PCR to analyze the expression and distribution of both CRH-R1 and CRH-R2 in human brain tissue and peripheral organs. Furthermore the expression of CRH receptors was analyzed for the first time in pituitaries of suicide victims by in situ hybridization and quantitative PCR. Our data demonstrated a different expression pattern in humans as compared to rodents. Both CRH-R1 and CRH-R2 were expressed in high amounts in the brain with the strongest expression in the pituitary. As described in rodents, however the CRH-R1 in human was the predominant receptor in the brain (82.7 +/- 11.0%), whilst CRH-R2 was the predominant receptor in peripheral organs (77.0 +/- 15.8%). There was a shift in the ratio of CRH-R1/R2 in the pituitaries of suicide victims. In conclusion, both CRH-R1 and CRH-R2 are widely expressed in human tissues with a distribution substantially different from rodents. Strong expression of both CRH-R1 and CRH-R2 in human pituitaries suggests that particularly under stress, activation of the HPA axis can be maintained through both receptors.
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Mantzoros CS, Ozata M, Negrao AB, Suchard MA, Ziotopoulou M, Caglayan S, Elashoff RM, Cogswell RJ, Negro P, Liberty V, Wong ML, Veldhuis J, Ozdemir IC, Gold PW, Flier JS, Licinio J. Synchronicity of frequently sampled thyrotropin (TSH) and leptin concentrations in healthy adults and leptin-deficient subjects: evidence for possible partial TSH regulation by leptin in humans. J Clin Endocrinol Metab 2001; 86:3284-91. [PMID: 11443202 DOI: 10.1210/jcem.86.7.7644] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Leptin signals the status of energy reserves to the brain. Leptin stimulates biosynthesis of TRH in vitro and influences the activity of the hypothalamic-pituitary-thyroid axis in vivo in rodents. Because blood levels of both leptin and TSH display diurnal variation with a distinct nocturnal rise, we sought to determine whether a relationship exists between fluctuations in circulating leptin and TSH. We measured serum leptin and TSH levels every 7 min for 24 h in five healthy men and found that both leptin and TSH levels are highly organized and pulsatile. A similar pattern of leptin and TSH rhythms was observed, with TSH and leptin levels reaching a nadir in late morning and a peak in the early morning hours. Importantly, cosinor analysis on the absolute leptin and TSH levels revealed a statistically significant fit for a 24-h period and the two hormones showed similar probabilities of rhythm and superimposable peak values. Furthermore, this study shows a strong positive Pearson correlation between the 24-h patterns of variability of leptin and TSH in healthy subjects. Finally, the ultradian fluctuations in leptin levels showed pattern synchrony with those of TSH as determined by cross-correlation analysis, by cross-approximate enthropy and Bayessian analysis applied independently. To further explore whether these associations could reflect an underlying regulation of TSH secretion by leptin, we also studied frequently sampled leptin and TSH levels in four brothers, members of a family with leptin deficiency (one normal homozygote, two heterozygotes, and one leptin-deficient homozygote). Leptin levels of the homozygous leptin-deficient subject are detectable but bioinactive, and the rhythm of his TSH is disorganized. 24-h pattern of leptin and TSH variability in the heterozygous subjects, although significantly correlated, showed a weaker correlation compared with the strong correlation in the normal subjects. These data are consistent with the possibility that leptin may regulate TSH pulsatility and circadian rhythmicity, but interventional studies are needed to definitively prove whether leptin regulates the minute-to-minute oscillations and ultradian rhythm of TSH levels.
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Saw SM, Koh D, Adjani MR, Wong ML, Hong CY, Lee J, Chia SE, Munoz CP, Ong CN. A population-based prevalence survey of skin diseases in adolescents and adults in rural Sumatra, Indonesia, 1999. Trans R Soc Trop Med Hyg 2001; 95:384-8. [PMID: 11579879 DOI: 10.1016/s0035-9203(01)90189-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Skin disorders are one of the most common presenting health problems and pose a considerable public health problem in developing and developed countries. A population-based survey (n = 917) was conducted in October and November 1999 to determine the prevalence of skin diseases in 3 rural villages in Indonesia (Riau province, Sumatra). The overall individual response rate was 96%. Household interviews were conducted to obtain information on skin conditions, basic socio-demographic factors and lifestyle habits. Trained doctors performed a thorough clinical skin examination of each subject in the household. The overall prevalence of skin disease in the 3 villages was 28.2% (95% confidence intervals 24.6-31.8). The prevalence of fungal infections (12.0%) was twice as high as dermatitis (5.1%). As skin conditions are common in rural Indonesia, it is advisable to improve the training of nurses and doctors in the prevention and treatment of skin disorders.
