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Chua KB, Lam SK, Tan CT, Hooi PS, Goh KJ, Chew NK, Tan KS, Kamarulzaman A, Wong KT. High mortality in Nipah encephalitis is associated with presence of virus in cerebrospinal fluid. Ann Neurol 2000; 48:802-5. [PMID: 11079547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
During the outbreak of Nipah virus encephalitis in Malaysia, stored cerebrospinal fluid (CSF) samples from 84 patients (27 fatal and 57 nonfatal cases) were cultured for the virus. The virus was isolated from 17 fatal cases and 1 nonfatal case. There were significant associations between CSF virus isolation and mortality as well as clinical features associated with poor prognosis. In addition, there was a positive linear correlation of CSF virus isolation with age. There was no significant association between CSF virus isolation and the character of the CSF, presence of Nipah-specific antibody in the serum or CSF, duration of illness before collection of samples, or sex or ethnicity of the patients. This study suggests that high viral replication in the central nervous system may be an important factor for high mortality.
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Sarji SA, Abdullah BJ, Goh KJ, Tan CT, Wong KT. MR imaging features of Nipah encephalitis. AJR Am J Roentgenol 2000; 175:437-42. [PMID: 10915690 DOI: 10.2214/ajr.175.2.1750437] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The newly discovered Nipah virus causes an acute febrile encephalitic illness in humans that is associated with a high mortality. The purpose of this study is to describe the MR imaging findings of Nipah encephalitis. MATERIALS AND METHODS MR imaging of the brain was performed in 31 patients with Nipah encephalitis divided into three groups. The first group (14 patients) underwent MR imaging during the acute phase of the illness and the second group (10 patients) during the later phase of the acute illness. The third group consisted of six patients who underwent MR imaging because they experienced neurologic relapse and one patient who had late-onset encephalitis. Spin-echo T1- and T2-weighted sequences and T2-weighted fluid attenuated inversion recovery (FLAIR) sequences were performed. Contrast-enhanced MR imaging was performed in four patients. RESULTS The FLAIR sequences revealed abnormalities in all patients studied. MR imaging findings in both the acute and later phases of encephalitis were similar; the main feature of both phases was the presence of discrete high-signal-intensity lesions, measuring 2-7 mm, disseminated throughout the brain, mainly in the subcortical and deep white matter of the cerebral hemispheres. Neither mass effect nor cerebral edema was seen. There was no correlation with the focal neurologic signs, depth of coma, and outcome of the patients. The lesions were attributed to widespread microinfarctions from underlying vasculitis of cerebral small vessels. Features found on MR imaging in relapsed and late-onset encephalitis differed from the features in acute encephalitis in that confluent cortical involvement was the prominent finding in the former, as opposed to discrete focal lesions in the subcortical and deep white matter in the latter. CONCLUSION MR imaging is a sensitive and specific diagnostic tool for evaluating Nipah encephalitis.
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Yue WM, Tan CT, Tan SB, Tan SK, Tay BK. Results of cervical laminoplasty and a comparison between single and double trap-door techniques. JOURNAL OF SPINAL DISORDERS 2000; 13:329-35. [PMID: 10941893 DOI: 10.1097/00002517-200008000-00010] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Thirty-seven patients were studied for an average of 32.1 months after canal-expansive laminoplasty for the treatment of multiple-level cervical stenosis caused by spondylosis, ossification of posterior longitudinal ligament, prolapsed intervertebral disc, and other conditions. Short-term and medium-term results were recorded clinically, using the scoring system proposed by the Japanese Orthopedic Association. The canal expansion was also recorded with radiological studies. The improvement rate was good to excellent in 58.3% of the patients. Postoperative neurological deterioration occurred in only four patients. Poorer results were observed in female patients and in those in whom surgery was delayed. Surgery within 12 months of onset of symptoms gave good results. Serious complications occurred in only two patients. There were 12 patients who were treated with the single trap-door (unilateral) laminoplasty and 25 patients treated with the double trap-door (sagittal splitting of the spinous processes) laminoplasty; their results were compared. There was no significant difference in neurological outcome between the two methods.
