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Biomedical subjects

S Lwin

Publications and source records attributed to S Lwin.

13 recordsLinked to original sources
PubMed2000

Emergence of new forms of human immunodeficiency virus type 1 intersubtype recombinants in central Myanmar.

We have previously shown that HIV-1 env subtypes B' (a Thai-B cluster within subtype B) and E (CRF01_AE) are distributed in Yangon, the capital city of Myanmar. However, HIV strains from the rest of country have not yet been genetically characterized. In the present study, we determined env (C2/V3) and gag (p17) subtypes of 25 specimens from central Myanmar (Mandalay). Phylogenetic analyses identified 5 subtype C (20%), in addition to 10 CRF01_AE (40%) and 4 subtype B' (16%). Interestingly, the remaining six specimens (24%) showed discordance between gag and env subtypes; three gag subtype B'/env subtype C, one gag subtype B'/env subtype E, one gag subtype C/env subtype B', and one gag subtype C/env subtype E. These discordant specimens were found frequently among injecting drug users (4 of 12, 33%) and female commercial sex workers (2 of 8, 25%) engaging in high-risk behaviors. The recombinant nature of these HIV-1 strains was verified in three specimens, indicating the presence of new forms of HIV-1 intersubtype C/B' and C/B'/E recombinants with different recombination breakpoints. The data suggest that multiple subtypes of B', C, and CRF01_AE are cocirculating in central Myanmar, leading to the evolution of new forms of intersubtype recombinants among the risk populations exhibiting one of the highest HIV infection rates in the region.

Adolescent↗
PubMed2000

Promotion of insecticide-treated mosquito nets in Myanmar.

A simple health promotion message administered by village midwives raised bednet usage to over 60% in trial hamlets in north Shan State, Myanmar. Treatment of the nets in the study villages produced a reduction in malaria cases. Most villagers were prepared to buy their nets at market prices and were willing to pay for the cost of re-treatment of nets, but very poor, members of the Wa ethnic group required a half-price subsidy for them to afford them. The use of insecticide treated bednets was felt to be appropriate for undeveloped and remote areas of the country where malaria control was difficult.

Adolescent↗
PubMed1999

Hospital-based study of severe malaria and associated deaths in Myanmar.

The present study identifies factors that contribute to malaria deaths in township hospitals reporting large numbers of such deaths in Myanmar. Between July and December 1995, we identified a total of 101 patients with severe and complicated malaria by screening the cases admitted to hospital with a primary diagnosis of falciparum malaria. Unrousable coma and less marked impairment of consciousness with or without other severe malaria complications, in contrast to severe malaria anaemia, were associated with all malaria deaths. Adult patients with severe malaria were 2.8 times more likely to die than child patients, with the higher risk of death among adults probably being associated with previous exposure to malaria, delay in seeking treatment and severity of the illness before admission. In view of this, we consider that malaria mortality could be reduced by improving peripheral facilities for the management of severe malaria and providing appropriate education to communities, without stepping up vector control activities.

Adolescent↗
PubMed1998

Genetic and serologic characterization of HIV type 1 prevailing in Myanmar (Burma).

To study the molecular epidemiology of HIV-1 spread in Myanmar and the interplay with the epidemic in surrounding Southeast Asian countries, we determined the HIV-1 subtypes prevailing in Myanmar. Thirty HIV-positive blood specimens were sampled in the capital city, Yangon, and an additional 459 sera were collected nationwide in 1995. Genetic subtyping based on the env C2/V3 sequence and serologic data, using a V3 peptide enzyme immunoassay (PEIA), revealed three patterns of HIV spread in different geographic regions in Myanmar: (1) in the capital city, Yangon, HIV-1 subtype B' ("Thai-B" cluster within subtype B) predominated both in IDUs and heterosexuals; (2) in the cities near the border with Thailand, including Tachelaik and Kawthaung, where heterosexual transmission is a major pathway of HIV-1 spread, HIV-1 subtype E was predominantly distributed among the commercial sex workers and heterosexuals; (3) in central and northeast Myanmar, both HIV-1 subtypes B' and E occurred in a mixed distribution, without showing any significant segregation by risk group. In addition, the PEIA data implied the occurrence of other subtype(s) in these areas. The interperson nucleotide sequence variations in env C2/V3 regions of B' and E, prevailing in Yangon, were 6.7 +/- 2.1 and 7.1 +/- 0.7%, respectively. They were similar to those levels observed in Thailand. These findings are consistent with the view that HIV spread in Myanmar might have taken place at about the same time as that in Thailand, and that multiple entries and exchanges of HIV-1 with neighboring countries are important factors contributing to the current distribution of subtypes in Myanmar.