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Abstract
Depression is a major cause of disability worldwide, but we know little about the underlying fundamental biology. Research is hindered by the difficulties of modelling a disorder of higher cognitive functions in animals. Depression can be understood as the interaction of genetic susceptibility and environmental factors; however, current classifications are purely descriptive. The complexity of this field is best approached by rigorous explorations of known candidate systems in conjunction with the use of genomic tools to discover new targets for antidepressants and to predict therapeutic outcomes.
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Quek SC, Yip CL, Wong ML, Chan KY, Wong CL. A case series of six children with primary pulmonary hypertension. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2001; 30:118-21. [PMID: 11379407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
INTRODUCTION Primary pulmonary hypertension is an uncommon but serious disease in children. Management is difficult despite recent advances in pharmacotherapy. CLINICAL PICTURE We reviewed patients with this condition with respect to their presenting symptoms, investigations, treatment and outcome. TREATMENT These children were treated with individualised combinations of oxygen, diuretics and calcium antagonists. OUTCOME In our follow-up of 5 children, 4 had died. CONCLUSION This condition is irreversible and progressive with a high mortality rate. A better understanding of, and research into, the pathogenesis would hopefully lead to the formulation of improved therapeutic strategies for this condition.
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Lewis SB, Wong ML, Bannan PE, Piper IR, Reilly PL. Transcranial Doppler identification of changing autoregulatory thresholds after autoregulatory impairment. Neurosurgery 2001; 48:369-75; discussion 375-6. [PMID: 11220381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
OBJECTIVE Transcranial Doppler (TCD) flow velocity (FV) assessment may provide a useful index of autoregulatory impairment after severe head injury. It may define a therapeutic end point against which cerebral perfusion pressure (CPP) can be titrated. This study examines the relationship between cerebral blood flow (CBF) and TCD FV indices in a laboratory model before and after autoregulatory impairment. METHODS CPP, CBF, and middle cerebral artery TCD FV were measured continuously in nine anesthetized and ventilated sheep. CPP was decreased by hemorrhagic hypotension. The process was repeated after impairment of autoregulation by cisternal infusion, which maintained CPP at 0 mm Hg for 15 minutes. Points of significant change (i.e., breakpoints) from baseline values for each of the measured flow parameters were identified by using a ratio of variance technique. RESULTS Before any significant change in CBF or systolic TCD, diastolic TCD FV decreased (mean breakpoint, 69 mm Hg; range, 56-78 mm Hg) as CPP was reduced. This divergence of diastolic and systolic TCD FV, which occurred before autoregulatory failure, was associated with an increasing TCD pulsatility index (mean breakpoint, 63 mm Hg; range, 53-70 mm Hg). At diastolic TCD FV congruent with 10 cm/s, systolic TCD FV (mean breakpoint, 48 mm Hg; range, 46-53 mm Hg) and CBF (mean breakpoint, 49 mm Hg; range, 47-51 mm Hg) decreased rapidly, indicating autoregulatory failure. After autoregulatory impairment, the breakpoints for all four indices shifted to higher CPP values (mean, 16 mm Hg). CONCLUSION TCD FV assessment identified two CPP thresholds of autoregulatory loss. Before autoregulatory failure, an earlier phase of autoregulatory disturbance may be detected by divergent systolic and diastolic TCD FVs. It is important to note that this phase may be detected before CBF decreases. These TCD FV breakpoints depend on the state of autoregulatory impairment and may provide potential targets for CPP-directed therapy.