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Abstract
We report two patients with myopathic dropped head syndrome, a rare and interesting neuromuscular syndrome characterised by a predominant weakness of the neck extensor muscles. The first patient, a middle aged Chinese man, presented with progressive weakness of neck extension but his clinical course later stabilised despite a lack of response to corticosteroids. Muscle biopsy revealed a necrotising myopathy with no evidence of inflammation. This patient supports the existence of an idiopathic restricted non-inflammatory myopathy, a so called isolated neck extensor myopathy syndrome which is recognised to pursue a less progressive, more benign course. Our second patient had histopathological evidence for polymyositis; there was a favourable response to steroids. Our cases underscore the fact that there may be a spectrum of pathological processes associated with the myopathic dropped head syndrome ranging from non-inflammatory muscle necrosis to a full blown inflammatory myositis.
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Lin MJ, Tan CT, Lee SY, Lin-Shiau SY. Suramin protects the murine motor nerves from the toxic effects of presynaptic Ca(2+) channel inhibitors. Neurosci Lett 2000; 287:97-100. [PMID: 10854721 DOI: 10.1016/s0304-3940(00)01136-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of this study is to investigate whether suramin is capable of preventing the neurotoxic effects of Ca(2+) channel inhibitors at the presynaptic sites. Mouse diaphragm and triangularis sterni preparations were used for this study in order to measure the muscle tension and nerve terminal Ca(2+) current, respectively. Both omega-conotoxin MVIIC and omega-agatoxin IVA markedly inhibit the nerve-evoked muscle contractions as well as the nerve terminal Ca(2+) current respectively. Pretreatment with suramin (0.3 mM) significantly reduced the inhibitory effect of nerve-evoked muscle contractions and Ca(2+) current induced by either omega-conotoxin MVIIC or omega-agatoxin IVA but not that induced by the non-selective Ca(2+) channel blocker, Cd(2+). Neither suramin nor Ca(2+)-channel toxins significantly affect Na(+)- and K(+) currents of the nerve terminals. These findings indicate that suramin selectively interferes the action of presynaptic Ca(2+) channel neurotoxins and thus reduces their depressant effects on the muscle contractions. The implication of these findings is that suramin and its derivatives may potentially become useful agents in management of intoxication of Ca(2+) channel neurotoxins.
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Goh KJ, Tan CT, Chew NK, Tan PS, Kamarulzaman A, Sarji SA, Wong KT, Abdullah BJ, Chua KB, Lam SK. Clinical features of Nipah virus encephalitis among pig farmers in Malaysia. N Engl J Med 2000; 342:1229-35. [PMID: 10781618 DOI: 10.1056/nejm200004273421701] [Citation(s) in RCA: 302] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Between September 1998 and June 1999, there was an outbreak of severe viral encephalitis due to Nipah virus, a newly discovered paramyxovirus, in Malaysia. METHODS We studied the clinical features of the patients with Nipah virus encephalitis who were admitted to a medical center in Kuala Lumpur. The case definition was based on epidemiologic, clinical, cerebrospinal fluid, and neuroimaging findings. RESULTS Ninety-four patients with Nipah virus infection were seen from February to June 1999 (mean age, 37 years; ratio of male patients to female patients, 4.5 to 1). Ninety-three percent had had direct contact with pigs, usually in the two weeks before the onset of illness, suggesting that there was direct viral transmission from pigs to humans and a short incubation period. The main presenting features were fever, headache, dizziness, and vomiting. Fifty-two patients (55 percent) had a reduced level of consciousness and prominent brain-stem dysfunction. Distinctive clinical signs included segmental myoclonus, areflexia and hypotonia, hypertension, and tachycardia and thus suggest the involvement of the brain stem and the upper cervical spinal cord. The initial cerebrospinal fluid findings were abnormal in 75 percent of patients. Antibodies against Hendra virus were detected in serum or cerebrospinal fluid in 76 percent of 83 patients tested. Thirty patients (32 percent) died after rapid deterioration in their condition. An abnormal doll's-eye reflex and tachycardia were factors associated with a poor prognosis. Death was probably due to severe brain-stem involvement. Neurologic relapse occurred after initially mild disease in three patients. Fifty patients (53 percent) recovered fully, and 14 (15 percent) had persistent neurologic deficits. CONCLUSIONS Nipah virus causes a severe, rapidly progressive encephalitis with a high mortality rate and features that suggest involvement of the brain stem. The infection is associated with recent contact with pigs.
