LPA kringle IV type 2 is associated with type 2 diabetes in a Chinese population with very high cardiovascular risk.

The connection between lipoprotein (a) [Lp(a)] levels and the risks of cardiovascular disease and diabetes remains poorly understood. Lp(a) is encoded by the LPA gene, and evidence suggests that the kringle IV type 2 (KIV-2) variant is particularly important to Lp(a) isoform size. A large isoform size, represented as a high number of KIV-2 repeats in LPA, is associated with low serum Lp(a) concentrations and an increased risk of type 2 diabetes. We investigated the associations among Lp(a) concentrations, LPA KIV-2 repeats, and type 2 diabetes in a Chinese population of 1,863 consecutive patients with very high cardiovascular risk, as identified by coronary angiography. Individuals with Lp(a) levels in the top tertile [67.86 (35.34-318.50) mg/dl] had a lower risk of diabetes compared with those in the bottom tertile [7.38 (0.60-12.91) mg/dl]. There was an inverse association between the number of KIV-2 repeats and serum Lp(a) concentrations. This study demonstrated that a high number of LPA KIV-2 repeats are associated with increased risk of type 2 diabetes in a Chinese population with very high cardiovascular risk, which suggests that large Lp(a) isoform size, associated with low Lp(a) concentration, has a causal effect on type 2 diabetes.

Enterovirus 71 encephalomyelitis and Japanese encephalitis can be distinguished by topographic distribution of inflammation and specific intraneuronal detection of viral antigen and RNA.

AIMS: To investigate if two important epidemic viral encephalitis in children, Enterovirus 71 (EV71) encephalomyelitis and Japanese encephalitis (JE) whose clinical and pathological features may be nonspecific and overlapping, could be distinguished. METHODS: Tissue sections from the central nervous system of infected cases were examined by light microscopy, immunohistochemistry and in situ hybridization. RESULTS: All 13 cases of EV71 encephalomyelitis collected from Asia and France invariably showed stereotyped distribution of inflammation in the spinal cord, brainstem, hypothalamus, cerebellar dentate nucleus and, to a lesser extent, cerebral cortex and meninges. Anterior pons, corpus striatum, thalamus, temporal lobe, hippocampus and cerebellar cortex were always uninflamed. In contrast, the eight JE cases studied showed inflammation involving most neuronal areas of the central nervous system, including the areas that were uninflamed in EV71 encephalomyelitis. Lesions in both infections were nonspecific, consisting of perivascular and parenchymal infiltration by inflammatory cells, oedematous/necrolytic areas, microglial nodules and neuronophagia. Viral inclusions were absent. CONCLUSIONS: Immunohistochemistry and in situ hybridization assays were useful to identify the causative virus, localizing viral antigens and RNA, respectively, almost exclusively to neurones. The stereotyped distribution of inflammatory lesions in EV71 encephalomyelitis appears to be very useful to help distinguish it from JE.

Genetic map construction and QTL mapping of resistance to blackleg (Leptosphaeria maculans) disease in Australian canola (Brassica napus L.) cultivars.

Genetic map construction and identification of quantitative trait loci (QTLs) for blackleg resistance were performed for four mapping populations derived from five different canola source cultivars. Three of the populations were generated from crosses between single genotypes from the blackleg-resistant cultivars Caiman, Camberra and (AV)Sapphire and the blackleg-susceptible cultivar Westar(10). The fourth population was derived from a cross between genotypes from two blackleg resistant varieties (Rainbow and (AV)Sapphire). Different types of DNA-based markers were designed and characterised from a collection of 20,000 EST sequences generated from multiple Brassica species, including a new set of 445 EST-SSR markers of high value to the international community. Multiple molecular genetic marker systems were used to construct linkage maps with locus numbers varying between 219 and 468, and coverage ranging from 1173 to 1800 cM. The proportion of polymorphic markers assigned to map locations varied from 70 to 89% across the four populations. Publicly available simple sequence repeat markers were used to assign linkage groups to reference nomenclature, and a sub-set of mapped markers were also screened on the Tapidor x Ningyou (T x N) reference population to assist this process. QTL analysis was performed based on percentage survival at low and high disease pressure sites. Multiple QTLs were identified across the four mapping populations, accounting for 13-33% of phenotypic variance (V (p)). QTL-linked marker data are suitable for implementation in breeding for disease resistance in Australian canola cultivars. However, the likelihood of shifts in pathogen race structure across different geographical locations may have implications for the long-term durability of such associations.

Nipah virus: a recently emergent deadly paramyxovirus.