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Cheng CK, Wong ML, Lee AW. PEG adsorption of autoantibodies and detection of alloantibodies in warm autoimmune hemolytic anemia. Transfusion 2001; 41:13-7. [PMID: 11161239 DOI: 10.1046/j.1537-2995.2001.41010013.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The purpose of this study was to evaluate the effectiveness of PEG in the adsorption of autoantibodies and the detection of alloantibodies in patients with warm autoimmune hemolytic anemia (WAIHA). STUDY DESIGN AND METHODS The study was divided into three parts. First, the effectiveness of antibody removal by a conventional adsorption procedure and that by the PEG adsorption method were compared by using commercial antisera adsorbed with antigen-positive RBCs. Second, patients' sera with known weak alloanti-E were used to test against screening cells after allogeneic adsorption to show nonspecific coating of antibodies and the dilution effect on the PEG adsorption procedure. Third, conventional and PEG one-cell sample allogeneic adsorptions of WAIHA patients' sera with and without alloantibodies were performed and compared. RESULTS In the first part, seven of the eight polyclonal antisera gave a lower titer and score when tested against antigen-positive RBCs in the indirect antiglobulin test; this indicated that PEG is more efficient in removing antibodies. In the second part, similar reaction patterns were observed in antibody screening tests on unadsorbed sera and on sera after the first, second, and third adsorptions, which indicated that there was no alloantibody loss, nonspecific antibody coating, or dilution effect when PEG was added in the allogeneic adsorption procedures. In the third part, a 40-percent increase in efficiency in reducing the number of adsorptions and an 85-percent decrease in completion time of the adsorption procedures were obtained when PEG was used for adsorbing sera from 16 patients with WAIHA. Both conventional and PEG procedures were capable of removing autoantibodies to identify the specificities of alloantibodies. CONCLUSION The PEG adsorption method is an effective, sensitive, and efficient method of enhancing auto- antibody adsorption and alloantibody detection. It can reduce the processing time and minimize the delay of urgent transfusions to patients with WAIHA and can indirectly enhance cost-effectiveness and decrease the labor-intensive testing required by these cases.
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Meredith GE, De Souza IE, Hyde TM, Tipper G, Wong ML, Egan MF. Persistent alterations in dendrites, spines, and dynorphinergic synapses in the nucleus accumbens shell of rats with neuroleptic-induced dyskinesias. J Neurosci 2000; 20:7798-806. [PMID: 11027244 PMCID: PMC6772873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Chronic treatment of humans or experimental animals with classical neuroleptic drugs can lead to abnormal, tardive movements that persist long after the drugs are withdrawn. A role in these neuroleptic-induced dyskinesias may be played by a structural change in the shell of the nucleus accumbens where the opioid peptide dynorphin is upregulated in treated rats that show vacuous chewing movements (VCMs). The shell of the nucleus accumbens normally contains a dense plexus of dynorphinergic fibers especially in its caudomedial part. After 27 weeks of haloperidol administration and 18 weeks of withdrawal, the immunoreactive labeling of this plexus is intensified when compared with that after vehicle treatment. In addition, medium spiny neurons here show a significant increase in spine density, dendritic branching, and numbers of terminal segments. In the VCM-positive animals, the dendritic surface area is reduced, and dynorphin-positive terminals contact more spines and form more asymmetrical specializations than do those in animals without the syndrome (VCM-negative and vehicle-treated groups). Persistent, neuroleptic-induced oral dyskinesias could therefore be caused by incontrovertible alterations, involving terminal remodeling or sprouting, to the synaptic connectivity of the accumbal shell.
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Chan HL, Leung NW, Lau TC, Wong ML, Sung JJ. Comparison of three different sensitive assays for hepatitis B virus DNA in monitoring of responses to antiviral therapy. J Clin Microbiol 2000; 38:3205-8. [PMID: 10970358 PMCID: PMC87356 DOI: 10.1128/jcm.38.9.3205-3208.2000] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/1999] [Accepted: 05/04/2000] [Indexed: 11/20/2022] Open
Abstract
The aim of our study was to compare the performances of two new hepatitis B virus (HBV) DNA assays, a cross-linking assay (NAXCOR) and a hybrid-capture amplification assay (Digene), versus the widely used branched-DNA (bDNA) assay (Chiron) in the monitoring of HBV DNA levels during antiviral treatment. Serial serum samples from 12 chronically HBV infected patients undergoing a phase II trial of an antiviral drug, 2',3'-dideoxy-5-fluoro-3'-thiacytidine (FTC), were studied. A total of 96 serum samples were tested for HBV DNA using the cross-linking, hybrid-capture amplification, and bDNA assays. In the comparison of the cross-linking and bDNA assays, concordant results were found in 77 (80.3%) samples, no significant difference was found between the median log(10) HBV DNA levels (6.66 versus 7. 17 meq/ml), and the results of the two assays were closely correlated (r = 0.95). In the comparison of the hybrid-capture amplification and bDNA assays, concordant results were found in 79 (82.3%) samples, no significant difference was found between the median log(10) HBV DNA levels (6.98 versus 6.99 meq/ml), and the results of the two assays were closely correlated (r = 0.99). Six (6. 3%) samples by the cross-linking assay and 10 (10.4%) samples by the bDNA assay required retesting because of unacceptably high within-run coefficients of variance. No sample required retesting in the hybrid-capture amplification assay according to the internal validation. In conclusion, the cross-linking and hybrid-capture amplification assays were as sensitive as the bDNA assay for HBV DNA detection and can be recommended for monitoring of HBV DNA levels during antiviral treatment.