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Lee SY, Yeh TH, Lou PJ, Tan CT, Su MC, Montgomery WW. Mucociliary transport pathway on laryngotracheal tract and stented glottis in guinea pigs. Ann Otol Rhinol Laryngol 2000; 109:210-5. [PMID: 10685575 DOI: 10.1177/000348940010900217] [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: 11/16/2022]
Abstract
We investigated the laryngotracheal mucociliary transport pathway of guinea pigs in vivo and immediately postmortem. Only intraperitoneal anesthesia was used during the procedure to avoid the disturbance of mucociliary function. Resin particles were used as the marking substance. A microcolpohysteroscope was placed at different levels in the laryngotracheal region for observing the marking particles and recording the transport pattern. The tracheal mucociliary transport flow primarily moved along the posterior wall and both lateral walls in a zigzag trace. Upon reaching the subglottis, the resin particles stayed underneath the vocal cords, and a whirlpool phenomenon developed. The majority of the particles were shifted and directed onto the posterior glottic area. With a short delay, some resin particles crossed over the free edge of the vocal cords and turned posteriorly along the medial upper cordal margin. No mucociliary transport could be observed on the entire upper surface of the true vocal cords, which is covered by squamous epithelium. Occasionally, a few resin particles in the vicinity of the epiglottic root traveled along the aryepiglottic folds toward the posterior commissure. All streams of mucociliary transport finally joined together in the interarytenoid area. After leaving the glottis, the resin particles traveled to the hypopharynx and entered the esophagus through the motion of deglutition. The pattern of mucociliary clearance in the laryngotracheal region was not delayed by stenting.
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Chua KB, Goh KJ, Wong KT, Kamarulzaman A, Tan PS, Ksiazek TG, Zaki SR, Paul G, Lam SK, Tan CT. Fatal encephalitis due to Nipah virus among pig-farmers in Malaysia. Lancet 1999; 354:1257-9. [PMID: 10520635 DOI: 10.1016/s0140-6736(99)04299-3] [Citation(s) in RCA: 471] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Between February and April, 1999, an outbreak of viral encephalitis occurred among pig-farmers in Malaysia. We report findings for the first three patients who died. METHODS Samples of tissue were taken at necropsy. Blood and cerebrospinal-fluid (CSF) samples taken before death were cultured for viruses, and tested for antibodies to viruses. FINDINGS The three pig-farmers presented with fever, headache, and altered level of consciousness. Myoclonus was present in two patients. There were signs of brainstem dysfunction with hypertension and tachycardia. Rapid deterioration led to irreversible hypotension and death. A virus causing syncytial formation of vero cells was cultured from the CSF of two patients after 5 days; the virus stained positively with antibodies against Hendra virus by indirect immunofluorescence. IgM capture ELISA showed that all three patients had IgM antibodies in CSF against Hendra viral antigens. Necropsy showed widespread microinfarction in the central nervous system and other organs resulting from vasculitis-induced thrombosis. There was no clinical evidence of pulmonary involvement. Inclusion bodies likely to be of viral origin were noted in neurons near vasculitic blood vessels. INTERPRETATION The causative agent was a previously undescribed paramyxovirus related to the Hendra virus. Close contact with infected pigs may be the source of the viral transmission. Clinically and epidemiologically the infection is distinct from infection by the Hendra virus. We propose that this Hendra-like virus was the cause of the outbreak of encephalitis in Malaysia.