Amino Acid Sequence↗
PubMed1994

Chronic neurobehavioural effects in paint formulators exposed to solvents and noise.

Twenty-one male paint formulators with an average age of 41.3 years (range 27-53), educational level of 7.4 years (range 5-10) and exposure level of 0.09 times Threshold Limit Value (TLV) index of solvent mixture (range 0.003-0.24 times TLV-index) for 20.2 years (range 7-39) were studied with a battery of neurobehavioural performance tests including digit span, digit symbol, Benton visual retention, finger tapping, grooved peg board, and aiming test. A group of 21 male workers matched for age (mean 40.8 years, range 25-53) and education (mean 6.9 years, range 5-12), and with no history of exposure to neurotoxic agents were selected as controls. In all the neurobehavioural tests, the exposed workers' performances were observed to be poorer than the controls'. Statistically significant differences were observed in digit span, grooved peg board, and the Z score after adjusting for age, level of education and ethnicity. The least square means for digit span were 11.7 (standard error [SE] 0.77) and 9.2 (SE 0.79); for grooved peg board were 60.5 (SE 2.1) and 69.7 (SE 2.1); and for neurobehavioural Z score were 0.02 (SE 0.11) and 0.50 (SE 0.11) in the controls and exposed workers respectively. The exposed group also performed significantly poorer in aiming test error score and digit span when compared to the controls after adjusted for age, education and ethnicity. The least square means for aiming test error score were 6.5 (SE 2.7) and 12.8 (SE 2.8) for the controls and exposed workers respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Some characteristics of hospitalized HIV seropositive patients in Myanmar.

Twenty-two hospitalized HIV seropositive patients were studied prospectively between July 1991 and January 1992. The majority of the patients were intravenous drug users (IVDUs). Their age ranged from 20 to 38 years with a male preponderance of 12 to 1. Anemia, lymphopenia and thrombocytopenia were observed in 100%, 36% and 41%, respectively. The common pathogens like malaria parasites, Mycobacterium tuberculosis, Entamoeba histolytica, Streptococcus and Salmonella were isolated/identified rather than opportunistic organisms.

Adult↗
PubMed1985

Micro-neutralization test for mumps virus using the 96-well tissue culture plate and PAP (peroxidase-antiperoxidase) staining technique.

A rapid micro-test method for mumps virus neutralization was developed. In this method, a 96-well tissue culture plate was used for preparation of cell monolayers and the PAP staining technique was used for visualization of mumps virus infected cells. Clusters of infected cells were observed as a focus and the numbers of foci could be counted by the naked eye 2 days after the infection. A linear relationship between virus dilutions and focus numbers was observed. When neutralizing antibodies in sera from cases of natural mumps infection were assayed, a good correlation was observed between those obtained by the focus reduction method applying the micromethod and those obtained by the ordinary plaque method. Our results indicate that this micromethod is useful in mumps virus neutralization tests and it has many advantages over other methods previously reported.

Animals↗
PubMedDate not supplied

Comparison of saliva and serum for HIV surveillance in developing countries.

Saliva has been proposed as a non-invasive alternative to serum for HIV antibody testing. In a field study in Myanmar (formerly Burma), we evaluated such an alternative to identify the frequency of HIV infection in a surveillance programme of high-risk and low-risk sentinel groups. Duplicate vials of saliva and serum were collected from 479 high-risk and 1039 low-risk subjects. One vial of each pair was analysed blind in two laboratories, one in the USA and the other in Myanmar. The US laboratory followed WHO confirmatory strategy III with three different enzyme-linked immunosorbent assays (ELISAs), while the laboratory in Myanmar followed strategy I with one ELISA. Serum testing in the US was the gold standard. The Cambridge ELISA with saliva was a more effective surveillance tool (sensitivity 90.5%, specificity 99.5-100%) for describing the frequency of subjects with HIV antibodies than the serum ELISA supplied to Myanmar by WHO (95.9% and 98.3%, respectively). Saliva is recommended as a safe and effective alternative to serum for HIV antibody testing with ELISA in surveillance programmes in developing countries.

AIDS Serodiagnosis↗