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Wong ML, Xie B, Beatini N, Phu P, Marathe S, Johns A, Gold PW, Hirsch E, Williams KJ, Licinio J, Tabas I. Acute systemic inflammation up-regulates secretory sphingomyelinase in vivo: a possible link between inflammatory cytokines and atherogenesis. Proc Natl Acad Sci U S A 2000; 97:8681-6. [PMID: 10890909 PMCID: PMC27008 DOI: 10.1073/pnas.150098097] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2000] [Indexed: 11/18/2022] Open
Abstract
Inflammation plays a critical role in atherogenesis, yet the mediators linking inflammation to specific atherogenic processes remain to be elucidated. One such mediator may be secretory sphingomyelinase (S-SMase), a product of the acid sphingomyelinase gene. The secretion of S-SMase by cultured endothelial cells is induced by inflammatory cytokines, and in vivo data have implicated S-SMase in subendothelial lipoprotein aggregation, macrophage foam cell formation, and possibly other atherogenic processes. Thus, the goal of this study was to seek evidence for S-SMase regulation in vivo during a physiologically relevant inflammatory response. First, wild-type mice were injected with saline or lipopolysaccharide (LPS) as a model of acute systemic inflammation. Serum S-SMase activity 3 h postinjection was increased 2- to 2.5-fold by LPS (P < 0.01). To determine the role of IL-1 in the LPS response, we used IL-1 converting enzyme knockout mice, which exhibit deficient IL-1 bioactivity. The level of serum S-SMase activity in LPS-injected IL-1 converting enzyme knockout mice was approximately 35% less than that in identically treated wild-type mice (P < 0.01). In LPS-injected IL-1-receptor antagonist knockout mice, which have an enhanced response to IL-1, serum S-SMase activity was increased 1. 8-fold compared with LPS-injected wild-type mice (P < 0.01). Finally, when wild-type mice were injected directly with IL-1beta, tumor necrosis factor alpha, or both, serum S-SMase activity increased 1. 6-, 2.3-, and 2.9-fold, respectively (P < 0.01). These data show regulation of S-SMase activity in vivo and they raise the possibility that local stimulation of S-SMase may contribute to the effects of inflammatory cytokines in atherosclerosis.
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Wong ML, Lam W, Leung KS, Ngan PS, Cheng JC. Discovering knowledge from medical databases using evolutionary algorithms. IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE : THE QUARTERLY MAGAZINE OF THE ENGINEERING IN MEDICINE & BIOLOGY SOCIETY 2000; 19:45-55. [PMID: 10916732 DOI: 10.1109/51.853481] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Wong ML, Sternberg EM. Immunological assays for understanding neuroimmune interactions. ARCHIVES OF NEUROLOGY 2000; 57:948-52. [PMID: 10891976 DOI: 10.1001/archneur.57.7.948] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Wong ML, Chan RK, Koh D, Wee S. A prospective study on condom slippage and breakage among female brothel-based sex workers in Singapore. Sex Transm Dis 2000; 27:208-14. [PMID: 10782742 DOI: 10.1097/00007435-200004000-00005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Concerns about the effectiveness of condoms in preventing sexually transmitted diseases have been raised. Data are lacking on condom failure and its associated factors among sex workers in Southeast Asia. GOAL To assess factors associated with condom breakage and slippage. STUDY DESIGN A prospective study on condom breakage and slippage over a 1-day period was conducted among 219 female brothel-based sex workers in Singapore in 1997. RESULTS Condom breakage and slippage rates among 1,885 episodes of condom use were 1.2% (95% CI, 0.7-1.8) and 2.1% (95% CI, 1.2-3.0), respectively. After adjusting for intracluster effects and confounders, condom breakage and slippage were significantly associated with duration of sex work and spontaneity of clients to use condoms. CONCLUSION Condom use among sex workers should be promoted in view of the low failure rates. Strategies to reduce condom breakage and slippage should be directed at sex workers with increased risk of condom failure.