A paramyxovirus virus termed Nipah virus has been identified as the etiologic agent of an outbreak of severe encephalitis in people with close contact exposure to pigs in Malaysia and Singapore. The outbreak was first noted in late September 1998 and by mid-June 1999, more than 265 encephalitis cases, including 105 deaths, had been reported in Malaysia, and 11 cases of encephalitis or respiratory illness with one death had been reported in Singapore. Electron microscopic, serologic, and genetic studies indicate that this virus belongs to the family Paramyxoviridae and is most closely related to the recently discovered Hendra virus. We suggest that these two viruses are representative of a new genus within the family Paramyxoviridae. Like Hendra virus, Nipah virus is unusual among the paramyxoviruses in its ability to infect and cause potentially fatal disease in a number of host species, including humans.

RT-PCR, nucleotide, amino acid and phylogenetic analyses of enterovirus type 71 strains from Asia.

A specific and sensitive method based on RT-PCR was developed to detect enterovirus 71 (EV71) from patients with hand, foot and mouth disease, myocarditis, aseptic meningitis and acute flaccid paralysis. RT-PCR primers from conserved parts of the VP1 capsid gene were designed on the basis of good correlation with sequences of EV71 strains. These primers successfully amplified 44 strains of EV71 including 34 strains isolated from Singapore in 1997 and 1998, eight strains from Malaysia isolated in 1997 and 1998, one Japanese strain and the neurovirulent strain EV71/7423/MS/87. RT-PCR of 30 strains of other enteroviruses including coxsackievirus A and B, and echoviruses failed to give any positive amplicons. Hence, RT-PCR with these primers showed 100% correlation with serotyping. Direct sequencing of the RT-PCR products of 20 EV71 strains revealed a distinct cluster with two major subgroups, thus enabling genetic typing of the viruses. The genetic heterogeneity of these strains culminated in amino acid substitutions within the VP1, VP2 and VP3 regions. The sequencing of a 2.9 kb fragment comprising the capsid region and the major part of 5' UTR of two Singapore strains revealed that they belonged to a group distinct from the prototype EV71/BrCr strain and the EV71/7423/MS/87 strain. The dendrogram generated from 341 bp fragments within the VP1 region revealed that the strains of Singapore, Malaysia and Taiwan belong to two entirely different EV71 genogroups, distinct from the three genogroups identified in another recent study.

The severe acute respiratory syndrome coronavirus in tears.

BACKGROUND: Severe acute respiratory syndrome (SARS) is a new infectious disease that caused a global outbreak in 2003. Research has shown that it is caused by a novel coronavirus. A series of cases is reported where polymerase chain reaction (PCR) testing on tears had demonstrated the presence of the virus. Detection of ocular infection from tears using the PCR technique has been widely used by ophthalmologists to diagnose infections for other viruses. METHODS: This is a case series report from cases classified as probable or suspect SARS cases. Tear samples were collected from 36 consecutive patients who were suspected of having SARS in Singapore over a period of 12 days (7-18 April 2003), and analysed by PCR using protocols developed by the WHO network of laboratories. RESULTS: Three patients with probable SARS (one female and two male patients) had positive results from their tear samples. Tear samples were used to confirm SARS in the female patient, who was positive only from her tears. The positive specimens were found in cases sampled early in their course of infection. CONCLUSIONS: This is the first case series reported with the detection of the SARS coronavirus from tears, and has important implications for the practice of ophthalmology and medicine. The ability to detect and isolate the virus in the early phase of the disease may be an important diagnostic tool for future patients and tear sampling is both simple and easily repeatable. Many healthcare workers are in close proximity to the eyes of patients and this may be a source of spread among healthcare workers and inoculating patients. Ophthalmic practices may need to change as more stringent barrier methods, appropriate quarantine, and isolation measures are vital when managing patients with SARS.

Comparison of tube cultures of Madin Darby canine kidney cells with shell-vial cultures after low-speed centrifugation for influenza virus isolation.

The efficacy of isolation of influenza viruses was compared in two systems--conventional tube cultures of Madin Darby canine kidney cells, and shell-vial cultures after low-speed centrifugation. One hundred and fifty eight throat and nasal swabs were inoculated and cultures screened by hemagglutination on days 1, 2, 3 and 5 post-inoculation. Twenty-four shell-vial cultures (15.2%) and 6 tube cultures (3.8%) were positive for influenza virus type B, indicating that shell-vial cultures with low-speed centrifugation are superior to tube cultures for influenza virus type B isolation (p less than 0.005 by McNemar's test for analysis of matched pairs data).