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Rikhraj IS, Tan CT, Tan SK, Teoh SH, Hastings GW. Use of titanium prosthesis to bridge a vertebral gap in the spine--a preliminary experimental study. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 1999; 28:20-4. [PMID: 10374021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Resection of a vertebral body for spine tumour or fracture results in a vertebral gap which has to be bridged by autogenous graft, allograft, bone cement or metal spacer. Recently, there have been several metal spacers in the market. We have designed a titanium vertebral spacer which is extensible by way of a threaded mechanism. Coating with hydroxyapatite enables bone ingrowth onto the surface of the titanium spacer. Biomechanical analysis, using the Instron biaxial electro-servohydraulic testing machine, showed that the segment bridging the spacer was rigid and stiffer than the adjacent vertebral body motion segment. Histological study showed that there was bone growth across the vertebral gap indicating fusion had taken place.
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Manonmani V, Tan CT. A study of newly diagnosed epilepsy in Malaysia. Singapore Med J 1999; 40:32-5. [PMID: 10361483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND/AIM OF STUDY To determine the characteristics of newly diagnosed epilepsy in the multiracial population of Malaysia. METHODS This is a prospective study of 165 consecutive newly diagnosed cases of epilepsy presenting to the neurology laboratory of the University Hospital, Kuala Lumpur. The inclusion criteria were: two or more seizures with interval of > 24 hours, age > 1 month, residents of Klang Valley. All the patients underwent an awake and sleep EEG. RESULTS One hundred and sixty-five cases were collected over 1992-1994. Their ethnic origin was: Chinese (36%), Indian (35%), Malay (29%). The mean age of onset of epilepsy was 18.7 years. Localisation related epilepsies accounted for 57.6% of cases while the remaining 42.4% were generalised epilepsies. Of the generalised epilepsies, subclassification was as follows: idiopathic generalised epilepsy 28.5%, juvenile myoclonic epilepsy 5.5%, childhood absence epilepsy 3.6%, West syndrome 3%, Lennox Gastaut syndrome 1.2% and photosensitive epilepsy 0.6%. Twenty-two percent of the cases were symptomatic and 78% were cryptogenic/idiopathic. The patients had a mean of 3.9 other siblings. Only 0.76% of the close relatives (parents and siblings) had a history of epilepsy. CONCLUSION The characteristics of epilepsy in Malaysia is largely similar to those reported elsewhere. Genetic factors may be playing a relatively minor role in causing epilepsy in this community.
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Tan CT. Recent advances in epilepsy. Singapore Med J 1998; 39:141-2. [PMID: 9676142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Herman P, Tan CT, Portier F, Clerici C, Escoubet B, Friedlander G, Tran Ba Huy P. Ion transports in the middle ear epithelium. KIDNEY INTERNATIONAL. SUPPLEMENT 1998; 65:S94-7. [PMID: 9551440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Ion transports in the middle ear epithelium have been recently characterized. Experimental data using cell culture have found the existence of a sodium transepithelial transport that drives a water flow. This is thought to play a key role in the maintain of air-filled and fluid-free cavities. Impairment of this process is involved in the pathogenesis of secretory otitis media, which is the main cause of acquired hearing loss. Several modulations of this transport have been evidenced: (i) reactive oxygen species induced an endogenous synthesis of prostaglandin E2 (PGE2), which in turn increased the cAMP level and modulated ion transport rate; (ii) steroids increased the expression of the alpha subunit sodium channel mRNA, which changes paralleled the modulation of ion transport in the middle ear epithelium; (iii) moderate hypoxia selectively and reversibly decreased the rate of sodium transport, as a result of a parallel decrease in alpha epithelial sodium channel subunit mRNA level. These modulations may explain the course of middle ear pathology. However, the development of an in vivo model has become mandatory to assess the relevance of these data in the pathophysiology of the middle ear.