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Yap AU, Wong ML, Lim AC. The effect of polishing systems on microleakage of tooth-coloured restoratives. Part 2: composite and polyacid-modified composite resins. J Oral Rehabil 2000; 27:205-10. [PMID: 10784332 DOI: 10.1046/j.1365-2842.2000.00500.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The purpose of this in vitro study was to investigate the effect of polishing systems on the microleakage of composite and polyacid-modified composite resins. Class V cavities were prepared at the cemento-enamel junction of 80 freshly extracted posterior teeth. The prepared teeth were randomly divided into two groups and restored with conventional or polyacid-modified composite resins. The restored teeth were stored in distilled water at 37 degrees C for 1 week after removal of excess restorative with diamond finishing burs. The restored teeth were then divided into four groups of ten and finished/polished using the following systems: Two Striper micron finishing system (MFS), Sof-Lex XT (Sof-Lex), Enhance composite finishing and polishing system (Enhance), and Shofu composite finishing kit (Shofu). The finished restorations were subjected to dye penetration testing. Results showed that the microleakage resistance at both enamel and dentin margins of composite and polyacid-modified composite resins are not significantly affected by the different polishing systems.
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Abstract
Hepatitis B e antigen-negative chronic hepatitis B (e-CHB) has been reported in Asia but its prevalence and clinical significance have not been determined. The aims of this study were to determine the prevalence of e-CHB in Hong Kong and the frequency of precore and core promoter mutations in these patients. A cross-sectional study was performed in 350 consecutive Chinese patients (230 men and 120 women; mean age +/-SD, 42 +/- 13 years) with chronic hepatitis B virus infection. A total of 243 (69%) patients were hepatitis B e antigen (HBeAg)-negative of whom 15% had clinical cirrhosis. In the remaining 85% of patients, 63% had normal and 22% had elevated transaminases. Serum hepatitis B virus (HBV) DNA was detectable using branched DNA assay in 46% of HBeAg-negative patients with clinical cirrhosis/elevated transaminases. Forty-five percent of the patients with e-CHB had the precore stop codon mutation, and an additional 41% had core promoter changes. There was no correlation between the presence of precore/core promoter mutations and liver disease or HBV-DNA levels. Overall, 17% of HBeAg-negative patients were viremic and had evidence of chronic liver disease (e-CHB) with mean HBV-DNA levels comparable with that in HBeAg-positive patients. In summary, we found that e-CHB may be present in up to 17% of HBeAg-negative patients seen in a tertiary referral center in Hong Kong. e-CHB may be a heterogeneous condition and is not invariably associated with the precore HBV mutant. Population studies are needed to determine the true prevalence of e-CHB in Asia and to assess its natural course and response to treatment.
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Wong ML, Kling MA, Munson PJ, Listwak S, Licinio J, Prolo P, Karp B, McCutcheon IE, Geracioti TD, DeBellis MD, Rice KC, Goldstein DS, Veldhuis JD, Chrousos GP, Oldfield EH, McCann SM, Gold PW. Pronounced and sustained central hypernoradrenergic function in major depression with melancholic features: relation to hypercortisolism and corticotropin-releasing hormone. Proc Natl Acad Sci U S A 2000; 97:325-30. [PMID: 10618417 PMCID: PMC26662 DOI: 10.1073/pnas.97.1.325] [Citation(s) in RCA: 391] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/1999] [Indexed: 12/16/2022] Open
Abstract
Both stress-system activation and melancholic depression are characterized by fear, constricted affect, stereotyped thinking, and similar changes in autonomic and neuroendocrine function. Because norepinephrine (NE) and corticotropin-releasing hormone (CRH) can produce these physiological and behavioral changes, we measured the cerebrospinal fluid (CSF) levels each hour for 30 consecutive hours in controls and in patients with melancholic depression. Plasma adrenocorticotropic hormone (ACTH) and cortisol levels were obtained every 30 min. Depressed patients had significantly higher CSF NE and plasma cortisol levels that were increased around the clock. Diurnal variations in CSF NE and plasma cortisol levels were virtually superimposable and positively correlated with each other in both patients and controls. Despite their hypercortisolism, depressed patients had normal levels of plasma ACTH and CSF CRH. However, plasma ACTH and CSF CRH levels in depressed patients were inappropriately high, considering the degree of their hypercortisolism. In contrast to the significant negative correlation between plasma cortisol and CSF CRH levels seen in controls, patients with depression showed no statistical relationship between these parameters. These data indicate that persistent stress-system dysfunction in melancholic depression is independent of the conscious stress of the disorder. These data also suggest mutually reinforcing bidirectional links between a central hypernoradrenergic state and the hyperfunctioning of specific central CRH pathways that each are driven and sustained by hypercortisolism. We postulate that alpha-noradrenergic blockade, CRH antagonists, and treatment with antiglucocorticoids may act at different loci, alone or in combination, in the treatment of major depression with melancholic features.