The effect of polyethylene glycol (PEG) on the isolation of Chlamydia trachomatis in H-1 HeLa cells.

One hundred and ninety-six urethral and endocervical swabs were processed for isolation of C. trachomatis, using H-1 HeLa cells on shell vials, in the presence and absence of 7% PEG in the chlamydial overlay medium. The results were divided into three evaluable groups based on the number of inclusions per coverslip in the shell vials without PEG. The number of inclusions were compared with that of PEG-treated cultures using the paired t-test. The ranges for the three evaluable groups were one to ten, 11-100 and 101-1000 inclusions per coverslip. All three groups showed a significant increase (2.8- to 3.8-fold) in the number of inclusion bodies in the PEG-treated cultures compared to the untreated cultures.

Gonorrhoea treatment failure and ciprofloxacin resistance.

Ciprofloxacin-resistant strains of Neisseria gonorrhoeae have been on the increase over the past few years in Singapore and worldwide. The aim of this study is to correlate treatment failures with in vitro ciprofloxacin resistance of N. gonorrhoeae. A total of 694 patients attending the Department of STD Control (DSC) clinic in 1996 who were diagnosed to have gonococcal infection confirmed by culture were analysed. Treatment failure rates for ciprofloxacin were determined and the minimum inhibitory concentration (MIC) of ciprofloxacin were traced for all cases of treatment failure. The case notes of all patients who had strains with MICs of ciprofloxacin in the resistant (> or = 1 microg/ml) and less sensitive (0.125-0.5 microg/ml) range were also reviewed to determine the clinical outcome. Ciprofloxacin treatment failure rate was 1.7% (8/461) which was lower than the percentage of ciprofloxacin-resistant strains isolated in the laboratory. Of these 8 cases, 6 were resistant and 2 were less sensitive to ciprofloxacin. Cure rates with ciprofloxacin for resistant and less sensitive strains were 40% and 92% respectively. In conclusion, in vitro resistance to ciprofloxacin may not translate into clinical treatment failure. Clinical treatment failures, on the other hand, are also seen in less sensitive strains.

Clinical and laboratory study of first episode genital herpes in Singapore.

A prospective study of the epidemiology, clinical aspects and laboratory features of first episode genital herpes was carried out in Middle Road Hospital, Singapore between June 1986 and December 1987. A total of 68 patients were studied. There were more women than men in the study population with a female to male ratio of 7.5 to 1. The peak incidence of first episode genital herpes was between 20 and 29 years of age. Specimens from 63 patients yielded positive culture for herpes simplex virus (HSV). HSV-1 was isolated from 21 patients (30.9%), HSV-2 from 41 patients (60.3%) and untyped HSV from one patient (1.5%). True primary genital herpes was diagnosed in 43 patients (68.3%) using a test for complement fixing antibodies to HSV. HSV-1 was found to be the causative agent in 18 (41.9%) of the true primary infections, HSV-2 in 24 (55.8%) and untyped HSV in one (2.3%). In comparison, HSV-1 was isolated in only 2 (10%) of the 20 patients with non-primary first episode genital herpes; HSV-2 was found in 13 patients (65%) and the culture was negative in 5 (25%).

PIP: A prospective study of the epidemiology, clinical aspects, and laboratory features of 1st episode genital herpes was conducted in Middle Road Hospital, Singapore between June 1986-December 1987. A total of 68 patients were studied and there were more women than men in the study population; the ratio of females:males was 7.5:1. The peak incidence of 1st episode genital herpes was between 20-29 years of age. Specimens from 63 patients yielded positive culture for herpes simplex virus (HSV). HSV-1 was isolated from 21 patients (30.9%), HSV-2 from 41 patients (60.3%), and untyped HSV from 1 patient (1.5%). True primary genital herpes was diagnosed in 43 patients (68.3%) using a test for complement fixing antibodies to HSV. HSV-1 was found to be the causative agent in 18 (41.9%) of the true primary infection, HSV-2 in 24 (55.8%), and untyped HSV in 1 (2.3%). In comparison, HSV-1 was isolated in only 2 (10%) of the 20 patients with nonprimary 1st episode genital herpes; HSV-2 was found in 13 patients (65%), and the culture was negative in 5 (25%).

The rationale for the use of diagnostic tests in herpes simplex virus infection.

All suspect herpes simplex lesions should be diagnosed by isolation methods where possible. Rapid tests ulitise antigen detection methods. The enzyme immunoassay method is the most sensitive of these, and the immunofluorescence method has the advantage of being able to type the virus, but has slightly lower sensitivity. Serological methods are only useful to exclude a herpes simplex infection in the past, and to establish a primary infection. They cannot be used to type an infection or give evidence of past infection to a particular type.