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Lin CD, Cheng YK, Tan CT, Chen JC, Yau KI, Lee SY. Clinical experience in airway endoscopy in children: an emphasis on the comparison between flexible and rigid endoscopy. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI ZA ZHI [JOURNAL]. ZHONGHUA MINGUO XIAO ER KE YI XUE HUI 1998; 39:103-8. [PMID: 9599899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Congenital and acquired lesions of the pediatric airway frequently pose perplexing problems in children, infants and newborns. Prompt investigation into the etiology and early intervention are essential to decrease the morbidity and to prevent some tragic events. Endoscopy grants access to the lesion sites for either diagnostic or therapeutic purposes. From April 1994 to May 1997, totally 509 endoscopic procedures, including 292 flexible and 217 rigid endoscopic procedures were performed in 296 pediatric patients at National Taiwan University Hospital. For routine diagnostic procedures, the flexible fiberscope is the instrument of choice which should include a detailed examination of entire upper airway, as farther to tracheobronchi as possible. When flexible endoscopy fails to demonstrate the exact airway lesion or certain surgical manipulation is demanded, rigid endoscopy is favored. The indications for endoscopy were: stridor, respiratory distress, follow-up endoscopy or tracheostoma evaluation, feeding difficulty, hoarseness or weak voice, and suspicious airway foreign body. Common airway problems in serial orders were: laryngomalacia, subglottic stenosis, tracheo/bronchomalacia and airway foreign body. Nearly 20% of patients in this series had multiple synchronous airway lesions. There was no major complication in our 292 flexible endoscopic procedures. Two major complications attributed to endoscopic manipulations occurred in 217 rigid endoscopic procedures.
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Abstract
We review our experience with 27 cases of pulmonary and meningeal cryptococcosis at the University Hospital, (Kuala Lumpar, Malaysia) where this is the most common cause of adult meningitis in patients without debilitating illnesses. Of the 27 cases analysed, six presented primarily with pulmonary symptomatology which usually were mainly cough, chest pain and low grade fever. The rest presented with primarily central nervous system (CNS) symptomatology of which headaches and fever were the most consistent symptoms although a third of these patients also had pulmonary lesions noted on chest radiographs. Treatment in all cases was with amphotericin B and 5-fluorocytosine and usually till a total cumulative dose of 1.5 g of amphotericin had been reached (an average of 10 weeks). Primary pulmonary presentations, if symptomatic, were treated as per CNS cryptococcosis due to the high likelihood of CNS dissemination. Incidental pulmonary cryptococcoma found on routine chest radiographs were confirmed by biopsy under ultrasound or fluoroscopy guidance and booked for surgical resection. Death usually occurred early in patients who presented late. Once patients responded to therapy, mortality was usually avoided. The only cause of morbidity in survivors was visual impairment or blindness, and this was attributed mainly to intracranial hypertension with residual deficits determined by the measures taken to lower intracranial pressures. Our experience suggests that: (i) symptomatic patients should have combination therapy with 5-fluorocytosine and amphotericin B till at least a cumulative dose of 1.5 g amphotericin B is reached irrespective of whether they have primary CNS or pulmonary symptomatology; (ii) non-symptomatic pulmonary cryptococcoma could be treated primarily by surgical resection; (iii) visual failure or papilloedema should be treated aggressively; and (iv) prognosis is good with adequate therapy and early presentation.