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Wong ML, Chan RK, Koh D, Wee S. Factors associated with condom use for oral sex among female brothel-based sex workers in Singapore. Sex Transm Dis 2000; 27:39-45. [PMID: 10654867 DOI: 10.1097/00007435-200001000-00008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND OBJECTIVE The prevalence of oral sex increased from 27.1% in 1992 to 81.1% in 1997, with a concomitant increase in pharyngeal gonorrhea, among female sex workers in Singapore. The extent of condom use for oral sex among them is unknown. GOAL To determine the prevalence of and factors associated with consistent condom use during oral sex. STUDY DESIGN A cross-sectional study of 225 women randomly selected from the surveillance scheme register of female brothel-based sex workers with a history of oral sex documented in their medical records. RESULTS Slightly more than half (56.9%) consistently used condoms for oral sex compared to 97% for vaginal sex. Condom use was significantly higher among middle than high class sex workers (adjusted rate ratio: 1.52, 95% CI: 1.01-2.29) and those with negotiation skills (adjusted rate ratio: 1.95, 95% CI: 1.32-2.07). CONCLUSION Sex workers should be taught skills to negotiate condom use for oral sex.
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Sim EK, Grignani RT, Wong ML, Quek SC, Wong JC, Yip WC, Lee CN. Influence of surgery on aortic valve prolapse and aortic regurgitation in doubly committed subarterial ventricular septal defect. Am J Cardiol 1999; 84:1445-8, A8. [PMID: 10606121 DOI: 10.1016/s0002-9149(99)00594-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Doubly committed subarterial ventricular septal defects should be closed surgically once aortic valve deformity is present before the onset of aortic regurgitation.
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Yao Y, Toth CR, Huang L, Wong ML, Dias P, Burlingame AL, Coffino P, Wang CC. alpha5 subunit in Trypanosoma brucei proteasome can self-assemble to form a cylinder of four stacked heptamer rings. Biochem J 1999; 344 Pt 2:349-58. [PMID: 10567215 PMCID: PMC1220650 DOI: 10.1042/0264-6021:3440349] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The proteasomes have a central role in catalysing protein degradation among both prokaryotes and eukaryotes. The 20 S proteasome constitutes their catalytic core. In studying the structure of Trypanosoma brucei 20 S proteasomes, we isolated by two-dimensional (2D) gel electrophoresis a 27 kDa subunit protein with an estimated pI of 4.7 and subjected it to mass spectrometric analysis. A tryptic peptide sequence from the protein was found identical with that of the rat alpha5 subunit. With the use of antiserum against T. brucei 20 S proteasomes to screen a T. b. rhodesiense lambda expression cDNA library, we obtained a cDNA clone encoding a full-length protein of 246 amino acid residues with a calculated molecular mass of 27174 Da and a pI of 4.71. It bears 50. 0% and 46.3% sequence identity with rat and yeast proteasome subunit alpha5 respectively, and matches all the peptide sequences derived from MS of the 2D gel-purified protein. The protein is thus designated the alpha5 subunit of T. brucei 20 S proteasome (TbPSA5). The recombinant protein, expressed in plasmid-transformed Escherichia coli, was found in a 27 kDa monomer form as well as polymerized forms with estimated molecular masses ranging from 190 to 800 kDa. Under the electron microscope, the most highly polymerized forms bear the appearance of cylinders of four-stacked heptamer rings with an estimated outer diameter of 14.5 nm and a length of 18 nm, which were immunoprecipitable by anti-(T. brucei 20 S proteasome) antiserum. In view of the documented self-assembly of the archaeon proteasome alpha subunit into double heptamer rings and the spontaneous assembly of the two alpha subunits from the 20 S proteasome of Rhodococcus erythropolis, the self-assembly of the T. brucei alpha subunit might reflect a common feature of proteasome biogenesis shared by prokaryotes and primitive eukaryotes such as the trypanosomes but apparently lost among the higher forms of eukaryote such as the yeast and the mammals.