CMV colitis masquerading as colon cancer--an unusual presentation of acquired immunodeficiency syndrome.

We present a case-report of a patient with a typical history and a barium enema study diagnostic of right-sided colonic cancer. Laparotomy and right hemicolectomy was carried out. Histological examination revealed Cytomegalovirus (CMV) colitis and the patient was subsequently tested positive for Human immunodeficiency Virus (HIV). Gastrointestinal symptoms are common in patients with Acquired Immune Deficiency Syndrome (AIDS) and up to 10% of all AIDS patients have CMV colitis. The diagnostic criteria for CMV colitis is reviewed. AIDS is likely to become more common and we stress the awareness of this condition as well as the need for preoperative colonoscopy and histological diagnosis in patients with radiological diagnosis of colorectal carcinoma.

Prevalence of varicella-zoster virus infection in Singapore.

The incidence of chickenpox in Singapore has been increasing since 1984. A seroepidemiological survey was conducted in 1989-90 to determine the prevalence of varicella-zoster virus-specific IgG antibody in the healthy population in Singapore aged from 6 months to over 45 years. Overall, 42.8% of 500 samples assayed qualitatively by the ELISA method were positive, with less than one fifth of those aged under 15 years and less than half of the 15-24 year olds possessing antibody to the virus. However, antibody prevalence increased markedly to between 86% and 98% in those over 25 years of age. No significant sex or ethnic difference was noted. The survey confirmed the low herd immunity and the higher susceptibility of the young adult population to varicella infection in a tropical city compared to that of temperate countries.

Patterns of viral respiratory tract infections in Singapore.

A second retrospective study on viral respiratory tract infections, based on 12 years' laboratory reports for the influenza viruses, and 9 years' reports for the other respiratory viruses was made. Seasonal variation in incidence was found to occur with infections due to the influenza viruses, respiratory syncytial virus, and parainfluenzavirus type 1. Observations made previously on the age distribution of specific respiratory viral infections, and the association of the viruses with various respiratory syndromes were generally confirmed.

Acute non-bacterial infections of the respiratory tract in Singapore children: an analysis of three years' laboratory findings.

A retrospective study of the laboratory results on respiratory specimens received from children under 12 years of age between January 1977 and December 1979 was carried out. These children were either hospital patients, usually with lower respiratory infections, or outpatients on the Influenza Surveillance Programme. The overall virus isolation rate was 26.8%, and the isolation rate among hospital patients, 38.5%. Epidemics or outbreaks were associated with infections due to the influenza viruses, respiratory syncytial virus (RSV), the parainfluenza viruses and the enteroviruses. RSV, parainfluenza virus types 1 and 3, and the adenoviruses caused infection mainly in young children under 3 years of age, while the influenza viruses and Mycoplasma pneumoniae caused infection more frequently in older, school-aged children. There was a strong clinical association of bronchiolitis with RSV and the rhinoviruses, of laryngitis or laryngotracheobronchitis with parainfluenza virus types 1 and 2, of pneumonia with Mycoplasma pneumoniae, and of upper respiratory infection or "flu" with the influenza viruses. The significance of some of these findings is discussed.

Epidemiology of viral infections in Singapore.

As Singapore is a densely populated island, and also a major air and sea port, the importation and dissemination of viral infections is facilitated. Respiratory viral infections have the highest prevalence rates, influenza and respiratory syncytial virus (RSV) being the most important ones. Seasonal variation occurs with influenza, RSV and parainfluenza virus type 1 infections. The age distribution and clinical picture associated with infections due to the various respiratory viruses are similar to those reported in other countries. Carrier rates for hepatitis B are high, but differ in the three major ethnic groups, vertical transmission from infected mothers being an important mode of transmission. Outbreaks of hepatitis A have been associated with the consumption of inadequately cooked shellfish. Cytomegalovirus and Epstein-Barr virus infections are acquired early in life and herpes simplex, more slowly. Genital herpes is increasing in incidence. Coxsackievirus A24 and enterovirus 70 have caused major epidemics of acute haemorrhagic conjunctivitis at 5-10 year intervals. Outbreaks of hand, foot and mouth disease due to coxsackievirus A16 have also occurred. With the declining incidence of dengue haemorrhagic fever, the percentage of susceptible individuals in children under 10 years, has increased markedly. Epidemics of rubella which occurred during the past decade, together with immunisation, have increased herd immunity to this virus.