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Tan CT, Herman P. Inflammatory mediators and otitis media with effusion. An experimental approach using cell culture. Auris Nasus Larynx 1998; 25:25-32. [PMID: 9512791 DOI: 10.1016/s0385-8146(97)10026-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Otitis media with effusion is characterized by the presence of an inflammatory cellular infiltrate of the submucosa and a poor ventilation of the middle ear. This result in hypersecretion of mucus and alteration of the mucociliary clearance, which produce accumulation of fluid and cellular debris in the middle ear. The aim of this work was to investigate whether inflammatory mediators such as prostaglandins and oxygen metabolites modulate the absorptive function of the middle ear epithelium. The data we present demonstrated that: (i) among prostanoids, only prostaglandin E2 modulated the rate of sodium transport; (ii) oxidants had a stimulatory effect on ion transport; (iii) the role of reactive oxygen species was mediated by prostaglandin E2. This process might be involved in the impairment of the mucociliary clearance.
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Yen PT, Herman P, Van den Abbeele T, Tan CT, Bordure P, Marianowski R, Friedlander G, Tran Ba Huy P. Extracellular ATP modulates ion transport via P2Y purinoceptors in a middle-ear epithelial cell line. ORL J Otorhinolaryngol Relat Spec 1997; 59:170-5. [PMID: 9186973 DOI: 10.1159/000276932] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mucus and cellular debris are eliminated from the middle-ear cavity through the E-tube by the mucociliary system. Depth of the periciliary fluid layer is thought to be regulated by epithelial ion transport activity. Since impairment of the mucociliary system is a key step in the development of otitis media with effusion, we investigated the ion transport mechanisms of the middle-ear epithelium using the middle-ear MESV cell line. ATP has been shown to modulate ion transport as well as various cellular functions in several cell types via purinoceptors. In order to investigate a possible modulation of the transport activity of MESV cells, we evaluated short-circuit current (Isc) changes in response to specific stimulation of putative purinoceptors by ATP and its various analogs. ATP dramatically increased Isc, while adenosine had no effect, thus demonstrating the presence of P2 receptors according to the original classification by Burnstock. The rank order of potency of purinoceptor agonists for stimulation of Isc on the apical side (ATP > UTP > gamma-SATP >> beta-SADP > 2-methylthio-ATP, 2MeSATP > beta, gamma-methylene-ATP, beta,gamma-MeATP) and on the basolateral side (ATP > gamma-SATP > UTP >> beta-SADP > 2 MeSATP > beta,gamma-MeATP), along with studies using selective antagonists and intracellular calcium measurements are consistent with a P2Y receptor subtype. The ATP-induced increase in Isc was related to sodium transport. This modulation might be of importance in stress conditions such as inflammation.
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Tan CT, Escoubet B, Van den Abbeele T, Friedlander G, Tran Ba Huy P, Herman P. Modulation of middle ear epithelial function by steroids: clinical relevance. Acta Otolaryngol 1997; 117:284-8. [PMID: 9105467 DOI: 10.3109/00016489709117788] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The efficacy of steroid therapy for the treatment of otitis media in children remains controversial, and a putative modulation of the middle ear epithelial function has to be demonstrated. Using the MESV cell line, short-circuit current (ISC) technique was used to evaluate changes in ion transport induced by glucocorticoids. Dexamethasone (DXM) produced a dose- and time-dependent increase in ISC in MESV cells. This effect was inhibited by specific glucocorticoid antagonist (RU-38486) and was related to a sodium transport, since the DXM-induced increase in ISC could be prevented or abolished i) by apical addition of the specific Na+ channel inhibitor benzamil; or ii) by substitution of sodium with N-Methyl-glucamine in the incubation medium. RNase protection assay revealed that DXM increased the expression of the alpha subunit sodium channel mRNA, which changes paralleled the modulation of ion transport. These data demonstrate that steroids up-regulate the trans-epithelial sodium transport in the middle ear epithelium. As far as these experimental data can be extrapolated to the in vivo situation, a component of the beneficial effect of steroid therapy for the treatment of otitis media may result from a corticosteroid-induced improvement in fluid clearance from the middle ear.