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Yao Y, Huang L, Krutchinsky A, Wong ML, Standing KG, Burlingame AL, Wang CC. Structural and functional characterizations of the proteasome-activating protein PA26 from Trypanosoma brucei. J Biol Chem 1999; 274:33921-30. [PMID: 10567354 DOI: 10.1074/jbc.274.48.33921] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The activated 20 S proteasome, which has been found only in mammalian cells, is composed of two heptamer rings of an activator protein on each end of the 20 S proteasome and is inducible by interferon-gamma. A 20 S proteasome has been recently identified in a protozoan pathogen Trypanosoma brucei, but there has been no experimental evidence yet for the presence of a 26 S proteasome. Instead, an activated form of 20 S proteasome was isolated from this organism, which has significantly enhanced peptidase activities. It consists of an additional activator protein with an estimated molecular mass of 26 kDa (PA26) (To, W. Y., and Wang, C. C. (1997) FEBS Lett. 404, 253-262). The profile and sequences of tryptic peptides from PA26 were determined by mass spectrometry; no matches were found in the data base. The peptide sequences were used in reverse transcriptase-polymerase chain reaction to isolate a full-length cDNA clone encoding PA26. The protein sequence thus derived from it indicates little sequence identity with those of mammalian activator proteins PA28 alpha, beta, or gamma. There is only a single copy of PA26 gene in T. brucei. Purified recombinant PA26 polymerizes spontaneously to form heptamer ring with an outer diameter of 8.5 nm. The ring binds and activates 20 S proteasomes from T. brucei as well as rat, whereas human PA28alpha can neither bind nor activate T. brucei 20 S proteasome. The former is thus apparently more ubiquitous than PA28 in its capability of binding to and activating 20 S proteasomes. Its presence in T. brucei may also suggest a more ancient origin of proteasome activator proteins and a much wider involvement in protein degradation among other eukaryotic organisms than was originally envisaged.
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MESH Headings
- Amino Acid Sequence
- Animals
- Blotting, Southern
- Cloning, Molecular
- Cysteine Endopeptidases/chemistry
- Cysteine Endopeptidases/genetics
- Cysteine Endopeptidases/metabolism
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Protozoan/analysis
- DNA, Protozoan/genetics
- Electrophoresis, Gel, Two-Dimensional
- Electrophoresis, Polyacrylamide Gel
- Enzyme Activation
- Gene Dosage
- Histidine/genetics
- Immunoblotting
- Insect Proteins/chemistry
- Insect Proteins/genetics
- Insect Proteins/metabolism
- Mass Spectrometry/methods
- Molecular Sequence Data
- Multienzyme Complexes/chemistry
- Multienzyme Complexes/genetics
- Multienzyme Complexes/metabolism
- Proteasome Endopeptidase Complex
- Protein Conformation
- Protein Isoforms/genetics
- Protozoan Proteins
- Rats
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/ultrastructure
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Analysis, Protein
- Sequence Homology, Amino Acid
- Trypanosoma brucei brucei/chemistry
- Trypanosoma brucei brucei/enzymology
- Trypanosoma brucei brucei/genetics
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72
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Wong ML, Chan RK, Chua WL, Wee S. Sexually transmitted diseases and condom use among female freelance and brothel-based sex workers in Singapore. Sex Transm Dis 1999; 26:593-600. [PMID: 10560725 DOI: 10.1097/00007435-199911000-00010] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND OBJECTIVES Most studies in Asia exclude freelance female sex workers because of difficulties in access and the illegality of their work. Data are lacking on their risk behaviors. GOAL To compare sexually transmitted disease (STD) rates, condom use, and health screening behavior between freelance and brothel-based sex workers in Singapore. STUDY DESIGN This is a cross-sectional survey of 111 free-lance sex workers arrested from November 1996 to March 1997 for illicit prostitution and 333 randomly selected brothel-based sex workers. All were tested for STDs. RESULTS STDs were significantly more prevalent among freelance than brothel-based sex workers (34.8% vs. 24.0%). Inconsistent condom use was significantly higher among freelance than brothel-based sex workers and was significantly associated with younger age, decreasing number of clients, and perception of non-condom use among peers. CONCLUSION Educational programs to promote condom use should target freelance sex workers and their clients.