Acute hepatitis A in Singapore: importance of shellfish ingestion in a non-epidemic period.

A case-control study based on 28 serologically confirmed cases of hepatitis A and 42 home contacts with no recent or past evidence of hepatitis A virus (HAV) infection was conducted to determine the importance of shellfish exposure in the transmission of HAV during a non-epidemic period in Singapore. It was found that consumption of partially-cooked cockles (Anadara granosa) was significantly associated with the illness (p less than 0.001). No other types of locally available shellfish including oysters, mussels and clams were incriminated. The public should be constantly reminded to refrain from consuming raw and inadequately cooked bivalve molluscs all the time, and not just during epidemics.

A comparative study of the Abbott and Murex enzyme immunoassay, and cell culture in the detection of cervical chlamydial infection in female sex workers in Singapore.

Endocervical smears from 200 female sex workers were tested for Chlamydia trachomatis infection using the Abbott and Murex enzyme immunoassay (EIA) kits and the standard cell culture technique to compare the performance of these tests. The Abbott test had a sensitivity, specificity, predictive value of a positive result (PVP) and predictive value of a negative result (PVN) of 83.3%, 97.8%, 78.9% and 98.3% respectively. The corresponding figures for the Murex system were 77.8%, 98.4%, 82.4% and 97.8%; and of the standard culture test were 55.6%, 100% and 95.8%. EIA tests were more sensitive but slightly less specific than cell culture in the detection of Chlamydia trachomatis cervical infection in female sex workers in Singapore.

Antineutrophil cytoplasmic antibodies (ANCAs) in patients with inflammatory bowel disease show no correlation with proteinase 3, lactoferrin, myeloperoxidase, elastase, cathepsin G and lysozyme: a Singapore study.

INTRODUCTION: The pathogenic importance of antineutrophil cytoplasmic antibodies (ANCAs) in inflammatory bowel disease (IBD) is unclear and target antigen localisation studies may lend insight to the specific pathogenic mechanisms of IBD. In this pilot study, we looked at occurrence of ANCA in Asian IBD patients. In ANCA-positive samples, we analysed for the presence of target antigens i.e. proteinase 3, lactoferrin, myeloperoxidase, elastase, cathepsin G and lysozyme. MATERIALS AND METHODS: This prospective study was carried out from July 1997 to February 1998. Sera were screened for ANCAs with indirect immunofluorescent test and tested with an enzyme immunoassay (ELISA) kit which provides a semi-quantitative assay for human IgG autoantibodies against 6 antigens: proteinase 3, lactoferrin, myeloperoxidase, elastase, cathepsin G and lysozyme. RESULTS: A total of 75 patients were studied: 50 with IBD and 25 controls with functional bowel disease. Ten had Crohn's disease (CD) and 40 had ulcerative colitis (UC). There was no racial predilection among the Chinese, Malays or Indians. In CD, 1 was positive for cytoplasmic ANCA (cANCA) and 2 for perinuclear ANCA (pANCA). In UC, 4 were positive for pANCA, 15 for atypical perinuclear ANCA (apANCA) and 1 for cANCA. In the CD and UC population, the proportion positive for ANCA was 30% and 50%, respectively. There was no ANCA detected among the controls. Of those ANCA-positive IBD patients (n:23), only 1 demonstrated anti-myeloperoxidase antibodies. No antibodies were detected against the other 5 antigens tested. CONCLUSIONS: This pilot Singapore study concludes that there is no significant ANCA association with proteinase 3, lactoferrin, myeloperoxidase, elastase, cathepsin G and lysozyme.

Foscarnet (phosphonoformate sodium) in the treatment of recurrent male genital herpes.

Foscarnet 0.3% cream was compared with placebo in a randomised double-blind study. The objective was to investigate the therapeutic efficacy and safety in men with recurrent genital herpes simplex virus (HSV) infections. A total of 51 patients were selected, of which 49 (25 treated with foscarnet) were valid for efficacy analysis. Different variables were analysed including the time to healing, alleviation of symptoms, side effects and the results of viral cultures. The median time to healing was 4 days in foscarnet treated patients compared to 5 days in placebo controls. The difference was not statistically significant (p = 0.22). However, foscarnet alleviated the severity of pain and also significantly reduced the median time to abolition pain to 3 days from 6.6 days in placebo treated patients (p = 0.0028). An antiviral effect of foscarnet was evident. The percentage of positive viral cultures found after starting treatment was 15% in the foscarnet-treated group compared to 44% in the placebo-treated group (p = 0.01). Treatment with foscarnet cream was not associated with any significant side effects.