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Herman P, Tan CT, van den Abbeele T, Escoubet B, Friedlander G, Huy PT. Glucocorticosteroids increase sodium transport in middle ear epithelium. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 272:C184-90. [PMID: 9038824 DOI: 10.1152/ajpcell.1997.272.1.c184] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The effect of glucocorticosteroids on ion transport was investigated on a middle ear cell line with the short-circuit current (Isc) technique. Dexamethasone (DXM) produced a dose- and time-dependent increase in Isc. Concentration of half-maximal stimulation was 2.68 x 10(-8) M. This effect was blunted by the glucocorticoid antagonist RU-38486 and was related to Na+ transport, as evidenced by the inhibition induced by 1) apical addition of the Na+ channel inhibitor benzamil (10(-6) M) or 2) substitution of Na+ with N-methylglucamine in the incubation medium. The increase in Na+ transport resulted from a primary modulation of apical Na+ entry, since 1) the Na(+)-K(+)-ATPase activity of cellular homogenates was not modified by corticosteroids and 2) the DXM-induced increase in the ouabain-sensitive uptake of 86Rb was blunted by benzamil. Ribonuclease protection assay revealed 1) a constitutive expression of the mRNA encoding the alpha-subunit of the epithelial Na+ channel and 2) that DXM increased the expression of this transcript. This increase was dose dependent and paralleled changes in transepithelial Na+ transport. This study suggests that a component of the beneficial effect of steroid therapy for the treatment of otitis media might be related to increased fluid clearance.
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Wang F, Wang CL, Tan CT, Manivasagar M. Systemic lupus erythematosus in Malaysia: a study of 539 patients and comparison of prevalence and disease expression in different racial and gender groups. Lupus 1997; 6:248-53. [PMID: 9104731 DOI: 10.1177/096120339700600306] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The aims of this study were to examine the clinical and laboratory features of Malaysian patients with systemic lupus erythematosus (SLE) and to identify any difference in disease expression between the different genders and among the three major ethnic groups of Malaysia. Retrospective analysis of all patients with SLE admitted to and followed-up at University Hospital Kuala Lumpur from 1974-90 was undertaken. Ethnic Chinese had the highest prevalence of SLE compared to other ethnic groups. There was a high incidence of renal disease, 74% of patient had significant proteinuria and half of these had associated nephrotic syndrome. Indian patients had significantly less incidence of skin manifestation compared to other racial groups. No difference in disease expression was detected between the ethnic Chinese and Indians and between the male and female patients. The overall 5 y and 10 y survival rates were 82% and 70% respectively. Indian patients had the poorest survival rates. Survival rates are similar among the Chinese and Malay patients. Our findings are in broad agreement with those previously reported.
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Herman P, Guichard JP, Van den Abbeele T, Tan CT, Bensimon JL, Marianowski R, Tran Ba Huy P. Traumatic luxation of the stapes evidenced by high-resolution CT. AJNR Am J Neuroradiol 1996; 17:1242-4. [PMID: 8871706 PMCID: PMC8338528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We encountered a case of acquired perilymphatic fistula in which the origin of the disease, namely, the stapes begin medially displaced into the vestibule, was shown by thin-section CT. Accordingly, we recommend that every patient with suspected perilymphatic fistula of traumatic origin undergo high-resolution CT of the petrous bone.
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Christensen HE, Ramachandran S, Tan CT, Surana U, Dong CH, Chua NH. Arabidopsis profilins are functionally similar to yeast profilins: identification of a vascular bundle-specific profilin and a pollen-specific profilin. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1996; 10:269-79. [PMID: 8771785 DOI: 10.1046/j.1365-313x.1996.10020269.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Four members of the Arabidopsis profilin (pfn) multigene family have been cloned, sequenced and analyzed. By RNA gel blot analysis it has been shown that these four genes fall into two groups: one group (pfn1 and pfn2) is expressed in all organs of the plant and the other group (pfn3 and pfn4) in floral tissues only. Based on amino acid sequence alignment Arabidopsis profilins can be divided into the same two groups: PFN1 and PFN2 are 89% identical and PFN3 and PFN4 are 91% identical. Between these two groups they are 71-75% identical. The Arabidopsis profilins bind poly-L-proline and can complement both the Saccharomyces cerevisiae profilin deletion mutant and the Schizosaccharomyces pombe cdc3-124/profilin mutation, showing that the plant profilins are functionally similar to yeast profilins despite the low amino acid sequence homology. Analysis of pfn promoter-GUS fusion genes in transgenic Arabidopsis shows that pfn2 is specifically expressed in the vascular bundles of roots, hypocotyls, cotyledons, leaves, sepals, petals, stamen filaments and stalks of developing seeds, whereas expression of pfn4 is restricted to mature and germinating pollen grains.