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73
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Wong ML, Chan RK, Koh D, Wee S. Increase in oral sex and pharyngeal gonorrhoea: an unintended effect of a successful condom promotion programme for vaginal sex. AIDS 1999; 13:1981-2. [PMID: 10513660 DOI: 10.1097/00002030-199910010-00024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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74
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Wong ML, Chan RK. A prospective study of pharyngeal gonorrhoea and inconsistent condom use for oral sex among female brothel-based sex workers in Singapore. Int J STD AIDS 1999; 10:595-9. [PMID: 10492426 DOI: 10.1258/0956462991914726] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Oral sex among female sex workers in Singapore has risen sharply from 27.1% in 1992 to 81.7% in 1997. A prospective cohort study was carried out on 724 female brothel-based sex workers who practised oral sex, to determine the risk of contracting pharyngeal gonorrhoea through inconsistent condom use. The prevalence of consistent condom use for oral sex was 70.4% compared to 96.8% for vaginal sex. One hundred and twenty-nine (17.8%) were lost to follow up because they quit prostitution. The other 595 sex workers were followed up for a maximum period of 6 months. Thirty-eight (5.2%) sex workers contracted pharyngeal gonorrhoea compared to 2.5% who contracted cervical gonorrhoea. Sex workers with inconsistent condom use for oral sex were 17.1 times (95% CI: 8.0-36.5) more likely than consistent condom users to develop pharyngeal gonorrhoea, after controlling for ethnic group, class and number of clients. STD control programmes for sex workers should place stress on consistent condom use for oral sex.
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75
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Vgontzas AN, Papanicolaou DA, Bixler EO, Lotsikas A, Zachman K, Kales A, Prolo P, Wong ML, Licinio J, Gold PW, Hermida RC, Mastorakos G, Chrousos GP. Circadian interleukin-6 secretion and quantity and depth of sleep. THE JOURNAL OF CLINICAL ENDOCRINOLOGY AND METABOLISM 1999. [PMID: 10443646 DOI: 10.1210/jc.84.8.2603] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Patients with pathologically increased daytime sleepiness and fatigue have elevated levels of circulating interleukin-6 (IL-6). The latter is an inflammatory cytokine, which causes sickness manifestations, including somnolence and fatigue, and activation of the hypothalamic-pituitary-adrenal axis. In this study, we examined: 1) the relation between serial measurements of plasma IL-6 and quantity and depth of sleep, evaluated by polysomnography; and 2) the effects of sleep deprivation on the nyctohemeral pattern of IL-6 secretion. Eight healthy young male volunteers were sampled for 24 h twice, at the baseline state, after a normal night's sleep and after total overnight sleep deprivation. At the baseline state, IL-6 was secreted in a biphasic circadian pattern with two nadirs at 0800 and 2100 and two zeniths at 1900 and 0500 (P < 0.01). The baseline amount of sleep correlated negatively with the overall daytime secretion of the cytokine (P < 0.05). Also, depth of sleep at baseline correlated negatively with the postdeprivation increase of daytime secretion of IL-6 (P < 0.05). Sleep deprivation changed the temporal pattern of circadian IL-6 secretion but not the overall amount. Indeed, during the post-deprivation period, the mean daytime (0800-2200 h) levels of IL-6 were significantly higher (P < 0.05), whereas the nighttime (2200-0600 h) levels were lower than the predeprivation values. Thus, sleep-deprived subjects had daytime oversecretion and nighttime under-secretion of IL-6; the former might be responsible for their daylong somnolence and fatigue, the latter for the better quality (depth) of their sleep. These data suggest that a good night's sleep is associated with decreased daytime secretion of IL-6 and a good sense of well-being and that good sleep is associated with decreased exposure of tissues to the proinflammatory and potentially detrimental actions of IL-6. Sleep deprivation increases daytime IL-6 and causes somnolence and fatigue during the next day, whereas postdeprivation decreases nighttime IL-6 and is associated with deeper sleep.
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