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Abstract
This community study on headache in Malaysia was based on IHS diagnostic criteria and showed the last-year prevalence of migraine was 9.0%. Migraine with aura accounted for only 10.6% of the migrainous population. The last-year prevalence of tension headache was 26.5% (94.4% episodic, 5.6% chronic) and 28.2% for other types of headache. No case of cluster headache was found. Almost two thirds of the migraine subjects graded their headaches as severe, while almost 60% of the tension headache subjects and almost 70% of the other headache subjects graded their headaches as mild. Overall, there was higher prevalence in females for migraine and tension headache, and in males for the other types of headache. The prevalence of headache was lower among those younger than 15 and older than 65 years of age. No significant differences were found in the prevalence of headache among the different racial groups nor among the urban versus the rural population. All the headache types shared the same triggering factors suggesting that different physiological characteristics are responsible for the type of pain suffered. In the location of this community with its tropical climate, headache was attributed to sun exposure in 51.9% of the migraine subjects, 55.7% of the tension headache subjects, and 36.6% of the group with other headaches.
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73
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Ng WK, Samad SA, Tan CT. Spinal dural arteriovenous malformation: a cause of myelopathy. THE MEDICAL JOURNAL OF MALAYSIA 1996; 51:151-3. [PMID: 10967999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Spinal vascular malformation is an uncommon but potentially treatable cause of myelopathy. We describe two cases of angiographically proven spinal vascular malformation in Malaysia. The first case is a 47-year-old man who had a progressive myelopathy and the second a 60-year-old man with intermittent attacks of transient paraparesis leading to paraplegia. As the clinical presentation of spinal vascular malformation is variable, it should be considered as a cause of patients with myelopathy.
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74
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Liam CK, How LG, Tan CT. Road traffic accidents in patients with obstructive sleep apnoea. THE MEDICAL JOURNAL OF MALAYSIA 1996; 51:143-5. [PMID: 10967996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Three patients involved in road traffic accidents were suspected to have obstructive sleep apnoea (OSA). Two of them fell asleep while riding motorcycles and one patient fell asleep behind the wheel of a truck causing it to overturn. The diagnosis of OSA in each case was suspected based on a history of loud snoring, restless sleep, and excessive daytime somnolence and was confirmed by sleep studies.
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75
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Sivasubramaniam S, Vanniasingham VM, Tan CT, Chua NH. Characterisation of HEVER, a novel stress-induced gene from Hevea brasiliensis. PLANT MOLECULAR BIOLOGY 1995; 29:173-178. [PMID: 7579163 DOI: 10.1007/bf00019129] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A novel stress-induced gene, HEVER (Hevea ethylene-responsive) from the rubber tree, Hevea brasiliensis, has been isolated and characterised. HEVER is encoded by a multigene family. The HEVER transcript is expressed at basal levels in Hevea tissues and is developmentally regulated. In addition, the HEVER transcript and protein are induced by stress treatment with salicylic acid and ethephon. Sequence analysis shows that HEVER encodes a 33 kDa protein that has significant homology to the hypothetical protein SLEXORFA-1 from the plant, Stellaria longipes, and two bacterial proteins, BAC180K-75 from Bacillus subtilis and MVRNO3-1 from Methanococcus vannielii.
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